37 CFR 202.16 - Preregistration of copyrights.

Code of Federal Regulations, 2013 CFR

2013-07-01

... comedy, soft rock, heavy metal, gospel, rap, hip-hop, blues, jazz), the titles of the musical... lyrics, if any, the genre of the work (for example, classical, pop, musical comedy, soft rock, heavy metal, gospel, rap, hip-hop, blues, jazz), the performer, principal recording location, record label...

Sense Things in the Big Deep Water Bring the Big Deep Water to Computers so People can understand the Deep Water all the Time without getting wet

NASA Astrophysics Data System (ADS)

Pelz, M.; Heesemann, M.; Scherwath, M.; Owens, D.; Hoeberechts, M.; Moran, K.

2015-12-01

Senses help us learn stuff about the world. We put sense things in, over, and under the water to help people understand water, ice, rocks, life and changes over time out there in the big water. Sense things are like our eyes and ears. We can use them to look up and down, right and left all of the time. We can also use them on top of or near the water to see wind and waves. As the water gets deep, we can use our sense things to see many a layer of different water that make up the big water. On the big water we watch ice grow and then go away again. We think our sense things will help us know if this is different from normal, because it could be bad for people soon if it is not normal. Our sense things let us hear big water animals talking low (but sometimes high). We can also see animals that live at the bottom of the big water and we take lots of pictures of them. Lots of the animals we see are soft and small or hard and small, but sometimes the really big ones are seen too. We also use our sense things on the bottom and sometimes feel the ground shaking. Sometimes, we get little pockets of bad smelling air going up, too. In other areas of the bottom, we feel hot hot water coming out of the rock making new rocks and we watch some animals even make houses and food out of the hot hot water that turns to rock as it cools. To take care of the sense things we use and control water cars and smaller water cars that can dive deep in the water away from the bigger water car. We like to put new things in the water and take things out of the water that need to be fixed at least once a year. Sense things are very cool because you can use the sense things with your computer too. We share everything for free on our computers, which your computer talks to and gets pictures and sounds for you. Sharing the facts from the sense things is the best part about having the sense things because we can get many new ideas about understanding the big water from anyone with a computer!

Deep Fracturing of the Hard Rock Surrounding a Large Underground Cavern Subjected to High Geostress: In Situ Observation and Mechanism Analysis

NASA Astrophysics Data System (ADS)

Feng, Xia-Ting; Pei, Shu-Feng; Jiang, Quan; Zhou, Yang-Yi; Li, Shao-Jun; Yao, Zhi-Bin

2017-08-01

Rocks that are far removed from caverns or tunnels peripheries and subjected to high geostress may undergo `deep fracturing'. Deep fracturing of hard rock can cause serious hazards that cause delays and increase the cost of construction of underground caverns with high sidewalls and large spans (especially when subjected to high geostress). To extensively investigate the mechanism responsible for deep fracturing, and the relationship between fracturing and the excavation & support of caverns, this paper presents a basic procedure for making in situ observations on the deep fracturing process in hard rock. The basic procedure involves predicting the stress concentration zones in the surrounding rocks of caverns induced by excavation using geomechanical techniques. Boreholes are then drilled through these stress concentration zones from pre-existing tunnels (such as auxiliary galleries) toward the caverns before its excavation. Continuous observations of the fracturing of the surrounding rocks are performed during excavation using a borehole camera in the boreholes in order to analyze the evolution of the fracturing process. The deep fracturing observed in a large underground cavern (high sidewalls and large span) in southwest China excavated in basalt under high geostress is also discussed. By continuously observing the hard rock surrounding the arch on the upstream side of the cavern during the excavation of the first three layers, it was observed that the fracturing developed into the surrounding rocks with downward excavation of the cavern. Fracturing was found at distances up to 8-9 m from the cavern periphery during the excavation of Layer III. Also, the cracks propagated along pre-existing joints or at the interfaces between quartz porphyry and the rock matrix. The relationship between deep fracturing of the surrounding rocks and the advance of the cavern working faces was analyzed during excavation of Layer Ib. The results indicate that the extent of the stress relief zone is about 7 m if footage of 3 m is adopted for the rate of advance of the cavern faces. An analysis of the effects of the initial geostress and evolving stress concentration on deep fracturing was also made. It could be concluded that the deep fracturing of the rocks in the upstream side of the cavern is caused by the combined effect of the high initial geostress, the transfer of the stress concentration zone toward the deep surrounding rocks, and the occurrence of discontinuities.

The role of post-failure brittleness of soft rocks in the assessment of stability of intact masses: FDEM technique applications to ideal problems

NASA Astrophysics Data System (ADS)

Lollino, Piernicola; Andriani, Gioacchino Francesco; Fazio, Nunzio Luciano; Perrotti, Michele

2016-04-01

Strain-softening under low confinement stress, i.e. the drop of strength that occurs in the post-failure stage, represents a key factor of the stress-strain behavior of rocks. However, this feature of the rock behavior is generally underestimated or even neglected in the assessment of boundary value problems of intact soft rock masses. This is typically the case when the stability of intact rock masses is treated by means of limit equilibrium or finite element analyses, for which rigid-plastic or elastic perfectly-plastic constitutive models, generally implementing peak strength conditions of the rock, are respectively used. In fact, the aforementioned numerical techniques are characterized by intrinsic limitations that do not allow to account for material brittleness, either for the method assumptions or due to numerical stability problems, as for the case of the finite element method, unless sophisticated regularization techniques are implemented. However, for those problems that concern the stability of intact soft rock masses at low stress levels, as for example the stability of shallow underground caves or that of rock slopes, the brittle stress-strain response of rock in the post-failure stage cannot be disregarded due to the risk of overestimation of the stability factor. This work is aimed at highlighting the role of post-peak brittleness of soft rocks in the analysis of specific ideal problems by means of the use of a hybrid finite-discrete element technique (FDEM) that allows for the simulation of the rock stress-strain brittle behavior in a proper way. In particular, the stability of two ideal cases, represented by a shallow underground rectangular cave and a vertical cliff, has been analyzed by implementing a post-peak brittle behavior of the rock and the comparison with a non-brittle response of the rock mass is also explored. To this purpose, the mechanical behavior of a soft calcarenite belonging to the Calcarenite di Gravina formation, extensively outcropping in Puglia (Southern Italy), and the corresponding features of the post-peak behavior as measured in the laboratory, have been used as a reference in this work, as well as the typical geometrical features of underground cavities and rock cliffs, as observed in Southern Italy, have been adopted for the simulations. The numerical results indicate the strong impact for the assessment of stability when rock post-peak brittleness is accounted for, if compared with perfectly plastic assumptions, and the need for adopting numerical techniques, as the FDEM approach, to take properly into account this important aspect of the rock behavior is highlighted.

Numerical simulation of phenomenon on zonal disintegration in deep underground mining in case of unsupported roadway

NASA Astrophysics Data System (ADS)

Han, Fengshan; Wu, Xinli; Li, Xia; Zhu, Dekang

2018-02-01

Zonal disintegration phenomenon was found in deep mining roadway surrounding rock. It seriously affects the safety of mining and underground engineering and it may lead to the occurrence of natural disasters. in deep mining roadway surrounding rock, tectonic stress in deep mining roadway rock mass, horizontal stress is much greater than the vertical stress, When the direction of maximum principal stress is parallel to the axis of the roadway in deep mining, this is the main reasons for Zonal disintegration phenomenon. Using ABAQUS software to numerical simulation of the three-dimensional model of roadway rupture formation process systematically, and the study shows that when The Direction of maximum main stress in deep underground mining is along the roadway axial direction, Zonal disintegration phenomenon in deep underground mining is successfully reproduced by our numerical simulation..numerical simulation shows that using ABAQUA simulation can reproduce Zonal disintegration phenomenon and the formation process of damage of surrounding rock can be reproduced. which have important engineering practical significance.

Role of Brittle Behaviour of Soft Calcarenites Under Low Confinement: Laboratory Observations and Numerical Investigation

NASA Astrophysics Data System (ADS)

Lollino, Piernicola; Andriani, Gioacchino Francesco

2017-07-01

The strength decay that occurs in the post-peak stage, under low confinement stress, represents a key factor of the stress-strain behaviour of rocks. However, for soft rocks this issue is generally underestimated or even neglected in the solution of boundary value problems, as for example those concerning the stability of underground cavities or rocky cliffs. In these cases, the constitutive models frequently used in limit equilibrium analyses or more sophisticated numerical calculations are, respectively, rigid-plastic or elastic-perfectly plastic. In particular, most of commercial continuum-based numerical codes propose a variety of constitutive models, including elasticity, elasto-plasticity, strain-softening and elasto-viscoplasticity, which are not exhaustive in simulating the progressive failure mechanisms affecting brittle rock materials, these being characterized by material detachment and crack opening and propagation. As a consequence, a numerical coupling with mechanical joint propagation is needed to cope with fracture mechanics. Therefore, continuum-based applications that treat the simulation of the failure processes of intact rock masses at low stress levels may need the adoption of numerical techniques capable of implementing fracture mechanics and rock brittleness concepts, as it is shown in this paper. This work is aimed at highlighting, for some applications of rock mechanics, the essential role of post-peak brittleness of soft rocks by means of the application of a hybrid finite-discrete element method. This method allows for a proper simulation of the brittle rock behaviour and the related mechanism of fracture propagation. In particular, the paper presents two ideal problems, represented by a shallow underground cave and a vertical cliff, for which the evolution of the stability conditions is investigated by comparing the solutions obtained implementing different brittle material responses with those resulting from the assumption of perfectly plastic behaviour. To this purpose, a series of petrophysical and mechanical tests were conducted on samples of soft calcarenite belonging to the Calcarenite di Gravina Fm. (Apulia, Southern Italy), focusing specific attention on the post-peak behaviour of the material under three types of loading (compression, indirect tension and shear). Typical geometrical features representative of real rock engineering problems observed in Southern Italy were assumed in the problems examined. The numerical results indicate the impact of soft rock brittleness in the assessment of stability and highlight the need for the adoption of innovative numerical techniques to analyse these types of problems properly.

New Soft Rock Pillar Strength Formula Derived Through Parametric FEA Using a Critical State Plasticity Model

NASA Astrophysics Data System (ADS)

Rastiello, Giuseppe; Federico, Francesco; Screpanti, Silvio

2015-09-01

Many abandoned room and pillar mines have been excavated not far from the surface of large areas of important European cities. In Rome, these excavations took place at shallow depths (3-15 m below the ground surface) in weak pyroclastic soft rocks. Many of these cavities have collapsed; others appear to be in a stable condition, although an appreciable percentage of their structural components (pillars, roofs, etc.) have shown increasing signs of distress from both the morphological and mechanical points of view. In this study, the stress-strain behaviour of soft rock pillars sustaining systems of cavities under vertical loads was numerically simulated, starting from the in situ initial conditions due to excavation of the cavities. The mechanical behaviour of the constituent material of the pillar was modelled according to the Modified Cam-Clay constitutive law (elasto-plastic with strain hardening). The influence of the pillar geometry (cross-section area, shape, and height) and mechanical parameters of the soft rock on the ultimate compressive strength of the pillar as a whole was parametrically investigated first. Based on the numerical results, an original relationship for pillar strength assessment was developed. Finally, the estimated pillar strengths according to the proposed formula and well-known formulations in the literature were compared.

Mineral resource of the month: diatomite

USGS Publications Warehouse

Founie, Alan

2006-01-01

Diatomite is a soft, very fine-grained, siliceous sedimentary rock that is usually very light grey or beige in color. It is very finely porous, very low in density and essentially chemically inert. Rocks containing diatomite are excellent reservoir rocks for hydrocarbons.

Sediments and fossiliferous rocks from the eastern side of the Tongue of the Ocean, Bahamas

USGS Publications Warehouse

Gibson, T.G.; Schlee, J.

1967-01-01

In August 1966, two dives were made with the deep-diving submersible Alvin along the eastern side of the Tongue of the Ocean to sample the rock and sediment. Physiographically, the area is marked by steep slopes of silty carbonate sediment and precipitous rock cliffs dusted by carbonate debris. Three rocks, obtained from the lower and middle side of the canyon (914-1676 m depth), are late Miocene-early Pliocene to late Pleistocene-Recent in age; all are deep-water pelagic limestones. They show (i) that the Tongue of the Ocean has been a deep-water area at least back into the Miocene, and (ii) that much shallow-water detritus has been swept off neighbouring banks to be incorporated with the deep-water fauna in the sediment. ?? 1967 Pergamon Press Ltd.

In Situ Observation of Hard Surrounding Rock Displacement at 2400-m-Deep Tunnels

NASA Astrophysics Data System (ADS)

Feng, Xia-Ting; Yao, Zhi-Bin; Li, Shao-Jun; Wu, Shi-Yong; Yang, Cheng-Xiang; Guo, Hao-Sen; Zhong, Shan

2018-03-01

This paper presents the results of in situ investigation of the internal displacement of hard surrounding rock masses within deep tunnels at China's Jinping Underground Laboratory Phase II. The displacement evolution of the surrounding rock during the entire excavation processes was monitored continuously using pre-installed continuous-recording multi-point extensometers. The evolution of excavation-damaged zones and fractures in rock masses were also observed using acoustic velocity testing and digital borehole cameras, respectively. The results show four kinds of displacement behaviours of the hard surrounding rock masses during the excavation process. The displacement in the inner region of the surrounding rock was found to be greater than that of the rock masses near the tunnel's side walls in some excavation stages. This leads to a multi-modal distribution characteristic of internal displacement for hard surrounding rock masses within deep tunnels. A further analysis of the evolution information on the damages and fractures inside the surrounding rock masses reveals the effects of excavation disturbances and local geological conditions. This recognition can be used as the reference for excavation and supporting design and stability evaluations of hard-rock tunnels under high-stress conditions.

Seismic performance evaluation of an infilled rocking wall frame structure through quasi-static cyclic testing

NASA Astrophysics Data System (ADS)

Pan, Peng; Wu, Shoujun; Wang, Haishen; Nie, Xin

2018-04-01

Earthquake investigations have illustrated that even code-compliant reinforced concrete frames may suffer from soft-story mechanism. This damage mode results in poor ductility and limited energy dissipation. Continuous components offer alternatives that may avoid such failures. A novel infilled rocking wall frame system is proposed that takes advantage of continuous component and rocking characteristics. Previous studies have investigated similar systems that combine a reinforced concrete frame and a wall with rocking behavior used. However, a large-scale experimental study of a reinforced concrete frame combined with a rocking wall has not been reported. In this study, a seismic performance evaluation of the newly proposed infilled rocking wall frame structure was conducted through quasi-static cyclic testing. Critical joints were designed and verified. Numerical models were established and calibrated to estimate frame shear forces. The results evaluation demonstrate that an infilled rocking wall frame can effectively avoid soft-story mechanisms. Capacity and initial stiffness are greatly improved and self-centering behavior is achieved with the help of the infilled rocking wall. Drift distribution becomes more uniform with height. Concrete cracks and damage occurs in desired areas. The infilled rocking wall frame offers a promising approach to achieving seismic resilience.

Sulfur-Rich Rocks and Dirt (False Color)

NASA Technical Reports Server (NTRS)

2005-01-01

NASA's Mars Rover Spirit has been analyzing sulfur-rich rocks and surface materials in the 'Columbia Hills' in Gusev Crater on Mars. This image of a very soft, nodular, layered rock nicknamed 'Peace' in honor of Martin Luther King Jr. shows a 4.5-centimeter-wide (1.8-inch-wide) hole Spirit ground into the surface with the rover's rock abrasion tool. The high sulfur content of the rock measured by Spirit's alpha particle X-ray spectrometer and its softness measured by the abrasion tool are probably evidence of past alteration by water. Spirit's panoramic camera took this false-color image on martian day, or sol, 381 (Jan. 27, 2005), using Pancam filters at wavelengths of 750, 530, and 430 nanometers. Darker red hues in the image correspond to greater concentrations of oxidized soil and dust. Bluer hues correspond to sulfur-rich rock excavated or exposed by the abrasion tool and not as heavily coated with soils or not as highly oxidized.

"Soft-shelled" monothalamid foraminifers as a modern analogue of early life

NASA Astrophysics Data System (ADS)

Kitazato, Hiroshi; Ohkawara, Nina; Gooday, Andrew

2017-04-01

According to the fossil record, the earliest undoubted foraminifers are found in the Early Cambrian, where they are represented by tubular agglutinated forms, thought to be the most primitive foraminiferal morphotypes. The numerous foraminifers with single-chambered, organic-walled tests (i.e. 'soft-shelled' monothalamids) exist in the deep sea and are difficult to preserve as fossils. Molecular phylogenetic data tell us that these 'primitive' taxa include the deepest foraminiferal clades, originating around 600 - 900 Ma. We found many soft-shelled monothalamids in sediment samples from deep trenches, including the Challenger Deep (Marianas Trench) and the Horizon Deep (Tonga Trench). Both deeps exceed 10,000 m water depth, well below the carbonate compensation depth, which represents an environmental barrier for calcareous foraminifera. The foraminifera at these extreme hadal sites include tubular and globular forms with organic walls, among which species of the genera Nodellum and Resigella are particularly abundant. Some forms selectively agglutinate minute flakes of clay minerals on the surface of the organic test. Many soft-shelled monothalamids, including most of those in deep tranches, contain stercomata, the function of which is currently unknown. Gromiids (a rhizarian group related to foraminifera) also accumulate stercomata in their sack-shaped tests. This suggests the possibility that the function of these waste particles is to add bulk, like the filling of soft bags or pillows. We suggest that the monothalamid foraminifera that dominate small-sized eukaryotes in extreme hadal settings may provide clues to understanding the biology and ecology of early life in Neoproterozoic sedimented habitats.

Coal Mine Roadway Stability in Soft Rock: A Case Study

NASA Astrophysics Data System (ADS)

Shen, Baotang

2014-11-01

Roadway instability has always been a major concern in deep underground coal mines where the surrounding rock strata and coal seams are weak and the in situ stresses are high. Under the high overburden and tectonic stresses, roadways could collapse or experience excessive deformation, which not only endangers mining personnel but could also reduce the functionality of the roadway and halt production. This paper describes a case study on the stability of roadways in an underground coal mine in Shanxi Province, China. The mine was using a longwall method to extract coal at a depth of approximately 350 m. Both the coal seam and surrounding rock strata were extremely weak and vulnerable to weathering. Large roadway deformation and severe roadway instabilities had been experienced in the past, hence, an investigation of the roadway failure mechanism and new support designs were needed. This study started with an in situ stress measurement programme to determine the stress orientation and magnitude in the mine. It was found that the major horizontal stress was more than twice the vertical stress in the East-West direction, perpendicular to the gateroads of the longwall panel. The high horizontal stresses and low strength of coal and surrounding rock strata were the main causes of roadway instabilities. Detailed numerical modeling was conducted to evaluate the roadway stability and deformation under different roof support scenarios. Based on the modeling results, a new roadway support design was proposed, which included an optimal cable/bolt arrangement, full length grouting, and high pre-tensioning of bolts and cables. It was expected the new design could reduce the roadway deformation by 50 %. A field experiment using the new support design was carried out by the mine in a 100 m long roadway section. Detailed extensometry and stress monitorings were conducted in the experimental roadway section as well as sections using the old support design. The experimental section produced a much better roadway profile than the previous roadway sections. The monitoring data indicated that the roadway deformation in the experimental section was at least 40-50 % less than the previous sections. This case study demonstrated that through careful investigation and optimal support design, roadway stability in soft rock conditions can be significantly improved.

Ice streams of the Late Wisconsin Cordilleran Ice Sheet in western North America

NASA Astrophysics Data System (ADS)

Eyles, Nick; Arbelaez Moreno, Lina; Sookhan, Shane

2018-01-01

The Late Wisconsin Cordilleran Ice Sheet (CIS) of western North America is thought to have reached its maximum extent (∼2.5 × 106 km2) as late at c. 14.5 ka. Most (80%) of the ice sheet's bed consists of high mountains but its 'core zone' sited on plateaux of the Intermontane Belt of British Columbia and coterminous parts of the USA, shows broad swaths of subglacially-streamlined rock and sediment. Broad scale mapping from new digital imagery data identifies three subglacial bed types: 1) 'hard beds' of variably streamlined bedrock; 2) drumlinized 'soft beds' of deformation till reworked from antecedent sediment, and 3) 'mixed beds' of variably-streamlined bedrock protruding through drumlinized sediment. Drumlins on soft beds appear to be erosional features cut into till and antecedent sediments, and identify the catchment areas of paleo ice streams expressed downglacier as flow sets of megascale glacial lineations (MSGLs). 'Grooved' and 'cloned' drumlins appear to record the transition from drumlins to MSGLs. The location of paleo ice streams reflects topographic funneling of ice from plateau surfaces through outlet valleys and a soft bed that sustained fast flow; rock-cut MSGLs are also present locally on the floors of outlet valleys. CIS disintegrated in <1000 years shortly after c. 13.0 ka releasing very large volumes of meltwater and sediment to the Pacific coast. Abrupt deglaciation may reflect unsustainable calving of marine-based ice streams along the glacio-isostatically depressed coast; large deep 'fiord lakes' in the ice sheet's interior may have played an analogous role. Mapping of the broad scale distribution of bed types across the Cordilleran Ice Sheet provides key information for paleoglaciological modelling and also for understanding the beds of modern ice masses such as the Greenland Ice Sheet which is of a comparable topographic setting.

Diamond formation due to a pH drop during fluid–rock interactions

DOE PAGES

Sverjensky, Dimitri A.; Huang, Fang

2015-11-03

Diamond formation has typically been attributed to redox reactions during precipitation from fluids or magmas. Either the oxidation of methane or the reduction of carbon dioxide has been suggested, based on simplistic models of deep fluids consisting of mixtures of dissolved neutral gas molecules without consideration of aqueous ions. The role of pH changes associated with water–silicate rock interactions during diamond formation is unknown. Here we show that diamonds could form due to a drop in pH during water–rock interactions. We use a recent theoretical model of deep fluids that includes ions, to show that fluid can react irreversibly withmore » eclogite at 900 °C and 5.0 GPa, generating diamond and secondary minerals due to a decrease in pH at almost constant oxygen fugacity. Overall, our results constitute a new quantitative theory of diamond formation as a consequence of the reaction of deep fluids with the rock types that they encounter during migration. Diamond can form in the deep Earth during water–rock interactions without changes in oxidation state.« less

Diamond formation due to a pH drop during fluid–rock interactions

PubMed Central

Sverjensky, Dimitri A.; Huang, Fang

2015-01-01

Diamond formation has typically been attributed to redox reactions during precipitation from fluids or magmas. Either the oxidation of methane or the reduction of carbon dioxide has been suggested, based on simplistic models of deep fluids consisting of mixtures of dissolved neutral gas molecules without consideration of aqueous ions. The role of pH changes associated with water–silicate rock interactions during diamond formation is unknown. Here we show that diamonds could form due to a drop in pH during water–rock interactions. We use a recent theoretical model of deep fluids that includes ions, to show that fluid can react irreversibly with eclogite at 900 °C and 5.0 GPa, generating diamond and secondary minerals due to a decrease in pH at almost constant oxygen fugacity. Overall, our results constitute a new quantitative theory of diamond formation as a consequence of the reaction of deep fluids with the rock types that they encounter during migration. Diamond can form in the deep Earth during water–rock interactions without changes in oxidation state. PMID:26529259

Biology of a deep-water sea anemone (Anthozoa: Actiniidae) from eastern Canada: Spawning, development, and growth

NASA Astrophysics Data System (ADS)

Mercier, Annie; Baillon, Sandrine; Daly, Marymegan; Macrander, Jason; Hamel, Jean-François

2017-03-01

Knowledge of the general biology and reproductive ecology of deep-water species can help predict their resilience to environmental and anthropogenic disturbances. The present study centers on live specimens of a deep-water sea anemone which were collected at bathyal depths between 1100 and 1400 m and kept in a mesocosm for over 6 years. Morphology and DNA sequencing confirmed that the species belongs to the genus Urticina. Male and female (9-10 cm pedal disk diameter, 90 tentacles) spawned 4 years post collection, in early spring (March). Both sexes released gametes through the mouth. The negatively buoyant oocytes (550-600 μm in diameter) quickly settled on the rocks and soft sediments surrounding the female. Lecithotrophic embryonic and larval development occurred on the substratum. Fully developed planula larvae were detected after 17-21 days. Planulae started to crawl and swim around but remained demersal. Metamorphosis and settlement occurred after 30-35 days, exclusively on hard substrata and preferentially on undersurfaces. Offspring grew slowly, developing 8 tentacles after 5 months and 24 tentacles after 12 months (3-4 mm pedal disk diameter). After 2.6 years of growth, the captive-born sea anemones reached 12-16 mm in pedal disk diameter and possessed 48-54 tentacles.

[Ecological basis of epiphytic Dendrobium officinale growth on cliff].

PubMed

Liu, Xiu-Juan; Zhu, Yan; Si, Jin-Ping; Wu, Ling-Shang; Cheng, Xue-Liang

2016-08-01

In order to make Dendrobium officinale return to the nature, the temperature and humidity in whole days of the built rock model with different slopes and aspects in the natural distribution of wild D. officinale in Tianmu Mountain were recorded by MH-WS01 automatic recorder. The results showed that the slope has a significant impact on the extreme temperature on the surface of the rocks. In summer, the extreme temperature on the surface of horizontal or soft rock can reach to 69.4 ℃, while the temperatures were lower than 50 ℃ on the vertical rock. In winter, the temperatures on the surface of vertical rock were higher and the low temperature duration was shorter than those on the horizontal or soft rock. Also, the humidity of the rocks was significantly influenced by the slope. The monthly average humidity on the surface of vertical rock was above 80%RH. Furthermore, the aspect had a significant impact on the temperature and humidity on the surface of the rocks, but had no significant effect on the daily mean temperature and extreme temperature on the surface of vertical rock. Therefore, the slope affects the survival of D. officinale by affecting the extreme temperature of rocks and affects the growth of D. officinale by affecting the humidity. The choice of slope is the key to the success of cliff epiphytic cultivation for D. officinale. Copyright© by the Chinese Pharmaceutical Association.

Rock- and Paleomagnetic Properties and Modeling of a Deep Crustal Volcanic System, the Reinfjord Ultramafic Complex, Seiland Igneous Province, Northern Norway

NASA Astrophysics Data System (ADS)

ter Maat, G. W.; Pastore, Z.; Michels, A.; Church, N. S.; McEnroe, S. A.; Larsen, R. B.

2017-12-01

The Reinfjord Ultramafic Complex is part of the 5000 km2 Seiland Igneous Province (SIP) in Northern Norway. The SIP is argued to be the deep-seated conduit system of a Large Igneous Province and was emplaced at 25-35 km depth in less than 10 Ma (570-560 Ma). The Reinfjord Ultramafic Complex was emplaced during three major successive events at 22-28km depth at pressures of 6-8kb, with associated temperatures 1450-1500°C (Roberts, 2006). The rocks are divided into three formations: the central series (CS) consisting of mainly dunites, upper layered series (ULS) consisting of dunites and wehrlites, a lower layered series (LLS) containing most pyroxene-rich rocks and a marginal zone (MZ) which formed where the ultramafic melts intruded the gabbro-norite and metasedimentary gneisses. Deep exposures such as the Reinfjord Ultramafic Complex are rare, therefore this study gives a unique insight in the rock magnetic properties of a deep ultramafic system. Localised serpentinised zones provide an opportunity to observe the effect of this alteration process on the magnetic properties of deep-seated rocks. Here, we present the results from the rock magnetic properties, a paleomagnetic study and combined potential-fields modeling. The study of the rock magnetic properties provides insight in primary processes associated with the intrusion, and later serpentinization. The paleomagnetic data yields two distinct directions. One direction corresponds to a Laurentia pole at ≈ 532 Ma while the other, though younger, is not yet fully understood. Rock magnetic properties were measured on > 700 specimens and used to constrain the modelling of gravity, high-resolution helicopter, and ground magnetic data. The intrusion is modelled as a cylindrically shaped complex with a dunite core surrounded by wehrlite and gabbro. The ultramafic part of the complex dips to the NE and its maximum vertical extent is modelled to 1400m. Furthermore, modelling allows estimation of relative volumes of ultramafic and mafic rocks below the surface. By integrating different methods this study contributes to the understanding of the magnetization of deep ultramafic rocks in the lithosphere, and to the refinement of the geological interpretation of the Reinfjord ultramafic intrusion.

ELLICOTT ROCK WILDERNESS AND ADDITIONS, SOUTH CAROLINA, NORTH CAROLINA, AND GEORGIA.

USGS Publications Warehouse

Bell, Henry; Gazdik, Gertrude C.

1984-01-01

A mineral survey was made of the Ellicott Rock Wilderness and additions located in the common corner of South Carolina, North Carolina, and Georgia. Surveys along the rivers, streams, and ridges indicated that there is little promise for the occurrence of metallic mineral or energy resources. Deeply buried sedimentary rocks have an unknown potential for hydrocarbons, probably gas. Until some deep drilling is done to test these deep sedimentary rocks no reasonable estimate of gas potential can be made, but it cannot be totally discounted.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sverjensky, Dimitri A.; Huang, Fang

Diamond formation has typically been attributed to redox reactions during precipitation from fluids or magmas. Either the oxidation of methane or the reduction of carbon dioxide has been suggested, based on simplistic models of deep fluids consisting of mixtures of dissolved neutral gas molecules without consideration of aqueous ions. The role of pH changes associated with water–silicate rock interactions during diamond formation is unknown. Here we show that diamonds could form due to a drop in pH during water–rock interactions. We use a recent theoretical model of deep fluids that includes ions, to show that fluid can react irreversibly withmore » eclogite at 900 °C and 5.0 GPa, generating diamond and secondary minerals due to a decrease in pH at almost constant oxygen fugacity. Overall, our results constitute a new quantitative theory of diamond formation as a consequence of the reaction of deep fluids with the rock types that they encounter during migration. Diamond can form in the deep Earth during water–rock interactions without changes in oxidation state.« less

Sulfur-Rich Rocks and Dirt (True Color)

NASA Technical Reports Server (NTRS)

2005-01-01

NASA's Mars Rover Spirit has been analyzing sulfur-rich rocks and surface materials in the 'Columbia Hills' in Gusev Crater on Mars. This image of a very soft, nodular, layered rock nicknamed 'Peace' in honor of Martin Luther King Jr. shows a 4.5-centimeter-wide (1.8-inch-wide) hole Spirit ground into the surface with the rover's rock abrasion tool. The high sulfur content of the rock measured by Spirit's alpha particle X-ray spectrometer and its softness measured by the abrasion tool are probably evidence of past alteration by water. Spirit's panoramic camera took this image on martian day, or sol, 381 (Jan. 27, 2005). The image represents the panoramic camera team's best current attempt at generating a true color view of what this scene would look like if viewed by a human on Mars. The image was generated from a combination of six calibrated, left-eye Pancam images acquired through filters ranging from 430-nanometer to 750-nanometer wavelengths.

Comparisons Between Experimental and Semi-theoretical Cutting Forces of CCS Disc Cutters

NASA Astrophysics Data System (ADS)

Xia, Yimin; Guo, Ben; Tan, Qing; Zhang, Xuhui; Lan, Hao; Ji, Zhiyong

2018-05-01

This paper focuses on comparisons between the experimental and semi-theoretical forces of CCS disc cutters acting on different rocks. The experimental forces obtained from LCM tests were used to evaluate the prediction accuracy of a semi-theoretical CSM model. The results show that the CSM model reliably predicts the normal forces acting on red sandstone and granite, but underestimates the normal forces acting on marble. Some additional LCM test data from the literature were collected to further explore the ability of the CSM model to predict the normal forces acting on rocks of different strengths. The CSM model underestimates the normal forces acting on soft rocks, semi-hard rocks and hard rocks by approximately 38, 38 and 10%, respectively, but very accurately predicts those acting on very hard and extremely hard rocks. A calibration factor is introduced to modify the normal forces estimated by the CSM model. The overall trend of the calibration factor is characterized by an exponential decrease with increasing rock uniaxial compressive strength. The mean fitting ratios between the normal forces estimated by the modified CSM model and the experimental normal forces acting on soft rocks, semi-hard rocks and hard rocks are 1.076, 0.879 and 1.013, respectively. The results indicate that the prediction accuracy and the reliability of the CSM model have been improved.

Localized and Areally Extensive Alterations in Marathon Valley, Endeavour Crater Rim, Mars

NASA Technical Reports Server (NTRS)

Mittlefehldt, David W.; Gellert, Ralf; Van Bommel, Scott; Arvidson, Raymond E.; Clark, Benton C.; Cohen, Barbara A.; Farrand, William H.; Ming, Douglas W.; Schroeder, Christian; Yen, Albert S.;

Rock Abrasion Tool Exhibits the Deep Red Pigment of Mars

NASA Image and Video Library

2006-07-21

This image shows the round, metallic working end of the rock abrasion tool at the end of a metallic cylinder. The flat grinding face, attached brush, and much of the smooth, metallic exterior of cylinder are covered with a deep reddish-brown layer of dust

Deep Bore Storage of Nuclear Waste Using MMW (Millimeter Wave) Technology. Full Project Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oglesby, Kenneth D.; Woskov, Paul; Einstein, Herbert

This DOE Nuclear STTR project DE-SC001238 investigated the use of MMW directed energy to form rock melt and steel plugs in deep wellbores to further isolate highly radioactive nuclear waste in ultra-deep basement rocks for long term storage. This current project builds upon a prior DOE project, DE-EE0005504, which developed the basic low power, low 28 GHz frequency waveguide setup, process and instruments. This research adds to our understanding of using MMW power to melt and vaporize rocks and steel/ metals and laid plans for future higher power field prototype testing. This technology also has potential for deep well drillingmore » for nuclear storage, geothermal and oil and gas industries. It also has the potential for simultaneously sealing and securing the wellbore with a thick rock melt liner as the wellbore is drilled, called 'mono-bore drilling'. This allows for higher levels of safety and protection of the environment during deep drilling operations while providing vast cost savings. The larger purpose of this project was to find answers to key questions in developing MMW technology for its many subsurface applications.« less

The research of breaking rock with liquid-solid two-phase jet flow

NASA Astrophysics Data System (ADS)

Cheng, X. Z.; Ren, F. S.; Fang, T. C.

2018-03-01

Abstracts. Particle impact drilling is an efficient way of breaking rock, which is mainly used in deep drilling and ultra-deep drilling. The differential equation was established based on the theory of Hertz and Newton’s second law, through the analysis of particle impact rock, the depth of particles into the rock was obtained. The mathematical model was established based on the effect of water impact crack. The research results show when water jet speed is more than 40 m/s, rock stability coefficient is more than 1.0, the rock fracture appear. Through the experimental research of particle impact drilling facilities, analysis of cuttings and the crack size which was analyzed through Scanning electron microscope consistent with the theoretical calculation, the validity of the model was verified.

A study of the depth of weathering and its relationship to the mechanical properties of near-surface rocks in the Mojave Desert

USGS Publications Warehouse

Stierman, D.J.; Healy, J.H.

1985-01-01

Weathered granite extends 70 m deep at Hi Vista in the arid central Mojave Desert of southern California. The low strength of this granite is due to the alteration of biotite and chlorite montmorillonite. Deep weathering probably occurs in most granites, although we cannot rule out some anomalous mechanisms at Hi Vista. Geophysical instruments set in these slightly altered rocks are limited by the unstable behavior of the rocks. Thus, tectonic signals from instruments placed in shallow boreholes give vague results. Geophysical measurements of these weathered rocks resemble measurements of granitic rocks near major faults. The rheology of the rocks in which instruments are placed limits the useful sensitivity of the instruments. ?? 1985 Birkha??user Verlag.

Endolithic Boring Enhance the Deep-sea Carbonate Lithification on the Southwest Indian Ridge

NASA Astrophysics Data System (ADS)

Peng, X.; Xu, H.

2017-12-01

Deep-sea carbonates represent an important type of sedimentary rock due to their effect on the composition of upper oceanic crust and their contribution to deep-sea geochemical cycles. However, the lithification of deep-sea carbonates at the seafloor has remained a mystery for many years. A large lithified carbonate area, characterized by thriving benthic faunas and tremendous amount of endolithic borings, was discovered in 2008, blanketed on the seafloor of ultraslow spreading Southwest Indian Ridge (SWIR). Macrofaunal inhabitants including echinoids, polychaetes, gastropods as well as crustaceans, are abundant in the sample. The most readily apparent feature of the sample is the localized enhancement of density around the borings. The boring features of these carbonate rocks and factors that may enhance deep-sea carbonate lithification are reported. The δ13CPDB values of 46 bulk samples are -0.37 to 1.86‰, while these samples have a relatively narrow δ18OPDB range of 1.35 to 3.79‰. The bulk δ13CPDB values of chalk and gray excrements are positively correlated with bulk δ18OPDB values (r = 0.91) (Fig. 8), which reflects that endolithic boring is possibly a critical factor influence the lithification. We suggest that active boring may trigger the dissolution of the original calcite and thus accelerate deep-sea carbonate lithification on mid-ocean ridges. Our study reports an unfamiliar phenomenon of non-burial carbonate lithification and interested by the observation that it is often associated with boring feature. These carbonate rocks may provide a novel mechanism for deep-sea carbonate lithification at the deep-sea seafloor and also illuminate the geological and biological importance of deep-sea carbonate rocks on mid-ocean ridges.

Microseismic monitoring during Hydraulic stimulation in Pohang (Korea) for EGS pilot project

NASA Astrophysics Data System (ADS)

Kim, M.; Yoon, B.; Lee, C.; Park, K. G.; Yoon, W. S.; Song, Y.; Lee, T. J.

2017-12-01

Since the geothermal anomaly in the Pohang area has been reported in 1960s, various geological and geophysical surveys have been conducted by Korea Institute of Geoscience and Mineral Resources (KIGAM) including gravity, seismic, airborne magnetic and magneto-telluric surveys. Based on these explorations, the Enhanced Geothermal System (EGS) pilot project has been carried out in Pohang since the end of 2010. One vertical well (PX-2, MD 4,348 m) and one deviated well (PX-1, MD 4,362 m) have been drilled in granite rock for the EGS. Microseismic (MS) monitoring is the best way to understand how the fracture grows during the hydraulic stimulation. KIGAM has set up 9 shallow borehole stations (100-130 m), 4 surface stations and two borehole geophones (1,350 and 1,550 m deep) within 5 km radius from injection well for the MS monitoring during hydraulic stimulation. The first hydraulic stimulation started on January 29th to February 20th, 2016 at PX-2 and the second stimulation was conducted in PX-1 from December 15th, 2016 to January 11th, 2017. Several hundreds of MS events occurred during stimulation and the biggest event was ML 2.3 during the shut in period of the second stimulation. Based on the results of the MS monitoring, a soft stimulation is scheduled at PX-1 in cooperation with one of the European Horizon2020 project, DESTRESS (Demonstration of soft stimulation treatments of geothermal reservoirs). We will present the MS monitoring system in Pohang and the data of the stimulation with the MS monitoring results. We believe that the data from Pohang will improve the understanding of seismic behavior due to hydraulic stimulation in crystalline rocks and also will contribute to success of the Pohang EGS project.

A Modular Soft Robotic Wrist for Underwater Manipulation.

PubMed

Kurumaya, Shunichi; Phillips, Brennan T; Becker, Kaitlyn P; Rosen, Michelle H; Gruber, David F; Galloway, Kevin C; Suzumori, Koichi; Wood, Robert J

2018-04-19

This article presents the development of modular soft robotic wrist joint mechanisms for delicate and precise manipulation in the harsh deep-sea environment. The wrist consists of a rotary module and bending module, which can be combined with other actuators as part of a complete manipulator system. These mechanisms are part of a suite of soft robotic actuators being developed for deep-sea manipulation via submersibles and remotely operated vehicles, and are designed to be powered hydraulically with seawater. The wrist joint mechanisms can also be activated with pneumatic pressure for terrestrial-based applications, such as automated assembly and robotic locomotion. Here we report the development and characterization of a suite of rotary and bending modules by varying fiber number and silicone hardness. Performance of the complete soft robotic wrist is demonstrated in normal atmospheric conditions using both pneumatic and hydraulic pressures for actuation and under high ambient hydrostatic pressures equivalent to those found at least 2300 m deep in the ocean. This rugged modular wrist holds the potential to be utilized at full ocean depths (>10,000 m) and is a step forward in the development of jointed underwater soft robotic arms.

Numerical Simulation of Rock Mass Damage Evolution During Deep-Buried Tunnel Excavation by Drill and Blast

NASA Astrophysics Data System (ADS)

Yang, Jianhua; Lu, Wenbo; Hu, Yingguo; Chen, Ming; Yan, Peng

2015-09-01

Presence of an excavation damage zone (EDZ) around a tunnel perimeter is of significant concern with regard to safety, stability, costs and overall performance of the tunnel. For deep-buried tunnel excavation by drill and blast, it is generally accepted that a combination of effects of stress redistribution and blasting is mainly responsible for development of the EDZ. However, few open literatures can be found to use numerical methods to investigate the behavior of rock damage induced by the combined effects, and it is still far from full understanding how, when and to what degree the blasting affects the behavior of the EDZ during excavation. By implementing a statistical damage evolution law based on stress criterion into the commercial software LS-DYNA through its user-subroutines, this paper presents a 3D numerical simulation of the rock damage evolution of a deep-buried tunnel excavation, with a special emphasis on the combined effects of the stress redistribution of surrounding rock masses and the blasting-induced damage. Influence of repeated blast loadings on the damage extension for practical millisecond delay blasting is investigated in the present analysis. Accompanying explosive detonation and secession of rock fragments from their initial locations, in situ stress in the immediate vicinity of the excavation face is suddenly released. The transient characteristics of the in situ stress release and induced dynamic responses in the surrounding rock masses are also highlighted. From the simulation results, some instructive conclusions are drawn with respect to the rock damage mechanism and evolution during deep-buried tunnel excavation by drill and blast.

Evaluating Macro and Microscopic Rock Damage from Explosions and the Effects on Shear Wave Generation

DTIC Science & Technology

2014-06-30

using the NEDE2 data to generate this model, we used data collected during NEDE1 to study Rg propagation in Barre Granite and nearby metamorphic rocks ...explosion using the soft rock coupling curve shown in Figure 10-3. ................................................................... 196 Figure 10-5...experiment under contract AFRL-FA9453-10-C-0257. Special thanks goes to Don Murray and Rock of Ages Corp. for allowing us to return and impose on their

Volatile transfer and recycling at convergent margins: Mass-balance and insights from high-P/T metamorphic rocks

NASA Astrophysics Data System (ADS)

Bebout, Gray E.

The efficiency with which volatiles are deeply subducted is governed by devolatilization histories and the geometries and mechanisms of fluid transport deep in subduction zones. Metamorphism along the forearc slab-mantle interface may prevent the deep subduction of many volatile components (e.g., H2O, Cs, B, N, perhaps As, Sb, and U) and result in their transport in fluids toward shallower reservoirs. The release, by devolatilization, and transport of such components toward the seafloor or into the forearc mantle wedge, could in part explain the imbalances between the estimated amounts of subducted volatiles and the amounts returned to Earth's surface. The proportion of the initially subducted volatile component that is retained in rocks subducted to depths greater than those beneath magmatic arcs (>100 km) is largely unknown, complicating assessments of deep mantle volatile budgets. Isotopic and trace element data and volatile contents for the Catalina Schist, the Franciscan Complex, and eclogite-facies complexes in the Alps (and elsewhere) provide insight into the nature and magnitude of fluid production and transport deep in subduction zones and into the possible effects of metamorphism on the compositions of subducting rocks. Compatibilities of the compositions of the subduction-related rocks and fluids with the isotopic and trace element compositions of various mantle-derived materials (igneous rocks, xenoliths, serpentinite seamounts) indicate the potential to trace the recycling of rock and fluid reservoirs chemically and isotopically fractionated during subduction-zone metamorphism.

Experimental Investigation of the Influence of Confining Stress on Hard Rock Fragmentation Using a Conical Pick

NASA Astrophysics Data System (ADS)

Li, Xibing; Wang, Shaofeng; Wang, Shanyong

2018-01-01

High geostress is a prominent condition in deep excavations and affects the cuttability of deep hard rock. This study aims to determine the influence of confining stress on hard rock fragmentation as applied by a conical pick. Using a true triaxial test apparatus, static and coupled static and dynamic loadings from pick forces were applied to end faces of cubic rock specimens to break them under biaxial, uniaxial and stress-free confining stress conditions. The cuttability indices (peak pick force, insertion depth and disturbance duration), failure patterns and fragment sizes were measured and compared to estimate the effects of confining stress. The results show that the rock cuttabilities decreased in order from rock breakages under stress-free conditions to uniaxial confining stress and then to biaxial confining stress. Under biaxial confining stress, only flake-shaped fragments were stripped from the rock surfaces under the requirements of large pick forces or disturbance durations. As the level of uniaxial confining stress increased, the peak pick force and the insertion depth initially increased and then decreased, and the failure patterns varied from splitting to partial splitting and then to rock bursts with decreasing average fragment sizes. Rock bursts will occur under elastic compression via ultra-high uniaxial confining stresses. There are two critical uniaxial confining stress levels, namely stress values at which peak pick forces begin to decrease and improve rock cuttability, and those at which rock bursts initially occur and cutting safety decreases. In particular, hard rock is easiest to split safely and efficiently under stress-free conditions. Moreover, coupled static preloading and dynamic disturbance can increase the efficiency of rock fragmentation with increasing preloading levels and disturbance amplitudes. The concluding remarks confirm hard rock cuttability using conical pick, which can improve the applicability of mechanical excavation in deep hard rock masses.

Three-dimensional distribution of igneous rocks near the Pebble porphyry Cu-Au-Mo deposit in southwestern Alaska: constraints from regional-scale aeromagnetic data

USGS Publications Warehouse

Anderson, Eric D.; Zhou, Wei; Li, Yaoguo; Hitzman, Murray W.; Monecke, Thomas; Lang, James R.; Kelley, Karen D.

2014-01-01

Aeromagnetic data helped us to understand the 3D distribution of plutonic rocks near the Pebble porphyry copper deposit in southwestern Alaska, USA. Magnetic susceptibility measurements showed that rocks in the Pebble district are more magnetic than rocks of comparable compositions in the Pike Creek–Stuyahok Hills volcano-plutonic complex. The reduced-to-pole transformation of the aeromagnetic data demonstrated that the older rocks in the Pebble district produce strong magnetic anomaly highs. The tilt derivative transformation highlighted northeast-trending lineaments attributed to Tertiary volcanic rocks. Multiscale edge detection delineated near-surface magnetic sources that are mostly outward dipping and coalesce at depth in the Pebble district. The total horizontal gradient of the 10-km upward-continued magnetic data showed an oval, deep magnetic contact along which porphyry deposits occur. Forward and inverse magnetic modeling showed that the magnetic rocks in the Pebble district extend to depths greater than 9 km. Magnetic inversion was constrained by a near-surface, 3D geologic model that is attributed with measured magnetic susceptibilities from various rock types in the region. The inversion results indicated that several near-surface magnetic sources with moderate susceptibilities converge with depth into magnetic bodies with higher susceptibilities. This deep magnetic source appeared to rise toward the surface in several areas. An isosurface value of 0.02 SI was used to depict the magnetic contact between outcropping granodiorite and nonmagnetic sedimentary host rocks. The contact was shown to be outward dipping. At depths around 5 km, nearly the entire model exceeded the isosurface value indicating the limits of nonmagnetic host material. The inversion results showed the presence of a relatively deep, northeast-trending magnetic low that parallels lineaments mapped by the tilt derivative. This deep low represents a strand of the Lake Clark fault.

Deep Learning MR Imaging-based Attenuation Correction for PET/MR Imaging.

PubMed

Liu, Fang; Jang, Hyungseok; Kijowski, Richard; Bradshaw, Tyler; McMillan, Alan B

2018-02-01

Purpose To develop and evaluate the feasibility of deep learning approaches for magnetic resonance (MR) imaging-based attenuation correction (AC) (termed deep MRAC) in brain positron emission tomography (PET)/MR imaging. Materials and Methods A PET/MR imaging AC pipeline was built by using a deep learning approach to generate pseudo computed tomographic (CT) scans from MR images. A deep convolutional auto-encoder network was trained to identify air, bone, and soft tissue in volumetric head MR images coregistered to CT data for training. A set of 30 retrospective three-dimensional T1-weighted head images was used to train the model, which was then evaluated in 10 patients by comparing the generated pseudo CT scan to an acquired CT scan. A prospective study was carried out for utilizing simultaneous PET/MR imaging for five subjects by using the proposed approach. Analysis of covariance and paired-sample t tests were used for statistical analysis to compare PET reconstruction error with deep MRAC and two existing MR imaging-based AC approaches with CT-based AC. Results Deep MRAC provides an accurate pseudo CT scan with a mean Dice coefficient of 0.971 ± 0.005 for air, 0.936 ± 0.011 for soft tissue, and 0.803 ± 0.021 for bone. Furthermore, deep MRAC provides good PET results, with average errors of less than 1% in most brain regions. Significantly lower PET reconstruction errors were realized with deep MRAC (-0.7% ± 1.1) compared with Dixon-based soft-tissue and air segmentation (-5.8% ± 3.1) and anatomic CT-based template registration (-4.8% ± 2.2). Conclusion The authors developed an automated approach that allows generation of discrete-valued pseudo CT scans (soft tissue, bone, and air) from a single high-spatial-resolution diagnostic-quality three-dimensional MR image and evaluated it in brain PET/MR imaging. This deep learning approach for MR imaging-based AC provided reduced PET reconstruction error relative to a CT-based standard within the brain compared with current MR imaging-based AC approaches. © RSNA, 2017 Online supplemental material is available for this article.

U.S. Geological Survey offshore program of resource and geo-environmental studies and topical investigations, Pacific-Arctic region

USGS Publications Warehouse

Scholl, David William

1978-01-01

The Geological Survey 's marine geology investigations in the Pacific-Arctic area are presented in this report in the context of the underlying socio-economic problem of expanding the domestic production of oil and gas and other mineral and hard- and soft-rock resources while maintaining acceptable standards in the marine environment. The primary mission of the Survey 's Pacific-Arctic Branch of Marine Geology is to provide scientifically interpreted information about the (1) resource potential, (2) geo-environmental setting, and (3) overall geologic characteristics of the continental margins (that is, the continental shelf, slope and rise) and adjacent deeper water and shallower coastal areas off California, Oregon, Washington, Alaska and Hawaii and also, where it is of interest to the U.S. Government, more remote deep-sea areas of the Pacific-Arctic realm. (Sinha-OEIS)

Alveolar soft part sarcoma causing perianal abscess.

PubMed

Sullivan, Niall; McCulloch, Tom; Leverton, David

2011-07-01

A 34-year-old woman presented with a perianal abscess that communicated with the vagina. There was a background of a one-year history of a conservatively treated, traumatic, paravaginal haematoma. Histology of the fistula tract showed alveolar soft part sarcoma and subsequent imaging identified a large soft tissue mass in the pelvis with lung metastases. Alveolar soft part sarcoma is a rare soft tissue sarcoma of unknown cellular origin affecting predominantly young women, often in deep soft tissues and lower extremities.

Mass timber rocking panel retrofit of a four-story soft-story building with full-scale shake table validation

Treesearch

Pouria Bahmani; John van de Lindt; Asif Iqbal; Douglas Rammer

2017-01-01

Soft-story wood-frame buildings have been recognized as a disaster preparedness problem for decades. There are tens of thousands of these multi-family three- and four-story structures throughout California and the United States. The majority were constructed between 1920 and 1970, with many being prevalent in the San Francisco Bay Area in California. The NEES Soft...

Pleistocene hydrovolcanism in the Tule Lake Basin, N. E. California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lavine, A.

1993-04-01

The Prisoners Rock and The Peninsula tuff cones and the North Crater tuff ring, located in the Tule Lake Basin of northeastern California formed along a north-trending fissure approximately 270 ka when basaltic magma interacted with abundant groundwater or shallow lake water, resulting in phreatomagmatic eruptions. Diatomite inclusions in the tuff ring and correlations with the corresponding depth and diatoms in a drill core taken in the center of the basin, 2.5 km to the west of the cones, indicate shallow, marshy or shallow, alkaline-open conditions at Tule Lake around 270 ka. Deposits at Prisoners Rock and The Peninsula indicatemore » subaerial emplacement, which allowed the deposits to lithify with little erosion by the lake. Subsequent wave erosion caused undercutting and breaking off of large blocks along mainly north-trending fractures forming vertical cliff faces on the east and west sides of the cones. The cones are elongated north-south with a greater thickness of deposits on the north and northeast, probably due to prevailing southwesterly winds at the time of eruptions. Deposits of the tuff cones at Prisoners Rock and The Peninsula resulted from deep explosions caused by water-magma ratios of around 3:1. The deposits are mainly inversely graded planar surge beds, ranging in thickness from 5 to 30 cm, and grading from very fine ash to 2 cm-diameter accretionary lapilli. Emplacement by highly steam-saturated, poorly inflated pyroclastic surges is indicated by the abundance of accretionary lapilli, vesiculated tuffs, soft-sediment deformation structures, steep bedding angles (20 to 40 degrees) lack of structures beneath country rock inclusions, massive bedding, and cementation of the deposits by alteration of basaltic glass to calcite, zeolites, clays, and chlorite.« less

The relationship between the deep-level structure in crust and brewing of strong earthquakes in Xingtai area

NASA Astrophysics Data System (ADS)

Xiao, Lan-Xi; Zhu, Yuan-Qing; Zhang, Shao-Quan; Liu, Xu; Guo, Yu

1999-11-01

In this paper, crust medium is treated as Maxwell medium, and crust model includes hard inclusion, soft inclusion, deep-level fault. The stress concentration and its evolution with time are obtained by using three-dimensional finite element method and differential method. The conclusions are draw as follows: (1) The average stress concentration and maximum shear stress concentration caused by non-heterogeneous of crust are very high in hard inclusion and around the deep fault. With the time passing by, the concentration of average stress in the model gradually trends to uniform. At the same time, the concentration of maximum shear stress in hard inclusion increases gradually. This character is favorable to transfer shear strain energy from soft inclusion to hard inclusion. (2) When the upper mantle beneath the inclusion upheave at a certain velocity of 1 cm/a, the changes of average stress concentration with time become complex, and the boundary of the hard and soft inclusion become unconspicuous, but the maximum shear stress concentration increases much more in the hard inclusion with time at a higher velocity. This feature make for transformation of energy from the soft inclusion to the hard inclusion. (3) The changes of average stress concentration and maximum shear stress concentration with time around the deep-level fault result in further accumulation of maximum shear stress concentration and finally cause the deep-level fault instable and accelerated creep along fault direction. (4) The changes of vertical displacement on the surface of the model, which is caused by the accelerated creep of the deep-level fault, is similar to that of the observation data before Xingtai strong earthquake.

Hydrogeologic controls imposed by mechanical stratigraphy in layered rocks of the Châteauguay River Basin, a U.S.-Canada transborder aquifer

NASA Astrophysics Data System (ADS)

Morin, Roger; Godin, RéJean; Nastev, Miroslav; Rouleau, Alain

2007-04-01

The Châteauguay River Basin delineates a transborder watershed with roughly half of its surface area located in northern New York State and half in southern Québec Province, Canada. As part of a multidisciplinary study designed to characterize the hydrogeologic properties of this basin, geophysical logs were obtained in 12 wells strategically located to penetrate the four major sedimentary rock formations that constitute the regional aquifers. The layered rocks were classified according to their elastic properties into three primary units: soft sandstone, hard sandstone, and dolostone. Downhole measurements were analyzed to identify fracture patterns associated with each unit and to evaluate their role in controlling groundwater flow. Fracture networks are composed of orthogonal sets of laterally extensive, subhorizontal bedding plane partings and bed-delimited, subvertical joints with spacings that are consistent with rock mechanics principles and stress models. The vertical distribution of transmissive zones is confined to a few select bedding plane fractures, with soft sandstone having the fewest (one per 70-m depth) and hard sandstone the most (five per 70-m depth). Bed-normal permeability is examined using a probabilistic model that considers the lengths of flow paths winding along joints and bedding plane fractures. Soft sandstone has the smallest bed-normal permeability primarily because of its wide, geomechanically undersaturated joint spacing. Results indicate that the three formations have similar values of bulk transmissivity, within roughly an order of magnitude, but that each rock unit has its own unique system of groundwater flow paths that constitute that transmissivity.

Hydrogeologic controls imposed by mechanical stratigraphy in layered rocks of the Chateauguay River Basin, a U.S.-Canada transborder aquifer

USGS Publications Warehouse

Morin, Roger H.; Godin, Rejean; Nastev, Miroslav; Rouleau, Alain

2007-01-01

[1] The Châteauguay River Basin delineates a transborder watershed with roughly half of its surface area located in northern New York State and half in southern Québec Province, Canada. As part of a multidisciplinary study designed to characterize the hydrogeologic properties of this basin, geophysical logs were obtained in 12 wells strategically located to penetrate the four major sedimentary rock formations that constitute the regional aquifers. The layered rocks were classified according to their elastic properties into three primary units: soft sandstone, hard sandstone, and dolostone. Downhole measurements were analyzed to identify fracture patterns associated with each unit and to evaluate their role in controlling groundwater flow. Fracture networks are composed of orthogonal sets of laterally extensive, subhorizontal bedding plane partings and bed-delimited, subvertical joints with spacings that are consistent with rock mechanics principles and stress models. The vertical distribution of transmissive zones is confined to a few select bedding plane fractures, with soft sandstone having the fewest (one per 70-m depth) and hard sandstone the most (five per 70-m depth). Bed-normal permeability is examined using a probabilistic model that considers the lengths of flow paths winding along joints and bedding plane fractures. Soft sandstone has the smallest bed-normal permeability primarily because of its wide, geomechanically undersaturated joint spacing. Results indicate that the three formations have similar values of bulk transmissivity, within roughly an order of magnitude, but that each rock unit has its own unique system of groundwater flow paths that constitute that transmissivity.

The major mass movements of the Western Dolomites (Italy)

NASA Astrophysics Data System (ADS)

Ostermann, Marc; Gruber, Alfred

2014-05-01

Major gravitational slope deformations are widely disseminated in the Dolomite Mountains (NE-Italy), one of the world's most conspicuous landscapes and part of the UNESCO world heritage list. Because of their unique geological composition the Dolomites provide a natural laboratory where nearly all kind of mass wasting processes, in all dimensions, can be investigated. Simplified there are thick, rigid carbonatic successions (Triassic-Jurassic) resting on and interfingering with relatively weak successions of shallow marine clastic and of pelagic sediments. In some areas even volcanic successions and crystalline basement rocks are outcropped. Hugh rockslides and long run-out rock avalanches are limited to the carbonates and volcanic rocks. The superposition of Middle and Upper Triassic reefs, showing brittle deformation behaviour, above weak successions of evaporites, clays and marls, characterised by ductile deformation behaviour, leads to a classical "hard on soft" situation. The observable results are rockslides and rock avalanches of several hundred millions of m³ in volume, large scale rock toppling and rock flows and deep-seated gravitational slope deformations (DSGSD). Within the weak successions slow moving rotational landslides and large dimensional earthflows are very common. We focused our research on an area of about 40*40km within the Western and Northern Dolomites, where an inventory of the major gravitational mass movements has been compiled. We combined detailed geological maps with high resolution DEMs and extensive fieldwork data within a GIS-system. The different processes have been characterised and classified based on kinematic criteria, dimension and involved material. Altogether the database consists of 186 entries. Most frequently are landslides and earthflows (146) followed by catastrophic rockslides and rock avalanches (26) and DSGSDs (14). The spatial distribution of the mapped processes has been analysed in terms of the main geomorphological and geological characteristics, and of their clustering. For some of the most impressive sites age data has been established and allows a supra-regional comparison. For each type of investigated mass movement we present an exemplary case study that shows the most important features of the major slope failures within the Dolomites.

Petrology and geochemistry of primitive lower oceanic crust from Pito Deep: Implications for the accretion of the lower crust at the Southern East Pacific Rise

USGS Publications Warehouse

Perk, N.W.; Coogan, L.A.; Karson, J.A.; Klein, E.M.; Hanna, H.D.

2007-01-01

A suite of samples collected from the uppermost part of the plutonic section of the oceanic crust formed at the southern East Pacific Rise and exposed at the Pito Deep has been examined. These rocks were sampled in situ by ROV and lie beneath a complete upper crustal section providing geological context. This is only the second area (after the Hess Deep) in which a substantial depth into the plutonic complex formed at the East Pacific Rise has been sampled in situ and reveals significant spatial heterogeneity in the plutonic complex. In contrast to the uppermost plutonic rocks at Hess Deep, the rocks studied here are generally primitive with olivine forsterite contents mainly between 85 and 88 and including many troctolites. The melt that the majority of the samples crystallized from was aggregated normal mid-ocean ridge basalt (MORB). Despite this high Mg# clinopyroxene is common despite model predictions that clinopyroxene should not reach the liquidus early during low-pressure crystallization of MORB. Stochastic modeling of melt crystallisation at various levels in the crust suggests that it is unlikely that a significant melt mass crystallized in the deeper crust (for example in sills) because this would lead to more evolved shallow level plutonic rocks. Similar to the upper plutonic section at Hess Deep, and in the Oman ophiolite, many samples show a steeply dipping, axis-parallel, magmatic fabric. This suggests that vertical magmatic flow is an important process in the upper part of the seismic low velocity zone beneath fast-spreading ridges. We suggest that both temporal and spatial (along-axis) variability in the magmatic and hydrothermal systems can explain the differences observed between the Hess Deep and Pito Deep plutonics. ?? Springer-Verlag 2007.

Rock Burst Monitoring by Integrated Microseismic and Electromagnetic Radiation Methods

NASA Astrophysics Data System (ADS)

Li, Xuelong; Wang, Enyuan; Li, Zhonghui; Liu, Zhentang; Song, Dazhao; Qiu, Liming

2016-11-01

For this study, microseismic (MS) and electromagnetic radiation (EMR) monitoring systems were installed in a coal mine to monitor rock bursts. The MS system monitors coal or rock mass ruptures in the whole mine, whereas the EMR equipment monitors the coal or rock stress in a small area. By analysing the MS energy, number of MS events, and EMR intensity with respect to rock bursts, it has been shown that the energy and number of MS events present a "quiet period" 1-3 days before the rock burst. The data also show that the EMR intensity reaches a peak before the rock burst and this EMR intensity peak generally corresponds to the MS "quiet period". There is a positive correlation between stress and EMR intensity. Buckling failure of coal or rock depends on the rheological properties and occurs after the peak stress in the high-stress concentration areas in deep mines. The MS "quiet period" before the rock burst is caused by the heterogeneity of the coal and rock structures, the transfer of high stress into internal areas, locked patches, and self-organized criticality near the stress peak. This study increases our understanding of coal and rock instability in deep mines. Combining MS and EMR to monitor rock burst could improve prediction accuracy.

Methods for assessing the polishing characteristics of coarse aggregates for use in pavement surface layers.

DOT National Transportation Integrated Search

2010-06-01

The predominant aggregate resources located in the western parts of Virginia are carbonate rocks. The mineral components of these rocks tend to be relatively soft and subject to abrasive wear under traffic that leads to a fairly rapid smoothing of th...

Radioactive springs geochemical data related to uranium exploration

USGS Publications Warehouse

Cadigan, R.A.; Felmlee, J.K.

1977-01-01

Radioactive mineral springs and wells at 33 localities in the States of Colorado, Utah, Arizona and New Mexico in the United States were sampled and studied to obtain geochemical data which might be used for U exploration. The major source of radioactivity at mineral spring sites is 226Ra. Minor amounts of 228Ra, 238U and 232Th are also present. Ra is presumed to have been selectively removed from possibly quite deep uranium-mineralized rock by hydrothermal solutions and is either precipitated at the surface or added to fresh surface water. In this way, the source rocks influence the geochemistry of the spring waters and precipitates. Characteristics of the spring waters at or near the surface are also affected by variations in total dissolved solids, alkalinity, temperature and co-precipitation. Spring precipitates, both hard and soft, consist of four major types: (1) calcite travertine; (2) iron- and arsenic-rich precipitates; (3) manganese- and barium-rich precipitates; and (4) barite, in some instances accompanied by S, Ra and U, if present in the spring water, are co-precipitated with the barite, Mn-Ba and Fe-As precipitates. Using parameters based on U and Ra concentrations in waters and precipitates springsite areas are tentatively rated for favourability as potential uraniferous areas. ?? 1977.

Site Classification using Multichannel Channel Analysis of Surface Wave (MASW) method on Soft and Hard Ground

NASA Astrophysics Data System (ADS)

Ashraf, M. A. M.; Kumar, N. S.; Yusoh, R.; Hazreek, Z. A. M.; Aziman, M.

2018-04-01

Site classification utilizing average shear wave velocity (Vs(30) up to 30 meters depth is a typical parameter. Numerous geophysical methods have been proposed for estimation of shear wave velocity by utilizing assortment of testing configuration, processing method, and inversion algorithm. Multichannel Analysis of Surface Wave (MASW) method is been rehearsed by numerous specialist and professional to geotechnical engineering for local site characterization and classification. This study aims to determine the site classification on soft and hard ground using MASW method. The subsurface classification was made utilizing National Earthquake Hazards Reduction Program (NERHP) and international Building Code (IBC) classification. Two sites are chosen to acquire the shear wave velocity which is in the state of Pulau Pinang for soft soil and Perlis for hard rock. Results recommend that MASW technique can be utilized to spatially calculate the distribution of shear wave velocity (Vs(30)) in soil and rock to characterize areas.

Art Rocks with Rock Art!

ERIC Educational Resources Information Center

Bickett, Marianne

2011-01-01

This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

Bedside ultrasound of the soft tissue of the face: a case of early Ludwig's angina.

PubMed

Gaspari, Romolo J

2006-10-01

A case is reported of a 38-year-old man presenting with early Ludwig's angina. It is difficult to differentiate superficial from deep infections of the face and neck by physical examination alone. The diagnosis of this condition with bedside soft tissue ultrasound of the face is described. Ludwig's angina is an uncommon infection of the deep tissues of the face and neck that usually evolves from more superficial infections such as dental abscesses.

New Bottom Roughness Calculation from Multibeam Echo Sounders for Mine Warfare

DTIC Science & Technology

2012-09-01

complex including craters, gullies, seaweed , rocks, sand ridges, tall obstructions, deep holes and sloping regions. Underwater mines can be hidden...and shadows for detecting objects lying on the seafloor. The seafloor is rather complex including craters, gullies, seaweed , rocks, sand ridges, tall...roughness as craters, gullies, seaweed , sand ridges, tall obstructions, deep holes, or steeply sloping regions. Slopes can make it possible for mines to

Molecular diversity of bacterial communities from subseafloor rock samples in a deep-water production basin in Brazil.

PubMed

von der Weid, Irene; Korenblum, Elisa; Jurelevicius, Diogo; Rosado, Alexandre Soares; Dino, Rodolfo; Sebastian, Gina Vasquez; Seldin, Lucy

2008-01-01

The deep subseafloor rock in oil reservoirs represents a unique environment in which a high oilcontamination and very low biomass can be observed. Sampling this environment has been a challenge owing to the techniques used for drilling and coring. In this study, the facilities developed by the Brazilian oil company PETROBRAS for accessing deep subsurface oil reservoirs were used to obtain rock samples at 2,822-2,828 m below the ocean floor surface from a virgin field located in the Atlantic Ocean, Rio de Janeiro. To address the bacterial diversity of these rock samples, PCR amplicons were obtained using the DNA from four core sections and universal primers for 16S rRNA and for APS reductase (aps) genes. Clone libraries were generated from these PCR fragments and 87 clones were sequenced. The phylogenetic analyses of the 16S rDNA clone libraries showed a wide distribution of types in the domain bacteria in the four core samples, and the majority of the clones were identified as belonging to Betaproteobacteria. The sulfate-reducing bacteria community could only be amplified by PCR in one sample, and all clones were identified as belonging to Gammaproteobacteria. For the first time, the bacterial community was assessed in such deep subsurface environment.

Origin and distribution of the organic matter in the distal lobe of the Congo deep-sea fan - A Rock-Eval survey

NASA Astrophysics Data System (ADS)

Baudin, François; Stetten, Elsa; Schnyder, Johann; Charlier, Karine; Martinez, Philippe; Dennielou, Bernard; Droz, Laurence

2017-08-01

The Congo River, the second largest river in the world, is a major source of organic matter for the deep Atlantic Ocean because of the connection of its estuary to the deep offshore area by a submarine canyon which feeds a vast deep-sea fan. The lobe zone of this deep-sea fan is the final receptacle of the sedimentary inputs presently channelled by the canyon and covers an area of 2500 km². The quantity and the source of organic matter preserved in recent turbiditic sediments from the distal lobe of the Congo deep-sea fan were assessed using Rock-Eval pyrolysis analyses. Six sites, located at approximately 5000 m water-depth, were investigated. The mud-rich sediments of the distal lobe contain high amounts of organic matter ( 3.5 to 4% Corg), the origin of which is a mixture of terrestrial higher-plant debris, soil organic matter and deeply oxidized phytoplanktonic material. Although the respective contribution of terrestrial and marine sources of organic matter cannot be precisely quantified using Rock-Eval analyses, the terrestrial fraction is dominant according to similar hydrogen and oxygen indices of both suspended and bedload sediments from the Congo River and that deposited in the lobe complex. The Rock-Eval signature supports the 70% to 80% of the terrestrial fraction previously estimated using C/N and δ13Corg data. In the background sediment, the organic matter distribution is homogeneous at different scales, from a single turbiditic event to the entire lobe, and changes in accumulation rates only have a limited effect on the quantity and quality of the preserved organic matter. Peculiar areas with chemosynthetic bivalves and/or bacterial mats, explored using ROV Victor 6000, show a Rock-Eval signature similar to background sediment. This high organic carbon content associated to high sedimentation rates (> 2 to 20 mm.yr-1) in the Congo distal lobe complex implies a high burial rate for organic carbon. Consequently, the Congo deep-sea fan represents an enormous sink of terrestrial organic matter when compared to other turbiditic systems over the world.

Bedrock, soils, and hillslope hydrology in the Central Texas Hill Country, USA: implications on environmental management in a carbonate-rock terrain

NASA Astrophysics Data System (ADS)

Woodruff, C. M.; Wilding, L. P.

2008-08-01

The Hill Country of Central Texas, USA, is undergoing rapid socioeconomic development, but environmental management of this region is hampered by misconceptions about local bedrock, soils, terrain, and hydrologic processes. The Hill Country is underlain mostly by Glen Rose Limestone (Lower Cretaceous) and exhibits a stepped terrain, which has been incorrectly attributed to alternating hard and soft bedrock strata. Other characteristics mistakenly attributed to this landscape include thin soils with scant water-retention capabilities, and rapid runoff as the dominant hydrologic process. This report presents new findings: unweathered bedrock is well indurated, but interbeds exhibit variable weathering rates. Recessive slopes (“risers”) on this stepped terrain result from rapid deterioration of strata having generally heterogeneous depositional fabrics (bioturbation and irregular clay partings) in contrast to ledge-forming strata having homogeneous fabrics. A stony regolith is thus formed beneath risers, providing porous and permeable ground that retards runoff and promotes the formation of moderately deep to deep (two-tiered) regolith/soil zones. These surficial materials on local steep slopes compose important natural environmental buffers; they support diverse biota and enhanced geochemical cycling of nutrients; they also exhibit significant water retention and enhanced erosion abatement. Proper land management demands recognition of these attributes in the siting, design, and construction of facilities.

Blueschist- and Eclogite facies Pseudotachylytes: Products of Earthquakes in Collision- and Subduction zones

NASA Astrophysics Data System (ADS)

Andersen, T. B.; Austrheim, H.; John, T.; Medvedev, S.; Mair, K.

2009-04-01

Pseudotachylytes are the products of violent geological processes such as metorite impacts and seismic faulting. The fault-rock weakening processes leading to release of earthquakes are commonly related to phenomena such as grain size reduction and gouge formation, pressurization of pore-fluids and in some cases to melting by frictional heating. Explaining the frequently observed intermediate and deep earthquakes by brittle failure is, however, inherently difficult to reconcile because of extremely high normal stresses occuring at depth. In recent years several mechanisms for seismic events on deep faults have been suggested. These include: a) The most commonly accepted mechanism, dehydration embrittlement coupled to prograde metamorphic dehydration of wet rocks, such as serpentinites, at depth. b) Grain-size dependent flow-laws coupled with shear heating instability has been suggested as an alternative to explain repeated seismic faulting in Wadati-Benioff zones. c) Self-localized-thermal-runaway (SLTR) has been forwarded as a mechanism for ultimate failure of visco-elastic materials and as mechanism to explain the co-existence of shear zones and pseudotachylyte fault veins formed at eclogite facies conditions. All these mechanism point to the importance of metamorphism and/or metasomatism in understanding the mechanism(s) of intermediate- and deep earthquakes. Exhumed high to ultra-high pressure [(U)HP] metamorphic rocks are recognized in many orogenic belts. These complexes provide avenues to study a number of important products of geological processes including earthquakes with hypocentres at great depths. (U)HP co-seismic fault rocks are difficult to find in the field; nevertheless, a number of occurrences of co-seismic fault rocks from such complexes have been described after the initial discovery of such rocks in Norway (see: Austrheim and Boundy, Science 1994). In this talk we review some observations and interpretations based on these hitherto rarely observed but important co-seismic fault rocks from deep-crust and mantle complexes.

Late Precambrian (740 Ma) charnockite, enderbite, and granite from Jebel Moya, Sudan: A link between the Mozambique Belt and the Arabian-Nubian Shield

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stern, R.J.; Dawoud, A.S.

1991-09-01

New Rb-Sr and whole rock and U-Pb zircon data are reported for deep-seated igneous rocks from Jebel Moya in east-central Sudan. This exposure is important because it may link the high-grade metamorphic and deep-seated igneous rocks of the Mozambique Belt with the greenschist-facies and ophiolitic assemblages of the Arabian-Nubian Shield, both of Pan-African (ca. 900-550 Ma) age. The rocks of Jebel Moya consist of pink granite, green charnockite, and dark enderbite. A twelve-point Rb-Sr whole rock isochron for all three lithologies yields an age of 730 {plus minus} 31 Ma and an initial {sup 87}Sr/{sup 86}Sr of 0.7031 {plus minus}more » 1. Nearly concordant zircon ages for granite, charnockite, and enderbite are 744 {plus minus} 2,742 {plus minus} 2, and 739 {plus minus} 2 Ma, respectively. Initial {epsilon}-Nd for these rocks are indistinguishable at 3.0 {plus minus} 0.4. The data suggest that the charnockite, enderbite, and granite are all part of a deep-seated igneous complex. The initial isotopic compositions of Sr and Nd indicate that Jebel Moya melts were derived from a mantle source that experienced significantly less time-integrated depletion of LRE and LIL elements than the source of Arabian-Nubian Shield melts. The ages for Jebel Moya deep-seated igneous rocks are in accord with data from elsewhere in the Mozambique Belt indicating that peak metamorphism occurred about 700-750 Ma. The northward extension of the Mozambique Belt to the Arabian-Nubian Shield defines a single east Pan-African orogen. The principal difference between the northern and southern sectors of this orogen may be the greater degree of thickening and subsequent erosion experienced in the south during the late Precambrian, perhaps a result of continental collision between East (Australia-India) and West Gondwanaland (S. America-Africa) about 750 Ma.« less

Geometrical and hydrogeological impact on the behaviour of deep-seated rock slides during reservoir impoundment

NASA Astrophysics Data System (ADS)

Lechner, Heidrun; Zangerl, Christian

2015-04-01

Given that there are still uncertainties regarding the deformation and failure mechanisms of deep-seated rock slides this study concentrates on key factors that influence the behaviour of rock slides in the surrounding of reservoirs. The focus is placed on the slope geometry, hydrogeology and kinematics. Based on numerous generic rock slide models the impacts of the (i) rock slide geometry, (ii) reservoir impoundment and level fluctuations, (iii) seepage and buoyancy forces and (iv) hydraulic conductivity of the rock slide mass and the basal shear zone are examined using limit equilibrium approaches. The geometry of many deep-seated rock slides in metamorphic rocks is often influenced by geological structures, e.g. fault zones, joints, foliation, bedding planes and others. With downslope displacement the rock slide undergoes a change in shape. Several observed rock slides in an advanced stage show a convex, bulge-like topography at the foot of the slope and a concave topography in the middle to upper part. Especially, the situation of the slope toe plays an important role for stability. A potentially critical situation can result from a partially submerged flat slope toe because the uplift due to water pressure destabilizes the rock slide. Furthermore, it is essential if the basal shear zone daylights at the foot of the slope or encounters alluvial or glacial deposits at the bottom of the valley, the latter having a buttressing effect. In this study generic rock slide models with a shear zone outcropping at the slope toe are established and systematically analysed using limit equilibrium calculations. Two different kinematic types are modelled: (i) a translational or planar and (ii) a rotational movement behaviour. Questions concerning the impact of buoyancy and pore pressure forces that develop during first time impoundment are of key interest. Given that an adverse effect on the rock slide stability is expected due to reservoir impoundment the extent of destabilisation is highly dependent on the ratio of the rock mass volume affected by buoyancy forces to the total volume of the rock slide. If a large rock mass volume ratio is submerged, huge buoyancy forces evolve and destabilize the slope significantly. Additionally, the influence of impoundment velocity on the rock slide behaviour and the impact of material properties of the rock masses are analysed. Reservoir water rapidly infiltrates into high-permeable rock slide masses evolving high pore pressures at the basal shear zone which leads to destabilisation. Conversely, reservoir water infiltrates slowly into low-permeable rock masses and the destabilizing effect of the pore water pressure might be compensated by a buttressing reservoir load over the low-permeable rock masses. Preliminary steady state calculations show that the factor of safety decreases constantly with increasing reservoir level until a certain threshold reservoir level and minimum factor of safety is reached. After exceeding this threshold level a further increase in reservoir impoundment leads to an increase of the factor of safety. This threshold reservoir level is reliant on the rock slide geometry and rock mass volume affected by buoyancy. Upcoming research is expected to provide new fundamentals for a comprehensive understanding of deformation and failure processes of deep-seated rock slides in order to perform reliable forecasts.

Computerized Cuff Pressure Algometry as Guidance for Circumferential Tissue Compression for Wearable Soft Robotic Applications: A Systematic Review.

PubMed

Kermavnar, Tjaša; Power, Valerie; de Eyto, Adam; O'Sullivan, Leonard W

2018-02-01

In this article, we review the literature on quantitative sensory testing of deep somatic pain by means of computerized cuff pressure algometry (CPA) in search of pressure-related safety guidelines for wearable soft exoskeleton and robotics design. Most pressure-related safety thresholds to date are based on interface pressures and skin perfusion, although clinical research suggests the deep somatic tissues to be the most sensitive to excessive loading. With CPA, pain is induced in deeper layers of soft tissue at the limbs. The results indicate that circumferential compression leads to discomfort at ∼16-34 kPa, becomes painful at ∼20-27 kPa, and can become unbearable even below 40 kPa.

Seismic anisotropy of the crystalline crust: What does it tell us?

USGS Publications Warehouse

Rabbel, Wolfgang; Mooney, Walter D.

1996-01-01

The study of the directional dependence of seismic velocities (seismic anisotropy) promises more refined insight into mineral composition and physical properties of the crystalline crust than conventional deep seismic refraction or reflection profiles providing average values of P-and S-wave velocities. The alignment of specific minerals by ductile rock deformation, for instance, causes specific types of seismic anisotropy which can be identified by appropriate field measurements.Vice versa, the determination of anisotropy can help to discriminate between different rock candidates in the deep crust. Seismic field measurements at the Continental Deep Drilling Site (KTB, S Germany) are shown as an example that anisotropy has to be considered in crustal studies. At the KTB, the dependence of seismic velocity on the direction of wave propagation in situ was found to be compatible with the texture, composition and fracture density of drilled crustal rocks.

Sensitivity Analysis of Mechanical Parameters of Different Rock Layers to the Stability of Coal Roadway in Soft Rock Strata

PubMed Central

Zhao, Zeng-hui; Wang, Wei-ming; Gao, Xin; Yan, Ji-xing

2013-01-01

According to the geological characteristics of Xinjiang Ili mine in western area of China, a physical model of interstratified strata composed of soft rock and hard coal seam was established. Selecting the tunnel position, deformation modulus, and strength parameters of each layer as influencing factors, the sensitivity coefficient of roadway deformation to each parameter was firstly analyzed based on a Mohr-Columb strain softening model and nonlinear elastic-plastic finite element analysis. Then the effect laws of influencing factors which showed high sensitivity were further discussed. Finally, a regression model for the relationship between roadway displacements and multifactors was obtained by equivalent linear regression under multiple factors. The results show that the roadway deformation is highly sensitive to the depth of coal seam under the floor which should be considered in the layout of coal roadway; deformation modulus and strength of coal seam and floor have a great influence on the global stability of tunnel; on the contrary, roadway deformation is not sensitive to the mechanical parameters of soft roof; roadway deformation under random combinations of multi-factors can be deduced by the regression model. These conclusions provide theoretical significance to the arrangement and stability maintenance of coal roadway. PMID:24459447

Hydromechanical Rock Mass Fatigue in Deep-Seated Landslides Accompanying Seasonal Variations in Pore Pressures

NASA Astrophysics Data System (ADS)

Preisig, Giona; Eberhardt, Erik; Smithyman, Megan; Preh, Alexander; Bonzanigo, Luca

2016-06-01

The episodic movement of deep-seated landslides is often governed by the presence of high pore pressures and reduced effective stresses along active shear surfaces. Pore pressures are subject to cyclic fluctuation under seasonal variations of groundwater recharge, resulting in an intermittent movement characterized by acceleration-deceleration phases. However, it is not always clear why certain acceleration phases reach alarming levels without a clear trigger (i.e., in the absence of an exceptional pore pressure event). This paper presents a conceptual framework linking hydromechanical cycling, progressive failure and fatigue to investigate and explain the episodic behavior of deep-seated landslides using the Campo Vallemaggia landslide in Switzerland as a case study. A combination of monitoring data and advanced numerical modeling is used. The principal processes forcing the slope into a critical disequilibrium state are analyzed as a function of rock mass damage and fatigue. Modeling results suggest that during periods of slope acceleration, the rock slope experiences localized fatigue and gradual weakening through slip along pre-existing natural fractures and yield of critically stressed intact rock bridges. At certain intervals, pockets of critically weakened rock may produce a period of enhanced slope movement in response to a small pore pressure increase similar to those routinely experienced each year. Accordingly, the distribution and connectivity of pre-existing permeable planes of weakness play a central role. These structures are often related to the rock mass's tectonic history or initiate (and dilate) in response to stress changes that disturb the entire slope, such as glacial unloading or seismic loading via large earthquakes. The latter is discussed in detail in a companion paper to this (Gischig et al., Rock Mech Rock Eng, 2015). The results and framework presented further demonstrate that episodic movement and progressive failure of deep-seated landslides cannot be analyzed by means of classical limit equilibrium tools but require advanced numerical models. When calibrated against slope monitoring data, the improved understanding of episodic slope movements can lead to more reliable early warning forecasting and improved landslide hazard management.

Deep Boreholes Seals Subjected to High P,T conditions - Proposed Experimental Studies

NASA Astrophysics Data System (ADS)

Caporuscio, F.

2015-12-01

Deep borehole experimental work will constrain the P,T conditions which "seal" material will experience in deep borehole crystalline rock repositories. The rocks of interest to this study include mafic (amphibolites) and silicic (granitic gneiss) end members. The experiments will systematically add components to capture discrete changes in both water and EBS component chemistries. Experiments in the system wall rock-clay-concrete-groundwater will evaluate interactions among components, including: mineral phase stability, metal corrosion rates and thermal limits. Based on engineered barrier studies, experimental investigations will move forward with three focusses. First, evaluation of interaction between "seal" materials and repository wall rock (crystalline) under fluid-saturated conditions over long-term (i.e., six-month) experiments; which reproduces the thermal pulse event of a repository. Second, perform experiments to determine the stability of zeolite minerals (analcime-wairakitess) under repository conditions. Both sets of experiments are critically important for understanding mineral paragenesis (zeolites and/or clay transformations) associated with "seals" in contact with wall rock at elevated temperatures. Third, mineral growth at the metal interface is a principal control on the survivability (i.e. corrosion) of waste canisters in a repository. The objective of this planned experimental work is to evaluate physio-chemical processes for 'seal' components and materials relevant to deep borehole disposal. These evaluations will encompass multi-laboratory efforts for the development of seals concepts and application of Thermal-Mechanical-Chemical (TMC) modeling work to assess barrier material interactions with subsurface fluids and other barrier materials, their stability at high temperatures, and the implications of these processes to the evaluation of thermal limits.

Crustal structure in the Elko-Carlin Region, Nevada, during Eocene gold mineralization: Ruby-East Humboldt metamorphic core complex as a guide to the deep crust

USGS Publications Warehouse

Howard, K.A.

2003-01-01

The deep crustal rocks exposed in the Ruby-East Humboldt metamorphic core complex, northeastern Nevada, provide a guide for reconstructing Eocene crustal structure ~50 km to the west near the Carlin trend of gold deposits. The deep crustal rocks, in the footwall of a west-dipping normal-sense shear system, may have underlain the Pinon and Adobe Ranges about 50 km to the west before Tertiary extension, close to or under part of the Carlin trend. Eocene lakes formed on the hanging wall of the fault system during an early phase of extension and may have been linked to a fluid reservoir for hydrothermal circulation. The magnitude and timing of Paleogene extension remain indistinct, but dikes and tilt axes in the upper crust indicate that spreading was east-west to northwest-southeast, perpendicular to a Paleozoic and Mesozoic orogen that the spreading overprinted. High geothermal gradients associated with Eocene or older crustal thinning may have contributed to hydrothermal circulation in the upper crust. Late Eocene eruptions, upper crustal dike intrusion, and gold mineralization approximately coincided temporally with deep intrusion of Eocene sills of granite and quartz diorite and shallower intrusion of the Harrison Pass pluton into the core-complex rocks. Stacked Mesozoic nappes of metamorphosed Paleozoic and Precambrian rocks in the core complex lay at least 13 to 20 km deep in Eocene time, on the basis of geobarometry studies. In the northern part of the complex, the presently exposed rocks had been even deeper in the late Mesozoic, to >30 km depths, before losing part of their cover by Eocene time. Nappes in the core plunge northward beneath the originally thicker Mesozoic tectonic cover in the north part of the core complex. Mesozoic nappes and tectonic wedging likely occupied the thickened midlevel crustal section between the deep crustal core-complex intrusions and nappes and the overlying upper crust. These structures, as well as the subsequent large-displacement Cenozoic extensional faulting and flow in the deep crust, would be expected to blur the expression of any regional structural roots that could correlate with mineral belts. Structural mismatch of the mineralized upper crust and the tectonically complex middle crust suggests that the Carlin trend relates not to subjacent deeply penetrating rooted structures but to favorable upper crustal host rocks aligned within a relatively coherent regional block of upper crust.

Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics.

PubMed

Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Jaung, Jae Yun; Kim, Yong-Hoon; Park, Sung Kyu

2015-09-28

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics

NASA Astrophysics Data System (ADS)

Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Yun Jaung, Jae; Kim, Yong-Hoon; Kyu Park, Sung

2015-09-01

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

The analysis of creep characteristics of the surrounding rock of the carbonaceous rock tunnel based on Singh-Mitchell model

NASA Astrophysics Data System (ADS)

Luo, Junhui; Mi, Decai; Ye, Qiongyao; Deng, Shengqiang; Zeng, Fuquan; Zeng, Yongjun

2018-01-01

Carbonaceous rock has the characteristics of easy disintegration, softening, swelling and environmental sensitivity, which belongs to soft surrounding rock, and the deformation during excavation and long-term stability of the surrounding rock of carbonaceous rock tunnel are common problems in the construction of carbonaceous rock tunnel. According to the above, the Monitor and measure the displacement, temperature and osmotic pressure of the surrounding carbonaceous rock of the tunnel of Guangxi Hebai highway. Then it based on the obtaining data to study the creep mechanism of surrounding rock using Singh-Mitchell model and predict the deformation of surrounding rock before the tunnel is operation. The results show that the Singh-Mitchell creep model can effectively analyse and predict the deformation development law of surrounding rock of tunnel without considering temperature and osmotic pressure, it can provide reference for the construction of carbonaceous rock tunnel and the measures to prevent and reinforce it..

Monitoring of Deep Foundation Pit Support and Construction Process in Soft Soil Area of Pearl River Delta

NASA Astrophysics Data System (ADS)

Weiyi, Xie; Pengcheng

2018-03-01

The deep foundation pit supporting technology in the soft soil area of the Pearl River Delta is more complicated, and many factors influence and restrict it. In this project as an example, according to the geological conditions and the surrounding circumstances, the main foundation using bored piles and pre-stressed anchor cable supporting structure + five axis cement mixing pile curtain supporting form; partial use of double row piles supporting structure + five axis cement mixing pile curtain support type. Through the monitoring results of construction show that the foundation pit, the indicators of environmental changes are in the design range, the supporting scheme of deep foundation pit technology is feasible and reliable.

Geology and stratigraphy of the San Lorenzo Tezonco deep well and its correlation to surrounding ranges, Mexico Basin

NASA Astrophysics Data System (ADS)

Arce, J. L.; Layer, P. W.; Morales-Casique, E.; Benowitz, J.

2014-12-01

The San Lorenzo Tezonco deep well stratigraphy records intense episodic volcanic activity in the Mexico Basin and surroundings during the past 20 Ma. The 2008-m deep lithological column is dominated by volcanic material, either as lava flows or pyroclastic deposits (97%), and only the upper most 70 m are composed of lacustrine deposits (3%). Based on geochronology and geochemistry, the lower part of the drill core is represented by rocks correlating to the Tepoztlán Formation (876-2008 m deep) that vary in composition from basaltic-andesite to rhyolite, and ages ranging from 13 to 21.2 Ma. On the surface this formation outcrops near the towns of Malinalco and Tepoztlán, ~43 km south of the deep well. Between depths of 581 and 875 m, volcanic rocks were recovered and are interpreted as lavas from the Sierra de las Cruces that vary in composition from andesite to dacite and range in age from 0.9 Ma to 5 Ma. Additionally, we documented rocks belonging to the Xochitepec Formation, outcropping around Xochimilco, in the Mexico City, with ages ranging from 1.2 and 1.7 Ma, in contrast with the Oligocene age proposed in previous works for these rocks. These new ages plus the chemical composition data, allow us to correlate the Xochitepec rocks with Sierra de las Cruces. Upward in the drill core (510-580 m) there are andesitic rocks that correlate with the 0.25 Ma Cerro de la Estrella volcanic center. The last volcanic package found in the well is correlated to the Santa Catarina basaltic andesites (70-120 m) that are younger than 0.25 Ma, and probably Holocene. Lacustrine deposits crown the stratigraphic column of the drill core with ages probably younger than 34 ka. The San Lorenzo Tezonco well is in a graben-like structure that was filled with more than 1900 m of volcanic products, suggesting that volcanism were intense in the Miocene to the Recent, and the south drainage of the Mexico Basin was closed probably in the early Pleistocene.

Deep-sea coral and hardbottom habitats on the west Florida slope, eastern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Ross, Steve W.; Rhode, Mike; Brooke, Sandra

2017-02-01

Until recently, benthic habitats dominated by deep-sea corals (DSC) appeared to be less extensive on the slope of the Gulf of Mexico (GOM) than in the northeast Atlantic Ocean or off the southeastern US. There are relatively few bioherms (i.e., coral-built mounds) in the northern GOM, and most DSCs are attached to existing hard substrata (e.g., authigenically formed carbonate). The primary structure-forming, DSC in the GOM is Lophelia pertusa, but structure is also provided by other living and dead scleractinians, antipatharians (black corals), octocorals (gorgonians, soft corals), hydrocorals and sponges, as well as abundant rocky substrata. The best development of DSCs in the GOM was previously documented within Viosca Knoll oil and gas lease blocks 826 and 862/906 (north-central GOM) and on the Campeche Bank (southern GOM in Mexican waters). This paper documents extensive deep reef ecosystems composed of DSC and rocky hard-bottom recently surveyed on the West Florida Slope (WFS, eastern GOM) during six research cruises (2008-2012). Using multibeam sonar, CTD casts, and video from underwater vehicles, we describe the physical and oceanographic characteristics of these deep reefs and provide size or area estimates of deep coral and hardground habitats. The multibeam sonar analyses revealed hundreds of mounds and ridges, some of which were subsequently surveyed using underwater vehicles. Mounds and ridges in <525 m depths were usually capped with living coral colonies, dominated by L. pertusa. An extensive rocky scarp, running roughly north-south for at least 229 km, supported lower abundances of scleractinian corals than the mounds and ridges, despite an abundance of settlement substrata. Areal comparisons suggested that the WFS may exceed other parts of the GOM slope in extent of living deep coral coverage and other deep-reef habitat (dead coral and rock). The complex WFS region warrants additional studies to better understand the influences of oceanography and geology on the occurrence of DSC and associated organisms. Protection measures are being considered to ensure the long-term integrity of this diverse ecosystem.

Reprint of - Deep-sea coral and hardbottom habitats on the west Florida slope, eastern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Ross, Steve W.; Rhode, Mike; Brooke, Sandra

2017-09-01

Until recently, benthic habitats dominated by deep-sea corals (DSC) appeared to be less extensive on the slope of the Gulf of Mexico (GOM) than in the northeast Atlantic Ocean or off the southeastern US. There are relatively few bioherms (i.e., coral-built mounds) in the northern GOM, and most DSCs are attached to existing hard substrata (e.g., authigenically formed carbonate). The primary structure-forming, DSC in the GOM is Lophelia pertusa, but structure is also provided by other living and dead scleractinians, antipatharians (black corals), octocorals (gorgonians, soft corals), hydrocorals and sponges, as well as abundant rocky substrata. The best development of DSCs in the GOM was previously documented within Viosca Knoll oil and gas lease blocks 826 and 862/906 (north-central GOM) and on the Campeche Bank (southern GOM in Mexican waters). This paper documents extensive deep reef ecosystems composed of DSC and rocky hard-bottom recently surveyed on the West Florida Slope (WFS, eastern GOM) during six research cruises (2008-2012). Using multibeam sonar, CTD casts, and video from underwater vehicles, we describe the physical and oceanographic characteristics of these deep reefs and provide size or area estimates of deep coral and hardground habitats. The multibeam sonar analyses revealed hundreds of mounds and ridges, some of which were subsequently surveyed using underwater vehicles. Mounds and ridges in <525 m depths were usually capped with living coral colonies, dominated by L. pertusa. An extensive rocky scarp, running roughly north-south for at least 229 km, supported lower abundances of scleractinian corals than the mounds and ridges, despite an abundance of settlement substrata. Areal comparisons suggested that the WFS may exceed other parts of the GOM slope in extent of living deep coral coverage and other deep-reef habitat (dead coral and rock). The complex WFS region warrants additional studies to better understand the influences of oceanography and geology on the occurrence of DSC and associated organisms. Protection measures are being considered to ensure the long-term integrity of this diverse ecosystem.

The Deep-Sea Benthos in the Gulf of Mexico.

DTIC Science & Technology

context has been a collection (by biological dredge) of rocks from the Sigsbee Knolls that date to Carboniferous age. Since the oldest rocks known...from any ocean basin up to this time are of Cretaceous age, the present discovery provides the oldest rock (318 million years) found in any ocean basin

Progress of the LASL dry hot rock geothermal energy project

NASA Technical Reports Server (NTRS)

Smith, M. C.

1974-01-01

The possibilities and problems of extracting energy from geothermal reservoirs which do not spontaneously yield useful amounts of steam or hot water are discussed. The system for accomplishing this which is being developed first is a pressurized-water circulation loop intended for use in relatively impermeable hot rock. It will consist of two holes connected through the hot rock by a very large hydraulic fracture and connected at the surface through the primary heat exchanger of an energy utilization system. Preliminary experiments in a hole 2576 ft (0.7852 km) deep, extending about 470 ft (143 m) into the Precambrian basement rock underlying the Jemez Plateau of north-central New Mexico, revealed no unexpected difficulties in drilling or hydraulically fracturing such rock at a temperature of approximately 100 C, and demonstrated a permeability low enough so that it appeared probable that pressurized water could be contained by the basement rock. Similar experiments are in progress in a second hole, now 6701 ft (2.043 km) deep, about 1.5 miles (2.4 km) south of the first one.

Macrostrat and GeoDeepDive: A Platform for Geological Data Integration and Deep-Time Research

NASA Astrophysics Data System (ADS)

Husson, J. M.; Peters, S. E.; Ross, I.; Czaplewski, J. J.

2016-12-01

Characterizing the quantity, lithology, age, and properties of rocks and sediments in the upper crust is central to many questions in Earth science. Although a large number of geological maps, regional syntheses, and sample-based measurements have been published in a variety of formats, there is no system for integrating and accessing rock record-derived data or for facilitating the large-scale quantitative interrogation of the physical, chemical, and biological properties of Earth's crust. Here we describe two data resources that aim to overcome some of these limitations: 1) Macrostrat, a geospatial database and supporting cyberinfrastructure that is designed to enable quantitative analyses of the entire assemblage of surface and subsurface sedimentary, igneous and metamorphic rocks, and 2) GeoDeepDive, a digital library and high throughput computing system designed to facilitate the location and extraction of information and data from the published literature. Macrostrat currently contains general summaries of the age and lithology of rocks and sediments in the upper crust at 1,474 regions in North and Central America, the Caribbean, New Zealand, and the deep sea. Distributed among these geographic regions are nearly 34,000 lithologically and chronologically-defined geological units, many of which are linked to a bedrock geologic map database with more than 1.7 million globally distributed units. Sample-derived data, including fossil occurrences in the Paleobiology Database and more than 180,000 geochemical and outcrop-derived measurements are linked to Macrostrat units and/or lithologies within those units. The rock names, lithological terms, and geological time intervals that are applied to Macrostrat units define a hierarchical, spatially and temporally indexed vocabulary that is leveraged by GeoDeepDive in order to provide researchers access to data within the scientific literature as it is published and ingested into the infrastructure. All data in Macrostrat are accessible via an Application Programming Interface, which enables the development of mobile and analytical applications. The GeoDeepDive infrastructure also supports the development and execution of applications that are tailored to the specific, literature-based data location and extraction needs of geoscientists.

Some constraints on levels of shear stress in the crust from observations and theory.

USGS Publications Warehouse

McGarr, A.

1980-01-01

In situ stress determinations in North America, southern Africa, and Australia indicate that on the average the maximum shear stress increases linearly with depth to at least 5.1 km measured in soft rock, such as shale and sandstone, and to 3.7 km in hard rock, including granite and quartzite. Regression lines fitted to the data yield gradients of 3.8 MPa/km and 6.6 MPa/km for soft and hard rock, respectively. Generally, the maximum shear stress in compressional states of stress for which the least principal stress is oriented near vertically is substantially greater than in extensional stress regimes, with the greatest principal stress in a vertical direction. The equations of equilibrium and compatibility can be used to provide functional constrains on the state of stress. If the stress is assumed to vary only with depth z in a given region, then all nonzero components must have the form A + Bz, where A and B are constants which generally differ for the various components. - Author

Sulfur mass-independent fractionation in subsurface fracture waters indicates a long-standing sulfur cycle in Precambrian rocks.

PubMed

Li, L; Wing, B A; Bui, T H; McDermott, J M; Slater, G F; Wei, S; Lacrampe-Couloume, G; Lollar, B Sherwood

2016-10-27

The discovery of hydrogen-rich waters preserved below the Earth's surface in Precambrian rocks worldwide expands our understanding of the habitability of the terrestrial subsurface. Many deep microbial ecosystems in these waters survive by coupling hydrogen oxidation to sulfate reduction. Hydrogen originates from water-rock reactions including serpentinization and radiolytic decomposition of water induced by decay of radioactive elements in the host rocks. The origin of dissolved sulfate, however, remains unknown. Here we report, from anoxic saline fracture waters ∼2.4 km below surface in the Canadian Shield, a sulfur mass-independent fractionation signal in dissolved sulfate. We demonstrate that this sulfate most likely originates from oxidation of sulfide minerals in the Archaean host rocks through the action of dissolved oxidants (for example, HO · and H 2 O 2 ) themselves derived from radiolysis of water, thereby providing a coherent long-term mechanism capable of supplying both an essential electron donor (H 2 ) and a complementary acceptor (sulfate) for the deep biosphere.

Sulfur mass-independent fractionation in subsurface fracture waters indicates a long-standing sulfur cycle in Precambrian rocks

PubMed Central

Li, L.; Wing, B. A.; Bui, T. H.; McDermott, J. M.; Slater, G. F.; Wei, S.; Lacrampe-Couloume, G.; Lollar, B. Sherwood

2016-01-01

The discovery of hydrogen-rich waters preserved below the Earth's surface in Precambrian rocks worldwide expands our understanding of the habitability of the terrestrial subsurface. Many deep microbial ecosystems in these waters survive by coupling hydrogen oxidation to sulfate reduction. Hydrogen originates from water–rock reactions including serpentinization and radiolytic decomposition of water induced by decay of radioactive elements in the host rocks. The origin of dissolved sulfate, however, remains unknown. Here we report, from anoxic saline fracture waters ∼2.4 km below surface in the Canadian Shield, a sulfur mass-independent fractionation signal in dissolved sulfate. We demonstrate that this sulfate most likely originates from oxidation of sulfide minerals in the Archaean host rocks through the action of dissolved oxidants (for example, HO· and H2O2) themselves derived from radiolysis of water, thereby providing a coherent long-term mechanism capable of supplying both an essential electron donor (H2) and a complementary acceptor (sulfate) for the deep biosphere. PMID:27807346

Demersal Fish Assemblages on Seamounts and Other Rugged Features in Deep Waters of the Greater and Lesser Antilles

NASA Astrophysics Data System (ADS)

Chaytor, J. D.; Quattrini, A.; Demopoulos, A. W.

2015-12-01

Caribbean fish communities in shallow waters have been well studied along the Greater and Lesser Antilles for decades; however, the deep (>200 m) assemblages remain poorly known due to the technical challenges associated with focused surveys at these greater depths. The numerous geological features (e.g., seamounts, island ridges, banks) that punctuate the insular margins increase habitat heterogeneity, which may lead to enhanced diversity of the deep demersal fish community in the region. Recent (2013-2014) expeditions in the area using the E/V Nautilus and the ROV Hercules surveyed fish communities during 17 dives across different seafloor features at depths ranging from 64 to 2944 m. These surveys enabled us to investigate whether demersal fish assemblages differed among these seafloor features and/or in response to other environmental factors. Preliminary analyses suggested that assemblage differences are influenced by depth, dissolved oxygen, and differences in benthic microhabitat (i.e., soft substrate, rock outcrop, slope angle). Notably, both abundance and diversity of fishes was low at depths >700 m on seamounts in the Anegada Passage. This pattern is likely due to limited food supply in the region. ROV surveys further elucidated the biogeography of numerous species, as several range and depth extensions were documented. For instance, the morid Lepidion sp., previously known only from the eastern Atlantic and the western North Atlantic, was documented on Norrôit Seamount. A new species, Polylepion sp. A, known only from Curacao, was documented on Conrad Seamount. Also, many common, mesophotic reef species were observed deeper than previously known, including the butterflyfishes Chaetodon sedentarius and Prognathodes aculeatus. This study further supports the importance of environmental conditions influencing local-scale distribution of deep-sea fishes, while demonstrating how little is still known about the biogeography of numerous deep-sea and mesophotic fish species.

Student-Chosen Criteria for Peer Assessment of Tertiary Rock Groups in Rehearsal and Performance: What's Important?

ERIC Educational Resources Information Center

Blom, Diana; Encarnacao, John

2012-01-01

The study investigates criteria chosen by music students for peer and self assessment of both the rehearsal process and performance outcome of their rock groups. The student-chosen criteria and their explanations of these criteria were analysed in relation to Birkett's skills taxonomy of "soft" and "hard" skills. In the rehearsal process, students…

Where tunneling equipment is heading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singhal, R.K.

1984-02-01

A variety of equipment is being used for roadheading and tunneling in the mining industry. This includes hydraulic/rotary precussive drills for use in conventional drill and blast, drum-type continuous miners, roadheaders, mini-and midi-full facers for small size openings, soft rock shielded tunnel boring machines, and hard rock tunnel boring machines. The availability, performance, and specifications for tunneling equipment are discussed.

Identification of Natural Frequency of Low Rise Building on Soft Ground Profile using Ambient Vibration Method

NASA Astrophysics Data System (ADS)

Kamarudin, A. F.; Zainal Abidin, M. H.; Mokhatar, S. N.; Daud, M. E.; Ibrahim, A.; Ibrahim, Z.; Noh, M. S. Md

2018-04-01

Natural frequency is the rate at which a body to vibrate or oscillate. Application of ambient vibration (AV) excitation is widely used nowadays as the input motion for building predominant frequency, fo, and ground fundamental frequency, Fo, prediction due to simple, fast, non-destructive, simple handling operation and reliable result. However, it must be emphasized and caution to isolate these frequencies (fo and Fo) from spurious frequencies of site-structure effects especially to low rise building on soft ground deposit. In this study, identification of fo and Fo by using AV measurements were performed on ground and 4-storey primary school reinforced concrete (RC) building at Sekolah Kebangsaan (SK) Sg. Tongkang, Rengit, Johor using 1 Hz of tri-axial seismometer sensor. Overlapping spectra between Fourier Amplitude Spectra (FAS) from and Horizontal to Vertical Spectra Ratio (HVSR) were used to distinguish respective frequencies of building and ground natural frequencies. Three dominant frequencies were identified from the FAS curves at 1.91 Hz, 1.98 Hz and 2.79 Hz in longitudinal (East West-EW), transverse (North South-NS) and vertical (UD) directions. It is expected the building has deformed in translational mode based on the first peak frequency by respective NS and EW components of FAS spectrum. Vertical frequency identified from the horizontal spectrums, might induces to the potential of rocking effect experienced by the school building. Meanwhile, single peak HVSR spectrum at low ground fundamental frequency concentrated at 0.93 Hz indicates to the existence deep contrast of soft deposit. Strong interaction between ground and building at similar frequency (0.93 Hz) observed from the FAS curves on the highest floor has shown the building to behave as a dependent unit against ground response as one rigid mass.

Analytical results and sample locality maps of stream-sediment, heavy-mineral-concentrate, and rock samples from the Little Jacks Creek (ID-111-006), Big Jacks Creek (ID-111-007C), Duncan Creek (ID-111-0007B), and Upper Deep Creek (ID-111-044) Wilderness Study Areas, Owyhee County, Idaho

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erickson, M.S.; Gent, C.A.; Bradley, L.A.

1989-01-01

A U.S. Geological Survey report detailing the analytical results and sample locality maps of stream-sediment, heavy-mineral-concentrate, and rock samples from the Little Jacks Creek, Big Jacks Creek, Duncan Creek, and Upper Deep Creek Wilderness Study Areas, Owyhee County, Idaho

Double-Pedicled Free Deep Inferior Epigastric Perforator Flap for the Coverage of Thigh Soft-Tissue Defect.

PubMed

Bota, Olimpiu; Spindler, Nick; Sauber, Jeannine; Aydogan, Emrah; Langer, Stefan

2017-08-01

Soft-tissue defects caused by radiation injury are a challenging task for the reconstructive surgeon, due to the extent of the soft-tissue damage and the associated injuries of the local blood vessels and bone tissue. We present the application of the versatile deep inferior epigastric perforator (DIEP) flap for the coverage of an extended lateral thigh soft-tissue defect after the surgical resection of an undifferentiated pleomorphic high-grade sarcoma, neoadjuvant chemotherapy, and adjuvant chemo- and radiotherapy. A double-pedicled free DIEP flap (756 cm 2 ) was harvested and anastomosed to the transverse branch of the lateral femoral circumflex artery and a lateral branch of the popliteal artery (P1). The flap survived completely without serious complications, and the patient was able to walk with crutches 3 months postoperatively. This is the first case report of a free bipedicled DIEP flap for the coverage of a thigh defect in a male patient.

Double-Pedicled Free Deep Inferior Epigastric Perforator Flap for the Coverage of Thigh Soft-Tissue Defect

PubMed Central

Spindler, Nick; Sauber, Jeannine; Aydogan, Emrah; Langer, Stefan

2017-01-01

Summary: Soft-tissue defects caused by radiation injury are a challenging task for the reconstructive surgeon, due to the extent of the soft-tissue damage and the associated injuries of the local blood vessels and bone tissue. We present the application of the versatile deep inferior epigastric perforator (DIEP) flap for the coverage of an extended lateral thigh soft-tissue defect after the surgical resection of an undifferentiated pleomorphic high-grade sarcoma, neoadjuvant chemotherapy, and adjuvant chemo- and radiotherapy. A double-pedicled free DIEP flap (756 cm2) was harvested and anastomosed to the transverse branch of the lateral femoral circumflex artery and a lateral branch of the popliteal artery (P1). The flap survived completely without serious complications, and the patient was able to walk with crutches 3 months postoperatively. This is the first case report of a free bipedicled DIEP flap for the coverage of a thigh defect in a male patient. PMID:28894652

Model test of anchoring effect on zonal disintegration in deep surrounding rock masses.

PubMed

Chen, Xu-Guang; Zhang, Qiang-Yong; Wang, Yuan; Liu, De-Jun; Zhang, Ning

2013-01-01

The deep rock masses show a different mechanical behavior compared with the shallow rock masses. They are classified into alternating fractured and intact zones during the excavation, which is known as zonal disintegration. Such phenomenon is a great disaster and will induce the different excavation and anchoring methodology. In this study, a 3D geomechanics model test was conducted to research the anchoring effect of zonal disintegration. The model was constructed with anchoring in a half and nonanchoring in the other half, to compare with each other. The optical extensometer and optical sensor were adopted to measure the displacement and strain changing law in the model test. The displacement laws of the deep surrounding rocks were obtained and found to be nonmonotonic versus the distance to the periphery. Zonal disintegration occurs in the area without anchoring and did not occur in the model under anchoring condition. By contrasting the phenomenon, the anchor effect of restraining zonal disintegration was revealed. And the formation condition of zonal disintegration was decided. In the procedure of tunnel excavation, the anchor strain was found to be alternation in tension and compression. It indicates that anchor will show the nonmonotonic law during suppressing the zonal disintegration.

Model Test of Anchoring Effect on Zonal Disintegration in Deep Surrounding Rock Masses

PubMed Central

Chen, Xu-Guang; Zhang, Qiang-Yong; Wang, Yuan; Liu, De-Jun; Zhang, Ning

2013-01-01

The deep rock masses show a different mechanical behavior compared with the shallow rock masses. They are classified into alternating fractured and intact zones during the excavation, which is known as zonal disintegration. Such phenomenon is a great disaster and will induce the different excavation and anchoring methodology. In this study, a 3D geomechanics model test was conducted to research the anchoring effect of zonal disintegration. The model was constructed with anchoring in a half and nonanchoring in the other half, to compare with each other. The optical extensometer and optical sensor were adopted to measure the displacement and strain changing law in the model test. The displacement laws of the deep surrounding rocks were obtained and found to be nonmonotonic versus the distance to the periphery. Zonal disintegration occurs in the area without anchoring and did not occur in the model under anchoring condition. By contrasting the phenomenon, the anchor effect of restraining zonal disintegration was revealed. And the formation condition of zonal disintegration was decided. In the procedure of tunnel excavation, the anchor strain was found to be alternation in tension and compression. It indicates that anchor will show the nonmonotonic law during suppressing the zonal disintegration. PMID:23997683

Analysis of Ground Water Flow and Deformation in the Vicinity of DUSEL Homestake

NASA Astrophysics Data System (ADS)

Murdoch, L. C.; Ebenhack, J.; Germanovich, L. N.; Wang, H. F.; Boutt, D. F.; Onstott, T. C.; Kieft, T.; Moser, D. P.; Elsworth, D.

2010-12-01

The Deep Underground Science and Engineering Laboratory (DUSEL) is an underground facility planned for the workings of the former Homestake gold mine in the northern Black Hills, South Dakota. The mine workings cover several km2 in plan and extend to a depth 2.4 km. The area is underlain by Proterozoic metamorphic rocks that were deformed into regional-scale folds whose axes plunge approximately 40o to the SSE. A conceptual model and preliminary numerical analysis of the hydrogeology of the area indicates that permeability depends on effective stress, with values ranging from 0.1 mD at a depth of 2 km to 100 mD at depths of 100m. A deep ground water flow system is contained within a surface-truncated ellipsoid roughly 8 km by 4 km in plan view and 5.5 km deep with its short-axis aligned to the strike of the workings. The deep flow system consists of a zone of relatively rapid flow from the ground surface to the workings overlying the southern part of the mine, and a much larger ellipsoidal zone extending up to several km from the workings where water has been removed from storage. Numerical analyses of the ground water flow and poroelastic deformation in the vicinity of Homestake DUSEL have been refined by sharpening the 3-D resolution of important features. Mine workings have been resolved into three to four major regions where relatively large densities of rock were removed. These mined regions are shaped roughly like plunging ellipsoids with minor axes of several hundred m and major axes up to more than 2 km. They are treated in the simulations as highly permeable regions with an average elastic modulus significantly less than the intact rock; e.g. like soft, permeable inclusions. Recent field investigations and evaluation of the mine database indicate the presence of a relatively large fault that strikes approximately N20W, roughly parallel to the mined out regions. The Homestake fault dips 60NE, cutting the top of one mined region and extending beneath and adjacent to another mined region. It extends at least 1.5 km along strike and dip, with a center roughly 1.5 km deep along the western side of the mine. The model includes large-scale folds, and in particular it includes the geometry of the Yates member at the core of the Lead Anticlinorium. Topography and the stream drainage network are also included. The findings generally confirm previous results of Murdoch et al. [Eos Trans. AGU, 90(52), Fall Meet. Suppl., Abstract H23E-1009], but the finer resolution from the new analyses provides improved detail on the distribution of hydraulic head and stress state in the vicinity of the workings. Including the poroelastic effect shows that dewatering of the mined workings may cause larger deformations than were previously expected, and it also indicates that dewatering should affect the distribution of stresses on the Homestake fault.

Tectonic constraints on a deep-seated rock slide in weathered crystalline rocks

NASA Astrophysics Data System (ADS)

Borrelli, Luigi; Gullà, Giovanni

2017-08-01

Deep-seated rock slides (DSRSs), recognised as one of the most important mass wasting processes worldwide, involve large areas and cause several consequences in terms of environmental and economic damage; they result from a complex of controlling features and processes. DSRSs are common in Calabria (southern Italy) where the complex geo-structural setting plays a key role in controlling the geometry of the failure surface and its development. This paper describes an integrated multi-disciplinary approach to investigate a DSRS in Palaeozoic high-grade metamorphic rocks of the Sila Massif; it focuses on the definition of the internal structure and the predisposing factors of the Serra di Buda landslide near the town of Acri, which is a paradigm for numerous landslides in this area. An integrated interdisciplinary study based on geological, structural, and geomorphological investigations-including field observations of weathering grade of rocks, minero-petrographic characterisations, geotechnical investigations and, in particular, fifteen years of displacement monitoring-is presented. Stereoscopic analysis of aerial photographs and field observations indicate that the Serra di Buda landslide consists of two distinct compounded bodies: (i) an older and dormant body ( 7 ha) and (ii) a more recent and active body ( 13 ha) that overlies the previous one. The active landslide shows movement linked to a deep-seated translational rock slide (block slide); the velocity scale ranges from slow (1.6 m/year during paroxysmal stages) to extremely slow (< 16 mm/year during stable creep stages). The geological structures and rock weathering have played a key role in the landslide's initiation and further development. Steep slope angles, rugged topography, river deepening and erosion at the toe of the slope are also responsible for the formation of this landslide. In particular, the landslide shows a strongly tectonic constraint: the flanks are bounded by high-angle faults, and the main basal failure surface developed inside an E-W southward-dipping thrust fault zone. The entire active rock mass (total volume of approximately 6 Mm3) slid at one time on a failure surface that dipped < 27°, and the maximum depth, as determined by inclinometer measurements, was approximately 58 m. Petrographic and mineralogical analyses suggest that the rocks in the thrust zones, where the failure surfaces develop, are highly affected by weathering processes that significantly reduce the rock strength and facilitate the extensive failure of the Serra di Buda landslide. Finally, the landslide's internal structure, according to geotechnical investigations and displacement monitoring, is proposed. The proposed approach and the obtained results can be generalised to typify other deep landslides in similar geological settings.

South Atlantic sag basins: new petroleum system components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henry, S.G.; Mello, M.R.

Newly discovered pre-salt source rocks, reservoirs and seals need to be included as components to the petroleum systems of both sides of the South Atlantic. These new components lie between the pre-salt rift strata and the Aptian salt layers, forming large, post-rift, thermal subsidence sag basins. These are differentiated from the older rift basins by the lack of syn-rift faulting and a reflector geometry that is parallel to the base salt regional unconformity rather than to the Precambrian basement. These basins are observed in deep water regions overlying areas where both the mantle and the crust have been involved inmore » the extension. This mantle involvement creates post-rift subsiding depocenters in which deposition is continuous while proximal rift-phase troughs with little or no mantle involvement are bypassed and failed to accumulate potential source rocks during anoxic times. These features have been recognized in both West African Kwanza Basin and in the East Brasil Rift systems. The pre-salt source rocks that are in the West African sag basins were deposited in lacustrine brackish to saline water environment and are geochemically distinct from the older, syn-rift fresh to brackish water lakes, as well as from younger, post-salt marine anoxic environments of the drift phase. Geochemical analyses of the source rocks and their oils have shown a developing source rock system evolving from isolated deep rift lakes to shallow saline lakes, and culminating with the infill of the sag basin by large saline lakes to a marginally marine restricted gulf. Sag basin source rocks may be important in the South Atlantic petroleum system by charging deep-water prospects where syn-rift source rocks are overmature and the post-salt sequences are immature.« less

Seismic tomography as a tool for measuring stress in mines

USGS Publications Warehouse

Scott, Douglas F.; Williams, T.J.; Denton, D.K.; Friedel, M.J.

1999-01-01

Spokane Research Center personnel have been investigating the use of seismic tomography to monitor the behavior of a rock mass, detect hazardous ground conditions and assess the mechanical integrity of a rock mass affected by mining. Seismic tomography can be a valuable tool for determining relative stress in deep, >1,220-m (>4,000-ft), underground pillars. If high-stress areas are detected, they can be destressed prior to development or they can be avoided. High-stress areas can be monitored with successive seismic surveys to determine if stress decreases to a level where development can be initiated safely. There are several benefits to using seismic tomography to identify high stress in deep underground pillars. The technique is reliable, cost-effective, efficient and noninvasive. Also, investigators can monitor large rock masses, as well as monitor pillars during the mining cycle. By identifying areas of high stress, engineers will be able to assure that miners are working in a safer environment.Spokane Research Center personnel have been investigating the use of seismic tomography to monitor the behavior of a rock mass, detect hazardous ground conditions and assess the mechanical integrity of a rock mass affected by mining. Seismic tomography can be a valuable tool for determining relative stress in deep, >1,200-m (>4,000-ft), underground pillars. If high-stress areas are detected, they can be destressed prior to development or they can be avoided. High-stress areas can be monitored with successive seismic surveys to determine if stress decreases to a level where development can be initiated safely. There are several benefits to using seismic tomography to identify high stress in deep underground pillars. The technique is reliable, cost-effective, efficient and noninvasive. Also, investigators can monitor large rock masses, as well as monitor pillars during the mining cycle. By identifying areas of high stress. engineers will be able to assure that miners are working in a safer environment.

A novel low temperature soft reflow process for the fabrication of deep-submicron (<0.35 μm) T-gate pseudomorphic high electron mobility transistor structures

NASA Astrophysics Data System (ADS)

Ian, Ka Wa; Exarchos, Michael; Missous, Mohamed

2013-02-01

We report a new and simple low temperature soft reflow process using solvent vapour. The combination of this soft reflow and conventional i-line lithography enables low cost, highly efficient fabrication at the deep-submicron scale. Compared to the conventional thermal reflow process, the key benefits of the new soft reflow process are its low temperature operation (<50 °C), greater shrinkage of the structure size (up to 75%) and better controllability. Gate openings reflowed from 1 μm to 250 nm have been routinely and reproducibly achieved by utilizing the saturation characteristics of the process. The feasibility of this soft reflow process is demonstrated in the fabrication of a 350 nm T-gate pseudomorphic high electron mobility transistor. By shrinking the gate length by a factor of three (from a 1 μm initial opening), the output current is improved by 60% (500 mA mm-1 from 300 mA mm-1) and fT and fMAX are increased to 70 GHz (from 20 GHz) and 120 GHz (from 40 GHz) respectively. The proposed soft reflow could potentially be applied on other compatible substrates such as polymer based material for organic or thin film devices, potentially leading to many new possible applications.

Deep Boreholes Seals Subjected to High P, T conditions – Preliminary Experimental Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caporuscio, Florie Andre; Norskog, Katherine Elizabeth; Maner, James Lavada

The objective of this planned experimental work is to evaluate physio-chemical processes for ‘seal’ components and materials relevant to deep borehole disposal. These evaluations will encompass multi-laboratory efforts for the development of seals concepts and application of Thermal-Mechanical-Chemical (TMC) modeling work to assess barrier material interactions with subsurface fluids, their stability at high temperatures, and the implications of these processes to the evaluation of thermal limits. Deep borehole experimental work will constrain the Pressure, Temperature (P, T) conditions which “seal” material will experience in deep borehole crystalline rock repositories. The rocks of interest to this study include the silicic (graniticmore » gneiss) end members. The experiments will systematically add components to capture discrete changes in both water and EBS component chemistries.« less

Rho kinase inhibitors: a patent review (2012 - 2013).

PubMed

Feng, Yangbo; LoGrasso, Philip V

2014-03-01

The Rho kinase/ROCK is critical in vital signal transduction pathways central to many essential cellular activities. Since ROCK possess multiple substrates, modulation of ROCK activity is useful for treatment of many diseases. Significant progress has been made in the development of ROCK inhibitors over the past two years (Jan 2012 to Aug 2013). Patent search in this review was based on FPO IP Research and Communities and Espacenet Patent Search. In this review, patent applications will be classified into four groups for discussions. The grouping is mainly based on structures or scaffolds (groups 1 and 2) and biological functions of ROCK inhibitors (groups 3 and 4). These four groups are i) ROCK inhibitors based on classical structural elements for ROCK inhibition; ii) ROCK inhibitors based on new scaffolds; iii) bis-functional ROCK inhibitors; and iv) novel applications of ROCK inhibitors. Although currently only one ROCK inhibitor (fasudil) is used as a drug, more drugs based on ROCK inhibition are expected to be advanced into market in the near future. Several directions should be considered for future development of ROCK inhibitors, such as soft ROCK inhibitors, bis-functional ROCK inhibitors, ROCK2 isoform-selective inhibitors, and ROCK inhibitors as antiproliferation agents.

A High-Resolution Multitechniques Approach to Characterize Bio-Organo-Mineral Associations Within Rock Samples: Tracking Biological vs Abiotic Processes? Towards a Better Understanding of the Deep Carbon Cycle.

NASA Astrophysics Data System (ADS)

Pisapia, C.

2015-12-01

Among all elements, carbon plays one of the major roles for the sustainability of life on Earth. Past considerations of the carbon cycle have mainly focused on surface processes occurring at the atmosphere, oceans and shallow crustal environments. By contrast, little is known about the Deep Carbon cycle whereas both geochemical and biological processes may induce organic carbon production and/or consumption at depth. Indeed, the nowadays-recognized capability of geochemical processes such as serpentinization to generate abiotic organic compounds as well as the existence of a potentially important intraterrestrial life raises questions about the limit of biotic/abiotic carbon on Earth's deep interior and how it impacts global biogeochemical cycles. It is then mandatory to increase our knowledge on the nature and extent of carbon reservoirs along with their sources, sinks and fluxes in the subsurface. This implies to be able to finely characterize organomineral associations within crustal rocks although it might be hampered by the scarceness and heterogeneous micrometric spatial distribution of organic molecules in natural rocks. We then developed an in situ analytical strategy based on the combination of high-resolution techniques to track organic molecules at the pore level in natural rocks and to determine their biological or abiotic origin. We associated classical high-resolution techniques and synchrotron-based imaging techniques in order to characterize their nature and localization (SEM/TEM, coupled CLSM/Raman spectroscopy, Tof-SIMS) along with their 3D-distribution relatively to mineral phases (S-FTIR, S-DeepUV, XANES, Biphoton microscopy). The effectiveness of this approach to shed light on the speciation and nature of carbon in subsurface environments will be illustrated through the study of (i) subsurface ecosystems and abiotic organic carbon within ultramafic rocks of the oceanic lithosphere as putative analogs for the nature and functioning of primitive ecosystems on Earth and of (ii) ecosystems inhabiting Archean craton and potentially playing a role in punk-rock karstification processes and rocks weathering.

Benchmark Design and Installation: A synthesis of Existing Information.

DTIC Science & Technology

1987-07-01

casings (15 ft deep) drilled to rock and filled with concrete. Disks - 1 . Set on vertically stable structures (e.g., dam monoliths). 2 . Set in rock ...Structural movement survey 1 . Rock outcrops (first choice) -- chiseled square on high point. 2 . Massive concrete structure (second choice) - cut square on...bolt marker (type 2 ). 58,. % %--"% %I 1 ± 4 -I,.- Table Cl. Recomnded benchmarks. Type of condition or terrain Type of markert Bedrock, rock outcrops

HIGH EXPLOSIVE CRATER STUDIES: TUFF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphey, B.F.

1961-04-01

Spherical charges of TNT, each weighing 256 pounds, were exploded at various depths in tuff to determine apparent crater dimensions in a soft rock. No craters were obtained for depths of burst equal to or greater than 13.3 feet. It was deduced that rock fragments were sufficiently large that charges of greater magnitude should be employed for crater experiments intended as models of nuclear explosions. (auth)

Microseism Induced by Transient Release of In Situ Stress During Deep Rock Mass Excavation by Blasting

NASA Astrophysics Data System (ADS)

Yang, Jianhua; Lu, Wenbo; Chen, Ming; Yan, Peng; Zhou, Chuangbing

2013-07-01

During deep rock mass excavation with the method of drill and blast, accompanying the secession of rock fragments and the formation of a new free surface, in situ stress on this boundary is suddenly released within several milliseconds, which is termed the transient release of in situ stress. In this process, enormous strain energy around the excavation face is instantly released in the form of kinetic energy and it inevitably induces microseismic events in surrounding rock masses. Thus, blasting excavation-induced microseismic vibrations in high-stress rock masses are attributed to the combined action of explosion and the transient release of in situ stress. The intensity of stress release-induced microseisms, which depends mainly on the magnitude of the in situ stress and the dimension of the excavation face, is comparable to that of explosion-induced vibrations. With the methods of time-energy density analysis, amplitude spectrum analysis, and finite impulse response (FIR) digital filter, microseismic vibrations induced by the transient release of in situ stress were identified and separated from recorded microseismic signals during a blast of deep rock masses in the Pubugou Hydropower Station. The results show that the low-frequency component in the microseismic records results mainly from the transient release of in situ stress, while the high-frequency component originates primarily from explosion. In addition, a numerical simulation was conducted to demonstrate the occurrence of microseismic events by the transient release of in situ stress, and the results seem to have confirmed fairly well the separated vibrations from microseismic records.

Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics

PubMed Central

Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Yun Jaung, Jae; Kim, Yong-Hoon; Kyu Park, Sung

2015-01-01

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics. PMID:26411932

Scalable sub-micron patterning of organic materials toward high density soft electronics

DOE PAGES

Kim, Jaekyun; Kim, Myung -Gil; Kim, Jaehyun; ...

2015-09-28

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. Inmore » this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. As a result, the successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.« less

POPO AGIE PRIMITIVE AREA, WYOMING.

USGS Publications Warehouse

Pearson, Robert C.; Patten, L.L.

1984-01-01

A mineral-resource appraisal was made of the Popo Agie Primitive Area and some adjoining lands. This scenic mountainous region of the Wind River Range in west-central Wyoming is composed largely of ancient granitic rocks in which virtually no evidence of mineral deposits was found. Deep crustal seismic-reflection profiles obtained across the southern Wind River Range suggest the possibility that young sedimentary rocks, similar to those at the surface along the northeast flank of the range, are present at depth beneath the granite in the Popo Agie primitive Area. If present, such buried sedimentary rocks could be petroleum bearing. Additional seismic and gravity studies would probably add valuable information, but ultimately very expensive, very deep drilling will be necessary to test this possibility.

Influence of Soft or Hard Floors before and after First Calving on Dairy Heifer Locomotion, Claw and Leg Health

PubMed Central

Bergsten, Christer; Telezhenko, Evgenij; Ventorp, Michael

2015-01-01

Simple Summary In this study the effect of different flooring systems on locomotion, claw conformation, loading, claw- and leg disorders was assessed in heifers from one year before to one year after calving. After calving, heifers kept on alleys covered with rubber flooring were found to develop less lameness, fewer claw disorders of the sole horn and fewer leg lesions than those kept on concrete alleys. Recruitment heifers reared on soft deep straw bedding had fewer sole horn lesions and more overgrown claws before calving, but were more prone to severe sole horn lesions after calving, than those reared in cubicles with hard concrete floors. Abstract Claw health, an important dairy cow welfare parameter, may be affected by early-life foot/leg stresses. To investigate this, groups of pregnant heifers were allocated to deep straw bedding (Soft) or cubicles (Hard), both with scraped concrete feeding alleys. After the grazing season, they were re-housed in cubicle systems, half on slatted concrete (Hard) and half on slatted rubber (Soft) alleys. Claw measurements, contact area and pressure distribution claw/flooring, claw disorders and leg lesions were recorded at the start and end of each housing season. Locomotion and leg lesions were also scored monthly after calving. Prevalence of sole haemorrhages was higher among pregnant heifers in cubicles than in deep straw. After calving, first-calvers on Hard floors had higher odds for lameness (OR = 3.6; p < 0.01), sole haemorrhages/ulcers (OR = 2.2; p < 0.05), white-line haemorrhages (OR = 2.8; p < 0.01) and leg lesions (OR = 2.6; p < 0.02) than those on Soft floors. Lowest prevalence and severity of sole and white-line haemorrhages (non-significant) in first-calvers was found in those on Soft floors and reared on Hard floors and the highest prevalence and severity on those on Hard floors reared on Soft floors. Soft flooring after calving is of most importance for healthy feet and legs. PMID:26479380

Sinkhole susceptibility in carbonate rocks of the Apulian karst (southern Italy)

NASA Astrophysics Data System (ADS)

Di Santo, Antonio; Fazio, Nunzio L.; Fiore, Antonio; Lollino, Piernicola; Luisi, Michele; Miccoli, Maria N.; Pagliarulo, Rosa; Parise, Mario; Perrotti, Michele; Pisano, Luca; Spalluto, Luigi; Vennari, Carmela; Vessia, Giovanna

2016-04-01

Apulia region, the foreland of the southern Italian Apennines, is made up of a 6-7 km-thick succession of Mesozoic shallow-water limestones and dolostones, locally covered by thin and discontinuous Tertiary and Quaternary carbonate and clastic deposits. Due to their long subaerial exposure, the Mesozoic carbonate bedrock recorded the development in the subsurface of a dense network of karst cavities, mostly controlled by tectonic discontinuities. As a result, a strong susceptibility to natural sinkholes has to be recorded in Apulia. In addition, the possibility of occurrence of other problems related to the high number of man-made cavities has to be added in the region. A great variety of different typologies of artificial cavities (mostly excavated in the Plio-Pleistocene soft calcarenites) is actually present, including underground quarries, worship sites, oil mills, civilian settlements, etc. Overall, 2200 natural and 1200 artificial cavities, respectively, have been so far surveyed in Apulia. Following the urban development in the last century in Apulia, many of these cavities lie nowadays below densely populated neighborhoods, roads or communication routes. These conditions are at the origin of the main geomorphological hazard for the human society in Apulia, which requires a careful evaluation, aimed at protecting and safeguarding the human life, and at providing the necessary information for a correct land use planning and management. The importance of the sinkhole hazard is further testified by the worrying increase in the number of events during the last 5-6 years. In response to these situations, joint research activities were started by the Institute of Research for Hydrological Protection of the National Research Council (CNR-IRPI) and the Basin Authority of Apulia, aimed at several goals, that include (but are not limited to) the collection of information on natural and anthropogenic sinkholes in Apulia, the implementation of numerical analyses for modelling the instability processes, and the development of charts for a preliminary evaluation of the stability of underground caves. Two distinct approaches were established to take into account the different petrographic, structural and geotechnical features of both the hard and soft carbonate rocks. The approach dealing with hard carbonate rocks (where natural karst caves develop) is based on speleological and geometrical surveys of the caves and on an integrated geological and geomechanical characterization of the carbonate rock mass, aimed at individuating the main critical aspects of the karst caves in terms of likely effects on the society. On the other hand, the approach to verify the stability of soft rocks where artificial cavities have been excavated is mostly dependent upon the peculiar petrographic and geomechanical characteristics of the calcarenite rock mass, typically massive and unaffected by tectonic discontinuities. As a consequence, the traditional analytical methods of rock mass classification fail in these materials, since the rock strength of soft calcarenites is mostly dependent upon sediment texture, porosity type and distribution and degree of cementation. The fluid circulation into the rock mass is also important because the removal of the rock matrix may induce a rapid deterioration of the mechanical behaviour of the rock mass. The approach to the calcarenite is mostly based on the characterization of petrographic and geotechnical parameters by means of direct sampling from the rock walls and in situ surveys (wells, trenches, etc.). Through implementation of the two approaches, our goal is to reconstruct accurate geometrical, geological and geotechnical models for both natural caves and artificial cavities. These models will be useful also to plan specific monitoring activities in order to understand the development of underground instability, and the related evolution through the rock mass, possibly threatening the urban areas and infrastructures above.

Sample from Deep in Martian Crust: Marquette Island

NASA Image and Video Library

2010-01-21

Perched on a rippled Martian plain, a dark rock not much bigger than a basketball was the target of interest for NASA Opportunity during the past two months; Opportunity rock abrasion tool brushed dust out of the circular area.

Characterization of rock thermal conductivity by high-resolution optical scanning

USGS Publications Warehouse

Popov, Y.A.; Pribnow, D.F.C.; Sass, J.H.; Williams, C.F.; Burkhardt, H.

1999-01-01

We compared thress laboratory methods for thermal conductivity measurements: divided-bar, line-source and optical scanning. These methods are widely used in geothermal and petrophysical studies, particularly as applied to research on cores from deep scientific boreholes. The relatively new optical scanning method has recently been perfected and applied to geophysical problems. A comparison among these methods for determining the thermal conductivity tensor for anisotropic rocks is based on a representative collection of 80 crystalline rock samples from the KTB continental deep borehole (Germany). Despite substantial thermal inhomogeneity of rock thermal conductivity (up to 40-50% variation) and high anisotropy (with ratios of principal values attaining 2 and more), the results of measurements agree very well among the different methods. The discrepancy for measurements along the foliation is negligible (<1%). The component of thermal conductivity normal to the foliation reveals somewhat larger differences (3-4%). Optical scanning allowed us to characterize the thermal inhomogeneity of rocks and to identify a three-dimensional anisotropy in thermal conductivity of some gneiss samples. The merits of optical scanning include minor random errors (1.6%), the ability to record the variation of thermal conductivity along the sample, the ability to sample deeply using a slow scanning rate, freedom from constraints for sample size and shape, and quality of mechanical treatment of the sample surface, a contactless mode of measurement, high speed of operation, and the ability to measure on a cylindrical sample surface. More traditional methods remain superior for characterizing bulk conductivity at elevated temperature.Three laboratory methods including divided-bar, line-source and optical scanning are widely applied in geothermal and petrophysical studies. In this study, these three methods were compared for determining the thermal conductivity tensor for anisotropic rocks. For this study, a representative collection of 80 crystalline rock samples from the KTB continental deep borehole was used. Despite substantial thermal inhomogeneity of rock thermal conductivity and high anisotropy, measurement results were in excellent agreement among the three methods.

High-Resolution Seafloor Mapping at A Deep-Sea Methane Seep Field with an Autonomous Underwater Vehicle

NASA Astrophysics Data System (ADS)

Skarke, A. D.

2017-12-01

A growing body of research indicates that points of seafloor gas emission, known as cold-seeps, are a common feature along many continental margins. Results from recent exploration efforts show that benthic environments at cold-seeps are characterized by extensive authigenic carbonate crusts and complex chemosynthetic communities. The seafloor morphology and geophysical properties of these locations are heterogeneous and relatively complex due to the three-dimensional structure created by carbonate buildups and dense bivalve beds. Seeps are often found clustered and the spatial extent of associated seafloor crusts and beds can reach multiple square kilometers. Here, the results of a 1.25 km2 autonomous underwater vehicle (AUV) survey of a deep-sea methane seep field with 13 vents, at a nominal depth of 1400 m, located near Veatch Canyon on the US Atlantic margin are presented. Multibeam sonar, sidescan sonar, and a sub bottom profiler on the AUV were used to make high-resolution observations of seafloor bathymetry (resolution 1m2) as well as water column, seafloor, and subsurface acoustic backscatter intensity. Additionally, a downward oriented camera was used to collect seafloor imagery coincident with acoustic observations at select locations. Acoustic results indicated the location of discrete gas plumes as well as a continuous area of elevated seafloor roughness and backscatter intensity consistent with the presence of large scale authigenic rock outcrops and extensive mussel beds, which were visually confirmed with camera imagery. Additionally, a linear area of particularly elevated seafloor roughness and acoustic backscatter intensity that lies sub-parallel to an adjacent ridge was interpreted to be controlled by underlying geologic processes such as soft sediment faulting. Automated analysis of camera imagery and coincident acoustic backscatter and bathymetry data as well as derivative metrics (e.g. slope and rugosity) was used to segment and classify bed type (carbonate rock, sediment, mussel bed), yielding insight into geologic and ecological processes within the seep field study area.

Deep-sea benthic habitats modeling and mapping in a NE Atlantic seamount (Galicia Bank)

NASA Astrophysics Data System (ADS)

Serrano, A.; González-Irusta, J. M.; Punzón, A.; García-Alegre, A.; Lourido, A.; Ríos, P.; Blanco, M.; Gómez-Ballesteros, M.; Druet, M.; Cristobo, J.; Cartes, J. E.

2017-08-01

This study presents the results of seafloor habitat identification and mapping of a NE Atlantic deep seamount. An ;assemble first, predict later; approach has been followed to identify and map the benthic habitats of the Galicia Bank (NW Iberian). Biotic patterns inferred from the survey data have been used to drive the definition of benthic assemblages using multivariate tools. Eight assemblages, four hard substrates and four sedimentary ones, have been described from a matrix of structural species. Distribution of these assemblages was correlated with environmental factors (multibeam and backscatter data) using binomial GAMs. Finally, the distribution model of each assemblage was applied to produce continuous maps and pooled in a final map with the distribution of the main benthic habitats. Depth and substrate type are key factors when determining soft bottom communities, whereas rocky habitat distribution is mainly explained by rock slope and orientation. Enrichment by northern water masses (LSW) arriving to GB and possible zooplankton biomass increase at vertical-steep walls by ;bottom trapping; can explain the higher diversity of habitat providing filter-feeders at slope rocky breaks. These results concerning vulnerable species and habitats, such as Lophelia and Madrepora communities and black and bamboo coral aggregations were the basis of the Spanish proposal of inclusion within the Natura 2000 network. The aim of the present study was to establish the scientific criteria needed for managing and protecting those environmental values.

Physical and chemical properties of submarine basaltic rocks from the submarine flanks of the Hawaiian Islands

USGS Publications Warehouse

Yokose, H.; Lipman, P.W.; Kanamatsu, T.

2005-01-01

To evaluate physical and chemical diversity in submarine basaltic rocks, approximately 280 deep submarine samples recovered by submersibles from the underwater flanks of the Hawaiian Islands were analyzed and compared. Based on observations from the submersibles and hand specimens, these samples were classified into three main occurrence types (lavas, coarse-grained volcaniclastic rocks, and fine-grained sediments), each with several subtypes. The whole-rock sulfur content and porosity in submarine basaltic rocks, recovered from depths greater than 2000 m, range from < 10 ppm and 2 vol.% to 2200 ppm and 47 vol.%, respectively. These wide variations cannot be due just to different ambient pressures at the collection depths, as inferred previously for submarine erupted lavas. The physical and chemical properties of the recovered samples, especially a combination of three whole-rock parameters (Fe-oxidation state, Sulfur content, and Porosity), are closely related to the occurrence type. The FSP triangular diagram is a valuable indicator of the source location of basaltic fragments deposited in deep submarine areas. This diagram can be applied to basaltic rocks such as clasts in debris-flow deposits, submarine-emplaced lava flows that may have crossed the shoreline, and slightly altered geological samples. ?? 2005 Elsevier B.V. All rights reserved.

Zonal disintegration of rocks around underground workings. Part II. Rock fracture simulated in equivalent materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shemyakin, E.I.; Fisenko, G.L.; Kurlenya, M.V.

1987-05-01

For a detailed testing of the effects discovered in situ, analysis of the patterns and origination conditions of fractured rock zones inside the bed around workings, and ways explosions affect the surrounding rocks, a program and a method of study on models of equivalent materials have been developed. The method of simulation on two- and three-dimensional models involved building in a solid or fissured medium a tunnel of a circular or arched cross section. The tests were done for elongate adit-type workings. At the first stage, three models were tested with different working support systems: anchor supports, concrete-spray supports andmore » no supports. Zone formation is shown and described. Tests were continued on two groups of three-dimensional models to bring the model closer to in situ conditions. The presence of gaping cracks and heavily fractured zones deep in the interior of the bed with a quasicylindrical symmetry indicates that the common views concerning the stressed-strained state of rocks around underground workings are at variance with the actual patterns of deformation and destruction of rocks near the workings in deep horizons.« less

Explosive Deep Sea Volcanism Produces Composite Volcanoes (Stratocones) with Predominantly Diffuse Flow Hydrothermal Ecosystems

NASA Astrophysics Data System (ADS)

Rubin, K. H.; Chadwick, W. C.; Embley, R. W.; Butterfield, D. A.

2018-05-01

Newly-discovered extensive explosive deep sea volcanism produces distinct stratovolcano structures and physical rock characteristics, and host primarily diffuse flow hydrothermal activity, unlike focused flow systems at effusive submarine volcanoes.

Active microbial biofilms in deep poor porous continental subsurface rocks.

PubMed

Escudero, Cristina; Vera, Mario; Oggerin, Monike; Amils, Ricardo

2018-01-24

Deep continental subsurface is defined as oligotrophic environments where microorganisms present a very low metabolic rate. To date, due to the energetic cost of production and maintenance of biofilms, their existence has not been considered in poor porous subsurface rocks. We applied fluorescence in situ hybridization techniques and confocal laser scanning microscopy in samples from a continental deep drilling project to analyze the prokaryotic diversity and distribution and the possible existence of biofilms. Our results show the existence of natural microbial biofilms at all checked depths of the Iberian Pyrite Belt (IPB) subsurface and the co-occurrence of bacteria and archaea in this environment. This observation suggests that multi-species biofilms may be a common and widespread lifestyle in subsurface environments.

A three-dimensional back-analysis of the collapse of an underground cavity in soft rocks

NASA Astrophysics Data System (ADS)

Fazio, Nunzio Luciano; Lollino, Piernicola; Perrotti, Michele; Parise, Mario; Bonamini, Marco; Di Maggio, Cipriano; Madonia, Giuliana; Vattano, Marco

2016-04-01

Anthropogenic sinkholes have recently occurred in built-up areas of Sicily (southern Italy) and are generally associated with the presence of ancient underground quarries for the extraction of soft calcarenite rock, used as building material. These quarries were poorly excavated and then were abandoned in the following decades; urban expansion has recently enlarged to involve the areas affected by presence of the cavities, so that the likely collapse of the underground systems poses serious risks to people, buildings and infrastructures. The present work focuses on the case of the town of Marsala, where in 2003 a sinkhole opened at the outskirts of town, near peri-urban buildings. Field surveys, structural analysis of the joint networks in the rock mass and numerical modeling were carried out in order to investigate the most significant factors responsible of the instability processes of the underground quarry. In particular, a geotechnical three-dimensional model has been defined based on in-situ measurements and surveys. The FEM analyses have been performed with the code Plaxis-3D, by using initially the Mohr-Coulomb elasto-plastic model and then assessing the influence of the joint systems on the rock-mass stability with a jointed rock anisotropic model. Discrete planar bands have been also used to simulate the effect of specific joints, as an alternative to the jointed rock model. The results are in good agreement with the failure mechanism generated during the 2003 sinkhole event, and confirm that reliable analyses of these problems requires 3-D sophisticated tools.

Experimental multi-phase CO2-brine-rock interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

USGS Publications Warehouse

Rosenbauer, R.J.; Koksalan, T.

2004-01-01

Long-term CO2 saturated brine-rock experiments were conducted to evaluate the effects of multiphase H2O-CO2 fluids on mineral equilibria and the potential for CO2 sequestration mineral phases within deep-saline aquifers. Experimental results were consistent with theoretical thermodynamic calculations when CO2-saturated brines were reacted with limestone rocks. The CO2-saturated brine-limestone reactions were characterized by compositional and mineralogical-changes in the aquifer fluid and formation rocks that were dependent on initial brine composition as were the changes in formation porosity, especially dissolved sulfate. The solubility of CO2 was enhanced in brines in the presence of both limestone and sandstone rocks relative to brines alone. Reactions between CO2 saturated brines and arkosic sandstones were characterized by desiccation of the brine and changes in the chemical composition of the brine suggesting fixation of CO2 in mineral phases. These reactions occured on a measurable but kinetically slow time scale at 120??C.

Rock magnetic and anisotropy of magnetic susceptibility(AMS) of earthquake affected soft sediments: Examples from Shillong and Latur (Deccan Trap), India.

NASA Astrophysics Data System (ADS)

Lakshmi, B. V., ,, Dr.; Gawali, Mr. Praveen B.; Deenadayalan, K., ,, Dr.; Ramesh, D. S., ,, Prof.

2017-04-01

Rock magnetic and anisotropy of magnetic susceptibility (AMS) of earthquake affected soft sediments: Examples from Shillong and Latur (Deccan Trap), India. B.V.Lakshmi, Praveen B.Gawali, K.Deenadayalan and D.S.Ramesh Indian Institute of Geomagnetism, plot 5, sector 18, Near Kalamboli Highway, New Panvel(W), Navi Mumbai 410218 Combined rock magnetism and anisotropy of magnetic susceptibility (AMS) studies on earthquake induced soft and non-soft sediments from Shillong and Latur, India have thrown up interesting results. The morphology of hysteresis loops, the pattern of isothermal remanent magnetization (IRM) acquisition, and temperature dependence of susceptibility indicate that titano-magnetite/magnetite is the main magnetic carrier in these sediments. We also analyzed the anisotropy of magnetic susceptibility (AMS) of liquefaction features within the seismically active Dauki fault, Shillong Plateau. We discovered that host sediments (non-liquefied), are characterized by an oblate AMS ellipsoid and liquefied sediment are characterized by a triaxial AMS ellipsoid, well grouped maximum susceptibility axis K1 (NNW-SSE trend). Field evidence and AMS analysis indicate that most of these features were emplaced by injection inferred to be due to seismically triggered fluidization. Anisotropy of magnetic susceptibility (AMS) of deformed and undeformed unconsolidated clay samples of Deccan Trap terrain from the 2000-year-old paleoearthquake site of Ther village, Maharashtra, India, was also studied. Such deposits are rare in the compact basaltic terrain because of which the results acquired are very important. The undeformed clay samples exhibit typical sedimentary fabric with an oblate AMS ellipsoid, whereas the deformed samples are tightly grouped in the inferred compression direction, probably effected by an earthquake, exhibiting prolate as well as oblate AMS ellipsoids. Rock magnetic and AMS methodology can help understand the behavior of different sediments to the regional deformational processes active in the Himalayan region, and possibly local deformational activities in the compact Deccan trap region. The accumulating stress and strain direction can be delineated to infer strike of the forces accumulating stresses. These studies can be used to build the chronology of past earthquakes.

Cooperative Learning and Soft Skills Training in an IT Course

ERIC Educational Resources Information Center

Zhang, Aimao

2012-01-01

Pedagogy of higher education is shifting from passive to active and deep learning. At the same time, the information technology (IT) industry and the Accreditation Board for Engineering and Technology (ABET) are demanding soft skills training. Thus, in designing an IT course, we devised group teaching projects where students learn to work with…

Applicability of geomechanical classifications for estimation of strength properties in Brazilian rock masses.

PubMed

Santos, Tatiana B; Lana, Milene S; Santos, Allan E M; Silveira, Larissa R C

2017-01-01

Many authors have been proposed several correlation equations between geomechanical classifications and strength parameters. However, these correlation equations have been based in rock masses with different characteristics when compared to Brazilian rock masses. This paper aims to study the applicability of the geomechanical classifications to obtain strength parameters of three Brazilian rock masses. Four classification systems have been used; the Rock Mass Rating (RMR), the Rock Mass Quality (Q), the Geological Strength Index (GSI) and the Rock Mass Index (RMi). A strong rock mass and two soft rock masses with different degrees of weathering located in the cities of Ouro Preto and Mariana, Brazil; were selected for the study. Correlation equations were used to estimate the strength properties of these rock masses. However, such correlations do not always provide compatible results with the rock mass behavior. For the calibration of the strength values obtained through the use of classification systems, ​​stability analyses of failures in these rock masses have been done. After calibration of these parameters, the applicability of the various correlation equations found in the literature have been discussed. According to the results presented in this paper, some of these equations are not suitable for the studied rock masses.

Brittleness Effect on Rock Fatigue Damage Evolution

NASA Astrophysics Data System (ADS)

Nejati, Hamid Reza; Ghazvinian, Abdolhadi

2014-09-01

The damage evolution mechanism of rocks is one of the most important aspects in studying of rock fatigue behavior. Fatigue damage evolution of three rock types (onyx marble, sandstone and soft limestone) with different brittleness were considered in the present study. Intensive experimental tests were conducted on the chosen rock samples and acoustic emission (AE) sensors were used in some of them to monitor the fracturing process. Experimental tests indicated that brittleness strongly influences damage evolution of rocks in the course of static and dynamic loading. AE monitoring revealed that micro-crack density induced by the applied loads during different stages of the failure processes increases as rock brittleness increases. Also, results of fatigue tests on the three rock types indicated that the rock with the most induced micro-cracks during loading cycles has the least fatigue life. Furthermore, the condition of failure surfaces of the studied rocks samples, subjected to dynamic and static loading, were evaluated and it was concluded that the roughness of failure surfaces is influenced by loading types and rock brittleness. Dynamic failure surfaces were rougher than static ones and low brittle rock demonstrate a smoother failure surface compared to high brittle rock.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jaekyun; Kim, Myung -Gil; Kim, Jaehyun

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. Inmore » this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. As a result, the successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.« less

Clinics in diagnostic imaging (169). Intermuscular lipoma in the thenar eminence of the right hand.

PubMed

Venkatesh, Sandeep Halagatti; Wong, Bak Siew Steven

2016-08-01

A 54-year-old woman presented with a large mass on her right hand that was progressively enlarging over a period of a few years. She had cosmetic concerns about the enlarging mass and experienced interference with routine activity. Physical examination revealed a soft, mobile, non-tender, lobulated mass with well-defined margins. Magnetic resonance imaging showed the soft lump to be a lipomatous mass in the deep palmar space of the hand, which was subsequently surgically resected. The imaging features of deep palmar lipomas of the hand and other common benign lesions at this location are discussed. Copyright: © Singapore Medical Association.

Oxidation preventative capping layer for deep-ultra-violet and soft x-ray multilayers

DOEpatents

Prisbrey, Shon T.

2004-07-06

The invention uses iridium and iridium compounds as a protective capping layer on multilayers having reflectivity in the deep ultra-violet to soft x-ray regime. The iridium compounds can be formed in one of two ways: by direct deposition of the iridium compound from a prepared target or by depositing a thin layer (e.g., 5-50 angstroms) of iridium directly onto an element. The deposition energy of the incoming iridium is sufficient to activate the formation of the desired iridium compound. The compounds of most interest are iridium silicide (IrSi.sub.x) and iridium molybdenide (IrMo.sub.x).

Incorporation of Metals into Calcite in a Deep Anoxic Granite Aquifer.

PubMed

Drake, Henrik; Mathurin, Frédéric A; Zack, Thomas; Schäfer, Thorsten; Roberts, Nick Mw; Whitehouse, Martin; Karlsson, Andreas; Broman, Curt; Åström, Mats E

2018-01-16

Understanding metal scavenging by calcite in deep aquifers in granite is of importance for deciphering and modeling hydrochemical fluctuations and water-rock interaction in the upper crust and for retention mechanisms associated with underground repositories for toxic wastes. Metal scavenging into calcite has generally been established in the laboratory or in natural environments that cannot be unreservedly applied to conditions in deep crystalline rocks, an environment of broad interest for nuclear waste repositories. Here, we report a microanalytical study of calcite precipitated over a period of 17 years from anoxic, low-temperature (14 °C), neutral (pH: 7.4-7.7), and brackish (Cl: 1700-7100 mg/L) groundwater flowing in fractures at >400 m depth in granite rock. This enabled assessment of the trace metal uptake by calcite under these deep-seated conditions. Aquatic speciation modeling was carried out to assess influence of metal complexation on the partitioning into calcite. The resulting environment-specific partition coefficients were for several divalent ions in line with values obtained in controlled laboratory experiments, whereas for several other ions they differed substantially. High absolute uptake of rare earth elements and U(IV) suggests that coprecipitation into calcite can be an important sink for these metals and analogousactinides in the vicinity of geological repositories.

Development and application of new composite grouting material for sealing groundwater inflow and reinforcing wall rock in deep mine.

PubMed

Jinpeng, Zhang; Limin, Liu; Futao, Zhang; Junzhi, Cao

2018-04-04

With cement, bentonite, water glass, J85 accelerator, retarder and water as raw materials, a new composite grouting material used to seal groundwater inflow and reinforce wall rock in deep fractured rock mass was developed in this paper. Based on the reaction mechanism of raw material, the pumpable time, stone rate, initial setting time, plastic strength and unconfined compressive strength of multi-group proportion grouts were tested by orthogonal experiment. Then, the optimum proportion of composite grouting material was selected and applied to the grouting engineering for sealing groundwater inflow and reinforcing wall rock in mine shaft lining. The results show the mixing proportion of the maximum pumpable time, maximum stone rate and minimum initial setting time of grout are A K4 B K1 C K4 D K2 , A K3 B K1 C K1 D K4 and A K3 B K3 C K4 D K1 , respectively. The mixing proportion of the maximum plastic strength and unconfined compressive strength of grouts concretion bodies are A K1 B K1 C K1 D K3 and A K1 B K1 C K1 D K1 , respectively. Balanced the above 5 indicators overall and determined the optimum proportion of grouts: bentonite-cement ratio of 1.0, water-solid ratio of 3.5, accelerator content of 2.9% and retarder content of 1.45%. This new composite grouting material had good effect on the grouting engineering for sealing groundwater inflow and reinforcing wall rock in deep fractured rock mass.

SAPHYR: the Swiss Atlas of PHYsical properties of Rocks

NASA Astrophysics Data System (ADS)

Wenning, Q. C.; Zappone, A. S.; Kissling, E.

2015-12-01

The Swiss Atlas of PHYsical properties of Rocks (SAPHYR) is a multi-year project, aiming to compile a comprehensive data set on physical properties of rocks exposed in Switzerland and surrounding areas. The ultimate goal of SAPHYR is to make these data accessible to an open and wide public, such as industrial, engineering, land and resource planning companies, as well as academic institutions. Since the early sixties worldwide geophysicists, petrologists, and engineers, focused their work on laboratory measurements of rocks physical properties, and their relations with microstructures, mineralogical compositions and other rock parameters, in the effort to constrain the geological interpretation of geophysical surveys. In combination with efforts to investigate deep structure of the continental crust by controlled source seismology, laboratories capable to reproduce pressure and temperature conditions to depth of 50km and more collected measurements of various parameters on a wide variety of rock types. In recent years, the increasing interest on non-traditional energy supply, (deep geothermal energy, shale gas) and CO2 storage renovated the interests in physical characterization of the deep underground. The idea to organize those laboratory data into a geographically referenced database (GIS) is supported by the Swiss Commission for Geophysics. The data refer to density and porosity, seismic, magnetic, thermal properties, permeability and electrical properties. An effort has been placed on collecting samples and measuring the physical properties of lithologies that are poorly documented in literature. The phase of laboratory measurements is still in progress. At present SAPHYR focuses towards developing a 3-D physical properties model of the Swiss subsurface, using the structure of the exposed geology, boreholes data and seismic surveys, combined with lab determined pressure and temperature derivatives. An early version of the final product is presented here.

Geophysical Properties of Hard Rock for Investigation of Stress Fields in Deep Mines

NASA Astrophysics Data System (ADS)

Tibbo, M.; Young, R. P.; Schmitt, D. R.; Milkereit, B.

2014-12-01

A complication in geophysical monitoring of deep mines is the high-stress dependency of the physical properties of hard rocks. In-mine observations show anisotropic variability of the in situ P- and S-wave velocities and resistivity of the hard rocks that are likely related to stress field changes. As part of a comprehensive study in a deep, highly stressed mine located in Sudbury, Ontario, Canada, data from in situ monitoring of the seismicity, conductivity, stress, and stress dependent physical properties has been obtain. In-laboratory experiments are also being performed on borehole cores from the Sudbury mines. These experiments will measure the Norite borehole core's properties including elastic modulus, bulk modulus, P- and S-wave velocities, and density. Hydraulic fracturing has been successfully implemented in industries such as oil and gas and enhanced geothermal systems, and is currently being investigated as a potential method for preconditioning in mining. However, further research is required to quantify how hydraulic fractures propagate through hard, unfractured rock as well as naturally fractured rock typically found in mines. These in laboratory experiments will contribute to a hydraulic fracturing project evaluating the feasibility and effectiveness of hydraulic fracturing as a method of de-stressing hard rock mines. A tri-axial deformation cell equipped with 18 Acoustic Emission (AE) sensors will be used to bring the borehole cores to a tri-axial state of stress. The cores will then be injected with fluid until the the hydraulic fracture has propagated to the edge of the core, while AE waveforms will be digitized continuously at 10 MHz and 12-bit resolution for the duration of each experiment. These laboratory hydraulic fracture experiments will contribute to understanding how parameters including stress ratio, fluid injection rate, and viscosity, affect the fracturing process.

Distinction between epigenic and hypogenic maze caves

NASA Astrophysics Data System (ADS)

Palmer, Arthur N.

2011-11-01

Certain caves formed by dissolution of bedrock have maze patterns composed of closed loops in which many intersecting fractures or pores have enlarged simultaneously. Their origin can be epigenic (by shallow circulation of meteoric groundwater) or hypogenic (by rising groundwater or production of deep-seated solutional aggressiveness). Epigenic mazes form by diffuse infiltration through a permeable insoluble caprock or by floodwater supplied by sinking streams. Most hypogenic caves involve deep sources of aggressiveness. Transverse hypogenic cave origin is a recently proposed concept in which groundwater of mainly meteoric origin rises across strata in the distal portions of large flow systems, to form mazes in soluble rock sandwiched between permeable but insoluble strata. The distinction between maze types is debated and is usually based on examination of diagnostic cave features and relation of caves to their regional setting. In this paper, the principles of mass transfer are applied to clarify the limits of each model, to show how cave origin is related to groundwater discharge, dissolution rate, and time. The results show that diffuse infiltration and floodwater can each form maze caves at geologically feasible rates (typically within 500 ka). Transverse hypogenic mazes in limestone, to enlarge significantly within 1 Ma, require an unusually high permeability of the non-carbonate beds (generally ≥ 10-4 cm/s), large discharge, and calcite saturation no greater than 90%, which is rare in deep diffuse flow in sedimentary rocks. Deep sources of aggressiveness are usually required. The origin of caves by transverse hypogenic flow is much more favorable in evaporite rocks than in carbonate rocks.

Combining conventional and thermal drilling in order to increase speed and reduce costs of drilling operations to access deep geothermal resources

NASA Astrophysics Data System (ADS)

Rossi, Edoardo; Kant, Michael A.; von Rohr, Philipp Rudolf; Saar, Martin O.

2017-04-01

The exploitation of deep geothermal resources for energy production relies on finding cost effective solutions to increase the drilling performance in hard rocks. Conventional rotary drilling techniques, based on mechanical rock exportation, result in high rates of drilling tool wearing, causing significant costs. Additionally, rotary drilling results in low drilling speeds in the typically hard crystalline basement rocks targeted for enhanced geothermal energy utilization technologies. Furthermore, even lower overall drilling rates result, when considering tripping times required to exchange worn drill tools. Therefore, alternative drilling techniques, such as hammering, thermal drilling, plasma drilling, and jetting processes are widely investigated in order to provide cost-effective alternatives to conventional drilling methods. A promising approach, that combines conventional rotary and thermal drilling techniques, is investigated in the present work. Here, the rock material is thermally weakened before being exported by conventional cutters. Heat is locally provided by a flame, which moves over the rock surface, heat-treating the material. Besides reducing the rock strength, an in-depth smoothening effect of the mechanical rock properties is observed due to the thermal treatment. This results in reduced rates of drill bit wearing and higher rates of penetration, which in turn decreases drilling costs significantly, particularly for deep-drilling projects. Due to the high heating rates, rock-hardening, commonly observed at moderate temperatures, can be avoided. The flame action can be modelled as a localized, high heat transfer coefficient flame treatment, which results in orders of magnitude higher heating rates than conventional oven treatments. Therefore, we analyse rock strength variations after different maximum temperatures, flame-based heating rates, and rock confinement pressures. The results show that flame treatments lead to a monotonous decrease of rock strength with temperature. This is different from oven treatments, where an initial increase of strength is typically observed, followed by a steep decrease upon further (slow) oven-heating. Thus, the weakening of sandstone and granite samples due to flame treatments indicates the feasibility of a combined mechanical-thermal drilling system. These results suggest that the new combined method enables improved rates of penetration in hard rocks while reducing the rate of drill tool wear. We also present possible implementations of this combined drilling system in the field. From field test results, advantages and limitations of the proposed new technology are presented, with an emphasis on accessing geothermal energy resources in crystalline basement rocks.

Door to 'Pilbara'

NASA Technical Reports Server (NTRS)

2004-01-01

This mosaic of five images taken by the microscopic imager on the Mars Exploration Rover Opportunity on sol 87 shows the hole drilled by the rover's rock abrasion tool into the rock dubbed 'Pilbara.' A sliced 'blueberry,' or spherule, which is darker and harder than the rest of the rock, can be seen near the center of the hole. The rock abrasion process left a pile of rock powder around the side of the hole, and to a lesser degree, inside the hole. The grinding penetrated an area of rock about 7.2 millimeters (about 0.28 inches) deep and 4.5 centimeters (about 1.8 inches) in diameter.

Challenges of constructing salt cavern gas storage in China

NASA Astrophysics Data System (ADS)

Xia, Yan; Yuan, Guangjie; Ban, Fansheng; Zhuang, Xiaoqian; Li, Jingcui

2017-11-01

After more than ten years of research and engineering practice in salt cavern gas storage, the engineering technology of geology, drilling, leaching, completion, operation and monitoring system has been established. With the rapid growth of domestic consumption of natural gas, the requirement of underground gas storage is increasing. Because high-quality rock salt resources about 1000m depth are relatively scarce, the salt cavern gas storages will be built in deep rock salt. According to the current domestic conventional construction technical scheme, construction in deep salt formations will face many problems such as circulating pressure increasing, tubing blockage, deformation failure, higher completion risk and so on, caused by depth and the complex geological conditions. Considering these difficulties, the differences between current technical scheme and the construction scheme of twin well and big hole are analyzed, and the results show that the technical scheme of twin well and big hole have obvious advantages in reducing the circulating pressure loss, tubing blockage and failure risk, and they can be the alternative schemes to solve the technical difficulties of constructing salt cavern gas storages in the deep rock salt.

Where fast weathering creates thin regolith and slow weathering creates thick regolith

USGS Publications Warehouse

Bazilevskaya, Ekaterina; Lebedeva, Marina; Pavich, Milan J.; Brantley, Susan L.; Rother, Gernot; Parkinson, Dilworth Y.; Cole, David

2013-01-01

Weathering disaggregates rock into regolith – the fractured or granular earth material that sustains life on the continental land surface. Here, we investigate what controls the depth of regolith formed on ridges of two rock compositions with similar initial porosities in Virginia (USA). A priori, we predicted that the regolith on diabase would be thicker than on granite because the dominant mineral (feldspar) in the diabase weathers faster than its granitic counterpart. However, weathering advanced 20 deeper into the granite than the diabase. The 20 -thicker regolith is attributed mainly to connected micron-sized pores, microfractures formed around oxidizing biotite at 20 m depth, and the lower iron (Fe) content in the felsic rock. Such porosity allows pervasive advection and deep oxidation in the granite. These observations may explain why regolith worldwide is thicker on felsic compared to mafic rock under similar conditions. To understand regolith formation will require better understanding of such deep oxidation reactions and how they impact fluid flow during weathering.

'The effect of different genres of music on the stress levels of kennelled dogs'.

PubMed

Bowman, A; Dowell, F J; Evans, N P

2017-03-15

Classical music has been shown to reduce stress in kennelled dogs; however, rapid habituation of dogs to this form of auditory enrichment has also been demonstrated. The current study investigated the physiological and behavioural response of kennelled dogs (n=38) to medium-term (5days) auditory enrichment with five different genres of music including Soft Rock, Motown, Pop, Reggae and Classical, to determine whether increasing the variety of auditory stimulation reduces the level of habituation to auditory enrichment. Dogs were found to spend significantly more time lying and significantly less time standing when music was played, regardless of genre. There was no observable effect of music on barking, however, dogs were significantly (z=2.2, P<0.05) more likely to bark following cessation of auditory enrichment. Heart Rate Variability (HRV) was significantly higher, indicative of decreased stress, when dogs were played Soft Rock and Reggae, with a lesser effect observed when Motown, Pop and Classical genres were played. Relative to the silent period prior to auditory enrichment, urinary cortisol:creatanine (UCCR) values were significantly higher during Soft Rock (t=2.781, P<0.01) and the second silent control period following auditory enrichment (t=2.46, P<0.05). Despite the mixed response to different genres, the physiological and behavioural changes observed remained constant over the 5d of enrichment suggesting that the effect of habituation may be reduced by increasing the variety of auditory enrichment provided. Copyright © 2017 Elsevier Inc. All rights reserved.

Damage evolution of bi-body model composed of weakly cemented soft rock and coal considering different interface effect.

PubMed

Zhao, Zenghui; Lv, Xianzhou; Wang, Weiming; Tan, Yunliang

2016-01-01

Considering the structure effect of tunnel stability in western mining of China, three typical kinds of numerical model were respectively built as follows based on the strain softening constitutive model and linear elastic-perfectly plastic model for soft rock and interface: R-M, R-C(s)-M and R-C(w)-M. Calculation results revealed that the stress-strain relation and failure characteristics of the three models vary between each other. The combination model without interface or with a strong interface presented continuous failure, while weak interface exhibited 'cut off' effect. Thus, conceptual models of bi-material model and bi-body model were established. Then numerical experiments of tri-axial compression were carried out for the two models. The relationships between stress evolution, failure zone and deformation rate fluctuations as well as the displacement of interface were detailed analyzed. Results show that two breakaway points of deformation rate actually demonstrate the starting and penetration of the main rupture, respectively. It is distinguishable due to the large fluctuation. The bi-material model shows general continuous failure while bi-body model shows 'V' type shear zone in weak body and failure in strong body near the interface due to the interface effect. With the increasing of confining pressure, the 'cut off' effect of weak interface is not obvious. These conclusions lay the theoretical foundation for further development of constitutive model for soft rock-coal combination body.

Geologic Map of the Warm Spring Canyon Area, Death Valley National Park, Inyo County, California, With a Discussion of the Regional Significance of the Stratigraphy and Structure

USGS Publications Warehouse

Wrucke, Chester T.; Stone, Paul; Stevens, Calvin H.

2007-01-01

Warm Spring Canyon is located in the southeastern part of the Panamint Range in east-central California, 54 km south of Death Valley National Park headquarters at Furnace Creek Ranch. For the relatively small size of the area mapped (57 km2), an unusual variety of Proterozoic and Phanerozoic rocks is present. The outcrop distribution of these rocks largely resulted from movement on the east-west-striking, south-directed Butte Valley Thrust Fault of Jurassic age. The upper plate of the thrust fault comprises a basement of Paleoproterozoic schist and gneiss overlain by a thick sequence of Mesoproterozoic and Neoproterozoic rocks, the latter of which includes diamictite generally considered to be of glacial origin. The lower plate is composed of Devonian to Permian marine formations overlain by Jurassic volcanic and sedimentary rocks. Late Jurassic or Early Cretaceous plutons intrude rocks of the area, and one pluton intrudes the Butte Valley Thrust Fault. Low-angle detachment faults of presumed Tertiary age underlie large masses of Neoproterozoic dolomite in parts of the area. Movement on these faults predated emplacement of middle Miocene volcanic rocks in deep, east-striking paleovalleys. Excellent exposures of all the rocks and structural features in the area result from sparse vegetation in the dry desert climate and from deep erosion along Warm Spring Canyon and its tributaries.

Deep Shear Wave Velocity of Southern Bangkok and Vicinity

NASA Astrophysics Data System (ADS)

Wongpanit, T.; Hayashi, K.; Pananont, P.

2017-09-01

Bangkok is located on the soft marine clay in the Lower Chao Phraya Basin which can amplify seismic wave and can affect the shaking of buildings during an earthquake. Deep shear wave velocity of the sediment in the basin are useful for study the effect of the soft sediment on the seismic wave and can be used for earthquake engineering design and ground shaking estimation, especially for a deep basin. This study aims to measure deep shear wave velocity and create 2D shear wave velocity profile down to a bedrock in the southern Bangkok by the Microtremor measurements with 2 seismographs using Spatial Autocorrelation (2-SPAC) technique. The data was collected during a day time on linear array geometry with offsets varying between 5-2,000 m. Low frequency of natural tremor (0.2-0.6 Hz) was detected at many sites, however, very deep shear wave data at many sites are ambiguous due to man-made vibration noises in the city. The results show that shear wave velocity of the sediment in the southern Bangkok is between 100-2,000 ms-1 and indicate that the bedrock depth is about 600-800 m, except at Bang Krachao where bedrock depth is unclear.

Distribution of Quercus agrifolia mycorrhizae deep within weathered bedrock: a potential mechanism for transport of stored water

Treesearch

M. Bornyasz; R. Graham; M. Allen

2002-01-01

In southwestern California, Quercus agrifolia distribution closely matches regions of granitic regolith. High annual evapotranspiration demand and inherent shallow soil conditions lead to a dependence on a deep rooting system and an ability to access water from deep within the regolith. Most of the plant available water in weathered granitic rock is...

Post-middle Miocene accretion of Franciscan rocks, northwestern California.

USGS Publications Warehouse

McLaughlin, R.J.; Kling, S.A.; Poore, R.Z.; McDougall, K.; Beutner, E.C.

1982-01-01

Deformed sedimentary rocks assigned to the Franciscan assemblage in the King Range S of Cape Mendocino, N California, are dominantly deep-water argillite and sandstone occurring as thick- to thin-bedded, locally channelized marine turbidities of arkosic to andesitic volcaniclastic composition. The King Range appears to be a displaced terrane of oceanic basement overlain by Palaeogene(?) and Neogene sedimentary and igneous rocks of continental and oceanic derivation.-Authors

Smaller Footprint Drilling System for Deep and Hard Rock Environments; Feasibility of Ultra-High-Speed Diamond Drilling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arnis Judzis; Alan Black; Homer Robertson

2006-03-01

The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high rotational speeds (greater than 10,000 rpm). The work includes a feasibility of concept research effort aimed at development that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with smaller, more mobile rigs. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration (ROP) rock cutting with substantially lower inputs of energymore » and loads. The significance of the ultra-high rotary speed drilling system is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm--usually well below 5,000 rpm. This document details the progress to date on the program entitled ''Smaller Footprint Drilling System for Deep and Hard Rock Environments: Feasibility of Ultra-High-Speed Diamond Drilling'' for the period starting 1 October 2004 through 30 September 2005. Additionally, research activity from 1 October 2005 through 28 February 2006 is included in this report: (1) TerraTek reviewed applicable literature and documentation and convened a project kick-off meeting with Industry Advisors in attendance. (2) TerraTek designed and planned Phase I bench scale experiments. Some difficulties continue in obtaining ultra-high speed motors. Improvements have been made to the loading mechanism and the rotational speed monitoring instrumentation. New drill bit designs have been provided to vendors for production. A more consistent product is required to minimize the differences in bit performance. A test matrix for the final core bit testing program has been completed. (3) TerraTek is progressing through Task 3 ''Small-scale cutting performance tests''. (4) Significant testing has been performed on nine different rocks. (5) Bit balling has been observed on some rock and seems to be more pronounces at higher rotational speeds. (6) Preliminary analysis of data has been completed and indicates that decreased specific energy is required as the rotational speed increases (Task 4). This data analysis has been used to direct the efforts of the final testing for Phase I (Task 5). (7) Technology transfer (Task 6) has begun with technical presentations to the industry (see Judzis).« less

ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thurman E. Scott, Jr., Ph.D.; Younane Abousleiman, Ph.D.; Musharraf Zaman, Ph.D., P.E.

2001-07-01

Mechanically weak formations, such as chalks, high porosity sandstones, and marine sediments, pose significant problems for oil and gas operators. Problems such as compaction, subsidence, and loss of permeability can affect reservoir production operations. For example, the unexpected subsidence of the Ekofisk chalk in the North Sea required over one billion dollars to re-engineer production facilities to account for losses created during that compaction (Sulak 1991). Another problem in weak formations is that of shallow water flows (SWF). Deep water drilling operations sometimes encounter cases where the marine sediments, at shallow depths just below the seafloor, begin to uncontrollably flowmore » up and around the drill pipe. SWF problems created a loss of $150 million for the Ursa development project in the U.S. Gulf Coast SWF (Furlow 1998a,b; 1999a,b). The goal of this project is to provide a database on both the rock mechanical properties and the geophysical properties of weak rocks and sediments. These could be used by oil and gas companies to detect, evaluate, and alleviate potential production and drilling problems. The results will be useful in, for example, pre-drill detection of events such as SWF's by allowing a correlation of seismic data (such as hazard surveys) to rock mechanical properties. The data sets could also be useful for 4-D monitoring of the compaction and subsidence of an existing reservoir and imaging the zones of damage. During the second quarter of the project the research team has: (1) completed acoustic sensor construction, (2) conducted reconnaissance tests to map the deformational behaviors of the various rocks, (3) developed a sample assembly for the measurement of dynamic elastic and poroelastic parameters during triaxial testing, and (4) conducted a detailed review of the scientific literature and compiled a bibliography of that review. During the first quarter of the project the research team acquired several rock types for testing including: (a) Danian chalk, (b) Cordoba Cream limestone, (c) Indiana limestone, (d) Ekofisk chalk, (e) Oil Creek sandstone, (f) unconsolidated Oil Creek sand, and (g) unconsolidated Brazos river sand. During the second quarter experiments were begun on these rock types. A series of reconnaissance experiments have been carried out on all but the Ekofisk (for which there is a preliminary data set already inhouse). A series of triaxial tests have been conducted on the Danian chalk, the Cordoba Cream limestone, the Indiana limestone, and sand samples to make a preliminary determination of the deformational mechanisms present in these samples.« less

About the geologic map in the National Atlas of the United States of America

USGS Publications Warehouse

Reed, John C.; Bush, Charles A.

2007-01-01

Introduction The geologic map in the National Atlas of the United States of America shows the age, distribution, and general character of the rocks that underlie the Nation, including Alaska, Hawaii, Puerto Rico, and the Virgin Islands (but excluding other small island possessions). (The National Atlas of the United States can be accessed at URL http://nationalatlas.gov/natlas/Natlasstart.asp.) The map depicts the bedrock that lies immediately beneath soils or surficial deposits except where these deposits are so thick and extensive that the type of bedrock beneath them can only be inferred by deep drilling or geophysical methods, or both. Thus, it does not show the extensive glacial deposits of the North Central and Northeastern States, the deep residuum of the Southeastern and South Central States, the relatively thin alluvium along many major rivers and basins, and extensive eolian deposits on the high plains. However, it does show, in a general way, the thick alluvial deposits along the lower Mississippi River and on the Atlantic and Gulf Coastal Plains, and in the deep basins of the western cordillera. The rocks are classified as either sedimentary, volcanic, plutonic, or metamorphic, and their geologic ages are given in terms using a simplified version of the 1999 Geological Society of America geologic time scale. In some places rocks depicted as sedimentary are interlayered with volcanic rocks, including tuff, volcanic breccia, and volcanic flows. Conversely, many of the rocks shown as volcanic include interlayered sedimentary rocks. Plutonic rocks are classified by age and as granitic, intermediate, mafic, or ultramafic, but no similar classification has been attempted for the volcanic rocks in this version of the map. Where sedimentary or volcanic rocks have been metamorphosed but still retain clear evidence of their depositional age and origin, the extent of the metamorphism is shown by a pattern. Where the metamorphism has been so intense that the rocks bear little resemblance to the rocks from which they were derived, they are mapped as gneiss, but the age given is generally the age of the original rocks. The map in the National Atlas is a generalization of a new geologic map of North America that has recently been published by the Geological Society of America. The original compilation was prepared at a scale of 1:2,500,000 for publication at a scale of 1:5,000,000. This generalized version is intended for viewing at scales between about 1:10,000,000 and 1:7,500,000.

Demersal fish distribution and habitat use within and near Baltimore and Norfolk Canyons, U.S. Middle Atlantic Slope

USGS Publications Warehouse

Ross, Steve W.; Rhode, Mike; Quattrini, Andrea M.

2015-01-01

Numerous submarine canyons along the United States middle Atlantic continental margin support enhanced productivity, diverse and unique habitats, active fisheries, and are vulnerable to various anthropogenic disturbances. During two cruises (15 Aug–2 Oct 2012 and 30 Apr–27 May 2013), Baltimore and Norfolk canyons and nearby areas (including two cold seeps) were intensively surveyed to determine demersal fish distributions and habitat associations. Overall, 34 ROV dives (234–1612 m) resulted in 295 h of bottom video observations and numerous collections. These data were supplemented by 40, 30-min bottom trawl samples. Fish observations were assigned to five general habitat designations: 1) sand-mud (flat), 2) sloping sand-mud with burrows, 3) low profile gravel, rock, boulder, 4) high profile, canyon walls, rocks or ridges, and 5) seep-mixed hard and soft substrata, the later subdivided into seven habitats based on amounts of dead mussel and rock cover. The influence of corals, sponges and live mussels (seeps only) on fish distributions was also investigated. Both canyon areas supported abundant and diverse fish communities and exhibited a wide range of habitats, including extensive areas of deep-sea corals and sponges and two nearby methane seeps (380–430 m, 1455–1610 m). All methods combined yielded a total of 123 species of fishes, 12 of which are either new records for this region or have new range data. Depth was a major factor that separated the fish faunas into two zones with a boundary around 1400 m. Fishes defining the deeper zone included Lycodes sp.,Dicrolene introniger, Gaidropsaurus ensis, Hydrolagus affinis, Antimora rostrata, andAldrovandia sp. Fishes in the deep zone did not exhibit strong habitat affinities, despite the presence of a quite rugged, extensive methane seep. We propose that habitat specificity decreases with increasing depth. Fishes in the shallower zone, characterized by Laemonema sp., Phycis chesteri, Nezumia bairdii, Brosme brosme, and Helicolenus dactylopterus, exhibited a variety of habitat use patterns. In general, fish assemblages in the soft substrata areas (dominated by P. chesteri, N. bairdii, Glyptocephalus cynoglossus, Lophius americanus, Merluccius albidus) were different from those in more complex habitats (dominated by Laemonema spp., Hoplostethus spp., B. brosme,Benthocometes robustus, L. americanus, Dysommina rugosa). Although, when present, the dense coral and sponge cover did not statistically affect general fish assemblage patterns in hard bottom habitats, these sessile organisms markedly increased habitat complexity, and some fish species exhibited close association with them. Fish species compositions in the two canyons were not substantially different from the surrounding slopes. However, the diversity of habitats within both the canyons and seeps exerted an important influence on assemblage structure. At least for some species (e.g., B. brosme) canyon and seep environments may be a refuge from intensive bottom fishing activities. We frequently observed evidence of commercial and recreational fishing activity (lost gear on bottom and fishing boats in the area) throughout the canyons and some resulting habitat damage. Conservation measures for the unique and more vulnerable areas (seep and coral habitats) have recently been approved.

Hydrogeologic Prospection With Vlf (very Low Frequency) In A Low Potential Hard Rock Aquifer Near Beja (south Portugal)

NASA Astrophysics Data System (ADS)

Duque, J.

The use of geophysics prospection in hydrogeology is widely used as a way to find groundwater under difficult hydrogeologic potential rocks. The porphyric rocks lay- ered in the northern part of Beja city, are the most unproductive regional aquifer. Usu- ally this aquifer has an upper layer of 5 to 15 meters deep of weathered rock and a second layer build by fractures rock till 30 metres deep. Above this deep the probabil- ity to find groundwater is extremely low. For instance it is a very superficial aquifer that usually accomplish the topographic surface. The water use is essential for human purposes and here are used mainly for human and cattle supply. In order verify the goodness of a geophysic method and at the same time to supply a large farm called Herdade da Apariça, it was performed the geophysical method of Very Low Frequency (VLF-EM) with ABEM (WADI) equipment, in three areas previously defined by inter- pretation of aerial photography, as zones that have relative hydrogeological potential. It was performed a total of 5 profiles with 1970 m. The geophysic prospecting and hydrogeologic research allowed to drill 5 boreholes, being 4 extraction wells and 1 piezometric well. The productivity of the abstraction wells are between 2,000 L/h and 10,000 L/h, which is a very good yield when compared with the other yield values get from wells inside this aquifer. VLF proved in this conditions to be an essential tool to increment the tax success of drilling wells.

Regional estimation of catchment-scale soil properties by means of streamflow recession analysis for use in distributed hydrological models

NASA Astrophysics Data System (ADS)

Vannier, Olivier; Braud, Isabelle; Anquetin, Sandrine

2013-04-01

The estimation of catchment-scale soil properties, such as water storage capacity and hydraulic conductivity, is of primary interest for the implementation of distributed hydrological models at the regional scale. This estimation is generally done on the basis of information provided by soil databases. However, such databases are often established for agronomic uses and generally do not document deep weathered rock horizons (i.e. pedologic horizons of type C and deeper), which can play a major role in water transfer and storages. Here we define the Drainable Storage Capacity Index (DSCI), an indicator that relies on the comparison of cumulated streamflow and precipitation to assess catchment-scale storage capacities. The DSCI is found to be reliable to detect underestimation of soil storage capacities in soil databases. We also use the streamflow recession analysis methodology defined by Brutsaert and Nieber (Water Resources Research 13(3), 1977) to estimate water storage capacities and lateral saturated hydraulic conductivities of the non-documented deep horizons. The analysis is applied to a sample of twenty-three catchments (0.2 km² - 291 km²) located in the Cévennes-Vivarais region (south of France). In a regionalisation purpose, the obtained results are compared to the dominant catchments geology. This highlights a clear hierarchy between the different geologies present in the area. Hard crystalline rocks are found to be associated to the thickest and less conductive deep soil horizons. Schist rocks present intermediate values of thickness and of saturated hydraulic conductivity, whereas sedimentary rocks and alluvium are found to be the less thick and the most conductive. Consequently, deep soil layers with thicknesses and hydraulic conductivities differing with the geology were added to a distributed hydrological model implemented over the Cévennes-Vivarais region. Preliminary simulations show a major improvement in terms of simulated discharge when compared to simulations done without deep soil layers. KEY WORDS: hydraulic soil properties, streamflow recession, deep soil horizons, soil databases, Boussinesq equation, storage capacity, regionalisation

A STUDY ON MECHANICAL BEHAVIOR OF SUPPORT ELEMENTS INDUCED BY SHAFT SINKING

NASA Astrophysics Data System (ADS)

Tsusaka, Kimikazu; Inagaki, Daisuke; Hatsuyama, Yoshihiro; Koike, Masashi; Shimada, Tomohiro; Ijiri, Yuji

Japan Atomic Energy Agency has been excavating three deep shafts through soft sedimentary rock in the Horonobe Underground Research Laboratory. In this paper, the authors discussed change in stress and the stress distribution in a concrete lining and steel arch ribs induced by the 6.5 m diameter shaft sinking. They conducted not only field measurements of stress in support elements at a depth of around 220 m but also three-dimensional numerical analysis which models the shaft excavation procedure such as timing of installation of support elements and setting and removal of a concrete form. As a result, it was clarified that more than 10 MPa difference in circumferential stress occurred in a 2 m high and 400 mm thick concrete lining due to anisotropy of initial stress and three-dimensional effect of an excavation face. It was also found that a concrete lining gradually deformed from an original cylindrical form to a shape of an ellipsis with the long axis pallarel to the direction of the minimum horizontal principal stress after a concrete form was removed.

Hydrocarbon Source Rocks in the Deep River and Dan River Triassic Basins, North Carolina

USGS Publications Warehouse

Reid, Jeffrey C.; Milici, Robert C.

2008-01-01

This report presents an interpretation of the hydrocarbon source rock potential of the Triassic sedimentary rocks of the Deep River and Dan River basins, North Carolina, based on previously unpublished organic geochemistry data. The organic geochemical data, 87 samples from 28 drill holes, are from the Sanford sub-basin (Cumnock Formation) of the Deep River basin, and from the Dan River basin (Cow Branch Formation). The available organic geochemical data are biased, however, because many of the samples collected for analyses by industry were from drill holes that contained intrusive diabase dikes, sills, and sheets of early Mesozoic age. These intrusive rocks heated and metamorphosed the surrounding sediments and organic matter in the black shale and coal bed source rocks and, thus, masked the source rock potential that they would have had in an unaltered state. In places, heat from the intrusives generated over-mature vitrinite reflectance (%Ro) profiles and metamorphosed the coals to semi-anthracite, anthracite, and coke. The maximum burial depth of these coal beds is unknown, and depth of burial may also have contributed to elevated thermal maturation profiles. The organic geochemistry data show that potential source rocks exist in the Sanford sub-basin and Dan River basin and that the sediments are gas prone rather than oil prone, although both types of hydrocarbons were generated. Total organic carbon (TOC) data for 56 of the samples are greater than the conservative 1.4% TOC threshold necessary for hydrocarbon expulsion. Both the Cow Branch Formation (Dan River basin) and the Cumnock Formation (Deep River basin, Sanford sub-basin) contain potential source rocks for oil, but they are more likely to have yielded natural gas. The organic material in these formations was derived primarily from terrestrial Type III woody (coaly) material and secondarily from lacustrine Type I (algal) material. Both the thermal alteration index (TAI) and vitrinite reflectance data (%Ro) indicate levels of thermal maturity suitable for generation of hydrocarbons. The genetic potential of the source rocks in these Triassic basins is moderate to high and many source rock sections have at least some potential for hydrocarbon generation. Some data for the Cumnock Formation indicate a considerably higher source rock potential than the basin average, with S1 + S2 data in the mid-20 mg HC/g sample range, and some hydrocarbons have been generated. This implies that the genetic potential for all of these strata may have been higher prior to the igneous activity. However, the intergranular porosity and permeability of the Triassic strata are low, which makes fractured reservoirs more attractive as drilling targets. In some places, gravity and magnetic surveys that are used to locate buried intrusive rock may identify local thermal sources that have facilitated gas generation. Alternatively, awareness of the distribution of large intrusive igneous bodies at depth may direct exploration into other areas, where thermal maturation is less than the limits of hydrocarbon destruction. Areas prospective for natural gas also contain large surficial clay resources and any gas discovered could be used as fuel for local industries that produce clay products (principally brick), as well as fuel for other local industries.

Pillar size optimization design of isolated island panel gob-side entry driving in deep inclined coal seam—case study of Pingmei No. 6 coal seam

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Wang, Xufeng; Fan, Gangwei; Zhang, Dongsheng; Jianbin, Cui

2018-06-01

There is a perception that deep roadways are difficult to maintain. To reverse this and to improve the recovery rate of coal resources, gob-side entry driving is widely used in coal mines, especially deep-mining coal mines, in China. Determination of the reasonable pillar size through in situ observation and experimentation plays a vital role for roadway maintenance. Based on the geological conditions of Pingmei No.6 coal seam, a theoretical analysis, numerical simulation, and industrial experiments are carried out to calculate the reasonable width of chain pillars, analyze the lateral support stress distribution law near the gob side, investigate the relationship between the coal pillar stress distribution, roadway surrounding rock stress distribution, roadway surrounding rock deformation and the coal pillar width. The results indicate that 5 m wide coal pillars can ensure that the chain pillars are at a lower stress level and the deformation of roadway surrounding rock is in a more reasonable range. Industrial experiments show that when the chain pillar width is 5 m, the deformation of roadway surrounding rock can meet the requirements of working face safe production. The numerical results agreed well with field measurement and observations, and the industrial experiments results further validated the results of the numerical simulation.

Characterizing and quantifying superparamagnetic magnetite particles in serpentinized mantle peridotite observed in continental ophiolite complexes.

NASA Astrophysics Data System (ADS)

Ortiz, E.; Vento, N. F. R.; Tominaga, M.; Beinlich, A.; Einsle, J. F.; Buisman, I.; Ringe, E.; Schrenk, M. O.; Cardace, D.

2017-12-01

Serpentinization of mantle peridotite has been recognized as one of the most important energy factories for the deep biosphere. To better evaluate the habitability of the deep biosphere, it is crucial to understand the link between in situ peridotite serpentinization processes and associated magnetite and hydrogen production. Previous efforts in correlating magnetite and hydrogen production during serpentinization processes are based primarily on laboratory experiments and numerical modeling, being challenged to include the contribution of superparamagnetic-sized magnetites (i.e., extremely fine-grained magnetite, petrographically observed as a "pepper flake" like texture in many natural serpentinized rock samples). To better estimate the abundance of superparamagnetic grains, we conducted frequency-dependent susceptibility magnetic measurements at the Institute of Rock Magnetism on naturally serpentinized rock samples from the Coast Range Ophiolite Microbial Observatory (CROMO) in California, USA and the Atlin Ophiolite (British Columbia). In addition, we conducted multiscale EDS phase mapping, BackScattered Electron (BSE) scanning, FIB-nanotomography and STEM-EELS to identify and quantify the superparamagnetic minerals that contribute to the measured magnetic susceptibility signals in our rock samples. Utilizing a multidisciplinary approach, we aim to improve the estimation of hydrogen production based on the abundance of magnetite, that includes the contribution of superparamagnetic particle size magnetite, to ultimately provide a more accurate estimation of bulk deep-biomass hosted by in situ serpentinization processes.

Mapping porosity of the deep critical zone in 3D using near-surface geophysics, rock physics modeling, and drilling

NASA Astrophysics Data System (ADS)

Flinchum, B. A.; Holbrook, W. S.; Grana, D.; Parsekian, A.; Carr, B.; Jiao, J.

2017-12-01

Porosity is generated by chemical, physical and biological processes that work to transform bedrock into soil. The resulting porosity structure can provide specifics about these processes and can improve understanding groundwater storage in the deep critical zone. Near-surface geophysical methods, when combined with rock physics and drilling, can be a tool used to map porosity over large spatial scales. In this study, we estimate porosity in three-dimensions (3D) across a 58 Ha granite catchment. Observations focus on seismic refraction, downhole nuclear magnetic resonance logs, downhole sonic logs, and samples of core acquired by push coring. We use a novel petrophysical approach integrating two rock physics models, a porous medium for the saprolite and a differential effective medium for the fractured rock, that drive a Bayesian inversion to calculate porosity from seismic velocities. The inverted geophysical porosities are within about 0.05 m3/m3 of lab measured values. We extrapolate the porosity estimates below seismic refraction lines to a 3D volume using ordinary kriging to map the distribution of porosity in 3D up to depths of 80 m. This study provides a unique map of porosity on scale never-before-seen in critical zone science. Estimating porosity on these large spatial scales opens the door for improving and understanding the processes that shape the deep critical zone.

Geology of the Sierra de Fiambala, northwestern Argentina: implications for Early Palaeozoic Andean tectonics

USGS Publications Warehouse

Grissom, G.C.; DeBari, S.M.; Snee, L.W.

1998-01-01

This paper is included in the Special Publication entitled 'The proto- Andean margin of Gondwana', edited by R.J. Pankhurst and C.W. Rapela. Field mapping in conjunction with structural, metamorphic, and geochronological data document the tectono-thermal history of exhumed deep crustal rocks in the Sierra de Fiambala, NW Argentina. The range consists of two structural blocks distinguished by different metasedimentary sequences and different grades of metamorphism. Orthogneiss and paragneiss in the northern structural block may have a Precambrian history. Greenschist- to amphibolite-facies metamorphism, intrusion, and injection magmatization affected all rocks at 540-550 Ma. A subsequent event in the Late Cambrian to Ordovician (c.515 to 470 Ma) involved amphibolite- to granulite-facies metamorphism, mafic intrusion, and deformation, followed by cooling through mid-Palaeozoic time. The emplacement of Carboniferous (325-350 Ma) post-tectonic granites caused reheating and retrogression that was strongest toward the northeast part of the range. The Cambrian, Ordovician, and Carboniferous events in the Sierra de Fiambala were of regional extent as indicated by temporal correlations with events reported for other deep crustal rocks of the northern Sierras Pampeanas. Correlations between periods of intrusion and high-grade metamorphism in the northern Sierras Pampeanas and volcanic-sedimentary events in the adjacent supracrustal exposures confirm that rocks in the northern Sierras Pampeanas formed at deep (10-25 km) structural levels in the early Palaeozoic continental margin of Gondwana.

Effect of Soft Tissue Releases on Joint Space Opening in Total Knee Arthroplasty.

PubMed

Burkhart, Timothy A; Perry, Kevin I; Dobbin, Emily; Howard, James; Lanting, Brent

2016-12-01

The purpose of this study was to determine the gap achieved to the medial and lateral compartments following sectioning and release of the relevant soft tissues in preparation for a total knee arthroplasty. A custom-designed knee tensioner allowed the application of forces to the medial and lateral compartments of 12 cadaveric knee specimens. Loads of 100 N and 200 N were applied to each compartment, and the resulting displacement was measured in the following conditions: (1) All soft tissues intact, (2) an arthrotomy, (3) anterior cruciate ligament (ACL) sectioned, (4) posterior cruciate ligament (PCL) sectioned, and (5) release of the anterior aspect of the deep medial collateral ligament (MCL) fibers. Tensions were applied for all conditions from 90° to 0° of knee flexion in 30° increments. No differences were found in medial or lateral displacement after the arthrotomy or releasing the ACL or PCL at either 100 N or 200 N. At the 100 N load application, there was a significant increase in gap width when the anterior portion of the deep MCL was released (7.49 mm) compared to the intact (5.28 mm) and arthrotomy (5.75 mm) conditions. With respect to the 200 N load application, there were statistically significant differences detected between the deep MCL fiber release (11.09 mm) and intact conditions (8.05 mm) and release of the deep MCL and arthrotomy conditions (8.77 mm). The medial parapetellar arthrotomy, ACL and PCL sectioning did not result in medial or lateral displacement changes. The release of the anterior fibers of the deep MCL as part of the surgical exposure increased the medial gap magnitude. Copyright © 2016 Elsevier Inc. All rights reserved.

Fluids of the Lower Crust: Deep Is Different

NASA Astrophysics Data System (ADS)

Manning, Craig E.

2018-05-01

Deep fluids are important for the evolution and properties of the lower continental and arc crust in tectonically active settings. They comprise four components: H2O, nonpolar gases, salts, and rock-derived solutes. Contrasting behavior of H2O-gas and H2O-salt mixtures yields immiscibility and potential separation of phases with different chemical properties. Equilibrium thermodynamic modeling of fluid-rock interaction using simple ionic species known from shallow-crustal systems yields solutions too dilute to be consistent with experiments and resistivity surveys, especially if CO2 is added. Therefore, additional species must be present, and H2O-salt solutions likely explain much of the evidence for fluid action in high-pressure settings. At low salinity, H2O-rich fluids are powerful solvents for aluminosilicate rock components that are dissolved as polymerized clusters. Addition of salts changes solubility patterns, but aluminosilicate contents may remain high. Fluids with Xsalt = 0.05 to 0.4 in equilibrium with model crustal rocks have bulk conductivities of 10‑1.5 to 100 S/m at porosity of 0.001. Such fluids are consistent with observed conductivity anomalies and are capable of the mass transfer seen in metamorphic rocks exhumed from the lower crust.

Apollo 15 Mg- and Fe-norites - A redefinition of the Mg-suite differentiation trend

NASA Technical Reports Server (NTRS)

Lindstrom, M. M.; Marvin, U. B.; Mittlefehldt, D. W.

1989-01-01

The Apollo 15 highland rocks from the Apennine Front include clasts of mafic plutonic rocks from deep in the lunar crust that were brought to the surface by the Imbrium and Serenitatis impacts. The Apollo 15 norites exhibit wide variations in mineral and bulk compositions and include Fe-norites that plot between the three major pristine rock fields on a diagram of Mg' in mafic minerals vs An in paglioclase. Based on assemblages and compositions of minerals, and on ratios of elemental abundances, it is concluded that these Apollo 15 Fe-norites are differentiated members of the Mg-norite suite. The Apollo 15 and 17 norites and troctolites form a closely related suite of rocks, whose variations in mineral compositions represent the main differentiation trend of the Mg-suite. This trend in mineral compositions has a steeper slope than the previous Mg-suite field. The parent magmas for these Mg-suite rocks formed by partial melting deep in the lunar mantle. Differentiation by fractional crystallization may also have included assimilation of crustal components as the magmas rose from the mantle and crystallized plutons in the lower crust.

Production of superheated steam from vapor-dominated geothermal reservoirs

USGS Publications Warehouse

Truesdell, A.H.; White, D.E.

1973-01-01

Vapor-dominated geothermal systems such as Larderello, Italy, The Geysers, California, and Matsukawa, Japan yield dry or superheated steam when exploited. Models for these systems are examined along with production data and the thermodynamic properties of water, steam and rock. It is concluded that these systems initially consist of a water and steam filled reservoir, a water-saturated cap rock, and a water or brine-saturated deep reservoir below a water table. Most liquid water in all parts of the system is relatively immobilized in small pores and crevices; steam dominates the large fractures and voids of the reservoir and is the continuous, pressure-controlling phase. With production, the pressure is lowered and the liquid water boils, causing massive transfer of heat from the rock and its eventual drying. Passage of steam through already dried rock produces superheating. After an initial vaporization of liquid water in the reservoir, the decrease in pressure produces increased boiling below the deep water table. With heavy exploitation, boiling extends deeper into hotter rock and the temperature of the steam increases. This model explains most features of the published production behavior of these systems and can be used to guide exploitation policies. ?? 1973.

Spirit's First Grinding of a Rock on Mars

NASA Technical Reports Server (NTRS)

2004-01-01

The round, shallow depression in this image resulted from history's first grinding of a rock on Mars. The rock abrasion tool on NASA's Spirit rover ground off the surface of a patch 45.5 millimeters (1.8 inches) in diameter on a rock called Adirondack. The hole is 2.65 millimeters (0.1 inch) deep, exposing fresh interior material of the rock for close inspection with the rover's microscopic imager and two spectrometers on the robotic arm. This image was taken by Spirit's panoramic camera, providing a quick visual check of the success of the grinding. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.

Colorado Potential Geothermal Pathways

DOE Data Explorer

Richard E. Zehner

2012-02-01

This layer contains the weakened basement rocks. Isostatic gravity was utilized to identify structural basin areas, characterized by gravity low values reflecting weakened basement rocks. Together interpreted regional fault zones and basin outlines define geothermal "exploration fairways", where the potential exists for deep, superheated fluid flow in the absence of Pliocene or younger volcanic units.

Lunar Heat Flux Measurements Enabled by a Microwave Radiometer Aboard the Deep Space Gateway

NASA Astrophysics Data System (ADS)

Siegler, M.; Ruf, C.; Putzig, N.; Morgan, G.; Hayne, P.; Paige, D.; Nagihara, S.; Weber, R.

2018-02-01

We would like to present a concept to use the Deep Space Gateway as a platform for constraining the geothermal heat production, surface, and near-surface rocks, and dielectric properties of the Moon from orbit with passive microwave radiometery.

Soft drink, software and softening of teeth - a case report of tooth wear in the mixed dentition due to a combination of dental erosion and attrition.

PubMed

Gambon, D L; Brand, H S; Nieuw Amerongen, A V

2010-10-21

This case report describes a 9-year-old boy with severe tooth wear as a result of drinking a single glass of soft drink per day. This soft drink was consumed over a period of one to two hours, while he was gaming intensively on his computer. As a result, a deep bite, enamel cupping, sensitivity of primary teeth and loss of fillings occurred. Therefore, dentists should be aware that in patients who are gaming intensively, the erosive potential of soft drinks can be potentiated by mechanical forces leading to excessive tooth wear.

Prefabricated Vertical Drain (PVD) and Deep Cement Mixing (DCM)/Stiffened DCM (SDCM) techniques for soft ground improvement

NASA Astrophysics Data System (ADS)

Bergado, D. T.; Long, P. V.; Chaiyaput, S.; Balasubramaniam, A. S.

2018-04-01

Soft ground improvement techniques have become most practical and popular methods to increase soil strength, soil stiffness and reduce soil compressibility including the soft Bangkok clay. This paper focuses on comparative performances of prefabricated vertical drain (PVD) using surcharge, vacuum and heat preloading as well as the cement-admixed clay of Deep Cement Mixing (DCM) and Stiffened DCM (SDCM) methods. The Vacuum-PVD can increase the horizontal coefficient of consolidation, Ch, resulting in faster rate of settlement at the same magnitudes of settlement compared to Conventional PVD. Several field methods of applying vacuum preloading are also compared. Moreover, the Thermal PVD and Thermal Vacuum PVD can increase further the coefficient of horizontal consolidation, Ch, with the associated reduction of kh/ks values by reducing the drainage retardation effects in the smear zone around the PVD which resulted in faster rates of consolidation and higher magnitudes of settlements. Furthermore, the equivalent smear effect due to non-uniform consolidation is also discussed in addition to the smear due to the mechanical installation of PVDs. In addition, a new kind of reinforced deep mixing method, namely Stiffened Deep Cement Mixing (SDCM) pile is introduced to improve the flexural resistance, improve the field quality control, and prevent unexpected failures of the Deep Cement Mixing (DCM) pile. The SDCM pile consists of DCM pile reinforced with the insertion of precast reinforced concrete (RC) core. The full scale test embankment on soft clay improved by SDCM and DCM piles was also analysed. Numerical simulations using the 3D PLAXIS Foundation finite element software have been done to understand the behavior of SDCM and DCM piles. The simulation results indicated that the surface settlements decreased with increasing lengths of the RC cores, and, at lesser extent, increasing sectional areas of the RC cores in the SDCM piles. In addition, the lateral movements decreased by increasing the lengths (longer than 4 m) and, the sectional areas of the RC cores in the SDCM piles. The results of the numerical simulations closely agreed with the observed data and successfully verified the parameters affecting the performances and behavior of both SDCM and DCM piles.

Site Characterization for a Deep Borehole Field Test

NASA Astrophysics Data System (ADS)

Kuhlman, K. L.; Hardin, E. L.; Freeze, G. A.; Sassani, D.; Brady, P. V.

2015-12-01

The US Department of Energy Office of Nuclear Energy is at the beginning of 5-year Deep Borehole Field Test (DBFT) to investigate the feasibility of constructing and characterizing two boreholes in crystalline basement rock to a depth of 5 km (16,400 ft). The concept of deep borehole disposal for radioactive waste has some advantages over mined repositories, including incremental construction and loading, the enhanced natural barriers provided by deep continental crystalline basement, and reduced site characterization. Site characterization efforts need to determine an eligible site that does not have the following disqualifying characteristics: greater than 2 km to crystalline basement, upward vertical fluid potential gradients, presence of economically exploitable natural resources, presence of high permeability connection to the shallow subsurface, and significant probability of future seismic or volcanic activity. Site characterization activities for the DBFT will include geomechanical (i.e., rock in situ stress state, and fluid pressure), geological (i.e., rock and fracture infill lithology), hydrological (i.e., quantity of fluid, fluid convection properties, and solute transport mechanisms), and geochemical (i.e., rock-water interaction and natural tracers) aspects. Both direct (i.e., sampling and in situ testing) and indirect (i.e., borehole geophysical) methods are planned for efficient and effective characterization of these site aspects and physical processes. Borehole-based characterization will be used to determine the variability of system state (i.e., stress, pressure, temperature, and chemistry) with depth, and interpretation of material and system parameters relevant to numerical site simulation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thurman E. Scott, Jr., Ph.D.; Younane Abousleiman, Ph.D.; Musharraf Zaman, Ph.D., P.E.

2002-11-18

During the sixth quarter of this research project the research team developed a method and the experimental procedures for acquiring the data needed for ultrasonic tomography of rock core samples under triaxial stress conditions as outlined in Task 10. Traditional triaxial compression experiments, where compressional and shear wave velocities are measured, provide little or no information about the internal spatial distribution of mechanical damage within the sample. The velocities measured between platen-to-platen or sensor-to-sensor reflects an averaging of all the velocities occurring along that particular raypath across the boundaries of the rock. The research team is attempting to develop andmore » refine a laboratory equivalent of seismic tomography for use on rock samples deformed under triaxial stress conditions. Seismic tomography, utilized for example in crosswell tomography, allows an imaging of the velocities within a discrete zone within the rock. Ultrasonic or acoustic tomography is essentially the extension of that field technology applied to rock samples deforming in the laboratory at high pressures. This report outlines the technical steps and procedures for developing this technology for use on weak, soft chalk samples. Laboratory tests indicate that the chalk samples exhibit major changes in compressional and shear wave velocities during compaction. Since chalk is the rock type responsible for the severe subsidence and compaction in the North Sea it was selected for the first efforts at tomographic imaging of soft rocks. Field evidence from the North Sea suggests that compaction, which has resulted in over 30 feet of subsidence to date, is heterogeneously distributed within the reservoir. The research team will attempt to image this very process in chalk samples. The initial tomographic studies (Scott et al., 1994a,b; 1998) were accomplished on well cemented, competent rocks such as Berea sandstone. The extension of the technology to weaker samples is more difficult but potentially much more rewarding. The chalk, since it is a weak material, also attenuates wave propagation more than other rock types. Three different types of sensors were considered (and tested) for the tomographic imaging project: 600 KHz PZT, 1 MHz PZT, and PVDF film sensors. 600 KHz PZT crystals were selected because they generated a sufficiently high amplitude pulse to propagate across the damaged chalk. A number of different configurations were considered for placement of the acoustic arrays. It was decided after preliminary testing that the most optimum arrangement of the acoustic sensors was to place three arrays of sensors, with each array containing twenty sensors, around the sample. There would be two horizontal arrays to tomographically image two circular cross-sectional planes through the rock core sample. A third array would be vertically oriented to provide a vertical cross-sectional view of the sample. A total of 260 acoustic raypaths would be shot and acquired in the horizontal acoustic array to create each horizontal tomographic image. The sensors can be used as both acoustic sources or as acoustic each of the 10 pulsers to the 10 receivers.« less

Immediate versus delayed intramedullary nailing for open fractures of the tibial shaft: a multivariate analysis of factors affecting deep infection and fracture healing.

PubMed

Yokoyama, Kazuhiko; Itoman, Moritoshi; Uchino, Masataka; Fukushima, Kensuke; Nitta, Hiroshi; Kojima, Yoshiaki

2008-10-01

The purpose of this study was to evaluate contributing factors affecting deep infection and fracture healing of open tibia fractures treated with locked intramedullary nailing (IMN) by multivariate analysis. We examined 99 open tibial fractures (98 patients) treated with immediate or delayed locked IMN in static fashion from 1991 to 2002. Multivariate analyses following univariate analyses were derived to determine predictors of deep infection, nonunion, and healing time to union. The following predictive variables of deep infection were selected for analysis: age, sex, Gustilo type, fracture grade by AO type, fracture location, timing or method of IMN, reamed or unreamed nailing, debridement time (< or =6 h or >6 h), method of soft-tissue management, skin closure time (< or =1 week or >1 week), existence of polytrauma (ISS< 18 or ISS> or =18), existence of floating knee injury, and existence of superficial/pin site infection. The predictive variables of nonunion selected for analysis was the same as those for deep infection, with the addition of deep infection for exchange of pin site infection. The predictive variables of union time selected for analysis was the same as those for nonunion, excluding of location, debridement time, and existence of floating knee and superficial infection. Six (6.1%; type II Gustilo n=1, type IIIB Gustilo n=5) of the 99 open tibial fractures developed deep infections. Multivariate analysis revealed that timing or method of IMN, debridement time, method of soft-tissue management, and existence of superficial or pin site infection significantly correlated with the occurrence of deep infection (P< 0.0001). In the immediate nailing group alone, the deep infection rate in type IIIB + IIIC was significantly higher than those in type I + II and IIIA (P = 0.016). Nonunion occurred in 17 fractures (20.3%, 17/84). Multivariate analysis revealed that Gustilo type, skin closure time, and existence of deep infection significantly correlated with occurrence of nonunion (P < 0.05). Gustilo type and existence of deep infection were significantly correlated with healing time to union on multivariate analysis (r(2) = 0.263, P = 0.0001). Multivariate analyses for open tibial fractures treated with IMN showed that IMN after EF (especially in existence of pin site infection) was at high risk of deep infection, and that debridement within 6 h and appropriate soft-tissue managements were also important factor in preventing deep infections. These analyses postulated that both the Gustilo type and the existence of deep infection is related with fracture healing in open fractures treated with IMN. In addition, immediate IMN for type IIIB and IIIC is potentially risky, and canal reaming did not increase the risk of complication for open tibial fractures treated with IMN.

Biodetection grinder

NASA Technical Reports Server (NTRS)

Beyerle, F. J.

1973-01-01

A biodetection grinder for sampling aerospace materials for microorganisms without killing them was constructed. The device employs a shearing action to generate controllable sized particles with a minimum of energy input. Tests were conducted on materials ranging from soft plastics to hard rocks.

Soap-stone in architecture of North European cities. A nomination as a candidate for a Global Heritage Stones Resource

NASA Astrophysics Data System (ADS)

Bulakh, Andrey

2016-04-01

Soap stone represents soft Proterozoic rock type from the deposit Nunnalahti situated on the western shore of the big Lake Pielinen in Eastern Finland. It consists of talc (40 - 50 %), magnesite MgCO3 (40 - 50 %), chlorite (5 - 8 %), dolomite, calcite, etc. The colour of the stone is very spectacular and varies from yellow and brownish-yellow to grey, greenish grey. The soft stone is a highly workable material for a sculptor's chisel. It was one of the most popular ornamental rocks used architecture of the Modern style in St Petersburg, Helsinki, Turku, Tampere and other North European cities lately in the XIX-th centuries. Examples are given and discussed. References: Bulakh, A.G., Abakumova, N.B., and Romanovsky, J.V. St Petersburg: a History in Stone. 2010. Print House of St Petersburg State University. 173 p. (In English).

Rockfall Modelling with Remedial Design and Measures along Part of a Mountainous Settlement Area, Southern Turkey

NASA Astrophysics Data System (ADS)

Güntel, Berna; Acar, Altay

2016-10-01

In June 2011, a heavy rainfall triggered a number of rockfalls from steep slopes and on slopes made of soft to loose soils capped by inhomogeneous hard rock blocks and masses in the Düziçi Town of Osmaniye Province in Turkey. Large rock blocks had damaged 15 prefabricated hotel rooms whereas the slope movement blocked the major road between Duzigi and hot spring facilities at numerous locations along 280 m. This paper describes remedial measures and design recommended according to the modelling process based on the collection of data and simulation of rockfall with Rocscience RockFall 5.0 software.

Biodiversity of the Deep-Sea Benthic Fauna in the Sangihe-Talaud Region, Indonesia: Observations from the INDEX-SATAL 2010 Expedition

NASA Astrophysics Data System (ADS)

Herrera, S.; Munro, C.; Nganro, N.; Tunnicliffe, V.; Wirasantosa, S.; Sibert, E.; Hammond, S. R.; Bors, E.; Butterfield, D.; Holden, J. F.; Baker, E. T.; Sherrin, J.; Makarim, S.; Troa, R.; Shank, T. M.

2010-12-01

The benthic ecosystems found in the deep-sea promontories of Sangihe Talaud region were explored, between June and August 2010, using the ROV Little Hercules aboard the NOAA ship Okeanos Explorer. The Sangihe-Talaud region is part of the Coral Triangle (CT) an area known for harboring the most biodiverse shallow-water coral reefs in the world. Notwithstanding the significant research efforts that have been undertaken to catalog and protect the biodiversity of the CT prior this expedition, virtually nothing was known about the life inhabiting the deep sea. The high-resolution imagery obtained from the 27 ROV dives revealed remarkably high abundances and diversity of animal species, many of which appear to be novel. On hard bottom substrates, cold-water corals were the dominant sessile macrofauna, in terms of biomass, followed by glass sponges (Hexactinellida) and sea lilies (Crinoidea). The coral taxa observed in this area represent six large orders of cnidarians: antipatharians (black corals), scleractinians (stony corals), zoanthideans (gold corals), alcyonaceans (octocorals), pennatulaceans (sea pens), and anthoathecates (hydrocorals). Most sessile species, independently of their size class or taxonomic affiliation, harbor a wide variety of associated fauna. Brittle stars (Ophiuroidea), squat lobsters (Galatheoidea), shrimp (Caridea), amphipods (Amphipoda), anemones (Actinaria), zanthideans, barnacles (Cirripedia), hydroids (Hydrozoa) and worms (Polychaeta) are the animal groups most commonly found forming these associations. In contrast, soft bottom habitats were dominated by stalked sponges, sea pens, sea cucumbers (Holothuroidea) and brittle stars. Other conspicuous fauna include fish, hermit crabs (Paguridae), urchins (Echinoidea) and octopuses (Cephalopoda). The abundance of habitats generated by the high number of geological and biological features and depth ranges present in the deep coral triangle (e.g., ridges, seamounts, island margins, plains, and rock types), and the complex history of tectonic dynamics of this region are among the likely causes for the high biodiversity found during this mission. Tectonic history and diverse habitats may also be factors that have played a similar role shaping the diversity of shallow water assemblages of the region. Such parallels between the biodiversity of deep and shallow waters will be presented.

Predicting the sinkage of a moving tracked mining vehicle using a new rheological formulation for soft deep-sea sediment

NASA Astrophysics Data System (ADS)

Xu, Feng; Rao, Qiuhua; Ma, Wenbo

2018-03-01

The sinkage of a moving tracked mining vehicle is greatly affected by the combined compression-shear rheological properties of soft deep-sea sediments. For test purposes, the best sediment simulant is prepared based on soft deep-sea sediment from a C-C poly-metallic nodule mining area in the Pacific Ocean. Compressive creep tests and shear creep tests are combined to obtain compressive and shear rheological parameters to establish a combined compressive-shear rheological constitutive model and a compression-sinkage rheological constitutive model. The combined compression-shear rheological sinkage of the tracked mining vehicle at different speeds is calculated using the RecurDyn software with a selfprogrammed subroutine to implement the combined compression-shear rheological constitutive model. The model results are compared with shear rheological sinkage and ordinary sinkage (without consideration of rheological properties). These results show that the combined compression-shear rheological constitutive model must be taken into account when calculating the sinkage of a tracked mining vehicle. The combined compression-shear rheological sinkage decrease with vehicle speed and is the largest among the three types of sinkage. The developed subroutine in the RecurDyn software can be used to study the performance and structural optimization of moving tracked mining vehicles.

Bedrock knobs, San Francisco Bay: Do navigation hazards outweigh other environment problems?

USGS Publications Warehouse

Carlson, P.R.; Chin, J.L.; Wong, F.L.

2000-01-01

Three bedrock knobs (Arch, Harding, and Shag rocks) rise above the unconsolidated sediment of central San Francisco Bay to a water depth of less than -12 m (<-39.4 ft MLLW). These rocks are within the westbound vessel traffic area, and the northernmost, Harding Rock, is ~300 m (984 ft) from the two-way deep water traffic lane. The rocks pose a hazard to deep-draft vessels. Large ships with drafts deeper than -17 m (-55.8 ft) cross central San Francisco Bay bound for and returning from major port cities of the Bay estuary. Acoustic profiling data show that bedrock extends at a gentle to moderate slope away from the knobs. These data also show that two of the knobs, Harding and Shag, may be part of a bedrock ridge that extends to Alcatraz Island and perhaps southeast to Blossom Rock. The tops of these rocks should be lowered to a depth of -17 m (-55.8 ft), with a total volume of as much as 245,000 m3 (320,460 yd3), at an estimated cost of nearly 27 million dollars, to eliminate the possibility that a tanker would strike one and rupture. A resulting large oil spill would likely cost many times more than the 10 million dollars needed to clean up a small 1996 spill. If the rocks were removed, local habitat for striped bass and other game fish would be altered, with potential negative impact on sport fishing. Currently, public officials are studying the benefits to the Bay environment of lowering the rock knobs.

A Case Study on the Strata Movement Mechanism and Surface Deformation Regulation in Chengchao Underground Iron Mine

NASA Astrophysics Data System (ADS)

Cheng, Guanwen; Chen, Congxin; Ma, Tianhui; Liu, Hongyuan; Tang, Chunan

2017-04-01

The regular pattern of surface deformation and the mechanism of underground strata movement, especially in iron mines constructed with the block caving method, have a great influence on infrastructure on the surface, so they are an important topic for research. Based on the engineering geology conditions and the surface deformation and fracture features in Chengchao Iron Mine, the mechanism of strata movement and the regular pattern of surface deformation in the footwall were studied by the geomechanical method, and the following conclusions can be drawn: I. The surface deformation process is divided into two stages over time, i.e., the chimney caving development stage and the post-chimney deformation stage. Currently, the surface deformation in Chengchao Iron Mine is at the post-chimney deformation stage. II. At the post-chimney deformation stage, the surface deformation and geological hazards in Chengchao Iron Mine are primarily controlled by the NWW-trending joints, with the phenomenon of toppling deformation and failure on the surface. Based on the surface deformation characteristics in Chengchao Iron Mine, the surface deformation area can be divided into the following four zones: the fracture extension zone, the fracture closure zone, the fracture formation zone and the deformation accumulation zone. The zones on the surface can be determined by the surface deformation characteristics. III. The cantilever beams near the chimney caving area, caused by the NWW-trending joints, have been subjected to toppling failure. This causes the different deformation and failure mechanisms in different locations of the deep rock mass. The deep rock can be divided into four zones, i.e., the fracture zone, fracture transition zone, deformation zone and undisturbed zone, according to the different deformation and failure mechanisms. The zones in the deep rock are the reason for the zones on the surface, so they can be determined by the zones on the surface. Through these findings, the degree of damage to the infrastructure in different locations can be determined based on the surface deformation zones. As the mining continues deeper, the development regulation of the zones on the surface and in deep rock mass can be further studied based on the zones in the deep rock.

Improving our understanding of the evolution of mountain belts via the Collisional Orogeny in the Scandinavian Caledonides (COSC) project: Results from seismic investigations and plans for the 2.5 km deep COSC-2 borehole

NASA Astrophysics Data System (ADS)

Juhlin, C.; Almqvist, B. S. G.; Buske, S.; Giese, R.; Hedin, P.; Lorenz, H.

2017-12-01

Mountain belts (orogens) have influenced, and do influence, geological processes and climatic conditions considerably, perhaps more than any other natural phenomenon. The Alpine-Himalayan mountain belt is the prime example of a collisional orogen today. However, research in an active orogen is mostly constrained to observe and interpret the expression of processes at the surface, while the driving processes act at depth, often at mid-crustal levels (20 km) and deeper. About 440 million years ago, an orogen comparable in dimension and tectonic setting to today's Alpine-Himalayan orogen was developing in what is western Scandinavia today. Since then, erosion has removed much of the overburden and exposed the deep interior of the orogen, facilitating direct observation of rocks that are deep in the crust in modern orogens. In the COSC project we study how large rock volumes (allochthons) were transported during the collision of two continents and the associated deformation. The emplacement of high-grade metamorphic allochthons during orogeny has been the focus of COSC-1 research, centered on a 2.5 km deep fully cored borehole drilled in the summer of 2014 through the lower part of the high-grade Seve Nappe Complex near the town of Åre in western Sweden. The planned COSC-2 borehole (also fully cored to 2.5 km) will complement the COSC-1 borehole and allow a 5 km deep tectonostratigraphic column of the Caledonides to be constructed. The rock volume in the proximity of the COSC-2 borehole will be imaged with a combination of very-high and high-resolution geophysical experiments, such as a combination of high frequency seismics; zero offset and walk-away vertical seismic profiling (VSP); and a sparse 3D coverage around the drill site combined with 2D seismic profiles of several kilometers length in different directions. Downhole geophysical logging will provide additional information on the in-situ rock physical properties. Data from surface surveys will be calibrated against and integrated with the borehole data and the geological interpretation of the drill core. The COSC-1 and COSC-2 boreholes will provide a field laboratory for investigating mountain building processes, how plates and rock units deform, what structures and units are formed and their physical properties.

Seismic measurements of the internal properties of fault zones

USGS Publications Warehouse

Mooney, W.D.; Ginzburg, A.

1986-01-01

The internal properties within and adjacent to fault zones are reviewed, principally on the basis of laboratory, borehole, and seismic refraction and reflection data. The deformation of rocks by faulting ranges from intragrain microcracking to severe alteration. Saturated microcracked and mildly fractured rocks do not exhibit a significant reduction in velocity, but, from borehole measurements, densely fractured rocks do show significantly reduced velocities, the amount of reduction generally proportional to the fracture density. Highly fractured rock and thick fault gouge along the creeping portion of the San Andreas fault are evidenced by a pronounced seismic low-velocity zone (LVZ), which is either very thin or absent along locked portions of the fault. Thus there is a correlation between fault slip behavior and seismic velocity structure within the fault zone; high pore pressure within the pronounced LVZ may be conductive to fault creep. Deep seismic reflection data indicate that crustal faults sometimes extend through the entire crust. Models of these data and geologic evidence are consistent with a composition of deep faults consisting of highly foliated, seismically anisotropic mylonites. ?? 1986 Birkha??user Verlag, Basel.

Safety-relevant hydrogeological properties of the claystone barrier of a Swiss radioactive waste repository: An evaluation using multiple lines of evidence

NASA Astrophysics Data System (ADS)

Gautschi, Andreas

2017-09-01

In Switzerland, the Opalinus Clay - a Jurassic (Aalenian) claystone formation - has been proposed as the first-priority host rock for a deep geological repository for both low- and intermediate-level and high-level radioactive wastes. An extensive site and host rock investigation programme has been carried out during the past 30 years in Northern Switzerland, comprising extensive 2D and 3D seismic surveys, a series of deep boreholes within and around potential geological siting regions, experiments in the international Mont Terri Rock Laboratory, compilations of data from Opalinus Clay in railway and motorway tunnels and comparisons with similar rocks. The hydrogeological properties of the Opalinus Clay that are relevant from the viewpoint of long-term safety are described and illustrated. The main conclusions are supported by multiple lines of evidence, demonstrating consistency of conclusions based on hydraulic properties, porewater chemistry, distribution of natural tracers across the Opalinus Clay as well as small- and large-scale diffusion models and the derived conceptual understanding of solute transport.

The Valley and Ridge Province of eastern Pennsylvania - stratigraphic and sedimentologic contributions and problems ( USA).

USGS Publications Warehouse

Epstein, J.B.

1986-01-01

The rocks in the area, which range from Middle Ordovician to Late Devonian in age, are more than 7620 m thick. This diversified group of sedimentary rocks was deposited in many different environments, ranging from deep sea, through neritic and tidal, to alluvial. In general, the Middle Ordovician through Lower Devonian strata are a sedimentary cycle related to the waxing and waning of Taconic tectonism. The sequence began with a greywacke-argillite suite (Martinsburg Formation) representing synorogenic basin deepening. This was followed by basin filling and progradation of a sandstone-shale clastic wedge (Shawangunk Formation and Bloomsburg Red Beds) derived from the erosion of the mountains that were uplifted during the Taconic orogeny. The sequence ended with deposition of many thin units of carbonate, sandstone, and shale on a shelf marginal to a land area of low relief. Another tectonic-sedimentary cycle, related to the Acadian orogeny, began with deposition of Middle Devonian rocks. Deep-water shales (Marcellus Shale) preceded shoaling (Mahantango Formation) and turbidite sedimentation (Trimmers Rock Formation) followed by another molasse (Catskill Formation). -from Author

Numerical Simulations of Thermo-Mechanical Processes during Thermal Spallation Drilling for Geothermal Reservoirs

NASA Astrophysics Data System (ADS)

Vogler, D.; Walsh, S. D. C.; Rudolf von Rohr, P.; Saar, M. O.

2017-12-01

Drilling expenses constitute a significant share of the upfront capital costs and thereby the associated risks of geothermal energy production. This is especially true for deep boreholes, as drilling costs per meter increase significantly with depth. Thermal spallation drilling is a relatively new drilling technique, particularly suited to the hard crystalline (e.g., basement) rocks in which many deep geothermal resources are located. The method uses a hot jet-flame to rapidly heat the rock surface, which leads to large temperature gradients in the rock. These temperature gradients cause localized thermal stresses that, in combination with the in situ stress field, lead to the formation and ejection of spalls. These spalls are then transported out of the borehole with the drilling mud. Thermal spallation not only in principle enables much faster rates of penetration than traditional rotary drilling, but is also contact-less, which significantly reduces the long tripping times associated with conventional rotary head drilling. We present numerical simulations investigating the influence of rock heterogeneities on the thermal spallation process. Special emphasis is put on different mineral compositions, stress regimes, and heat sources.

Highly Manufacturable Deep (Sub-Millimeter) Etching Enabled High Aspect Ratio Complex Geometry Lego-Like Silicon Electronics.

PubMed

Ghoneim, Mohamed Tarek; Hussain, Muhammad Mustafa

2017-04-01

A highly manufacturable deep reactive ion etching based process involving a hybrid soft/hard mask process technology shows high aspect ratio complex geometry Lego-like silicon electronics formation enabling free-form (physically flexible, stretchable, and reconfigurable) electronic systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clastic rocks associated with the Midcontinent rift system in Iowa

USGS Publications Warehouse

Anderson, Raymond R.; McKay, Robert M.

1997-01-01

The Middle Proterozoic Midcontinent Rift System (MRS) of North America is a failed rift that formed in response to region-wide stresses about 1,100 Ma. In Iowa, the MRS is buried beneath 2,200?3,500 ft of Paleozoic and Mesozoic sedimentary rocks and Quaternary glaciogenic deposits. An extremely large volume of sediments was deposited within basins associated with the rift at several stages during its development. Although the uplift of a rift-axial horst resulted in the erosional removal of most of these clastic rocks from the central region of the MRS in Iowa, thick sequences are preserved in a series of horst-bounding basins. Recent studies incorporating petrographic analysis, geophysical modeling, and other analytical procedures have led to the establishment of a preliminary stratigraphy for these clastic rocks and interpretations of basin geometries. This information has allowed the refinement of existing theories and history of MRS formation in Iowa. Additionally, drill samples previously interpreted as indicating the existence of early Paleozoic basins overlying the Proterozoic MRS basins were re-examined. Samples previously interpreted as deep-lying Paleozoic rocks are now known to have caved from upper levels of the drillhole and were out of stratigraphic position. No deep Paleozoic basins exist in this area. These investigations led to the development of petrographic parameters useful in differentiating the Proterozoic MRS Red clastics from Paleozoic clastic rocks having similar lithologies.

First Grinding of a Rock on Mars

NASA Technical Reports Server (NTRS)

2004-01-01

The round, shallow depression in this image resulted from history's first grinding of a rock on Mars. The rock abrasion tool on NASA's Spirit rover ground off the surface of a patch 45.5 millimeters (1.8 inches) in diameter on a rock called Adirondack during Spirit's 34th sol on Mars, Feb. 6, 2004. The hole is 2.65 millimeters (0.1 inch) deep, exposing fresh interior material of the rock for close inspection with the rover's microscopic imager and two spectrometers on the robotic arm. This image was taken by Spirit's panoramic camera, providing a quick visual check of the success of the grinding. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.

Petrographic and geochemical comparisons between the lower crystalline basement-derived section and the granite megablock and amphibolite megablock of the Eyreville B core, Chesapeake Bay impact structure, USA

USGS Publications Warehouse

Townsend, G.N.; Gibson, R.L.; Horton, J. Wright; Reimold, W.U.; Schmitt, R.T.; Bartosova, K.

2009-01-01

The Eyreville B core from the Chesapeake Bay impact structure, Virginia, USA, contains a lower basement-derived section (1551.19 m to 1766.32 m deep) and two megablocks of dominantly (1) amphibolite (1376.38 m to 1389.35 m deep) and (2) granite (1095.74 m to 1371.11 m deep), which are separated by an impactite succession. Metasedimentary rocks (muscovite-quartz-plagioclase-biotite-graphite ?? fibrolite ?? garnet ?? tourmaline ?? pyrite ?? rutile ?? pyrrhotite mica schist, hornblende-plagioclase-epidote-biotite- K-feldspar-quartz-titanite-calcite amphibolite, and vesuvianite-plagioclase- quartz-epidote calc-silicate rock) are dominant in the upper part of the lower basement-derived section, and they are intruded by pegmatitic to coarse-grained granite (K-feldspar-plagioclase-quartz-muscovite ?? biotite ?? garnet) that increases in volume proportion downward. The granite megablock contains both gneissic and weakly or nonfoliated biotite granite varieties (K-feldspar-quartz-plagioclase-biotite ?? muscovite ?? pyrite), with small schist xenoliths consisting of biotite-plagioclase-quartz ?? epidote ?? amphibole. The lower basement-derived section and both megablocks exhibit similar middleto upper-amphibolite-facies metamorphic grades that suggest they might represent parts of a single terrane. However, the mica schists in the lower basement-derived sequence and in the megablock xenoliths show differences in both mineralogy and whole-rock chemistry that suggest a more mafi c source for the xenoliths. Similarly, the mineralogy of the amphibolite in the lower basement-derived section and its association with calc-silicate rock suggest a sedimentary protolith, whereas the bulk-rock and mineral chemistry of the megablock amphibolite indicate an igneous protolith. The lower basement-derived granite also shows bulk chemical and mineralogical differences from the megablock gneissic and biotite granites. ?? 2009 The Geological Society of America.

Equality of hemisphere soft functions for e + e - , DIS and pp collisions at O ( α s 2 )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Daekyoung; Labun, Ou Z.; Lee, Christopher

We present a simple observation about soft amplitudes and soft functions appearing in factorizable cross sections in ee, ep, and pp collisions that has not clearly been made in previous literature, namely, that the hemisphere soft functions that appear in event shape distributions in e +e - → dijets, deep inelastic scattering (DIS), and in Drell–Yan (DY) processes are equal in perturbation theory up to O(α s 2), even though individual amplitudes may have opposite sign imaginary parts due to changing complex pole prescriptions in eikonal propagators for incoming vs. outgoing lines. We also explore potential generalizations of this observationmore » to soft functions for other observables or with more jets in the final state.« less

Research on Equivalent Tests of Dynamics of On-orbit Soft Contact Technology Based on On-Orbit Experiment Data

NASA Astrophysics Data System (ADS)

Yang, F.; Dong, Z. H.; Ye, X.

2018-05-01

Currently, space robots have been become a very important means of space on-orbit maintenance and support. Many countries are taking deep research and experiment on this. Because space operation attitude is very complicated, it is difficult to model them in research lab. This paper builds up a complete equivalent experiment framework according to the requirement of proposed space soft-contact technology. Also, this paper carries out flexible multi-body dynamics parameters verification for on-orbit soft-contact mechanism, which combines on-orbit experiment data, the built soft-contact mechanism equivalent model and flexible multi-body dynamics equivalent model that is based on KANE equation. The experiment results approve the correctness of the built on-orbit soft-contact flexible multi-body dynamics.

Anaerobic consortia of fungi and sulfate reducing bacteria in deep granite fractures.

PubMed

Drake, Henrik; Ivarsson, Magnus; Bengtson, Stefan; Heim, Christine; Siljeström, Sandra; Whitehouse, Martin J; Broman, Curt; Belivanova, Veneta; Åström, Mats E

2017-07-04

The deep biosphere is one of the least understood ecosystems on Earth. Although most microbiological studies in this system have focused on prokaryotes and neglected microeukaryotes, recent discoveries have revealed existence of fossil and active fungi in marine sediments and sub-seafloor basalts, with proposed importance for the subsurface energy cycle. However, studies of fungi in deep continental crystalline rocks are surprisingly few. Consequently, the characteristics and processes of fungi and fungus-prokaryote interactions in this vast environment remain enigmatic. Here we report the first findings of partly organically preserved and partly mineralized fungi at great depth in fractured crystalline rock (-740 m). Based on environmental parameters and mineralogy the fungi are interpreted as anaerobic. Synchrotron-based techniques and stable isotope microanalysis confirm a coupling between the fungi and sulfate reducing bacteria. The cryptoendolithic fungi have significantly weathered neighboring zeolite crystals and thus have implications for storage of toxic wastes using zeolite barriers.Deep subsurface microorganisms play an important role in nutrient cycling, yet little is known about deep continental fungal communities. Here, the authors show organically preserved and partly mineralized fungi at 740 m depth, and find evidence of an anaerobic fungi and sulfate reducing bacteria consortium.

Swiss Atlas of PHYsical properties of Rocks (SAPHYR)

NASA Astrophysics Data System (ADS)

Zappone, Alba; Kissling, Eduard

2015-04-01

The Swiss Atlas of PHYsical properties of Rocks (SAPHYR), is a multi-year project, funded entirely by Swiss Commission for Geophysics (SGPK), with the aim to compile a comprehensive data set in digital form on physical properties of rocks exposed in Switzerland and surrounding regions. The ultimate goal of SAPHYR is to make these data accessible to an open and wide public including industrial, engineering, land and resource planning companies, as well as academic institutions, or simply people interested in geology. Since the early sixties worldwide many scientists, i.e. geophysicists, petrologists, and engineers, focused their work on laboratory measurements of rocks physical properties, and their relations with microstructures, mineralogical compositions and other rock parameters, in the effort to constrain the geological interpretation of geophysical surveys. Particularly in the years in which seismic reflection and refraction crustal scale projects were investigating the deep structures of the Alps, laboratories capable to reproduce the pressure and temperature ranges of the continental crust were collecting measurements of various rock parameters on a wide variety of lithologies, developing in the meantime more and more sophisticated experimental methodologies. In recent years, the increasing interest of European Countries on non-traditional energy supply, (i.e. Deep Geothermal Energy and shale gas) and CO2 storage renovated the interests in physical characterization of the deep underground. SAPHYR aims to organize all those laboratory data into a geographically referenced database (GIS). The data refer to density, porosity, permeability, and seismic, magnetic, thermal and electric properties. In the past years, effort has been placed on collecting samples and measuring the physical properties of lithologies that were poorly documented in literature. The phase of laboratory measurements is still in progress. Recently, SAPHYR project focused towards developing a 3-D physical properties model of the Swiss subsurface, using the structure of the exposed geology and data from boreholes and seismic surveys, combined with empirically determined pressure and temperature derivatives. The product is now almost ready for publication and an early version is presented here.

The seismo-hydromechanical behavior during deep geothermal reservoir stimulations: open questions tackled in a decameter-scale in situ stimulation experiment

NASA Astrophysics Data System (ADS)

Amann, Florian; Gischig, Valentin; Evans, Keith; Doetsch, Joseph; Jalali, Reza; Valley, Benoît; Krietsch, Hannes; Dutler, Nathan; Villiger, Linus; Brixel, Bernard; Klepikova, Maria; Kittilä, Anniina; Madonna, Claudio; Wiemer, Stefan; Saar, Martin O.; Loew, Simon; Driesner, Thomas; Maurer, Hansruedi; Giardini, Domenico

2018-02-01

In this contribution, we present a review of scientific research results that address seismo-hydromechanically coupled processes relevant for the development of a sustainable heat exchanger in low-permeability crystalline rock and introduce the design of the In situ Stimulation and Circulation (ISC) experiment at the Grimsel Test Site dedicated to studying such processes under controlled conditions. The review shows that research on reservoir stimulation for deep geothermal energy exploitation has been largely based on laboratory observations, large-scale projects and numerical models. Observations of full-scale reservoir stimulations have yielded important results. However, the limited access to the reservoir and limitations in the control on the experimental conditions during deep reservoir stimulations is insufficient to resolve the details of the hydromechanical processes that would enhance process understanding in a way that aids future stimulation design. Small-scale laboratory experiments provide fundamental insights into various processes relevant for enhanced geothermal energy, but suffer from (1) difficulties and uncertainties in upscaling the results to the field scale and (2) relatively homogeneous material and stress conditions that lead to an oversimplistic fracture flow and/or hydraulic fracture propagation behavior that is not representative of a heterogeneous reservoir. Thus, there is a need for intermediate-scale hydraulic stimulation experiments with high experimental control that bridge the various scales and for which access to the target rock mass with a comprehensive monitoring system is possible. The ISC experiment is designed to address open research questions in a naturally fractured and faulted crystalline rock mass at the Grimsel Test Site (Switzerland). Two hydraulic injection phases were executed to enhance the permeability of the rock mass. During the injection phases the rock mass deformation across fractures and within intact rock, the pore pressure distribution and propagation, and the microseismic response were monitored at a high spatial and temporal resolution.

Soft Drink, Software and Softening of Teeth – a Case Report of Tooth Wear in the Mixed Dentition Due to a Combination of Dental Erosion and Attrition

PubMed Central

Gambon, D. L; Brand, H. S; Nieuw Amerongen, A.V

2010-01-01

This case report describes a 9-year-old boy with severe tooth wear as a result of drinking a single glass of soft drink per day. This soft drink was consumed over a period of one to two hours, while he was gaming intensively on his computer. As a result, a deep bite, enamel cupping, sensitivity of primary teeth and loss of fillings occurred. Therefore, dentists should be aware that in patients who are gaming intensively, the erosive potential of soft drinks can be potentiated by mechanical forces leading to excessive tooth wear. PMID:21243073

Exploiting broadband seismograms and the mechanism of deep-focus earthquakes

NASA Astrophysics Data System (ADS)

Jiao, Wenjie

1997-09-01

Modern broadband seismic instrumentation has provided enormous opportunities to retrieve the information in almost any frequency band of seismic interest. In this thesis, we have investigated the long period responses of the broadband seismometers and the problem of recovering actual groundmotion. For the first time, we recovered the static offset for an earthquake from dynamic seismograms. The very long period waves of near- and intermediate-field term from 1994 large Bolivian deep earthquake (depth = 630km, Msb{W}=8.2) and 1997 large Argentina deep earthquake (depth = 285km, Msb{W}=7.1) are successfully recovered from the portable broadband recordings by BANJO and APVC networks. These waves provide another dynamic window into the seismic source process and may provide unique information to help constrain the source dynamics of deep earthquakes in the future. We have developed a new method to locate global explosion events based on broadband waveform stacking and simulated annealing. This method utilizes the information provided by the full broadband waveforms. Instead of "picking times", the character of the wavelet is used for locating events. The application of this methodology to a Lop Nor nuclear explosion is very successful, and suggests a procedure for automatic monitoring. We have discussed the problem of deep earthquakes from the viewpoint of rock mechanics and seismology. The rupture propagation of deep earthquakes requires a slip-weakening process unlike that for shallow events. However, this process is not necessarily the same as the process which triggers the rupture. Partial melting due to stress release is developed to account for the slip-weakening process in the deep earthquake rupture. The energy required for partial melting in this model is on the same order of the maximum energy required for the slip-weakening process in the shallow earthquake rupture. However, the verification of this model requires experimental work on the thermodynamic properties of rocks under non-hydrostatic stress. The solution of the deep earthquake problem will require an interdisciplinary study of seismology, high pressure rock mechanics, and mineralogy.

Occurrence Prospect of HDR and Target Site Selection Study in Southeastern of China

NASA Astrophysics Data System (ADS)

Lin, W.; Gan, H.

2017-12-01

Hot dry rock (HDR) geothermal resource is one of the most important clean energy in future. Site selection a HDR resource is a fundamental work to explore the HDR resources. This paper compiled all the HDR development projects domestic and abroad, and summarized the location of HDR geothermal geological index. After comparing the geological background of HDR in the southeast coastal area of China, Yangjiang Xinzhou in Guangdong province, Leizhou Peninsula area, Lingshui in Hainan province and Huangshadong in Guangzhou were selected from some key potential target area along the southeast coast of China. Deep geothermal field model of the study area is established based on the comprehensive analysis of the target area of deep geothermal geological background and deep thermal anomalies. This paper also compared the hot dry rock resources target locations, and proposed suggestions for the priority exploration target area and exploration scheme.

Threshold factorization redux

NASA Astrophysics Data System (ADS)

Chay, Junegone; Kim, Chul

2018-05-01

We reanalyze the factorization theorems for the Drell-Yan process and for deep inelastic scattering near threshold, as constructed in the framework of the soft-collinear effective theory (SCET), from a new, consistent perspective. In order to formulate the factorization near threshold in SCET, we should include an additional degree of freedom with small energy, collinear to the beam direction. The corresponding collinear-soft mode is included to describe the parton distribution function (PDF) near threshold. The soft function is modified by subtracting the contribution of the collinear-soft modes in order to avoid double counting on the overlap region. As a result, the proper soft function becomes infrared finite, and all the factorized parts are free of rapidity divergence. Furthermore, the separation of the relevant scales in each factorized part becomes manifest. We apply the same idea to the dihadron production in e+e- annihilation near threshold, and show that the resultant soft function is also free of infrared and rapidity divergences.

The post-collisional late Variscan ferroan granites of southern Sardinia (Italy): Inferences for inhomogeneity of lower crust

NASA Astrophysics Data System (ADS)

Conte, Aida Maria; Cuccuru, Stefano; D'Antonio, Massimo; Naitza, Stefano; Oggiano, Giacomo; Secchi, Francesco; Casini, Leonardo; Cifelli, Francesca

2017-12-01

The post-collisional late Variscan magmatism of Sardinia-Corsica batholith attained a peak at about 290 Ma. In southern Sardinia, in the frontal part of the Variscan orogenic wedge, this magmatism is represented by three suites of granitoids, here defined as GS1, GS2 and GS3. GS1, GS2 and GS3 are slightly peraluminous and F-bearing granitoids; GS1 and GS3 granites show in addition a ferroan character, whereas GS2 rocks range from magnesian to ferroan, from granodiorites to leucogranites. From magnetic susceptibility data, GS1 and GS2 belong to the ilmenite series, whereas GS3 is a slightly oxidized rock-suite plotting on the ilmenite/magnetite series boundary. Each rock-suite shows distinctive characters, in terms of petrography, petrochemistry, rock associations, as well as metallogenic signature of the related fluids. The distinction among rock-suite types is made on the basis of both mafic and characteristic accessory minerals. Siderophyllitic dark mica as the only mafic phase, and accessory xenotime (Y) characterize the GS1 rocks; GS2 mineral associations include biotite ± hornblende + allanite + magnetite; GS3 rocks show an association of hastingsite + annite + allanite + magnetite. Chemical variations in the studied samples suggest different magmatic evolution of independent magmas. Pb, Sr and Nd isotopic data constrain the origin of magmas to lower crustal sources. Chemical composition of rocks and dark micas meet those of liquids experimentally obtained by low degrees of partial melting of different meta-igneous deep crustal sources, felsic for GS1 rock-types and more mafic for GS3 rock-types. GS1 intrusions show granophile-type (Sn-W-Mo) metallogenic signatures, very low magnetic susceptibility, and Nd model ages (referred to the Depleted Mantle - TDM) of 2.3 Ga, coherent with a possible derivation from an old (early Proterozoic-Neoarchean), reduced and weathered basement, tectonically buried under Variscan covers. A definite deep crustal inhomogeneity is mirrored by GS3 granites, whose compositional and isotopic features indicate a younger (Nd model age: 1.6 Ga) tonalitic amphibolite source. Overall, the peculiarities of the studied granitoids suggest further compositional differences in the deep crust between southern and northern portion of the Sardinia-Corsica Variscan transect. Late Variscan lithospheric delamination appears as the most reliable mechanism that may have determined the high thermal regime that triggered partial melting of the crust. The close field association, at 290 Ma, of tholeiitic dike swarms and ferroan granitoids, supports this inference.

Erosion-tectonics feedbacks in shaping the landscape: An example from the Mekele Outlier (Tigray, Ethiopia)

NASA Astrophysics Data System (ADS)

Sembroni, Andrea; Molin, Paola; Dramis, Francesco; Faccenna, Claudio; Abebe, Bekele

2017-05-01

An outlier consists of an area of younger rocks surrounded by older ones. Its formation is mainly related to the erosion of surrounding rocks which causes the interruption of the original continuity of the rocks. Because of its origin, an outlier is an important witness of the paleogeography of a region and, therefore, essential to understand its topographic and geological evolution. The Mekele Outlier (N Ethiopia) is characterized by poorly incised Mesozoic marine sediments and dolerites (∼2000 m in elevation), surrounded by strongly eroded Precambrian and Paleozoic rocks and Tertiary volcanic deposits in a context of a mantle supported topography. In the past, studies about the Mekele outlier focused mainly in the mere description of the stratigraphic and tectonic settings without taking into account the feedback between surface and deep processes in shaping such peculiar feature. In this study we present the geological and geomorphometric analyses of the Mekele Outlier taking into account the general topographic features (slope map, swath profiles, local relief), the river network and the principal tectonic lineaments of the outlier. The results trace the evolution of the study area as related not only to the mere erosion of the surrounding rocks but to a complex interaction between surface and deep processes where the lithology played a crucial role.

Geoengineering Research for a Deep Underground Science and Engineering Laboratory in Sedimentary Rock

NASA Astrophysics Data System (ADS)

Mauldon, M.

2004-12-01

A process to identify world-class research for a Deep Underground Science and Engineering Laboratory (DUSEL) in the USA has been initiated by NSF. While allowing physicists to study, inter alia, dark matter and dark energy, this laboratory will create unprecedented opportunities for biologists to study deep life, geoscientists to study crustal processes and geoengineers to study the behavior of rock, fluids and underground cavities at depth, on time scales of decades. A substantial portion of the nation's future infrastructure is likely to be sited underground because of energy costs, urban crowding and vulnerability of critical surface facilities. Economic and safe development of subsurface space will require an improved ability to engineer the geologic environment. Because of the prevalence of sedimentary rock in the upper continental crust, much of this subterranean infrastructure will be hosted in sedimentary rock. Sedimentary rocks are fundamentally anisotropic due to lithology and bedding, and to discontinuities ranging from microcracks to faults. Fractures, faults and bedding planes create structural defects and hydraulic pathways over a wide range of scales. Through experimentation, observation and monitoring in a sedimentary rock DUSEL, in conjunction with high performance computational models and visualization tools, we will explore the mechanical and hydraulic characteristics of layered rock. DUSEL will permit long-term experiments on 100 m blocks of rock in situ, accessed via peripheral tunnels. Rock volumes will be loaded to failure and monitored for post-peak behavior. The response of large rock bodies to stress relief-driven, time-dependent strain will be monitored over decades. Large block experiments will be aimed at measurement of fluid flow and particle/colloid transport, in situ mining (incl. mining with microbes), remediation technologies, fracture enhancement for resource extraction and large scale long-term rock mass response to induced stresses - with parallel geophysical imaging of the rock mass (and subsequent verification) flow and transport processes, and time-dependent stress and strain. An experimental advantage of sedimentary rock is the presence of pervasive mechanical interfaces (bedding planes), which suggest a host of experimental designs on large rock blocks and slabs (induced flexure, shear strength of interfaces, etc). Thus DUSEL will enable fundamental research about the behavior of a layered rock mass - the dominant structural architecture in near-surface environments worldwide. A further benefit is the natural suitability of sedimentary rocks for experiments related to oil and gas production, or to CO2 sequestration. For example, fluid-induced fracturing of sedimentary rock has long been used by the hydrocarbon industry to improve oil and coal bed methane recovery. Since some fracturing agents are potential contaminants, a major concern and legal responsibility in the US is ensuring the integrity of nearby aquifers. Hydraulic fracturing from a sedimentary rock DUSEL will be followed by injection of low viscosity grout. The rock mass will then be mined back to expose network characteristics of the induced hydraulic fractures. Key questions related to hydrocarbon extraction, CO2 sequestration, waste isolation, and remediation of subsurface contaminants depend critically on the connectivity and architecture of fractures and on coupled thermal, hydrological, mechanical and chemical processes. Fluid flow, particle transport and reaction transport processes are coupled to the stress across fractures, and to thermal, chemical and hydraulic gradients. All can best be studied via large block tests in a subterranean laboratory, ideally in a sedimentary environment.

SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alan Black; Arnis Judzis

2004-10-01

The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high (greater than 10,000 rpm) rotational speeds. The work includes a feasibility of concept research effort aimed at development and test results that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with rigs having a smaller footprint to be more mobile. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration rockmore » cutting with substantially lower inputs of energy and loads. The project draws on TerraTek results submitted to NASA's ''Drilling on Mars'' program. The objective of that program was to demonstrate miniaturization of a robust and mobile drilling system that expends small amounts of energy. TerraTek successfully tested ultrahigh speed ({approx}40,000 rpm) small kerf diamond coring. Adaptation to the oilfield will require innovative bit designs for full hole drilling or continuous coring and the eventual development of downhole ultra-high speed drives. For domestic operations involving hard rock and deep oil and gas plays, improvements in penetration rates is an opportunity to reduce well costs and make viable certain field developments. An estimate of North American hard rock drilling costs is in excess of $1,200 MM. Thus potential savings of $200 MM to $600 MM are possible if drilling rates are doubled [assuming bit life is reasonable]. The net result for operators is improved profit margin as well as an improved position on reserves. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm--usually well below 5,000 rpm. This document details the progress to date on the program entitled ''SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING'' for the period starting June 23, 2003 through September 30, 2004. TerraTek has reviewed applicable literature and documentation and has convened a project kick-off meeting with Industry Advisors in attendance. TerraTek has designed and planned Phase I bench scale experiments. Some difficulties in obtaining ultra-high speed motors for this feasibility work were encountered though they were sourced mid 2004. TerraTek is progressing through Task 3 ''Small-scale cutting performance tests''. Some improvements over early NASA experiments have been identified.« less

SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alan Black; Arnis Judzis

2004-10-01

The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high (greater than 10,000 rpm) rotational speeds. The work includes a feasibility of concept research effort aimed at development and test results that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with rigs having a smaller footprint to be more mobile. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration rockmore » cutting with substantially lower inputs of energy and loads. The project draws on TerraTek results submitted to NASA's ''Drilling on Mars'' program. The objective of that program was to demonstrate miniaturization of a robust and mobile drilling system that expends small amounts of energy. TerraTek successfully tested ultrahigh speed ({approx}40,000 rpm) small kerf diamond coring. Adaptation to the oilfield will require innovative bit designs for full hole drilling or continuous coring and the eventual development of downhole ultra-high speed drives. For domestic operations involving hard rock and deep oil and gas plays, improvements in penetration rates is an opportunity to reduce well costs and make viable certain field developments. An estimate of North American hard rock drilling costs is in excess of $1,200 MM. Thus potential savings of $200 MM to $600 MM are possible if drilling rates are doubled [assuming bit life is reasonable]. The net result for operators is improved profit margin as well as an improved position on reserves. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm--usually well below 5,000 rpm. This document details the progress to date on the program entitled ''SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING'' for the period starting June 23, 2003 through September 30, 2004. (1) TerraTek has reviewed applicable literature and documentation and has convened a project kick-off meeting with Industry Advisors in attendance. (2) TerraTek has designed and planned Phase I bench scale experiments. Some difficulties in obtaining ultra-high speed motors for this feasibility work were encountered though they were sourced mid 2004. (3) TerraTek is progressing through Task 3 ''Small-scale cutting performance tests''. Some improvements over early NASA experiments have been identified.« less

The Ajo Mining District, Pima County, Arizona--Evidence for Middle Cenozoic Detachment Faulting, Plutonism, Volcanism, and Hydrothermal Alteration

USGS Publications Warehouse

Cox, Dennis P.; Force, Eric R.; Wilkinson, William H.; More, Syver W.; Rivera, John S.; Wooden, Joseph L.

2006-01-01

Introduction: The Ajo porphyry copper deposit and surrounding Upper Cretaceous rocks have been separated from their plutonic source and rotated by detachment faulting. Overlying middle Cenozoic sedimentary and volcanic rocks have been tilted and show evidence for two periods of rotation. Following these rotations, a granitic stock (23.7?0.2 Ma) intruded basement rocks west of the Ajo deposit. This stock was uplifted 2.5 km to expose deep-seated Na-Ca alteration.

Methane clumped isotopes in the Songliao Basin (China): New insights into abiotic vs. biotic hydrocarbon formation

NASA Astrophysics Data System (ADS)

Shuai, Yanhua; Etiope, Giuseppe; Zhang, Shuichang; Douglas, Peter M. J.; Huang, Ling; Eiler, John M.

2018-01-01

Abiotic hydrocarbon gas, typically generated in serpentinized ultramafic rocks and crystalline shields, has important implications for the deep biosphere, petroleum systems, the carbon cycle and astrobiology. Distinguishing abiotic gas (produced by chemical reactions like Sabatier synthesis) from biotic gas (produced from degradation of organic matter or microbial activity) is sometimes challenging because their isotopic and molecular composition may overlap. Abiotic gas has been recognized in numerous locations on the Earth, although there are no confirmed instances where it is the dominant source of commercially valuable quantities in reservoir rocks. The deep hydrocarbon reservoirs of the Xujiaweizi Depression in the Songliao Basin (China) have been considered to host significant amounts of abiotic methane. Here we report methane clumped-isotope values (Δ18) and the isotopic composition of C1-C3 alkanes, CO2 and helium of five gas samples collected from those Xujiaweizi deep reservoirs. Some geochemical features of these samples resemble previously suggested identifiers of abiotic gas (13C-enriched CH4; decrease in 13C/12C ratio with increasing carbon number for the C1-C4 alkanes; abundant, apparently non-biogenic CO2; and mantle-derived helium). However, combining these constraints with new measurements of the clumped-isotope composition of methane and careful consideration of the geological context, suggests that the Xujiaweizi depression gas is dominantly, if not exclusively, thermogenic and derived from over-mature source rocks, i.e., from catagenesis of buried organic matter at high temperatures. Methane formation temperatures suggested by clumped-isotopes (167-213 °C) are lower than magmatic gas generation processes and consistent with the maturity of local source rocks. Also, there are no geological conditions (e.g., serpentinized ultramafic rocks) that may lead to high production of H2 and thus abiotic production of CH4 via CO2 reduction. We propose that the Songliao gas is representative of an atypical type of thermogenic gas that can be mistaken for abiotic gas. Such gases may be encountered more frequently in future exploration of deep or over-mature petroleum systems.

Sedimentary modeling and analysis of petroleum system of the upper Tertiary sequences in southern Ulleung sedimentary Basin, East Sea (Sea of Japan)

NASA Astrophysics Data System (ADS)

Cheong, D.; Kim, D.; Kim, Y.

2010-12-01

The block 6-1 located in the southwestern margin of the Ulleung basin, East Sea (Sea of Japan) is an area where recently produces commercial natural gas and condensate. A total of 17 exploratory wells have been drilled, and also many seismic explorations have been carried out since early 1970s. Among the wells and seismic sections, the Gorae 1 well and a seismic section through the Gorae 1-2 well were chosen for this simulation work. Then, a 2-D graphic simulation using SEDPAK elucidates the evolution, burial history and diagenesis of the sedimentary sequence. The study area is a suitable place for modeling a petroleum system and evaluating hydrocarbon potential of reservoir. Shale as a source rock is about 3500m deep from sea floor, and sandstones interbedded with thin mud layers are distributed as potential reservoir rocks from 3,500m to 2,000m deep. On top of that, shales cover as seal rocks and overburden rocks upto 900m deep. Input data(sea level, sediment supply, subsidence rate, etc) for the simulation was taken from several previous published papers including the well and seismic data, and the thermal maturity of the sediment was calculated from known thermal gradient data. In this study area, gas and condensate have been found and commercially produced, and the result of the simulation also shows that there is a gas window between 4000m and 6000m deep, so that three possible interpretations can be inferred from the simulation result. First, oil has already moved and gone to the southeastern area along uplifting zones. Or second, oil has never been generated because organic matter is kerogen type 3, and or finally, generated oil has been converted into gas by thermally overcooking. SEDPAK has an advantage that it provides the timing and depth information of generated oil and gas with TTI values even though it has a limit which itself can not perform geochemical modeling to analyze thermal maturity level of source rocks. Based on the result of our simulation, added exploratory wells are required to discover deeper gas located in the study area.

Botanical survey of Rock Creek Research Natural Area, Kentucky

Treesearch

Ralph L. Thompson; Ronald L. Jones; J. Richard Abbott; W. Neal Denton

2000-01-01

A 10-year survey of vascular plants was made of Rock Creek Research Natural Area, a 77-ha deep, narrow gorge of old-growth Hemlock-Mixed Mesophytic Forest located in Laurel County, Kentucky, on the Daniel Boone National Forest. The study documented 350 specific and infraspecific taxa in 223 genera and 93 families. Thirteen are nonindigenous naturalized species....

A Brief Analysis of Sister Carrie's Character

ERIC Educational Resources Information Center

Yu, Hanying

2010-01-01

Carrie is always dreaming while the rocking chair is rocking again and again, this is the deep impression on us after we read "Sister Carrie" which is the first novel of Theodore Dreiser. In this novel the protagonist Sister Carrie is a controversial person. This paper tries to analyze the character of Sister Carrie in order to find out…

Investigating the effects of high temperature and a deep SMTZ on rock magnetic properties at Site C0023, IODP Expedition 370

NASA Astrophysics Data System (ADS)

Kars, M. A. C.; Henkel, S.

2017-12-01

In 2016, International Ocean Discovery Program (IODP) Expedition 370 drilled Site C0023 in the Nankai Trough, off Cape Muroto (Shikoku Island, Japan, NW Pacific Ocean). The aim of this expedition was to explore the limits of life in the deep subseafloor sediments in a high temperature environment (up to 120°C), and to investigate, among other objectives, the processes at the biotic-abiotic transition. A deep sulfate-methane transition zone (SMTZ) was identified between 630 and 750 meters below sea floor (mbsf). Based on the magnetic data profiles and results from previous ODP expeditions in the area, four magnetic zones were defined mostly reflecting changes in detrital supply and alteration/diagenetic features.Here, a rock magnetic study is conducted in order to document the downhole changes in magnetic properties and magnetic mineralogy (content, grain size and composition of the magnetic mineral assemblage) related to post-depositional diagenetic processes from 200 to 1100 mbsf, with a focus on the deep SMTZ. Natural remanent magnetization and its alternating-field demagnetization, magnetic susceptibility and acquisition of isothermal remanent magnetization are measured on 225 discrete samples for concentration and composition of the magnetic assemblage. Hysteresis properties and first order reversal curves are measured on respective dry powders for magnetic grain size study and composition of the magnetic assemblage. The preliminary rock magnetic results are presented and discussed based on the shipboard inorganic geochemical data.

First Observation of Rock Motion on Racetrack Playa, Death Valley National Park—Role of a Persistent Pool, Sun, Zephyrs, Windowpane Ice, and Tugboats

NASA Astrophysics Data System (ADS)

Norris, R. D.; Norris, J. M.

2014-12-01

Trails in the mud-cracked surface of Racetrack Playa have been scored by hundreds of rocks up to 320 kg, but the mechanism of movement is debated. In Winter 2013-2014, we observed rocks in motion associated with a transient pool formed by winter precipitation. The pond was 7 cm deep on the southern edge of the playa, tapering to a mud flat to the north. Freezing during cold winter nights formed floating "windowpane" ice 3-5 mm thick. Rocks repeatedly moved on sunny days under light winds of 3-5 m/second, as the ice broke up near midday and was set into motion by wind stress on melt pools and the ice surface. Ice panels shoved rocks along the mud like a tugboat, sometimes forming moving imbricated ice piles upstream of the rocks and in other cases moving faster than the rocks and forming brash-filled leads downstream. GPS units mounted in experimental rocks recorded a creeping pace of 2-6 m/minute, a speed that made it difficult to observe trail formation visually. The 2013-2014 pond formed on November 20-24 and persisted through early February 2014. During this time rocks were observed moving at least five times, and studies of "stiz marks" formed by rocks at the ends of trail segments show that there were likely 3-5 additional move events. Observed travel times ranged from a few seconds to 16 minutes. In one event, two experimental rocks 153 m apart began moving simultaneously and traveled 64.1 and 65.6 m respectively, ultimately moving 157-162 m in subsequent events. Rock motion depends on the creation of winter pools sufficiently deep to allow the formation of floating ice and exposed to the light winds and sun needed for ice breakup. The combination of these events is extremely rare, leading to highly episodic trail formation. Our observations differ from previous hypotheses in that the rocks were moved by thinner ice, at slower speeds, and by lighter winds than predicted.

Landslide Hazard Map of The Upper Tiber River Basin, Central Italy

NASA Astrophysics Data System (ADS)

Cardinali, M.; Carrara, A.; Guzzetti, F.; Reichenbach, P.

For the Upper Tiber River basin, which extends over 4000 km2 in Central Italy, a landslide hazard map was derived from a statistical model based on a mix of morpho- logical, lithological, structural and land use data. All these data were obtained from the analysis of different sets of aerial photographs, ranging in scale from 1:33,000 to 1:13,000, systematic field surveys and bibliographical information. Rock types were grouped in 37 units on the basis of the hard vs. soft rock percentage, as as- certained from photo-geological interpretation and field surveys. During the photo- interpretation, the spatial relations between bedding plane attitude and slope aspect were also systematically determined. The landslide inventory map recognised 17,600 slope-failures that cover nearly 12.5% of the basin area. Landslides, which are mainly slide flow slide earth-flow and compound or complex movements, were classified and mapped as shallow or deep seated. A DTM, with a grid resolution of 25x25 m, was derived from digitised contour lines of base topographic maps, 1:25,000.in scale. The basin was then automatically partitioned into nearly 16,000 main slope-units through a specifically-designed software module that, starting from a high quality DTM gen- erates fully connected and complementary drainage and divide networks and a wide spectrum of morphometric parameters. Main slope-units were then subdivided accord- ing to the major rock types cropping out in the basin generating over 28,700 hydro- morphological-lithological terrain-units. Using the presence/absence of landslide in each terrain unit, as the grouping variable, a stepwise discriminant function was ap- plied to the terrain units. of the 50 variables entered into the discriminant function, 15 are lithological, 15 morphological, 11 express the structural setting or bedding plane attitude, 7 refer to land use and the last 2 reflect local climatic conditions. The model proved to be capable of correctly classifying as stable or unstable over 75% of the terrain units.

Temperature profiles in the earth of importance to deep electrical conductivity models

NASA Astrophysics Data System (ADS)

Čermák, Vladimír; Laštovičková, Marcela

1987-03-01

Deep in the Earth, the electrical conductivity of geological material is extremely dependent on temperature. The knowledge of temperature is thus essential for any interpretation of magnetotelluric data in projecting lithospheric structural models. The measured values of the terrestrial heat flow, radiogenic heat production and thermal conductivity of rocks allow the extrapolation of surface observations to a greater depth and the calculation of the temperature field within the lithosphere. Various methods of deep temperature calculations are presented and discussed. Characteristic geotherms are proposed for major tectonic provinces of Europe and it is shown that the existing temperatures on the crust-upper mantle boundary may vary in a broad interval of 350 1,000°C. The present work is completed with a survey of the temperature dependence of electrical conductivity for selected crustal and upper mantle rocks within the interval 200 1,000°C. It is shown how the knowledge of the temperature field can be used in the evaluation of the deep electrical conductivity pattern by converting the conductivity-versustemperature data into the conductivity-versus-depth data.

A mechanism for high wall-rock velocities in rockbursts

USGS Publications Warehouse

McGarr, A.

1997-01-01

Considerable evidence has been reported for wall-rock velocities during rockbursts in deep gold mines that are substantially greater than ground velocities associated with the primary seismic events. Whereas varied evidence suggests that slip across a fault at the source of an event generates nearby particle velocities of, at most, several m/s, numerous observations, in nearby damaged tunnels, for instance, imply wall-rock velocities of the order of 10 m/s and greater. The common observation of slab buckling or breakouts in the sidewalls of damaged excavations suggests that slab flexure may be the mechanism for causing high rock ejection velocities. Following its formation, a sidewall slab buckles, causing the flexure to increase until the stress generated by flexure reaches the limit 5 that can be supported by the sidewall rock. I assume here that S is the uniaxial compressive strength. Once the flexural stress exceeds S, presumably due to the additional load imposed by a nearby seismic event, the slab fractures and unflexes violently. The peak wall-rock velocity v thereby generated is given by v=(3 + 1-??2/2)1 2 S/?????E for rock of density ??, Young's modulus E, and Poisson's ratio ??. Typical values of these rock properties for the deep gold mines of South Africa yield v= 26 m/s and for especially strong quartzites encountered in these same mines, v> 50m/s. Even though this slab buckling process leads to remarkably high ejection velocities and violent damage in excavations, the energy released during this failure is only a tiny fraction of that released in the primary seismic event, typically of magnitude 2 or greater.

Geological and geotechnical properties of the medieval rock hewn churches of Lalibela, Northern Ethiopia

NASA Astrophysics Data System (ADS)

Asrat, Asfawossen; Ayallew, Yodit

2011-01-01

Lalibela is a medieval settlement in Northern Ethiopia famous for its 11 beautifully carved rock hewn churches, registered as World Heritage Site in 1978. The rock hewn churches are grouped into three based on their proximity: the Bete Medhane Alem (Church of the Holy Saviour), Bete Gabriel-Rufael (Church of St. Gabriel-Rafael) and Bete Giorgis (Church of St. George) groups. The churches are carved out of a single, massive scoriaceous basalt hill which was deposited along an East-West extending palaeovalley in the Oligo-Miocene Trap basalt of the northwestern Ethiopian plateau. The Rock Mass Rating (RMR) classification scheme was used to classify the rock mass (assuming each church as a separate rock mass) based on their uniaxial compressive strength and the spacing and conditions of discontinuities. Though most of the churches are hewn from medium to high strength rock mass, discontinuities make them vulnerable to other deteriorating agents mainly weathering, and water infiltration. Most of the rock hewn churches are affected by pre-carving cooling joints and bedding plane discontinuities, and by mostly but not necessarily post-carving tectonic and seismic induced cracks and fractures. Material loss due to deep weathering triggered by rain water infiltration and uncontrolled groundwater seepage affects most of the churches, particularly the Bete Merqorios (Church of St. Mark) and Bete Aba Libanos (Church of Father Libanos) churches. The scoriaceous basalt which is porous and permeable allows easy passage of water while the underlying basalt is impermeable, increasing the residence time of water in the porous material, causing deep weathering and subsequent loss of material in some of the churches and adjoining courtyards.

Hydrology of some deep mines in Precambrian rocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yardley, D.H.

1975-10-01

A number of underground mines were investigated during the summer of 1975. All of them are in Precambrian rocks of the Lake Superior region. They represent a variety of geologic settings. The purpose of the investigations was to make a preliminary study of the dryness, or lack of dryness of these rocks at depth. In other words, to see if water was entering the deeper workings through the unmined rock by some means such as fracture or fault zones, joints or permeable zones. Water entering through old mine workings extending to, or very near to the surface, or from themore » drilling equipment, was of interest only insofar as it might mask any water whose source was through the hanging or footwall rocks. No evidence of running, seeping or moving water was seen or reported at depths exceeding 3,000 feet. At depths of 3,000 feet or less, water seepages do occur in some of the mines, usually in minor quantities but increased amounts occur as depth becomes less. Others are dry at 2,000 feet of depth. Rock movements associated with extensive mining should increase the local secondary permeability of the rocks adjoining the mined out zones. Also most ore bodies are located where there has been a more than average amount of faulting, fracturing, and folding during the geologic past. They tend to cluster along crustal flows. In general, Precambrian rocks of similar geology, to those seen, well away from zones that have been disturbed by extensive deep mining, and well away from the zones of more intense geologic activity ought to be even less permeable than their equivalents in a mining district.« less

Petrology and geochemistry of mafic magmatic rocks from the Sarve-Abad ophiolites (Kurdistan region, Iran): Evidence for interaction between MORB-type asthenosphere and OIB-type components in the southern Neo-Tethys Ocean

NASA Astrophysics Data System (ADS)

Saccani, Emilio; Allahyari, Khalil; Rahimzadeh, Bahman

2014-05-01

The Sarve-Abad (Sawlava) ophiolites crop out in the Main Zagros Thrust Zone and represent remnants of the Mesozoic southern Neo-Tethys Ocean that was located between the Arabian shield and Sanandaj-Sirjan continental block. They consist of several incomplete ophiolitic sequences including gabbroic bodies, a dyke complex, and pillow lava sequences. These rocks generally range from sub-alkaline to transitional character. Mineral chemistry and whole-rock geochemistry indicate that they have compositions akin to enriched-type mid-ocean ridge basalts (E-MORB) and plume-type MORB (P-MORB). Nonetheless, the different depletion degrees in heavy rare earth elements (HREE), which can be observed in both E-MORB like and P-MORB like rocks enable two main basic chemical types of rocks to be distinguished as Type-I and Type-II. Type-I rocks are strongly depleted in HREE (YbN < ~ 6), whereas Type-II rocks are moderately depleted in HREE (YbN > 9.0). Petrogenetic modeling shows that Type-I rocks originated from 7 to 16% polybaric partial melting of a MORB-type mantle source, which was significantly enriched by plume-type components. These rocks resulted from the mixing of variable fractions of melts generated in garnet-facies and the spinel-facies mantle. In contrast, Type-II rocks originated from 5 to 8% partial melting in the spinel-facies of a MORB-type source, which was moderately enriched by plume-type components. A possible tectono-magmatic model for the generation of the southern Neo-Tethys oceanic crust implies that the continental rift and subsequent oceanic spreading were associated with uprising of MORB-type asthenospheric mantle featuring plume-type component influences decreasing from deep to shallow mantle levels. These deep plume-type components were most likely inherited from Carboniferous mantle plume activity that was associated with the opening of Paleo-Tethys in the same area.

A New Method of Stress Measurement Based upon Elastic Deformation of Core Sample with Stress Relief by Drilling

NASA Astrophysics Data System (ADS)

Ito, T.; Funato, A.; Tamagawa, T.; Tezuka, K.; Yabe, Y.; Abe, S.; Ishida, A.; Ogasawara, H.

2017-12-01

When rock is cored at depth by drilling, anisotropic expansion occurs with the relief of anisotropic rock stresses, resulting in a sinusoidal variation of core diameter with a period of 180 deg. in the core roll angle. The circumferential variation of core diameter is given theoretically as a function of rock stresses. These new findings can lead various ideas to estimate the rock stress from circumferential variation of core diameter measured after the core retrieving. In the simplest case when a single core sample is only available, the difference between the maximum and minimum components of rock stress in a plane perpendicular to the drilled hole can be estimated from the maximum and minimum core diameters (see the detail in, Funato and Ito, IJRMMS, 2017). The advantages of this method include, (i) much easier measurement operation than those in other in-situ or in-lab estimation methods, and (ii) applicability in high stress environment where stress measurements need pressure for packers or pumping system for the hydro-fracturing methods higher than their tolerance levels. We have successfully tested the method at deep seismogenic zones in South African gold mines, and we are going to apply it to boreholes collared at 3 km depth and intersecting a M5.5 rupture plane several hundred meters below the mine workings in the ICDP project of "Drilling into Seismogenic zones of M2.0 - M5.5 earthquakes in deep South African gold mines" (DSeis) (e.g., http://www.icdp-online.org/projects/world/africa/orkney-s-africa/details/). If several core samples with different orientation are available, all of three principal components of 3D rock stress can be estimated. To realize this, we should have several boreholes drilled in different directions in a rock mass where the stress field is considered to be uniform. It is commonly carried out to dill boreholes in different directions from a mine gallery. Even in a deep borehole drilled vertically from the ground surface, the downhole tool of rotary sidewall coring allows us to take core samples with different orientations at depths of interest from the sidewall of the vertically-drilled borehole. The theoretical relationship between the core expansion and rock stress has been verified through the examination of core samples prepared in laboratory experiments and retrieved field cores.

Pito Deep reveals spatial/temporal variability of accretionary processes in the lower oceanic crust at fast-spread MOR

NASA Astrophysics Data System (ADS)

John, B. E.; Cheadle, M. J.; Gee, J. S.; Coogan, L. A.; Gillis, K. M.

2017-12-01

During January and February 2017, the 42-day RV Atlantis PMaG cruise mapped and sampled in-situ fast spread lower crust for 35 km along a flow line at Pito Deep Rift (northeastern Easter microplate). There, ridge-perpendicular escarpments bound Pito Deep and expose up to 3 km sections of crust parallel to the paleo-spreading direction, providing a unique opportunity to test models for the architecture of fast spread lower ocean crust (the plutonic section). Shipboard operations included a >57,000 km2 multi-beam survey; ten Sentry dives over 70 km2 (nominal m-scale resolution) to facilitate acquisition of detailed magnetic and bathymetric data, and optimize Jason II dive siting for rock sampling and geologic mapping; nine Jason II dives in 4 areas, recovering >400 samples of gabbroic lower crust, of which 80% are approximately oriented. Combined Sentry mapping and Jason II sampling and imaging of one area, provides the most detailed documentation of in situ gabbroic crust (>3 km2 of seafloor, over 1000+m vertical section) ever completed. Significantly, the area exposes distinct lateral variation in rock type: in the west 100m of Fe-Ti oxide rich gabbroic rocks overly gabbro and olivine gabbro; however, to the east, exposures of primitive, layered troctolitic rocks extend to within 100m below the dike-gabbro transition. Equivalent troctolitic rocks are found 13 km to the southeast parallel to a flow line, implying shallow primitive rocks are a characteristic feature of EPR lower crust at this location. The high-level position of troctolitic rocks is best explained by construction in a shallow, near steady-state melt lens at a ridge segment center, with some form of gabbro glacier flow active during formation of at least the uppermost lower ocean crust (Perk et al., 2007). Lateral variation in rock type (adjacent oxide gabbro, gabbro, olivine-rich gabbro and troctolite) over short distances taken with complexity in magmatic fabric orientation (mineral and grain size layering, mineral shape preferred orientation/foliation) on the 100m-scale is perhaps surprising. Post cruise evaluation is required to determine how much of this variability is due to rift related tectonics and/or slumping. If such deformation is limited, our mapping will require adding complexity to current models of fast spread lower ocean crust.

Contamination Tracer Testing With Seabed Rock Drills: IODP Expedition 357

NASA Astrophysics Data System (ADS)

Orcutt, B.; Bergenthal, M.; Freudenthal, T.; Smith, D. J.; Lilley, M. D.; Schneiders, L.; Fruh-Green, G. L.

2016-12-01

IODP Expedition 357 utilized seabed rock drills for the first time in the history of the ocean drilling program, with the aim of collecting intact core of shallow mantle sequences from the Atlantis Massif to examine serpentinization processes and the deep biosphere. This new drilling approach required the development of a new system for delivering synthetic tracers during drilling to assess for possible sample contamination. Here, we describe this new tracer delivery system, assess the performance of the system during the expedition, provide an overview of the quality of the core samples collected for deep biosphere investigations based on tracer concentrations, and make recommendations for future applications of the system.

Viscoelastic Thin Polymer Films under Transient Residual Stresses: Two-Stage Dewetting on Soft Substrates

NASA Astrophysics Data System (ADS)

Al Akhrass, S.; Reiter, G.; Hou, S. Y.; Yang, M. H.; Chang, Y. L.; Chang, F. C.; Wang, C. F.; Yang, A. C.-M.

2008-05-01

A nonmonotonic, two-stage dewetting behavior was observed for spin coated thin viscoelastic polymer films on soft elastic substrates. At times shorter than the relaxation time of the polymer (t<τrep), dewetting generated deep trenches in the soft rubbery substrate which, in turn, almost stopped dewetting. At later stages (t≫τrep), dewetting accelerated, accompanied by an unstable rim. However, holes nucleated at t<τrep showed only this second-stage behavior. Our observations are attributed to large elastic deformations in the substrate caused by transient residual stresses within the film.

Possible Cinder Cone on the Southern Flank of Pavonis Mons

NASA Image and Video Library

2010-10-13

This image from NASA Mars Reconnaissance Orbite is centered on a small cone on the side of one of Mars giant shield volcanoes. The cone shows some layers of hard rock but most of it is made of relatively soft material.

Li/B ratio in deep fluids an indicator of their generation depth

NASA Astrophysics Data System (ADS)

Hirajima, Takao; Sengen, Yoshiteru; Nishimura, Koshi; Ohsawa, Shinji

2010-05-01

Deep fluids derived from subducted terrestrial materials significantly affect and cause various physicochemical processes in the subduction zone, e.g., earthquakes in the subducting plate, partial melting in the mantle wedge, which causes island arc volcanism, the exhumation of high pressure metamorphic rocks, and so on (e.g., Schmidt and Poli, 1998). However, nature of deep fluids is still under the deep veil. To evaluate precisely the effect of deep fluids which affect various subduction processes, following aspects concerning the nature of deep fluids should be evaluated well, 1) the depths and the amounts of fluid release, 2) species and compositions of fluids, 3) the fluid paths and scale of motion, and etc. (e.g., Scambelluri and Philippot, 2001). In recent years, the depths and amounts of fluid release become to be evaluated well by synthetic experiments and thermodynamic calculation in the basaltic system (e.g., Schmidt and Poli, 1998; Hacker et al., 2003). The information on species and compositions of fluids can be obtained directly from fluid inclusions trapping in natural HP/UHP metamorphic rocks, but quantitative analyses of their major and trace element composition are still in the hard task. This paper reports the Li-B-Cl ratio of deep fluids extracted from quartz veins/lenses developing parallel to the main foliation of LT/HP type metamorphic rocks crystallized from 20 to 60 km depths in the Sanbagawa belt, Japan. The quartz veins crosscutting the main foliation, i.e., formed during the retrograde stage, are out of scope in this paper. Raman spectroscopy for fluid inclusions in quartz veins/lenses reveals that most inclusions are composed of aqueous liquid and gas species of CO2, CH4 and/or N2. Aqueous bubble was not detected. Microthermometry for them reveals that freezing temperature varies from -15oC to 0oC .Rough negative correlation is detected between the freezing temperature and homogenization temperature (120-450 oC). These results suggest that the fluid inclusions in the studied specimens were produced during multi-stages, probably higher salinity syn-metamorphic ones and lower salinity post-peak metamorphic ones. The deep fluids contained in the quartz veins/lenses were leached into the extra-pure water by the crush leaching technique, mainly following Banks and Yardley (1992) and Bottrell et al. (1988). Composition in the leached fluids was analyzed using gas-chromatography and ICP-MS. All extracted fluids are characterized by significantly lower Cl/(Lix2000+Bx500+Cl) (<0.2) ratio than the value of the modern sea water (ca. 0.8). Li(x2000)/B(x500) ratio of extracted fluids varies from 0.1 to 1.0 and shows a positive correlation with the metamorphic grade of the host rock., i.e., ca. 0.1 in the chlorite zone, ca. 0.2 in the garnet zone, ca. 0.4 in the biotite zone and 0.4-1.0 in the eclogite unit. Literature data of Li-B contents in natural HP metamorphic rocks suggest that Li/B ration of dehydrated fluid released from subducted meta-basalts increases with the metamorphic depth (Marschall et al., 2006; 2007). These evidences suggest that Li/B ratio of deep fluids has a potential evaluating the generated depth, although there remains several factors which control should Li/B ration ratio in the fluid should be clarified.

The coolest DA white dwarfs detected at soft X-ray wavelengths

NASA Technical Reports Server (NTRS)

Kidder, K. M.; Holberg, J. B.; Barstow, M. A.; Tweedy, R. W.; Wesemael, F.

1992-01-01

New soft X-ray/EUV photometric observations of the DA white dwarfs KPD 0631 + 1043 = WD 0631 + 107 and PG 1113 + 413 = WD 1113 + 413 are analyzed. Previously reported soft X-ray detections of three other DAs and the failure to detect a fourth DA in deep Exosat observations are investigated. New ground-based spectra are presented for all of the objects, with IUE Ly-alpha spectra for some. These data are used to constrain the effective temperatures and surface gravities. The improved estimates of these parameters are employed to refer a photospheric He abundance for the hotter objects and to elucidate an effective observational low-temperature threshold for the detection of pure hydrogen DA white dwarfs at soft X-ray wavelengths.

The origin, source, and cycling of methane in deep crystalline rock biosphere.

PubMed

Kietäväinen, Riikka; Purkamo, Lotta

2015-01-01

The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments. This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock. Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites.

The origin, source, and cycling of methane in deep crystalline rock biosphere

PubMed Central

Kietäväinen, Riikka; Purkamo, Lotta

2015-01-01

The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments. This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock. Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites. PMID:26236303

Hydromechanical coupling in fractured rock masses: mechanisms and processes of selected case studies

NASA Astrophysics Data System (ADS)

Zangerl, Christian

2015-04-01

Hydromechanical (HM) coupling in fractured rock play an important role when events including dam failures, landslides, surface subsidences due to water withdrawal or drainage, injection-induced earthquakes and others are analysed. Generally, hydromechanical coupling occurs when a rock mass contain interconnected pores and fractures which are filled with water and pore/fracture pressures evolves. In the on hand changes in the fluid pressure can lead to stress changes, deformations and failures of the rock mass. In the other hand rock mass stress changes and deformations can alter the hydraulic properties and fluid pressures of the rock mass. Herein well documented case studies focussing on surface subsidence due to water withdrawal, reversible deformations of large-scale valley flanks and failure as well as deformation processes of deep-seated rock slides in fractured rock masses are presented. Due to pore pressure variations HM coupling can lead to predominantly reversible rock mass deformations. Such processes can be considered by the theory of poroelasticity. Surface subsidence reaching magnitudes of few centimetres and are caused by water drainage into deep tunnels are phenomenas which can be assigned to processes of poroelasticity. Recently, particular focus was given on large tunnelling projects to monitor and predict surface subsidence in fractured rock mass in oder to avoid damage of surface structures such as dams of large reservoirs. It was found that surface subsidence due to tunnel drainage can adversely effect infrastructure when pore pressure drawdown is sufficiently large and spatially extended and differential displacements which can be amplified due to topographical effects e.g. valley closure are occurring. Reversible surface deformations were also ascertained on large mountain slopes and summits with the help of precise deformation measurements i.e. permanent GPS or episodic levelling/tacheometric methods. These reversible deformations are often in the range of millimetres to a very few centimetres and can be linked to annual groundwater fluctuations. Due to pore pressure variations HM coupling can influence seepage forces and effective stresses in the rock mass. Effective stress changes can adversely affect the stability and deformation behaviour of deep-seated rock slides by influencing the shear strength or the time dependent (viscous) material behaviour of the basal shear zone. The shear strength of active shear zones is often reasonably well described by Coulomb's law. In Coulomb's law the operative normal stresses to the shear surface/zone are effective stresses and hence pore pressures which should be taken into account reduces the shear strength. According to the time dependent material behaviour a few effective stress based viscous models exists which are able to consider pore pressures. For slowly moving rock slides HM coupling could be highly relevant when low-permeability clayey-silty shear zones (fault gouges) are existing. An important parameters therefore is the hydraulic diffusivity, which is controlled by the permeability and fluid-pore compressibility of the shear zone, and by fluid viscosity. Thus time dependent pore pressure diffusion in the shear zone can either control the stability condition or the viscous behaviour (creep) of the rock slide. Numerous cases studies show that HM coupling can effect deformability, shear strength and time dependent behaviour of fractured rock masses. A process-based consideration can be important to avoid unexpected impacts on infrastructures and to understand complex rock mass as well rock slide behaviour.

The Chemical Behavior of Fluids Released during Deep Subduction Based on Fluid Inclusions

NASA Astrophysics Data System (ADS)

Frezzotti, M. L.; Ferrando, S.

2014-12-01

We present a review of current research on fluid inclusions in (HP-) UHP metamorphic rocks that, combined with existing experimental research and thermodynamic models, allow us to investigate the chemical and physical properties of fluids released during deep subduction, their solvent and element transport capacity, and the subsequent implications for the element recycling in the mantle wedge. An impressive number of fluid inclusion studies indicate three main populations of fluid inclusions in HP and UHP metamorphic rocks: i) aqueous and/or non-polar gaseous fluid inclusions (FI), ii) multiphase solid inclusions (MSI), and iii) melt inclusions (MI). Chemical data from preserved fluid inclusions in rocks match with and implement "model" fluids by experiments and thermodynamics, revealing a continuity behind the extreme variations of physico-chemical properties of subduction-zone fluids. From fore-arc to sub-arc depths, fluids released by progressive devolatilization reactions from slab lithologies change from relatively diluted chloride-bearing aqueous solutions (± N2), mainly influenced by halide ligands, to (alkali) aluminosilicate-rich aqueous fluids, in which polymerization probably governs the solubility and transport of major (e.g., Si and Al) and trace elements (including C). Fluid inclusion data implement the petrological models explaining deep volatile liberation in subduction zones, and their flux into the mantle wedge.

Western rock lobsters ( Panulirus cygnus) in Western Australian deep coastal ecosystems (35-60 m) are more carnivorous than those in shallow coastal ecosystems

NASA Astrophysics Data System (ADS)

Waddington, Kris I.; Bellchambers, Lynda M.; Vanderklift, Mathew A.; Walker, Diana I.

2008-08-01

The western rock lobster ( Panurilus cygnus George.) is a conspicuous consumer in the coastal ecosystems of temperate Western Australia. We used stable isotope analysis and gut content analysis to determine the diet and trophic position of western rock lobsters from mid-shelf coastal ecosystems (35-60 m depth) at three locations. Lobsters were primarily carnivorous, and no consistent differences in diet were detected with varying lobster size, sex or among locations. The main components of the diet were bait (from the fishery) and small crustaceans - crabs and amphipods/isopods. Foliose red algae, bivalves/gastropods and sponges were minor contributors to diet. The diet of lobsters in deep coastal ecosystems differed from the results of previous studies of diets of lobsters from shallow coastal ecosystems. In particular, coralline algae and molluscs - important prey in studies of lobsters from shallow coastal ecosystems - were minor components of the diet. These differences are likely to reflect differences in food availability between these systems and potentially, differences in choice of prey by lobsters that inhabit deeper water. Given the high contribution of bait to lobster diet, bait is likely to be subsidizing lobster production in deep coastal ecosystems during the fishing season.

Sources of Hydrogen as Food for Deep Microbial Communities

NASA Technical Reports Server (NTRS)

Freund, Friedemann; Fonda, Mark (Technical Monitor)

1998-01-01

To survive in deep subsurface environments autolithotrophic microbial communities require a sustainable food supply. One possible source is H2 which forms when H2O reacts with ferrous iron at rock surfaces or mineral grain boundaries to produce H2 plus ferric iron. The amount of H2 that can be supplied in this way, however, is relatively small and may not last for more than a few hundred or thousand years. A much larger reservoir of H2 exists in the rocks, inside mineral grains, arising from an as yet little-known redox conversion that affects OH- in nominally anhydrous minerals. These OH- represent small amounts of "water" that become incorporated during crystallization in H2O-laden environments. A corollary of the H2 formation from OH- is the formation of peroxy, an oxidized form of oxygen. While the peroxy become part of the mineral structure, the H2 molecules are diffusively mobile and can escape from within the mineral grains, entering the intergranular space. Assuming cautiously realistic number densities of OH- undergoing the in situ redox conversion to H2 plus peroxy, a 10 km deep rock column is expected to contain enough H2 to allow for a constant degassing rate of 50-100 nmole H2 per day per sq cm over 30 million years.

Technical Note: Deep learning based MRAC using rapid ultra-short echo time imaging.

PubMed

Jang, Hyungseok; Liu, Fang; Zhao, Gengyan; Bradshaw, Tyler; McMillan, Alan B

2018-05-15

In this study, we explore the feasibility of a novel framework for MR-based attenuation correction for PET/MR imaging based on deep learning via convolutional neural networks, which enables fully automated and robust estimation of a pseudo CT image based on ultrashort echo time (UTE), fat, and water images obtained by a rapid MR acquisition. MR images for MRAC are acquired using dual echo ramped hybrid encoding (dRHE), where both UTE and out-of-phase echo images are obtained within a short single acquisition (35 sec). Tissue labeling of air, soft tissue, and bone in the UTE image is accomplished via a deep learning network that was pre-trained with T1-weighted MR images. UTE images are used as input to the network, which was trained using labels derived from co-registered CT images. The tissue labels estimated by deep learning are refined by a conditional random field based correction. The soft tissue labels are further separated into fat and water components using the two-point Dixon method. The estimated bone, air, fat, and water images are then assigned appropriate Hounsfield units, resulting in a pseudo CT image for PET attenuation correction. To evaluate the proposed MRAC method, PET/MR imaging of the head was performed on 8 human subjects, where Dice similarity coefficients of the estimated tissue labels and relative PET errors were evaluated through comparison to a registered CT image. Dice coefficients for air (within the head), soft tissue, and bone labels were 0.76±0.03, 0.96±0.006, and 0.88±0.01. In PET quantification, the proposed MRAC method produced relative PET errors less than 1% within most brain regions. The proposed MRAC method utilizing deep learning with transfer learning and an efficient dRHE acquisition enables reliable PET quantification with accurate and rapid pseudo CT generation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Zero-Echo-Time and Dixon Deep Pseudo-CT (ZeDD CT): Direct Generation of Pseudo-CT Images for Pelvic PET/MRI Attenuation Correction Using Deep Convolutional Neural Networks with Multiparametric MRI.

PubMed

Leynes, Andrew P; Yang, Jaewon; Wiesinger, Florian; Kaushik, Sandeep S; Shanbhag, Dattesh D; Seo, Youngho; Hope, Thomas A; Larson, Peder E Z

2018-05-01

Accurate quantification of uptake on PET images depends on accurate attenuation correction in reconstruction. Current MR-based attenuation correction methods for body PET use a fat and water map derived from a 2-echo Dixon MRI sequence in which bone is neglected. Ultrashort-echo-time or zero-echo-time (ZTE) pulse sequences can capture bone information. We propose the use of patient-specific multiparametric MRI consisting of Dixon MRI and proton-density-weighted ZTE MRI to directly synthesize pseudo-CT images with a deep learning model: we call this method ZTE and Dixon deep pseudo-CT (ZeDD CT). Methods: Twenty-six patients were scanned using an integrated 3-T time-of-flight PET/MRI system. Helical CT images of the patients were acquired separately. A deep convolutional neural network was trained to transform ZTE and Dixon MR images into pseudo-CT images. Ten patients were used for model training, and 16 patients were used for evaluation. Bone and soft-tissue lesions were identified, and the SUV max was measured. The root-mean-squared error (RMSE) was used to compare the MR-based attenuation correction with the ground-truth CT attenuation correction. Results: In total, 30 bone lesions and 60 soft-tissue lesions were evaluated. The RMSE in PET quantification was reduced by a factor of 4 for bone lesions (10.24% for Dixon PET and 2.68% for ZeDD PET) and by a factor of 1.5 for soft-tissue lesions (6.24% for Dixon PET and 4.07% for ZeDD PET). Conclusion: ZeDD CT produces natural-looking and quantitatively accurate pseudo-CT images and reduces error in pelvic PET/MRI attenuation correction compared with standard methods. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Numerical Study on Stress Heterogeneity Development in Two-Phase Rocks with Large Rheological Contrast and Implications in the Lower Crust

NASA Astrophysics Data System (ADS)

Xu, Junshan; Zhang, Baohua

2018-03-01

Development of stress heterogeneity in two-phase rocks was investigated via a finite element method at 1000-1200 K and 100 MPa. Two groups of rock models were considered: anorthite-diopside and anorthite-clinopyroxene, with a phase volume ratio of 1:1 in each group and different dislocation creep rates between phases ( 4-8 orders of magnitude). Our numerical results indicate that the stress inside the model can be several times higher than the differential stress applied to the model and stress will tend to concentrate in hard phase, especially near the sharp boundaries with soft phase. Moreover, large stress gradient in hard phase and nearly homogeneous stress in soft phase will lead to the initialization of localized dynamic recrystallization or fracture. These numerical observations suggest that the rheological contrast between two phases plays a crucial role in stress heterogeneity rather than other factors (such as grain size, the boundary conditions or mesh density), which may eventually accelerate development of stress heterogeneity in the lower crust. Our study provides new insights into the dynamic processes of grain size reduction in the lower crust, which may cause the transformation from dislocation creep to diffusion creep and enable the weakened shear zones.

Cosmogenic nuclides in football-sized rocks.

NASA Technical Reports Server (NTRS)

Wahlen, M.; Honda, M.; Imamura, M.; Fruchter, J. S.; Finkel, R. C.; Kohl, C. P.; Arnold, J. R.; Reedy, R. C.

1972-01-01

The activity of long- and short-lived isotopes in a series of samples from a vertical column through the center of rock 14321 was measured. Rock 14321 is a 9 kg fragmental rock whose orientation was photographically documented on the lunar surface. Also investigated was a sample from the lower portion of rock 14310, where, in order to study target effects, two different density fractions (mineral separates) were analyzed. A few nuclides in a sample from the comprehensive fines 14259 were measured. This material has been collected largely from the top centimeter of the lunar soil. The study of the deep samples of 14321 and 14310 provided values for the activity of isotopes at points where only effects produced by galactic cosmic rays are significant.

Australian toon planted in Hawaii: tree quality, growth, and stocking

Treesearch

Herbert L. Wick; Robert E. Nelson; Libert K. Landgraf

1971-01-01

Tree quality and rates of growth and survival were higher in 5- to 8-year-old Australian toon (Toona australis) plantations on sites with deep soils, good drainage, and as or broken pahoehoe rock than in plantations on sites with poor drainage or unbroken pahoehoe rock. Stocking averaged 236 trees per acre. Spacing in initial plants should be about 6...

In Situ Observation of Rock Spalling in the Deep Tunnels of the China Jinping Underground Laboratory (2400 m Depth)

NASA Astrophysics Data System (ADS)

Feng, Xia-Ting; Xu, Hong; Qiu, Shi-Li; Li, Shao-Jun; Yang, Cheng-Xiang; Guo, Hao-Sen; Cheng, Yuan; Gao, Yao-Hui

2018-04-01

To study rock spalling in deep tunnels at China Jinping Underground Laboratory Phase II (CJPL-II), photogrammetry method and digital borehole camera were used to quantify key features of rock spalling including orientation, thickness of slabs and the depth of spalling. The failure mechanism was analysed through scanning electron microscope and numerical simulation based on FLAC3D. Observation results clearly showed the process of rock spalling failure: a typical spalling pattern around D-shaped tunnels after top-heading and bottom bench were discovered. The orientation and thickness of the slabs were obtained. The slabs were parallel to the excavated surfaces of the tunnel and were related to the shape of the tunnel surface and orientation of the principal stress. The slabs were alternately thick and thin, and they gradually increased in thickness from the sidewall inwards. The form and mechanism of spalling at different locations in the tunnels, as influenced by stress state and excavation, were analysed. The result of this study was helpful to those rethinking the engineering design, including the excavation and support of tunnels, or caverns, at high risk of spalling.

Detection of soft tissue densities from digital breast tomosynthesis: comparison of conventional and deep learning approaches

NASA Astrophysics Data System (ADS)

Fotin, Sergei V.; Yin, Yin; Haldankar, Hrishikesh; Hoffmeister, Jeffrey W.; Periaswamy, Senthil

2016-03-01

Computer-aided detection (CAD) has been used in screening mammography for many years and is likely to be utilized for digital breast tomosynthesis (DBT). Higher detection performance is desirable as it may have an impact on radiologist's decisions and clinical outcomes. Recently the algorithms based on deep convolutional architectures have been shown to achieve state of the art performance in object classification and detection. Similarly, we trained a deep convolutional neural network directly on patches sampled from two-dimensional mammography and reconstructed DBT volumes and compared its performance to a conventional CAD algorithm that is based on computation and classification of hand-engineered features. The detection performance was evaluated on the independent test set of 344 DBT reconstructions (GE SenoClaire 3D, iterative reconstruction algorithm) containing 328 suspicious and 115 malignant soft tissue densities including masses and architectural distortions. Detection sensitivity was measured on a region of interest (ROI) basis at the rate of five detection marks per volume. Moving from conventional to deep learning approach resulted in increase of ROI sensitivity from 0:832 +/- 0:040 to 0:893 +/- 0:033 for suspicious ROIs; and from 0:852 +/- 0:065 to 0:930 +/- 0:046 for malignant ROIs. These results indicate the high utility of deep feature learning in the analysis of DBT data and high potential of the method for broader medical image analysis tasks.

Scary gas: pathways in the axial body for soft tissue gas dissection (part I).

PubMed

Sandstrom, Claire K; Osman, Sherif F; Linnau, Ken F

2017-10-01

Gas is often encountered in abnormal locations in the torso, including within soft tissue compartments, vessels, and bones. The clinical significance of this gas ranges from incidental, benign, and self-limited to aggressive infection requiring immediate surgery. As a result of fascial interconnectivity and pressure differences between compartments, gas can dissect distant from its source. Gas can easily dissect between spaces of the extrapleural thorax, subperitoneal abdomen, deep cervical spaces, and subcutaneous tissues. The pleural and peritoneal cavities are normally isolated but may communicate with the other spaces in select situations. Dissection of gas may cause confusion as to its origin, potentially delaying treatment or prompting unnecessary and/or distracting workup and therapies. The radiologist might be the first to suggest and identify a remote source of dissecting gas when the clinical manifestation alone might be misleading. The purpose of this paper, the first in a three-part series on soft tissue gas, is to explore the various pathways by which gas dissects through the superficial and deep compartments of the torso.

Hydraulic and solute-transport properties and simulated advective transport of contaminated ground water in a fractured rock aquifer at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

USGS Publications Warehouse

Lewis-Brown, Jean C.; Carleton, Glen B.; Imbrigiotta, Thomas E.

2006-01-01

Volatile organic compounds, predominantly trichloroethylene and its degradation products, have been detected in ground water at the Naval Air Warfare Center (NAWC), West Trenton, New Jersey. An air-stripping pump-and-treat system has been in operation at the NAWC since 1998. An existing ground-water-flow model was used to evaluate the effect of a change in the configuration of the network of recovery wells in the pump-and-treat system on flow paths of contaminated ground water. The NAWC is underlain by a fractured-rock aquifer composed of dipping layers of sedimentary rocks of the Lockatong and Stockton Formations. Hydraulic and solute-transport properties of the part of the aquifer composed of the Lockatong Formation were measured using aquifer tests and tracer tests. The heterogeneity of the rocks causes a wide range of values of each parameter measured. Transmissivity ranges from 95 to 1,300 feet squared per day; the storage coefficient ranges from 9 x 10-5 to 5 x 10-3; and the effective porosity ranges from 0.0003 to 0.002. The average linear velocity of contaminated ground water was determined for ambient conditions (when no wells at the site are pumped) using an existing ground-water-flow model, particle-tracking techniques, and the porosity values determined in this study. The average linear velocity of flow paths beginning at each contaminated well and ending at the streams where the flow paths terminate ranges from 0.08 to 130 feet per day. As a result of a change in the pump-and-treat system (adding a 165-foot-deep well pumped at 5 gallons per minute and reducing the pumping rate at a nearby 41-foot-deep well by the same amount), water in the vicinity of three 100- to 165-foot-deep wells flows to the deep well rather than the shallower well.

First-Year Students' Approaches to Learning, and Factors Related to Change or Stability in Their Deep Approach during a Pharmacy Course

ERIC Educational Resources Information Center

Varunki, Maaret; Katajavuori, Nina; Postareff, Liisa

2017-01-01

Research shows that a surface approach to learning is more common among students in the natural sciences, while students representing the "soft" sciences are more likely to apply a deep approach. However, findings conflict concerning the stability of approaches to learning in general. This study explores the variation in students'…

Interaction of Rock Minerals with Carbon Dioxide and Brine: A Hydrothermal Investigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sass, Bruce M.; Gupta, Neeraj; Ickes, Jennifer A.

2002-02-02

This paper presents interim results of a feasibility study on carbon dioxide (CO{sub 2}) sequestration in deep saline formations. The focus of the investigation is to examine factors that may affect chemical sequestration of CO{sub 2} in deep saline formations. Findings of the first phase of this investigation were presented in a topical report (Sass et al., 1999a). Preliminary results of the second phase, now underway, have been reported elsewhere (Sass et al., 1999b; 2001). Evaluations of the suitability of Mt. Simon formation for sequestering CO{sub 2} and economic issues are reported by Gupta et al., 1999; 2001; Smith etmore » al., 2001. This study is sponsored by the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) under a Novel Concepts project grant. The overall objectives of Phase II experiments were to determine: (1) the potential for long-term sequestration of CO{sub 2} in deep, regional host rock formations; and (2) the effectiveness of overlying caprock as a barrier against upward migration of the injected CO{sub 2}. To meet these goals, experiments were conducted using rock samples from different potential host reservoirs and overlying rocks. In addition, pure mineral samples were used in some experimental runs to investigate specific mineralogical reactions. Due to space limitations, the scope of this paper will be limited to two types of equilibration experiments using pure minerals. Implications for more complex natural systems will be discussed in the report for Phase II being finalized at this time.« less

Fluid-rock reactions in an evaporitic melange, Permian Haselgebirge, Austrian Alps

USGS Publications Warehouse

Spotl, C.; Longstaffe, F.J.; Ramseyer, K.; Kunk, Michael J.; Wiesheu, R.

1998-01-01

Tectonically isolated blocks of carbonate rocks present within the anhydritic Haselgebirge melange of the Northern Calcareous Alps record a complex history of deformation and associated deep-burial diagenetic to very low-grade metamorphic reactions. Fluids were hot (up to ~ 250 ??C) and reducing brines charged with carbon dioxide. Individual carbonate outcrops within the melange record different regimes of brine-rock reactions, ranging from pervasive dolomite recrystallization to dedolomitization. Early diagenetic features in these carbonates were almost entirely obliterated. Matrix dolomite alteration was related to thermochemical sulphate reduction (TSR) recognized by the replacement of anhydrite by calcite + pyrite ?? native sulphur. Pyrite associated with TSR is coarsely crystalline and characterized by a small sulphur isotope fractionation relative to the precursor Permian anhydrite. Carbonates associated with TSR show low Fe/Mn ratios reflecting rapid reaction of ferrous iron during sulphide precipitation. As a result, TSR-related dolomite and calcite typically show bright Mn(II)-activated cathodoluminescence in contrast to the dull cathodoluminescence of many (ferroan) carbonate cements in other deep-burial settings. In addition to carbonates and sulphides, silicates formed closely related to TSR, including quartz, K-feldspar, albite and K-mica. 40Ar/39Ar analysis of authigenic K-feldspar yielded mostly disturbed step-heating spectra which suggest variable cooling through the argon retention interval for microcline during the Late Jurassic. This timing coincides with the recently recognized subduction and closure of the Meliata-Hallstatt ocean to the south of the Northern Calcareous Alps and strongly suggests that the observed deep-burial fluid-rock reactions were related to Jurassic deformation and melange formation of these Permian evaporites.

Wind Carved Rock

NASA Image and Video Library

2016-10-19

The distinctively fluted surface and elongated hills in this image in Medusae Fossae are caused by wind erosion of a soft fine-grained rock. Called yardangs, these features are aligned with the prevailing wind direction. This wind direction would have dominated for a very long time to carve these large-scale features into the exposed rock we see today. Yardangs not only reveal the strength and direction of historic winds, but also reveal something of the host rock itself. Close inspection by HiRISE shows an absence of boulders or rubble, especially along steep yardang cliffs and buttresses. The absence of rubble and the scale of the yardangs tells us that the host rock consists only of weakly cemented fine granules in tens of meters or more thick deposits. Such deposits could have come from extended settling of volcanic ash, atmospheric dust, or accumulations of wind deposited fine sands. After a time these deposits became cemented and cohesive, illustrated by the high standing relief and exposed cliffs. http://photojournal.jpl.nasa.gov/catalog/PIA21111

Deep Geothermal Energy for Lower Saxony (North Germany) - Combined Investigations of Geothermal Reservoir Characteristics

NASA Astrophysics Data System (ADS)

Hahne, Barbara; Thomas, Rüdiger

2014-05-01

In Germany, successful deep geothermal projects are mainly situated in Southern Germany in the Molassebecken, furthermore in the Upper Rhine Graben and, to a minor extend, in the North German Basin. Mostly they are hydrothermal projects with the aim of heat production. In a few cases, they are also constructed for the generation of electricity. In the North German Basin temperature gradients are moderate. Therefore, deep drilling of several thousand meters is necessary to reach temperatures high enough for electricity production. However, the porosity of the sedimentary rocks is not sufficient for hydrothermal projects, so that natural fracture zones have to be used or the rocks must be hydraulically stimulated. In order to make deep geothermal projects in Lower Saxony (Northern Germany) economically more attractive, the interdisciplinary research program "Geothermal Energy and High-Performance Drilling" (gebo) was initiated in 2009. It comprises four focus areas: Geosystem, Drilling Technology, Materials and Technical System and aims at improving exploration of the geothermal reservoir, reducing costs of drilling and optimizing exploitation. Here we want to give an overview of results of the focus area "Geosystem" which investigates geological, geophysical, geochemical and modeling aspects of the geothermal reservoir. Geological and rock mechanical investigations in quarrys and core samples give a comprehensive overview on rock properties and fracture zone characteristics in sandstones and carbonates. We also show that it is possible to transfer results of rock property measurements from quarry samples to core samples or to in situ conditions by use of empirical relations. Geophysical prospecting methods were tested near the surface in a North German Graben system. We aim at transferring the results to the prospection of deep situated fracture zones. The comparison of P- and S-wave measurements shows that we can get hints on a possible fluid content of the fracture zone. The assumed elastic rock properties can be evaluated by FD modeling. Geoelectric and electromagnetic investigations of the fracture zone were carried out to investigate their potential to give hints on minerals, brines or hydrothermal fluids within the fracture zone. Measurements of the Spectral Induced Polarization show that anisotropy of phase angles may not be neglected, because otherwise data may be misinterpreted and structural models become unnecessarily complicated. A crucial aspect for the performance of a Geothermal plant is the mineral contents of the formation water. Scalings and corrosion can severely disturb the operation and the properties of the reservoir. Therefore, North German formation waters were analysed and categorized and a thermodynamic database was developed. It allows hydrogeochemical modeling of geothermally used waters and of hydrogeochemically and technically induced processes under North German conditions. Hydromechanical modeling showed that differences of elastic rock properties between neighboring layers does not strongly influence propagation paths of fractures, whereas they significantly influence fracture aperture. On the other hand, differences of mechanical rock properties significantly influence propagation paths of fractures. Existing fractures are also affected by the induced fracture - after stimulation, they propagate further in the direction of maximum shear stress. Furthermore, rock deformation during the production phase depends strongly on the contrast of hydraulic conductivity between highly permeable fracture core and low permeable rock matrix. The projects within gebo-Geosystem are well interconnected. Both the focus area "Geosystem" as well as the whole collaborative research program "gebo" offer different approaches that lead to an improvement of geothermal exploration and exploitation as well as a better understanding of the processes within geothermal reservoirs. Acknowledgement: The gebo project is funded by the "Niedersächsisches Ministerium für Wissenschaft und Kultur" and the industry partner Baker Hughes, Celle, Germany.

Map showing relative ease of excavation in the Salina quadrangle, Utah

USGS Publications Warehouse

Williams, Paul L.

1972-01-01

This map shows the relative ease (or difficulty) with which rocks and surficial deposits can be excavated. Because of rapidly changing technology of excavation and considerable local variability of many rock units, it is not practical to specifically categorize rock units according to type of equipment needed for their excavations. However, it may be stated in general that rock units classed as very easy and easy can in most places be excavated by hand tools and by light machinery such as backhoes and small bulldozers; units included in easy to difficult require blasting and (or) heavy machinery such as rippers and large bulldozers for resistant rocks, and hand tools or light power equipment for soft rocks; and units classes as difficult and very difficult probably require blasting and heavy machinery.The excavation units shown here are based on map units of the geologic map of the Salina quadrangle. Where bedrock is mantled with thin unmapped surficial deposits, ease of excavation shown is that of the bedrock, not that of the thin surficial mantle; where surficial deposits are mapped, ease of excavation shown is that of surficial deposits.

Geology of the Deep Creek area, Washington, and its regional significance

USGS Publications Warehouse

Yates, Robert Giertz

1976-01-01

This report, although primarily concerned with the stratigraphy and structure of a lead-zinc mining district in northern Stevens County, Washington, discusses and integrates the geology of the region about the Deep Creek area. Although the study centers in an area of about 200 square miles immediately south of the International Boundary, the regional background comes from: (1)the previously undescribed Northport quadrangle to the west, (2) published reports and reconnaissance of the Metaline quadrangle to the east, and (3) from published reports and maps of a 16 mile wide area that lies to the north adjacent to these three quadrangles in British Columbia. The report is divided into three parts: (1) descriptions of rocks and structures of the Deep Creek area, (2) descriptions of the regional setting of the Deep Creek area, and (3) an analysis and interpretation of the depositional and tectonic events that produced the geologic features exposed today. In the Deep Creek area surficial deposits of sand and gravel of glacial origin cover much of the consolidated rocks, which range in age from greenschist of the late Precambrlan to albite granite of the Eocene. Three broad divisions of depositional history are represented: (1) Precambrian, (2) lower Paleozoic and (3) upper Paleozoic; the record of the Mesozoic and Eocene is fragmentary. The lower Paleozoic division is the only fossil-controlled sequence; the age of the other two divisions were established by less direct methods. Both Precambrian and upper Paleozoic sequences are dominated by fine-grained detrital sediments, the Precambrian tending towards the alumina-rich and the upper Paleozoic tending towards the black shale facies with high silica. Neither sequence has more than trivial amounts of coarse clastics. Both include limestones, but in minor abundance. The lower Paleozoic sequence, on the other hand, represents a progressive change in deposition. The sequence began during the very late Precambrian with the deposition of clean quartz sand. This was followed by the accumulation of a comparatively thin limestone unit succeeded by a thick shale. The shale grades into a thick carbonate unit which in turn is overlain by black graptolitic slates (Ordovician). This general order of deposition holds for the Cambro-Ordovician throughout the area. Precambrian rocks indigenous to the Deep Creek area, have undergone at least six tectonic events of greatly different intensities. The first three of these events are epeirogentic, the fourth involves intense folding, the fifth, crossfolding, and the sixth, block faulting without folding. These events are dated with varying degrees of precision. The two epeirogentic events of the Precambrian, one gentle folding at the beginning of Windermere time and the other high angle faulting and volcanism in mid-Windermere time, did little to deform or metamorphose the rocks. The third event consists of uplift of northern Idaho and adjacent Montana and westward decollement thrusting of essentially unfolded lower Paleozoic rocks. The decollement faulting is inferred to explain anomalous rock distribution and cannot be accurately dated. It occurred sometime after the Devonian and before the Jurassic. A late Paleozoic age is favored.

Deep Bore Storage of Nuclear Waste Using MMW (Millimeter Wave) Technology, STTR Fast Track Project, Phase I Final Report-Revised

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oglesby, Kenneth D.; Woskov, Paul; Einstein, Herbert

This report covers the technical work in Phase I of this DOE-Nuclear Program STTR Fast Track project. All key tasks were successfully performed, new tasks were added to utilize DOD-AFRL’s 95 GigaHertz (GHz) gyrotron in Phase II, while other lesser tasks were left for Phase II efforts or were requested to be made optional. This research adds to our understanding of using MMW power to melt and vaporize rocks and steel/ metals and laid plans for future testing in Phase II. This work built upon a prior DOE project DE-EE0005504 that developed the basic waveguide setup, process and instruments. Inmore » this project we were investigating the use of MMW to form rock melt and steel plugs in deep wells to further isolate highly radioactive nuclear waste in ultra-deep basement rocks for long term storage. This technology also has potential for deep well drilling for nuclear storage, geothermal and oil and gas industries. It also has the potential for simultaneously sealing and securing the wellbore with a thick rock melt liner as the wellbore is drilled. This allows for higher levels of safety and protection of the environment during deep drilling operations. The larger purpose of this project was to find answers to key questions in progressing MMW technology for these applications. Phase I of this project continued bench testing using the MIT 10 kilo-Watt (kW), 28 GHz frequency laboratory gyrotron, literature searches, planning and design of equipment for Phase II efforts. Furnace melting and rock testing (Tasks 4 and 5) were deferred to Phase II due to lack of concurrent availability of the furnace and personnel at MIT. That delay and lower temperature furnace (limited to 1650oC) caused rethinking of Task 4 to utilize coordinated rock selection with the DOD testing in Phase II. The high pressure and high power window design work (moved to Phase I Task 3 from Phase II Task 20) and Additive materials and methods (Tasks 7 & 8) performed in Phase I may become patentable and thus little detail can be provided in this public report. A version of that new high pressure, high MMW power window may be built for possible Phase II testing at the DOD site. Most significantly, additional tasks were added for planning the use of the Department of Defense, Air Force Research Laboratory’s (DOD-AFRL’s) System 0 gyrotron in Phase II. Specifically added and accomplished were multiple discussions on DOD and DOE-MIT-Impact goals, timing between ongoing DOD testing, outlining the required equipment and instruments for rock testing, and terms for an agreement. That addition required a visit to Kirtland AFB in Albuquerque, New Mexico to talk to key DOD-AFRL personnel and management. A DOD-Impact-MIT charter (i.e., contract) is now being circulated for signatures. Also added task to Phase I, MIT designed the critical path reflected power isolator screen for Phase II testing. To ensure compatibility, that design was computer simulated for the expected heat load distribution and the resulting temperature increase. Advancing the MMW testing up to the optimum 95 GHz and 100kW (5X higher) power levels was stated in the original proposal to be a key required development step for this technology to achieve prototype drilling, lining, and rock melting/ vaporization for creating sealing plugs.« less

Demonstrations of Gravity-Independent Mobility and Drilling on Natural Rock using Microspines

NASA Technical Reports Server (NTRS)

Parness, Aaron; Frost, Matthew; King, Jonathan P.; Thatte, Nitish

2012-01-01

The video presents microspine-based anchors be ing developed for gripping rocks on the surfaces of comets and asteroids, or for use on cliff faces and lava tubes on Mars. Two types of anchor prototypes are shown on supporting forces in all directions away from the rock; >160 N tangent, >150 N at 45?, and >180 N normal to the surface of the rock. A compliant robotic ankle with two active degrees of freedom interfaces these anchors to the Lemur IIB robot for future climbing trials. Finally, a rotary percussive drill is shown coring into rock regardless of gravitational orientation. As a harder- than-zero-g proof of concept, inverted drilling was performed creating 20mm diameter boreholes 83 mm deep in vesicular basalt samples while retaining 12 mm diameter rock cores in 3-6 pieces.

Recent Opportunity Microscopic Imager Results from the Western Rim of Endeavour Crater

NASA Astrophysics Data System (ADS)

Herkenhoff, K. E.; Arvidson, R. E.; Jolliff, B. L.; Mittlefehldt, D. W.; Sullivan, R. J., Jr.; Gellert, R.; Sims, M. H.

2016-12-01

The Athena science payload on the Mars Exploration Rover Oppor­tunity includes the Microscopic Imager (MI), a fixed-focus close-up camera mounted on the instrument arm. The MI acquires images at a scale of 31 µm/pixel over a broad spectral range (400 to 700 nm) using only natural illumination of target surfaces. Opportunity has been exploring exposures of Noachian-age rocks along the rim of Endeavour crater since August 2011, moti­vated by orbital spectral evidence for phyllosilicates at multiple locations along the crater's rim. Because Opportunity can no longer directly sense phyllosilicate mineralogy with the MiniTES or Mössbauer spectrometers, the rover mis­sion is focusing on characterizing outcrop multispectral reflectance with Pancam, elemental chemistry with the Alpha Particle X-ray Spectrometer (APXS) and microtexture with the MI of potential phyllosilicate host rocks. In addition, the Rock Abrasion Tool (RAT) gives an indication of rock hardness. After traversing more than 42 km (26 miles) since landing in 2004, the rover entered "Marathon Valley" to investigate rock exposures in which phyllosili­cates were detected by the CRISM instrument on the Mars Reconnaissance Orbiter. Where clastic textures are resolved, the outcrop pavement in Marathon Valley consists of poorly-sorted dark, sub-rounded to sub-angular clasts in a soft (based on RAT grind data), fine-grained, brighter matrix (see Figure showing 5x5 cm post-grind MI mosaic of "Pierre Pinaut3," acquired on Sol 4373 when target was fully shadowed). These observations are consistent with high-energy emplacement due to impact cratering. The soft, recessive, altered appearance of the matrix material suggests that it is the likely host of phyllosilicate alteration in these rocks. The bedrock appears to have been aqueously altered, but APXS measurements of major elements indicate that the alteration was isochemical, unlike in other Endeavour rim rocks. Also, MI views of a small patch of dark sand (dubbed "Joseph Collin") shed from the top of the rover's solar panels indicate that they were emplaced by active saltation of wind-driven, well-sorted fine sand grains in the current surface environment. The latest Opportunity MI results will be presented at the conference.

Rare Earth Element and Trace Element Data Associated with Hydrothermal Spring Reservoir Rock, Idaho

DOE Data Explorer

Quillinan, Scott; Bagdonas, Davin

2017-06-22

These data represent rock samples collected in Idaho that correspond with naturally occurring hydrothermal samples that were collected and analyzed by INL (Idaho Falls, ID). Representative samples of type rocks were selected to best represent the various regions of Idaho in which naturally occurring hydrothermal waters occur. This includes the Snake River Plain (SRP), Basin and Range type structures east of the SRP, and large scale/deep seated orogenic uplift of the Sawtooth Mountains, ID. Analysis includes ICP-OES and ICP-MS methods for Major, Trace, and REE concentrations.

Smaller Footprint Drilling System for Deep and Hard Rock Environments; Feasibility of Ultra-High-Speed Diamond Drilling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arnis Judzis; Homer Robertson; Alan Black

2006-06-22

The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high rotational speeds (greater than 10,000 rpm). The work includes a feasibility of concept research effort aimed at development that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with smaller, more mobile rigs. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration (ROP) rock cutting with substantially lower inputs of energymore » and loads. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm-usually well below 5,000 rpm. This document details the progress at the end of Phase 1 on the program entitled ''Smaller Footprint Drilling System for Deep and Hard Rock Environments: Feasibility of Ultra-High-Speed Diamond Drilling'' for the period starting 1 March 2006 and concluding 30 June 2006. (Note: Results from 1 September 2005 through 28 February 2006 were included in the previous report (see Judzis, Black, and Robertson)). Summarizing the accomplished during Phase 1: {lg_bullet} TerraTek reviewed applicable literature and documentation and convened a project kickoff meeting with Industry Advisors in attendance (see Black and Judzis). {lg_bullet} TerraTek designed and planned Phase I bench scale experiments (See Black and Judzis). Some difficulties continued in obtaining ultra-high speed motors. Improvements were made to the loading mechanism and the rotational speed monitoring instrumentation. New drill bit designs were developed to provided a more consistent product with consistent performance. A test matrix for the final core bit testing program was completed. {lg_bullet} TerraTek concluded Task 3 ''Small-scale cutting performance tests.'' {sm_bullet} Significant testing was performed on nine different rocks. {sm_bullet} Five rocks were used for the final testing. The final tests were based on statistical design of experiments. {sm_bullet} Two full-faced bits, a small diameter and a large diameter, were run in Berea sandstone. {lg_bullet} Analysis of data was completed and indicates that there is decreased specific energy as the rotational speed increases (Task 4). Data analysis from early trials was used to direct the efforts of the final testing for Phase I (Task 5). {lg_bullet} Technology transfer (Task 6) was accomplished with technical presentations to the industry (see Judzis, Boucher, McCammon, and Black).« less

Correlating confocal microscopy and atomic force indentation reveals metastatic cancer cells stiffen during invasion into collagen I matrices

NASA Astrophysics Data System (ADS)

Staunton, Jack R.; Doss, Bryant L.; Lindsay, Stuart; Ros, Robert

2016-01-01

Mechanical interactions between cells and their microenvironment dictate cell phenotype and behavior, calling for cell mechanics measurements in three-dimensional (3D) extracellular matrices (ECM). Here we describe a novel technique for quantitative mechanical characterization of soft, heterogeneous samples in 3D. The technique is based on the integration of atomic force microscopy (AFM) based deep indentation, confocal fluorescence microscopy, finite element (FE) simulations and analytical modeling. With this method, the force response of a cell embedded in 3D ECM can be decoupled from that of its surroundings, enabling quantitative determination of the elastic properties of both the cell and the matrix. We applied the technique to the quantification of the elastic properties of metastatic breast adenocarcinoma cells invading into collagen hydrogels. We found that actively invading and fully embedded cells are significantly stiffer than cells remaining on top of the collagen, a clear example of phenotypical change in response to the 3D environment. Treatment with Rho-associated protein kinase (ROCK) inhibitor significantly reduces this stiffening, indicating that actomyosin contractility plays a major role in the initial steps of metastatic invasion.

Assessment of liquefaction potential during earthquakes by arias intensity

USGS Publications Warehouse

Kayen, R.E.; Mitchell, J.K.

1997-01-01

An Arias intensity approach to assess the liquefaction potential of soil deposits during earthquakes is proposed, using an energy-based measure of the severity of earthquake-shaking recorded on seismograms of the two horizontal components of ground motion. Values representing the severity of strong motion at depth in the soil column are associated with the liquefaction resistance of that layer, as measured by in situ penetration testing (SPT, CPT). This association results in a magnitude-independent boundary that envelopes initial liquefaction of soil in Arias intensity-normalized penetration resistance space. The Arias intensity approach is simple to apply and has proven to be highly reliable in assessing liquefaction potential. The advantages of using Arias intensity as a measure of earthquake-shaking severity in liquefaction assessment are: Arias intensity is derived from integration of the entire seismogram wave form, incorporating both the amplitude and duration elements of ground motion; all frequencies of recorded motion are considered; and Arias intensity is an appropriate measure to use when evaluating field penetration test methodologies that are inherently energy-based. Predictor equations describing the attenuation of Arias intensity as a function of earthquake magnitude and source distance are presented for rock, deep-stiff alluvium, and soft soil sites.

Magnetic Properties of Three Impact Structures in Canada

NASA Astrophysics Data System (ADS)

Scott, R. G.; Pilkington, M.; Tanczyk, E. I.; Grieve, R. A. F.

1995-09-01

Magnetic anomaly lows associated with the West Hawk Lake (Manitoba), Deep Bay (Saskatchewan) and Clearwater Lakes (Quebec) impact structures, are variable in lateral extent and intensity, a characteristic shared with most impact structures [1]. Drill core from the centres of these structures provides a unique opportunity to ground truth the causes of the reduction in magnetic field intensity in impact structures. Magnetic susceptibility and remanent magnetization levels have been found to be well below regional levels in melt rocks, impact breccias, fractured/shocked basement rocks in the central uplifts, and post-impact sediments. Deep Bay, formed in Pre-Cambrian paragneisses, is a complex crater with a submerged central uplift. It has been extensively infilled with non-magnetic black shales of Cretaceous age [2]. An airborne magnetic low of about 100 nT is associated with the Deep Bay structure. Below the shales and along the rim of the structure are highly brecciated country rocks with variable amounts of very fine rock flour. Susceptibility and remanent magnetization are both weak due to extensive alteration in the brecciated rocks. Alteration of the brecciated rocks, and the effect of several hundred meters of non-magnetic sedimentary infill, both contribute to the magnetic low. West Hawk Lake, a simple crater, was excavated in metavolcanic and metasedimentary rocks of the Superior Province [3], and has a ground magnetic low of about 250 nT. As with Deep Bay, West Hawk Lake has been infilled with dominantly non-magnetic sediments. Brecciation and alteration are extensive, with breccia derived from greenschist-facies meta-andesite displaying slightly higher susceptibilities and remanent magnetizations than breccia derived from the more felsic metasediments. Brecciation has effectively randomized magnetization vectors, and subsequent alteration resulted in the destruction of magnetic phases. These two factors contribute to the magnetic low over this structure. The Clearwater Lakes impact structures are two complex craters formed in Archean retrograde granulite facies rocks [4]. Clearwater West, at 36 km diameter, has an annular ring of islands and a shallowly submerged central uplift. Clearwater East, at 26 km diameter, has a more deeply submerged central uplift. The structures are characterised by highly oxidized melt rock and melt- breccia lenses exposed at the surface. Shocked crystalline basement rocks and minor amounts of breccia and melt rock occur in the central uplifts [5]. Despite relatively little alteration at depth, these rocks exhibit both susceptibilities and remanent magnetizations well below the regionally high values. The Clearwater rocks also contain a thermoremanent reversed magnetization, acquired at the time of impact, and characteristic of the Permo-Carboniferous Reversed Polarity Superchron. The magnetization is carried by titanomagnetite in Clearwater West, and both magnetite and pyrrhotite in Clearwater East. This reversed magnetization contributes to the magnetic low, but cannot account for all of it. The intense airborne magnetic low (> 500 nT) requires a significant contribution from the shocked basement at depth, produced by either alteration of magnetic phases along fractures, or reduction in magnetic properties by lower shock levels away from the point of impact [6]. References: [1] Pilkington M. and Grieve R. A. F. (1992) Rev. Geophys., 30, 161-181. [2] Innes M. J. S. et al. (1964) Publ. Dom. Obs. Ottawa, 31, 19-52. [3] Halliday I. and Griffin A. A. (1967) J. Roy. Astron. Soc. Can., 61, 1-8. [4] Simonds C. H. et al. (1978) LPS IX, 2633-2658. [5] Hische R. (1994) Unpublished Ph.D. thesis, Munster. [6] Pohl J. (1994) 3rd Intl. Wkshp., ESF Network Impact Cratering and Evol. of Planet Earth, Shockwave Behavior in Nature and Expt., Progr. Abstr., 51.

The Magmatic Structure of Mt. Vesuvius: Isotopic and Thermal Constraints

NASA Astrophysics Data System (ADS)

Civetta, L.; D'Antonio, M.; de Lorenzo, S.; Gasparini, P.

2002-12-01

Mt. Vesuvius is an active volcano famous for the AD 79 eruption that destroyed Pompeii, Herculaneum and Stabiae. Because of the intense urbanization around and on the volcano, the risk today is very high. Therefore, the knowledge of the structure and behavior of the magmatic system is fundamental both for the interpretation of any change in the dynamics of the volcano and for prediction of eruptions. A review of available and new isotopic data on rocks from Mt. Vesuvius, together with mineralogical and geochemical data and recent geophysical results, allow us to constrain a thermal modeling that describes history and present state of Mt. Vesuvius magmatic system. This system is formed by a "deep", complex magmatic reservoir where mantle-derived magmas arrive, stagnate and differentiate. The reservoir extends discontinuously between 10 and 20 km of depth, is hosted in densely fractured crustal rocks, where magmas and crust can interact, and has been fed more than once since 400 ka. The hypothesis of crustal contamination is favored by the high temperatures reached by crustal rocks as a consequence of repetitive intrusions of magma. From the "deep" reservoir magmas of K-basaltic to K-tephritic to K-phonotephritic composition rise to shallow depths where they stagnate at 3-5 km of depth before plinian eruptions, and through crystallization and mixing processes with the residual portion of the feeding systems, generate isotopically and geochemically layered reservoirs. Alternatively, during "open conduit" conditions deep, volatile-rich magma batches rise from the "deep" reservoir to less than 1 km of depth and mix with the crystal-rich, volatile-poor resident magma, triggering eruptions.

Compaction of mixtures of hard rocks and soft shales and non-durable shales using impact compactors.

DOT National Transportation Integrated Search

2007-06-01

Impact roller compaction has been used to improve embankment and highway subgrades in South Africa, Australia, Europe, and China and other areas of the world. In September of 2003, the International Technology Scanning Program, sponsored by the Feder...

New approaches in the indirect quantification of thermal rock properties in sedimentary basins: the well-log perspective

NASA Astrophysics Data System (ADS)

Fuchs, Sven; Balling, Niels; Förster, Andrea

2016-04-01

Numerical temperature models generated for geodynamic studies as well as for geothermal energy solutions heavily depend on rock thermal properties. Best practice for the determination of those parameters is the measurement of rock samples in the laboratory. Given the necessity to enlarge databases of subsurface rock parameters beyond drill core measurements an approach for the indirect determination of these parameters is developed, for rocks as well a for geological formations. We present new and universally applicable prediction equations for thermal conductivity, thermal diffusivity and specific heat capacity in sedimentary rocks derived from data provided by standard geophysical well logs. The approach is based on a data set of synthetic sedimentary rocks (clastic rocks, carbonates and evaporates) composed of mineral assemblages with variable contents of 15 major rock-forming minerals and porosities varying between 0 and 30%. Petrophysical properties are assigned to both the rock-forming minerals and the pore-filling fluids. Using multivariate statistics, relationships then were explored between each thermal property and well-logged petrophysical parameters (density, sonic interval transit time, hydrogen index, volume fraction of shale and photoelectric absorption index) on a regression sub set of data (70% of data) (Fuchs et al., 2015). Prediction quality was quantified on the remaining test sub set (30% of data). The combination of three to five well-log parameters results in predictions on the order of <15% for thermal conductivity and thermal diffusivity, and of <10% for specific heat capacity. Comparison of predicted and benchmark laboratory thermal conductivity from deep boreholes of the Norwegian-Danish Basin, the North German Basin, and the Molasse Basin results in 3 to 5% larger uncertainties with regard to the test data set. With regard to temperature models, the use of calculated TC borehole profiles approximate measured temperature logs with an error of <3°C along a 4 km deep profile. A benchmark comparison for thermal diffusivity and specific heat capacity is pending. Fuchs, Sven; Balling, Niels; Förster, Andrea (2015): Calculation of thermal conductivity, thermal diffusivity and specific heat capacity of sedimentary rocks using petrophysical well logs, Geophysical Journal International 203, 1977-2000, doi: 10.1093/gji/ggv403

Hydrogen in rocks: an energy source for deep microbial communities

NASA Technical Reports Server (NTRS)

Freund, Friedemann; Dickinson, J. Thomas; Cash, Michele

2002-01-01

To survive in deep subsurface environments, lithotrophic microbial communities require a sustainable energy source such as hydrogen. Though H2 can be produced when water reacts with fresh mineral surfaces and oxidizes ferrous iron, this reaction is unreliable since it depends upon the exposure of fresh rock surfaces via the episodic opening of cracks and fissures. A more reliable and potentially more voluminous H2 source exists in nominally anhydrous minerals of igneous and metamorphic rocks. Our experimental results indicate that H2 molecules can be derived from small amounts of H2O dissolved in minerals in the form of hydroxyl, OH- or O3Si-OH, whenever such minerals crystallized in an H2O-laden environment. Two types of experiments were conducted. Single crystal fracture experiments indicated that hydroxyl pairs undergo an in situ redox conversion to H2 molecules plus peroxy links, O3Si/OO\\SiO3. While the peroxy links become part of the mineral structure, the H2 molecules diffused out of the freshly fractured mineral surfaces. If such a mechanism occurred in natural settings, the entire rock column would become a volume source of H2. Crushing experiments to facilitate the outdiffusion of H2 were conducted with common crustal igneous rocks such as granite, andesite, and labradorite. At least 70 nmol of H2/g diffused out of coarsely crushed andesite, equivalent at standard pressure and temperature to 5,000 cm3 of H2/m3 of rock. In the water-saturated, biologically relevant upper portion of the rock column, the diffusion of H2 out of the minerals will be buffered by H2 saturation of the intergranular water film.

Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China

NASA Astrophysics Data System (ADS)

Zhu, Guang-You; Ren, Rong; Chen, Fei-Ran; Li, Ting-Ting; Chen, Yong-Quan

2017-12-01

The Proterozoic is demonstrated to be an important period for global petroleum systems. Few exploration breakthroughs, however, have been obtained on the system in the Tarim Basin, NW China. Outcrop, drilling, and seismic data are integrated in this paper to focus on the Neoproterozoic rift basins and related hydrocarbon source rocks in the Tarim Basin. The basin consists of Cryogenian to Ediacaran rifts showing a distribution of N-S differentiation. Compared to the Cryogenian basins, those of the Ediacaran are characterized by deposits in small thickness and wide distribution. Thus, the rifts have a typical dual structure, namely the Cryogenian rifting and Ediacaran depression phases that reveal distinct structural and sedimentary characteristics. The Cryogenian rifting basins are dominated by a series of grabens or half grabens, which have a wedge-shaped rapid filling structure. The basins evolved into Ediacaran depression when the rifting and magmatic activities diminished, and extensive overlapping sedimentation occurred. The distributions of the source rocks are controlled by the Neoproterozoic rifts as follows. The present outcrops lie mostly at the margins of the Cryogenian rifting basins where the rapid deposition dominates and the argillaceous rocks have low total organic carbon (TOC) contents; however, the source rocks with high TOC contents should develop in the center of the basins. The Ediacaran source rocks formed in deep water environment of the stable depressions evolving from the previous rifting basins, and are thus more widespread in the Tarim Basin. The confirmation of the Cryogenian to Ediacaran source rocks would open up a new field for the deep hydrocarbon exploration in the Tarim Basin.

Europa's differentiated internal structure: inferences from two Galileo encounters.

PubMed

Anderson, J D; Lau, E L; Sjogren, W L; Schubert, G; Moore, W B

1997-05-23

Doppler data generated with the Galileo spacecraft's radio carrier wave during two Europa encounters on 19 December 1996 (E4) and 20 February 1997 (E6) were used to measure Europa's external gravitational field. The measurements indicate that Europa has a predominantly water ice-liquid outer shell about 100 to 200 kilometers thick and a deep interior with a density in excess of about 4000 kilograms per cubic meter. The deep interior could be a mixture of metal and rock or it could consist of a metal core with a radius about 40 percent of Europa's radius surrounded by a rock mantle with a density of 3000 to 3500 kilograms per cubic meter. The metallic core is favored if Europa has a magnetic field.

Deep Crustal Melting and the Survival of Continental Crust

NASA Astrophysics Data System (ADS)

Whitney, D.; Teyssier, C. P.; Rey, P. F.; Korchinski, M.

2017-12-01

Plate convergence involving continental lithosphere leads to crustal melting, which ultimately stabilizes the crust because it drives rapid upward flow of hot deep crust, followed by rapid cooling at shallow levels. Collision drives partial melting during crustal thickening (at 40-75 km) and/or continental subduction (at 75-100 km). These depths are not typically exceeded by crustal rocks that are exhumed in each setting because partial melting significantly decreases viscosity, facilitating upward flow of deep crust. Results from numerical models and nature indicate that deep crust moves laterally and then vertically, crystallizing at depths as shallow as 2 km. Deep crust flows en masse, without significant segregation of melt into magmatic bodies, over 10s of kms of vertical transport. This is a major mechanism by which deep crust is exhumed and is therefore a significant process of heat and mass transfer in continental evolution. The result of vertical flow of deep, partially molten crust is a migmatite dome. When lithosphere is under extension or transtension, the deep crust is solicited by faulting of the brittle upper crust, and the flow of deep crust in migmatite domes traverses nearly the entire thickness of orogenic crust in <10 million years. This cycle of burial, partial melting, rapid ascent, and crystallization/cooling preserves the continents from being recycled into the mantle by convergent tectonic processes over geologic time. Migmatite domes commonly preserve a record of high-T - low-P metamorphism. Domes may also contain rocks or minerals that record high-T - high-P conditions, including high-P metamorphism broadly coeval with host migmatite, evidence for the deep crustal origin of migmatite. There exists a spectrum of domes, from entirely deep-sourced to mixtures of deep and shallow sources. Controlling factors in deep vs. shallow sources are relative densities of crustal layers and rate of extension: fast extension (cm/yr) promotes efficient ascent of deep crust, whereas slow extension (mm/yr) produces significantly less exhumation. Recognition of the importance of migmatite (gneiss) domes as archives of orogenic deep crust is applicable to determining the chemical and physical properties of continental crust, as well as mechanisms and timescales of crustal differentiation.

The Influence of Stratigraphic History on Landscape Evolution

NASA Astrophysics Data System (ADS)

Forte, A. M.; Yanites, B.; Whipple, K. X.

2016-12-01

Variation in rock erodibility can play a significant role in landscape evolution. Using a version of the CHILD landscape evolution model that allows for variations in rock erodibility, we found surprisingly complex landscape evolution in simulations with simple, two unit stratigraphies with contrasting erodibility. This work indicated that the stratigraphic order of units in terms of erodibility, the orientation of the contact with respect to the main drainage direction, and the contact dip angle all have pronounced effects on landscape evolution. Here we expand that work to explore the implications of more complicated stratigraphies on landscape evolution. Introducing multiple units adds additional controls on landscape evolution, namely the thicknesses and relative erodibility of rock layers. In models with a sequence of five alternating hard and soft units embedded within arbitrarily thick over- and underlying units, the number of individual layers that noticeably influence landscape morphology decreases as the thickness of individual layers reduces. Contacts with soft rocks over hard produce the most noticeable effect in model output such as erosion rate and channel steepness. For large contrasts in erodibility of 25 m thick layers, only one soft over hard contact is clearly manifest in the landscape. Between 50 and 75 m, two such contacts are manifest, and by 100 m thickness, all three of these contacts are manifest. However, for a given thickness of layers, more units are manifest in the landscape as the erodibility contrast between units decreases. This is true even though the magnitude of landscape effects away from steady-state erosion rates or channel steepness also decrease with decreasing erodibility contrast. Finally, we explore suites of models with alternating layers reflecting either `hardening-' or `softening-upwards' stratigraphies and find that the two scenarios result in decidedly different landscape forms. Hardening-upwards sections produce a gradational change where as individual layers have more influence in the landscape form in softening-upwards sections. Generally, our modeling highlights that past depositional history can exert a fundamental control on landscape evolution during later erosion through the resulting layered stratigraphy.

Novel determination of radon-222 velocity in deep subsurface rocks and the feasibility to using radon as an earthquake precursor

NASA Astrophysics Data System (ADS)

Zafrir, Hovav; Ben Horin, Yochai; Malik, Uri; Chemo, Chaim; Zalevsky, Zeev

2016-09-01

A novel technique utilizing simultaneous radon monitoring by gamma and alpha detectors to differentiate between the radon climatic driving forces and others has been improved and used for deep subsurface investigation. Detailed long-term monitoring served as a proxy for studying radon movement within the shallow and deep subsurface, as well as for analyzing the effect of various parameters of the radon transport pattern. The main achievements of the investigation are (a) determination, for the first time, of the radon movement velocity within rock layers at depths of several tens of meters, namely, 25 m/h on average; (b) distinguishing between the diurnal periodical effect of the ambient temperature and the semidiurnal effect of the ambient pressure on the radon temporal spectrum; and (c) identification of a radon random preseismic anomaly preceding the Nuweiba, M 5.5 earthquake of 27 June 2015 that occurred within Dead Sea Fault Zone.

Inter-disciplinary Interactions in Underground Laboratories

NASA Astrophysics Data System (ADS)

Wang, J. S.; Bettini, A.

2010-12-01

Many of underground facilities, ranging from simple cavities to fully equipped laboratories, have been established worldwide (1) to evaluate the impacts of emplacing nuclear wastes in underground research laboratories (URLs) and (2) to measure rare physics events in deep underground laboratories (DULs). In this presentation, we compare similarities and differences between URLs and DULs in focus of site characterization, in quantification of quietness, and in improvement of signal to noise ratios. The nuclear waste URLs are located primarily in geological medium with potentials for slow flow/transport and long isolation. The URL medium include plastic salt, hard rock, soft clay, volcanic tuff, basalt and shale, at over ~500 m where waste repositories are envisioned to be excavated. The majority of URLs are dedicated facilities excavated after extensive site characterization. The focuses are on fracture distributions, heterogeneity, scaling, coupled processes, and other fundamental issues of earth sciences. For the physics DULs, the depth/overburden thickness is the main parameter that determines the damping of cosmic rays, and that, consequently, should be larger than, typically, 800m. Radioactivity from rocks, neutron flux, and radon gas, depending on local rock and ventilation conditions (largely independent of depth), are also characterized at different sites to quantify the background level for physics experiments. DULs have been constructed by excavating dedicated experimental halls and service cavities near to a road tunnel (horizontal access) or in a mine (vertical access). Cavities at shallower depths are suitable for experiments on neutrinos from artificial source, power reactors or accelerators. Rocks stability (depth dependent), safe access, and utility supply are among factors of main concerns for DULs. While the focuses and missions of URLs and DULs are very different, common experience and lessons learned may be useful for ongoing development of new facilities needed for next generation of underground assessments and experiments. There are growing interests in developing multi-disciplinary programs in DULs and some URLs have rooms set aside for physics experiments. Examples of DULs and URLs with interactions between earth sciences and physics include Gran Sasso in Italy, Kaimioka in Japan, Canfranc in Spain, LSBB in France, WIPP in New Mexico, DUSEL in South Dakota, and Jing Ping deep tunnel underground laboratory proposal in China. Instruments of common interests include interferometers, laser strain meters, seismic networks, tiltmeters, gravimeters, magnetometers, and other sensors to detect signals over different frequencies and water chemical analyses, including radon concentrations. Radon emissions are of concern for physics experiments and are studied as possible precursors of earthquakes. Measuring geoneutrino flux and energy spectrum in different locations is of interests to both physics and earth sciences. The contributions of U and Th in the crust and the mantle to the energy production in the Earth can be studied. One final note is that our ongoing reviews are aimed to contribute to technological innovations anticipated through inter-disciplinary interactions.

Experimental ductile reactivation of pseudotachylyte-bearing faults.

NASA Astrophysics Data System (ADS)

Tielke, J.; Di Toro, G.; Passelegue, F. X.; Mecklenburgh, J.

2017-12-01

In most large earthquakes, afterslip is primarily accommodated by ductile deformation in the deep crust and upper mantle. In the last decades, field and experimental studies highlighted that seismic rupture can induce frictional meltin. The product of frictional melting, called pseudotachylyte, is considered the best signature of seismic rupture in exposed sections of rocks. Deformation of pseudotachylyte in the deep crust may explain the observed reduction of the strength after earthquakes, providing an explanation for the large afterslip or creep phenomena. In addition, the observation of natural mylonitized pseudotachylytes confirms the hypothesis of ductile reactivations. In this study, we conducted experiments under deep crust PT conditions on natural pseudotachylyte and tonalite from the Gole Larghe fault zone. Deformation experiments were carried out using a gas-medium apparatus at temperatures of 700° to 900°C, a confining pressure of 300 MPa, differential stresses stages of 5 to 400 MPa resulting in different strain rates. Mechanical data were used to derive flow law parameters. The intact tonalite present the largest strength of the rocks tested. The deformation mechanisms remain mostly brittle even at 900°C, and experiments finished by the brittle failure of the rock specimens. In pseudotachylyte-bearing tonalite, strain is strongly localized within pseudotachylyte-rich regions. While the rocks samples remain strong at 700°C , weakening initiates at 800°C. The dependence of strain rate on stress follows a power-law relationship with a stress exponent (n) of 1 at low differential stress, and 3 at high differential stress. At 900°C, the strength of the pseudotachylyte vein samples drastically weakens and values of n of 3 are observed even at low differential stress. Microstructural analyses demonstrate that strain localization in pseudotachylite-bearing rocks corresponds with the initiation of partial melting at 800°C. In contrast, tonalite that is free of pseudotachylite only exhibits brittle processes. Evidence of the initiation of mylonitization is observed at low strain conditions. Our results suggest that the presence of pseudotachylyte in crustal rocks drastically reduces the strength of the system when the temperature allows for initiation of partial melting.

Petrographic and geochemical comparisons between the lower crystalline basement-derived section and the granite megablock and amphibolite megablock of the Eyreville-B core, Chesapeake Bay impact structure

USGS Publications Warehouse

Townsend, Gabrielle N.; Gibson, Roger L.; Horton, J. Wright; Reimold, Wolf Uwe; Schmitt, Ralf T.; Bartosova, Katerina

2009-01-01

The Eyreville B core from the Chesapeake Bay impact structure, Virginia, USA, contains a lower basement-derived section (1551.19 m to 1766.32 m deep) and two megablocks of dominantly (1) amphibolite (1376.38 m to 1389.35 m deep) and (2) granite (1095.74 m to 1371.11 m deep), which are separated by an impactite succession. Metasedimentary rocks (muscovite-quartz-plagioclase-biotite-graphite ± fibrolite ± garnet ± tourmaline ± pyrite ± rutile ± pyrrhotite mica schist, hornblende-plagioclase-epidote-biotite-K-feldspar-quartz-titanite-calcite amphibolite, and vesuvianite-plagioclase-quartz-epidote calc-silicate rock) are dominant in the upper part of the lower basement-derived section, and they are intruded by pegmatitic to coarse-grained granite (K-feldspar-plagioclase-quartz-muscovite ± biotite ± garnet) that increases in volume proportion downward. The granite megablock contains both gneissic and weakly or nonfoliated biotite granite varieties (K-feldspar-quartz-plagioclase-biotite ± muscovite ± pyrite), with small schist xenoliths consisting of biotite-plagioclase-quartz ± epidote ± amphibole. The lower basement-derived section and both megablocks exhibit similar middle- to upper-amphibolite-facies metamorphic grades that suggest they might represent parts of a single terrane. However, the mica schists in the lower basement-derived sequence and in the megablock xenoliths show differences in both mineralogy and whole-rock chemistry that suggest a more mafic source for the xenoliths. Similarly, the mineralogy of the amphibolite in the lower basement-derived section and its association with calc-silicate rock suggest a sedimentary protolith, whereas the bulk-rock and mineral chemistry of the megablock amphibolite indicate an igneous protolith. The lower basement-derived granite also shows bulk chemical and mineralogical differences from the megablock gneissic and biotite granites.

Lake

ERIC Educational Resources Information Center

Wien, Carol Anne

2008-01-01

The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

SHINING ROCK WILDERNESS, NORTH CAROLINA.

USGS Publications Warehouse

Lesure, Frank G.; Dunn, Maynard L.

1984-01-01

The Shining Rock Wilderness, in the Blue Ridge Mountains of Haywood County, North Carolina, is underlain by complexly folded mica gneiss and schist of Precambrian age. A mineral-resource survey determined that two commodities, quartz as a source of silica (SiO//2) and gneiss and schist suitable for common building stone and crushed rock, are present in large quantities. Demonstrated resources of silica occur at Shining Rock Mountain and small amounts of sheet muscovite (mica) and scrap mica are present at about 10 localities. Until deep drilling is done to test the results of the seismic studies, no estimate of the potential for gas can be made, but the presence of gas cannot be totally discounted.

Dedifferentiated liposarcoma of the deep (paralaryngeal) soft tissue: lessons learnt from a case with a partly deceptively benign appearing dedifferentiated component.

PubMed

Petersson, Fredrik; Murugasu, Euan

2014-06-01

We present a case (female, 61 years of age) of dedifferentiated liposarcoma of the deep, cervical (paralaryngeal) soft tissue with a significant myxoid component and characteristic immunohistochemical (strong and diffuse expression of p16, mdm2 and cdk4 in both the well differentiated liposarcomatous and dedifferentiated components) and molecular genetic findings (MDM2-gene amplification on fluorescence in situ hybridization). The myxoid component which was present in the well differentiated liposarcomatous component gave the tumor atypical radiological features. The case presented initial diagnostic difficulties, mainly because of the bland histomorphological appearance of the limited biopsy material from the sampled non-lipogenic, dedifferentiated component. The dedifferentiated part of the tumor turned out to harbor significant heterogeneity with regards to cellularity, cytomorphology and proliferative activity.

Numerical Simulation of Focused Shock Shear Waves in Soft Solids and a Two-Dimensional Nonlinear Homogeneous Model of the Brain

PubMed Central

Giammarinaro, B.; Coulouvrat, F.; Pinton, G.

2016-01-01

Shear waves that propagate in soft solids, such as the brain, are strongly nonlinear and can develop into shock waves in less than one wavelength. We hypothesize that these shear shock waves could be responsible for certain types of traumatic brain injuries (TBI) and that the spherical geometry of the skull bone could focus shear waves deep in the brain, generating diffuse axonal injuries. Theoretical models and numerical methods that describe nonlinear polarized shear waves in soft solids such as the brain are presented. They include the cubic nonlinearities that are characteristic of soft solids and the specific types of nonclassical attenuation and dispersion observed in soft tissues and the brain. The numerical methods are validated with analytical solutions, where possible, and with self-similar scaling laws where no known solutions exist. Initial conditions based on a human head X-ray microtomography (CT) were used to simulate focused shear shock waves in the brain. Three regimes are investigated with shock wave formation distances of 2.54 m, 0.018 m, and 0.0064 m. We demonstrate that under realistic loading scenarios, with nonlinear properties consistent with measurements in the brain, and when the shock wave propagation distance and focal distance coincide, nonlinear propagation can easily overcome attenuation to generate shear shocks deep inside the brain. Due to these effects, the accelerations in the focal are larger by a factor of 15 compared to acceleration at the skull surface. These results suggest that shock wave focusing could be responsible for diffuse axonal injuries. PMID:26833489

Geophysical investigations in deep horizontal holes drilled ahead of tunnelling

USGS Publications Warehouse

Carroll, R.D.; Cunningham, M.J.

1980-01-01

Deep horizontal drill holes have been used since 1967 by the Defense Nuclear Agency as a primary exploration tool for siting nuclear events in tunnels at the Nevada Test Site. The U.S. Geological Survey had developed geophysical logging techniques for obtaining resistivity and velocity in these holes, and to date 33 horizontal drill holes in excess of 300 m in depth have been successfully logged. The deepest hole was drilled to a horizontal depth of 1125 m. The purposes of the logging measurements are to define clay zones, because of the unstable ground conditions such zones can present to tunnelling, and to define zones of partially saturated rock, because of the attenuating effects such zones have on the shock wave generated by the nuclear detonation. Excessive attenuation is undesirable because the shock wave is used as a tunnel closure mechanism to contain debris and other undesirable explosion products. Measurements are made by pumping resistivity, sonic and geophone probes down the drill string and out of the bit into the open hole. Clay zones are defined by the electrical resistivity technique based on empirical data relating the magnitude of the resistivity measurement to qualitative clay content. Rock exhibiting resistivity of less than 20 ??-m is considered potentially unstable, and resistivities less than 10 ??-m indicate appreciable amounts of clay are present in the rock. Partially saturated rock zones are defined by the measurement of the rock sound speed. Zones in the rock which exhibit velocities less than 2450 m/sec are considered of potential concern. ?? 1980.

The underwater photic environment of Cape Maclear, Lake Malawi: comparison between rock- and sand-bottom habitats and implications for cichlid fish vision.

PubMed

Sabbah, Shai; Gray, Suzanne M; Boss, Emmanuel S; Fraser, James M; Zatha, Richard; Hawryshyn, Craig W

2011-02-01

Lake Malawi boasts the highest diversity of freshwater fishes in the world. Nearshore sites are categorized according to their bottom substrate, rock or sand, and these habitats host divergent assemblages of cichlid fishes. Sexual selection driven by mate choice in cichlids led to spectacular diversification in male nuptial coloration. This suggests that the spectral radiance contrast of fish, the main determinant of visibility under water, plays a crucial role in cichlid visual communication. This study provides the first detailed description of underwater irradiance, radiance and beam attenuation at selected sites representing two major habitats in Lake Malawi. These quantities are essential for estimating radiance contrast and, thus, the constraints imposed on fish body coloration. Irradiance spectra in the sand habitat were shifted to longer wavelengths compared with those in the rock habitat. Beam attenuation in the sand habitat was higher than in the rock habitat. The effects of water depth, bottom depth and proximity to the lake bottom on radiometric quantities are discussed. The radiance contrast of targets exhibiting diffused and spectrally uniform reflectance depended on habitat type in deep water but not in shallow water. In deep water, radiance contrast of such targets was maximal at long wavelengths in the sand habitat and at short wavelengths in the rock habitat. Thus, to achieve conspicuousness, color patterns of rock- and sand-dwelling cichlids would be restricted to short and long wavelengths, respectively. This study provides a useful platform for the examination of cichlid visual communication.

Asbestos. LC Science Tracer Bullet.

ERIC Educational Resources Information Center

Evans, Joanna, Comp.

Asbestos is a generic term that refers to several silicate materials occurring naturally as fibrous rocks. Insignificant amounts of asbestos fiber can be found in ambient air, but this, and materials containing hard asbestos, usually do not create problems. Soft materials, however, can release high amounts of asbestos fibers into the air, and…

Distinguishing Indigenous from Contaminating Microorganisms in Rock Samples from a Deep Au Mine in South Africa

NASA Technical Reports Server (NTRS)

Onstott, T. C.; Moser, D. P.; Fredrickson, J. K.; Pfiffner, S. M.; Phelps, T. J.; White, D. C.; Peacock, A.; Balkwill, D.; Hoover, R. B.; Krumholz, L.;

Mega-features at the Table Rock phreatomagmatic complex in Christmas Valley, Oregon; Law of original horizontality need not apply

NASA Astrophysics Data System (ADS)

Brand, B. D.; Clarke, A.

2006-12-01

The Table Rock Complex (TRC; Pliocene-Pleistocene), first documented and described by (Heiken, 1971, J. Geophy Res, 76, 5615-5626) is a large and well exposed phreatomagmatic complex in the Fort Rock- Christmas Lake Valley Basin, south-central Oregon. It is ~7 by 5 km and contains two large phreatomagmatic edifices; a large southern tuff cone with a capping lava lake (TRC1), and a large broad tuff ring in the northeast (TRC2). At least five additional, smaller tuff rings were identified along the flanks of the complex, yielding a complicated network of tuff ring-tuff cone deposits. Based on the low accidental component and evidence for a lake during this time, the cause of the explosive eruptions is interpreted to be due to interaction of magma with shallow standing water. The TRC1 consists of fining-up sequences, large erosive channel scour and fill deposits, massive tuff breccias, and abundant soft sediment deformation, which suggests deposition within a standing body of water. Subaerial TRC1 deposits are found south of the edifice, but are not exposed in the north. A significant repose period occurred between the TRC1 and TRC2 eruptions, evidenced by a wave-cut terrace and 25-50 cm of diatomitic lake sediments. TRC2 produced multiple, extremely erosive pyroclastic surges, which cut and scour the TRC1 deposits. Surge deposits consist of 50-200 m wavelength cross-beds, in some areas form large U-shaped features (10-100 m deep), and can be seen plastering up and around large obstacles from previous vents. The surge-deposits blanket all other sequences and create a hummocky topography around the edifice. This suggests that TRC2 was the last eruption in the sequence. The weight of the TRC2 sediments caused the water-saturated TRC1 sediments to plastically deform into large ball and pillow features and overturned slump blocks on the order of 20-50 m thick. The smaller flank tuff-ring eruptions likely occurred sometime between the TRC1 and TRC2 events. The inner-craters of these vents are well exposed and show features such as near-vertical plastered beds, large-scale convolute bedding, and in some places deformed and folded slump blocks up to 20-120 m thick. The features observed in both TRC deposits and in the smaller flank tuff rings (e.g., large-scale soft sediment deformation, plastered-vertical bedding, accretionary/armored lapilli) are consistent with a high water-magma ratio. The highly erosive surge beds of TRC2 represent the most energetic pulse of the eruptions.

Strontium isotope constraints on fluid flow in the sheeted dike complex of fast spreading crust: Pervasive fluid flow at Pito Deep

NASA Astrophysics Data System (ADS)

Barker, A. K.; Coogan, L. A.; Gillis, K. M.; Weis, D.

2008-06-01

Fluid flow through the axial hydrothermal system at fast spreading ridges is investigated using the Sr-isotopic composition of upper crustal samples recovered from a tectonic window at Pito Deep (NE Easter microplate). Samples from the sheeted dike complex collected away from macroscopic evidence of channelized fluid flow, such as faults and centimeter-scale hydrothermal veins, show a range of 87Sr/86Sr from 0.7025 to 0.7030 averaging 0.70276 relative to a protolith with 87Sr/86Sr of ˜0.7024. There is no systematic variation in 87Sr/86Sr with depth in the sheeted dike complex. Comparison of these new data with the two other localities that similar data sets exist for (ODP Hole 504B and the Hess Deep tectonic window) reveals that the extent of Sr-isotope exchange is similar in all of these locations. Models that assume that fluid-rock reaction occurs during one-dimensional (recharge) flow lead to significant decreases in the predicted extent of isotopic modification of the rock with depth in the crust. These model results show systematic misfits when compared with the data that can only be avoided if the fluid flow is assumed to be focused in isolated channels with very slow fluid-rock exchange. In this scenario the fluid at the base of the crust is little modified in 87Sr/86Sr from seawater and thus unlike vent fluids. Additionally, this model predicts that some rocks should show no change from the fresh-rock 87Sr/86Sr, but this is not observed. Alternatively, models in which fluid-rock reaction occurs during upflow (discharge) as well as downflow, or in which fluids are recirculated within the hydrothermal system, can reproduce the observed lack of variation in 87Sr/86Sr with depth in the crust. Minimum time-integrated fluid fluxes, calculated from mass balance, are between 1.5 and 2.6 × 106 kg m-2 for all areas studied to date. However, new evidence from both the rocks and a compilation of vent fluid compositions demonstrates that some Sr is leached from the crust. Because this leaching lowers the fluid 87Sr/86Sr without changing the rock 87Sr/86Sr, these mass balance models must underestimate the time-integrated fluid flux. Additionally, these values do not account for fluid flow that is channelized within the crust.

Deep dopamine extravasation injury: a case report.

PubMed

Phillips, Reid A; Andrades, Patricio; Grant, John H; Ray, Peter D

2009-07-01

We report the case of a 3-month-old girl with Down's syndrome, who sustained a deep and massive extravasation of dopamine, resulting in segmented, full-thickness skin necrosis and transient brachial plexus palsy of her left upper extremity. The patient was managed conservatively, including wound care, de-bridement of necrotic tissue, secondary wound healing and intensive physical therapy. The patient showed a satisfactory outcome with complete secondary closure of her wounds and full brachial plexus recovery after 1 year of follow-up. The mechanism of action of dopamine in the deep soft tissue, the difficulties of an adequate diagnosis of a deep dopamine extravasation and alternative treatments are presented in this article.

The cosmic native iron in Upper Jurassic to Miocene deep-sea deposits of the western North Atlantic

NASA Astrophysics Data System (ADS)

Murdmaa, Ivar; Pechersky, Diamar; Nurgaliev, Danis; Gilmanova, Di; Sloistov, Sergey

2014-05-01

Thermomagnetic analysis of 335 rock samples from DSDP sites 386, 387 (Leg 43) and 391 A, C (Leg 44) drilled in the western North Atlantic revealed distribution patterns of native Fe particles in Upper Jurassic to Miocene deep-sea deposits. Native iron occurs in deep-sea rocks as individual particles from tens of nm to 100 µm in size. The native Fe is identified throughout the sections recovered. Its concentration ranges from nx10-6% to 5x10-3%, but zero values persist to occur in each lithostratigraphic unit studied. The bimodal distribution of the native iron concentration with a zero mode is typical for the cosmic dust in sedimentary rocks, because of its slow flux to the Earth surface, as compared to sedimentation fluxes. Ni admixture in native Fe also demonstrates bimodal distribution with the zero mode (pure Fe) and a mode 5 - 6% that corresponds to average Ni content in the cosmic dust and meteorites. Concentration of native Fe does not depend on rock types and geological age. Relatively high mean native Fe concentrations (less zero values) occur in Lower Cretaceous laminated limestones (sites 387, 391) interpreted as contourites and in Oligocene volcaniclastic turbidites of the Bermuda Rise foot (Site 386), whereas minimum values are measured in Miocene mass flow deposits (Site 391). We suggest that concentration of native Fe increases in deposits of pulsating sedimentation (turbidites, laminated contourites) due to numerous short hiatuses and slow sedimentation events in between instantaneous turbidite or contourite deposition pulses. Extreme values possibly indicate cosmic dust flux anomalies. The study was partially supported by RFBR, research project No. 14-05-00744a.

Discontinuum-Equivalent Continuum Analysis of the Stability of Tunnels in a Deep Coal Mine Using the Distinct Element Method

NASA Astrophysics Data System (ADS)

Shreedharan, Srisharan; Kulatilake, Pinnaduwa H. S. W.

2016-05-01

An imperative task for successful underground mining is to ensure the stability of underground structures. This is more so for deep excavations which may be under significantly high stresses. In this manuscript, we present stability studies on two tunnels, a horseshoe-shaped and an inverted arch-shaped tunnel, in a deep coal mine in China, performed using the 3DEC distinct element code. The rock mass mechanical property values for the tunnel shapes have been estimated through a back-analysis procedure using available field deformation data. The back-analysis has been carried out through a pseudo-time dependent support installation routine which incorporates the effect of time through a stress-relaxation mechanism. The back-analysis indicates that the rock mass cohesion, tensile strength, uniaxial compressive strength, and elastic modulus values are about 35-45 % of the corresponding intact rock property values. Additionally, the importance of incorporating stress relaxation before support installation has been illustrated through the increased support factor of safety and reduced grout failures. The calibrated models have been analyzed for different supported and unsupported cases to estimate the significance and adequacy of the current supports being used in the mine and to suggest a possible optimization. The effects of supports have been demonstrated using deformations and yield zones around the tunnels, and average factors of safety and grout failures of the supports. The use of longer supports and floor bolting has provided greater stability for the rock masses around the tunnels. Finally, a comparison between the two differently shaped tunnels establishes that the inverted arch tunnel may be more efficient in reducing roof sag and floor heave for the existing geo-mining conditions.

Element mobilization and redistribution under extreme tropical weathering of basalts from the Hainan Island, South China

NASA Astrophysics Data System (ADS)

Jiang, Ke; Qi, Hua-Wen; Hu, Rui-Zhong

2018-06-01

Chemical weathering of rocks has substantial influence on the global geochemical cycle. In this paper, the geochemical profile of a well-developed basalt weathering profile (>15 m thick, including soil, saprolite, semi-weathered rock and fresh basalt) on the Island of Hainan (South China) was presented. The soil and saprolite samples from this profile are characterized by high Al2O3 and Fe2O3 concentrations (up to 32.3% and 28.5%, respectively). The mineral assemblage is dominated by kaolinite, Fe-oxides/-hydroxides and gibbsite (or boehmite), indicating extensive desilicate and ferrallitic weathering. The acidic and organic-rich environment in the soil horizon may have promoted elemental remobilization and leaching. The strongest SiO2 depletion and Al2O3 enrichment at about 2.4 m deep indicate that the main kaolinite hydrolysis and gibbsite formation occurred near the soil-saprolite interface. The mild Sr reconcentration at about 3.9 m and 7.1 m deep may be attributed to secondary carbonate precipitation. Mn-oxides/-hydroxides precipitated at 6.1 m deep, accompanied by the strongest enrichment of Ba and Co. Uranium is mildly enriched in the middle part (about 7.1 m and 9.1 m deep) of the weathering profile, and the enrichment may have been caused by the decomposition of uranyl carbonates or the accumulation of zircon. Immobile element (i.e., Zr, Hf, Nb, Ta, Th and Ti) distributions at different depths are mainly controlled by secondary Fe-oxides/-hydroxides, and follow the stability sequence of Nb ≈ Ta ≈ Th > Zr ≈ Hf > Ti. The limited thickness (∼15 cm) of the semi-weathered basalt horizon at the rock-regolith interface (15.28 m deep) suggests that plagioclase and pyroxene are readily altered to kaolinite, smectite and Fe-oxides under tropical climate. The marked enrichment of transitional metals (such as Cu, Zn, Ni, and Sc) along the rock-regolith interface may have associated mainly with increasing pH values, as well as the dissolution of primary apatite and formation of secondary phosphates. Our findings highlight the importance of secondary phosphates in the redistribution of transition metals, and in the possible Mg, Cu, and Ni isotopic fractionation under extreme weathering of basalt in tropic climate.

Stability of column-supported embankments.

DOT National Transportation Integrated Search

2006-01-01

Column-supported embankments have a great potential for application in the coastal regions of Virginia, where highway embankments are often constructed on soft ground. The columns can be driven piles, vibro-concrete columns, deep-mixing-method column...

ANALYSIS OF LABOUR ACCIDENTS DUE TO ROCK FALL EVENTS IN CUTTING FACE OF TUNNEL AND STUDY OF THE COUNTERMEASURES FOR SAFETY

NASA Astrophysics Data System (ADS)

Kikkawa, Naotaka; Itoh, Kazuya; Hori, Tomohito; Tamate, Satoshi; Toyosawa, Yasuo

In this paper, we analysed the labour accidents which had casualties due to rock fall events in the headings of tunnel and cleared the condition of the occurrence. It was clearly revealed that the accidents mostly happened when the workers mounted the explosive and the steel arch in the headings of the mountain tunnel. In addition, the dimension of the rocks fallen were averagely 0.6m diameter, it was not so much large. Therefore, the countermeasures based on both soft and hard faces would be useful and effective, such as the displacement measurement of a cutting face of tunnel, securing the sufficient lights to observe the cutting face, boring for drainage and shotcreting in a heading of tunnel.

Potassium metasomatism of volcanic and sedimentary rocks in rift basins, calderas and detachment terranes

NASA Technical Reports Server (NTRS)

Chapin, C. E.; drographic basins.

1985-01-01

The chemical, mineralogical, and oxygen-isotopic changes accompanying K-metasomatism are described. The similarities with diagenetic reactions in both deep marine and alkaline, saline-lake environments are noted. The common occurrence of K-metasomatism in upper-plate rocks of detachment terranes indicates that the early stage of severe regional extension causes crustal downwarping and, in arid to semi-arid regions, development of closed hydrographic basins.

A minimalistic microbial food web in an excavated deep subsurface clay rock.

PubMed

Bagnoud, Alexandre; de Bruijn, Ino; Andersson, Anders F; Diomidis, Nikitas; Leupin, Olivier X; Schwyn, Bernhard; Bernier-Latmani, Rizlan

2016-01-01

Clay rocks are being considered for radioactive waste disposal, but relatively little is known about the impact of microbes on the long-term safety of geological repositories. Thus, a more complete understanding of microbial community structure and function in these environments would provide further detail for the evaluation of the safety of geological disposal of radioactive waste in clay rocks. It would also provide a unique glimpse into a poorly studied deep subsurface microbial ecosystem. Previous studies concluded that microorganisms were present in pristine Opalinus Clay, but inactive. In this work, we describe the microbial community and assess the metabolic activities taking place within borehole water. Metagenomic sequencing and genome-binning of a porewater sample containing suspended clay particles revealed a remarkably simple heterotrophic microbial community, fueled by sedimentary organic carbon, mainly composed of two organisms: a Pseudomonas sp. fermenting bacterium growing on organic macromolecules and releasing organic acids and H2, and a sulfate-reducing Peptococcaceae able to oxidize organic molecules to CO(2). In Opalinus Clay, this microbial system likely thrives where pore space allows it. In a repository, this may occur where the clay rock has been locally damaged by excavation or in engineered backfills. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Biogeography of serpentinite-hosted microbial ecosystems

NASA Astrophysics Data System (ADS)

Brazelton, W.; Cardace, D.; Fruh-Green, G.; Lang, S. Q.; Lilley, M. D.; Morrill, P. L.; Szponar, N.; Twing, K. I.; Schrenk, M. O.

2012-12-01

Ultramafic rocks in the Earth's mantle represent a tremendous reservoir of carbon and reducing power. Upon tectonic uplift and exposure to fluid flow, serpentinization of these materials generates copious energy, sustains abiogenic synthesis of organic molecules, and releases hydrogen gas (H2). To date, however, the "serpentinite microbiome" is poorly constrained- almost nothing is known about the microbial diversity endemic to rocks actively undergoing serpentinization. Through the Census of Deep Life, we have obtained 16S rRNA gene pyrotag sequences from fluids and rocks from serpentinizing ophiolites in California, Canada, and Italy. The samples include high pH serpentinite springs, presumably representative of deeper environments within the ophiolite complex, wells which directly access subsurface aquifers, and rocks obtained from drill cores into serpentinites. These data represent a unique opportunity to examine biogeographic patterns among a restricted set of microbial taxa that are adapted to similar environmental conditions and are inhabiting sites with related geological histories. In general, our results point to potentially H2-utilizing Betaproteobacteria thriving in shallow, oxic-anoxic transition zones and anaerobic Clostridia thriving in anoxic, deep subsurface habitats. These general taxonomic and biogeochemical trends were also observed in seafloor Lost City hydrothermal chimneys, indicating that we are beginning to identify a core serpentinite microbial community that spans marine and continental settings.

Microtomography-based Inter-Granular Network for the simulation of radionuclide diffusion and sorption in a granitic rock

NASA Astrophysics Data System (ADS)

Iraola, Aitor; Trinchero, Paolo; Voutilainen, Mikko; Gylling, Björn; Selroos, Jan-Olof; Molinero, Jorge; Svensson, Urban; Bosbach, Dirk; Deissmann, Guido

2017-12-01

Field investigation studies, conducted in the context of safety analyses of deep geological repositories for nuclear waste, have pointed out that in fractured crystalline rocks sorbing radionuclides can diffuse surprisingly long distances deep into the intact rock matrix; i.e. much longer distances than those predicted by reactive transport models based on a homogeneous description of the properties of the rock matrix. Here, we focus on cesium diffusion and use detailed micro characterisation data, based on micro computed tomography, along with a grain-scale Inter-Granular Network model, to offer a plausible explanation for the anomalously long cesium penetration profiles observed in these in-situ experiments. The sparse distribution of chemically reactive grains (i.e. grains belonging to sorbing mineral phases) is shown to have a strong control on the diffusive patterns of sorbing radionuclides. The computed penetration profiles of cesium agree well with an analytical model based on two parallel diffusive pathways. This agreement, along with visual inspection of the spatial distribution of cesium concentration, indicates that for sorbing radionuclides the medium indeed behaves as a composite system, with most of the mass being retained close to the injection boundary and a non-negligible part diffusing faster along preferential diffusive pathways.

Gravity-Independent Mobility and Drilling on Natural Rock using Microspines

NASA Technical Reports Server (NTRS)

Parness, Aaron; Frost, Matthew; Thatte, Nitish; King, Jonathan P.

2012-01-01

To grip rocks on the surfaces of asteroids and comets, and to grip the cliff faces and lava tubes of Mars, a 250 mm diameter omni-directional anchor is presented that utilizes a hierarchical array of claws with suspension flexures, called microspines, to create fast, strong attachment. Prototypes have been demonstrated on vesicular basalt and a'a lava rock supporting forces in all directions away from the rock. Each anchor can support >160 N tangent, >150 N at 45?, and >180 N normal to the surface of the rock. A two-actuator selectively- compliant ankle interfaces these anchors to the Lemur IIB robot for climbing trials. A rotary percussive drill was also integrated into the anchor, demonstrating self-contained rock coring regardless of gravitational orientation. As a harder- than-zero-g proof of concept, 20mm diameter boreholes were drilled 83 mm deep in vesicular basalt samples, retaining a 12 mm diameter rock core in 3-6 pieces while in an inverted configuration, literally drilling into the ceiling.

New Frontiers for Deep Fluids and Geobiology Research in the World's Oldest Rocks

NASA Astrophysics Data System (ADS)

Sherwood Lollar, B.; Li, L.; Wing, B. A.; Warr, O.; Sica, C. S.; Lollar, G. S.; Sutcliffe, N. C.; Telling, J.; Ballentine, C. J.; Giunta, T.; McDermott, J. M.

2016-12-01

Discovery of new environmental systems that facilitate investigation of biodiversity, microbial metabolism, life's adaptation to extreme conditions, and limits to life, have expanded our conception of Earth's habitability and informed search strategies for life elsewhere in the solar system. While chemolithotrophic microbial ecosystems in the marine biosphere have been investigated for decades, the geobiology of terrestrial systems is undergoing a recent expansion, in particular to include the > 70% of the continental lithosphere comprised of Precambrian rocks - the oldest rocks on Earth. Underground research laboratories and mines worldwide provide access to the deep subsurface in Precambrian settings, and targets for investigation of extant microbial ecosystems. Kidd Creek Mine located in Tmmins Ontario on the Canadian Shield is an iconic site. Investigation of fracture fluids here to 3 km revealed H2 production via radiolysis and serpentinization [1]; production of methane and higher hydrocarbons via abiotic organic synthesis [2]; and fracture fluids with mean residence times on the order of a billion years [3]. Recently, investigation of the sulfur cycle in these fluids has revealed a mass independent sulfur isotope signature in the dissolved sulfate, whereby oxidants from radiolysis oxidize Archean sulfide minerals, providing a mechanism to supply both electron donors (H2) and electron acceptors (sulfate) that could fuel a deep microbial biosphere [4]. Recent MPNs results demonstrate the presence of sulfate-reducing bacteria in these waters in the present day. Beginning in 2016 the deep levels at this site are providing access to international teams of researchers to collaborate with the University of Toronto in a multi-year program to characterize the deep CHONS cycles, as terrestrial geobiology continues to expand our understanding of the habitability of the Earth. [1] Sherwood Lollar et al. (2014) Nature 516,379-382. [2] Sherwood Lollar et al. (2002) Nature 416,522-524. [3] Holland et al. (2013) Nature 497,357-360. [4] Li et al. (2016) Nature Communications in press.

Delving into the Deep Biosphere

NASA Astrophysics Data System (ADS)

Grim, S. L.; Sogin, M. L.; Boetius, A.; Briggs, B. R.; Brazelton, W. J.; D'Hondt, S. L.; Edwards, K. J.; Fisk, M. R.; Gaidos, E.; Gralnick, J.; Hinrichs, K.; Lazar, C.; Lavalleur, H.; Lever, M. A.; Marteinsson, V.; Moser, D. P.; Orcutt, B.; Pedersen, K.; Popa, R.; Ramette, A.; Schrenk, M. O.; Sylvan, J. B.; Smith, A. R.; Teske, A.; Walsh, E. A.; Colwell, F. S.

2013-12-01

The Census of Deep Life organized an international survey of microbial community diversity in terrestrial and marine deep subsurface environments. Habitats included subsurface continental fractured rock aquifers, volcanic and metamorphic subseafloor sedimentary units from the open ocean, subsurface oxic and anoxic sediments and underlying basaltic oceanic crust, and their overlying water columns. Our survey employed high-throughput pyrosequencing of the hypervariable V4-V6 16S rRNA gene of bacteria and archaea. We detected 1292 bacterial genera representing 40 phyla, and 99 archaeal genera from 30 phyla. Of these, a core group of thirteen bacterial genera occurred in every environment. A genus of the South African Goldmine Group (Euryarchaeota) was always present whenever archaea were detected. Members of the rare biosphere in one system often represented highly abundant taxa in other environments. Dispersal could account for this observation but mechanisms of transport remain elusive. Ralstonia (Betaproteobacteria) represented highly abundant taxa in marine communities and terrestrial rock, but generally low abundance organisms in groundwater. Some of these taxa could represent sample contamination, and their extensive distribution in several systems requires further assessment. An unknown Sphingobacteriales (Bacteroidetes) genus, Stenotrophomonas (Gammaproteobacteria), Acidovorax and Aquabacterium (both Betaproteobacteria), a Chlorobiales genus, and a TM7 genus were in the core group as well but more prevalent in terrestrial environments. Similarly, Bacillus (Firmicutes), a new cyanobacterial genus, Bradyrhizobium and Sphingomonas (both Alphaproteobacteria), a novel Acidobacteriaceae genus, and Variovorax (Betaproteobacteria) frequently occurred in marine systems but represented low abundance taxa in other environments. Communities tended to cluster by biome and material, and many genera were unique to systems. For example, certain Rhizobiales (Alphaproteobacteria) only occurred in groundwater, and select Firmicutes and actinobacterial taxa were specific to rock environments. We continue to investigate the ecological and physiological context of these organisms. By combining deep sequencing of microbial communities and geochemical and physical evaluations of their environments, we bring to light the diversity and scope of the deep biosphere and insight into the factors that determine the nature of these communities.

Geophysical characterization of Range-Front Faults, Snake Valley, Nevada

USGS Publications Warehouse

Asch, Theodore H.; Sweetkind, Donald S.

2010-01-01

In September 2009, the U.S. Geological Survey, in cooperation with the National Park Service, collected audiomagnetotelluric (AMT) data along two profiles on the eastern flank of the Snake Range near Great Basin National Park to refine understanding of the subsurface geology. Line 1 was collected along Baker Creek, was approximately 6.7-km long, and recorded subsurface geologic conditions to approximately 800-m deep. Line 2, collected farther to the southeast in the vicinity of Kious Spring, was 2.8-km long, and imaged to depths of approximately 600 m. The two AMT lines are similar in their electrical response and are interpreted to show generally similar subsurface geologic conditions. The geophysical response seen on both lines may be described by three general domains of electrical response: (1) a shallow (mostly less than 100-200-m deep) domain of highly variable resistivity, (2) a deep domain characterized by generally high resistivity that gradually declines eastward to lower resistivity with a steeply dipping grain or fabric, and (3) an eastern domain in which the resistivity character changes abruptly at all depths from that in the western domain. The shallow, highly variable domain is interpreted to be the result of a heterogeneous assemblage of Miocene conglomerate and incorporated megabreccia blocks overlying a shallowly eastward-dipping southern Snake Range detachment fault. The deep domain of generally higher resistivity is interpreted as Paleozoic sedimentary rocks (Pole Canyon limestone and Prospect Mountain Quartzite) and Mesozoic and Cenozoic plutonic rocks occurring beneath the detachment surface. The range of resistivity values within this deep domain may result from fracturing adjacent to the detachment, the presence of Paleozoic rock units of variable resistivities that do not crop out in the vicinity of the lines, or both. The eastern geophysical domain is interpreted to be a section of Miocene strata at depth, overlain by Quaternary alluvial fill. These deposits lie east of a steeply east-dipping normal fault that cuts all units and has about 100 m of east-side-down offset.

Lateral groundwater inflows into alluvial aquifers of main alpine valleys

NASA Astrophysics Data System (ADS)

Burger, Ulrich

2015-04-01

In alpine regions the topography is mainly characterised by deep incised valleys, mountain slopes and ridges. Usually the main valleys contain aquifers in alluvial soft rock. Lateral these aquifers are confined by mountainous hard rock slopes covered by heterogeneous sediments with different thickness. The slopes can be incised by lateral valleys. Numerical models for the main alluvial aquifers ask for lateral hydrogeological boundaries. Usually no flow boundaries or Constant head Boundaries are used, even if the lateral inflows to the main aquifers are rarely known. In this example a data set for a detailed investigated and monitored area is studied to give an answer on the location and the quantification of these lateral subsurface inflows. The study area is a typical main alpine valley with a thick alluvial aquifer (appr. 120m thick), lateral confined by granite, covered at the base of the steep slopes by quaternary sediments (Burger at al. 2012). The study consists of several steps 1.) Analytical calculation of the inflows on the base of investigated and monitored 2d profiles along fault zones (Perello et al 2013) which pinch out in the main valley 2.) Analytical models along typical W-dipping slopes with monitored slope springs 3.) Evaluating temperature and electrical conductivity profiles measured in approx. 30 groundwater wells in the alluvial aquifers and along the slopes to locate main lateral subsurface inflows 4.) Output of a regional model used for the hydrogeological back analyses of the excavation of a tunnel (Baietto et al. 2014) 5.) Output of a local numerical model calibrated with a monitoring dataset and results of a pumping test of big scale (450l/s for 10days) Results of these analyses are shown to locate and quantify the lateral groundwater inflows in the main alluvial aquifer. References Baietto A., Burger U., Perello P. (2014): Hydrogeological modelling applications in tunnel excavations: examples from tunnel excavations in granitic rocks; congress of IAEG, Engineering Geology for Society and Territory, Torino Burger U., San Nicoló L. Bösel D. und Perello P. (2012): Hydrogeologische Modelle - Hilfsmittel für die Planung am Beispiel des Brenner Basistunnel, Beiträge zur Beiträge zur COGeo 2011, Salzburg COGEO Perello P., Baietto A., Burger U., Skuk S. (2013): Excavation of the Aica-Mules pilot tunnel for the Brenner base tunnel: information gained on water inflows in tunnels in granitic massifs, Rock Mechanics and Rock Engineering, DOI 10.1007/s00603-013-0480-x

Performance of deep geothermal energy systems

NASA Astrophysics Data System (ADS)

Manikonda, Nikhil

Geothermal energy is an important source of clean and renewable energy. This project deals with the study of deep geothermal power plants for the generation of electricity. The design involves the extraction of heat from the Earth and its conversion into electricity. This is performed by allowing fluid deep into the Earth where it gets heated due to the surrounding rock. The fluid gets vaporized and returns to the surface in a heat pipe. Finally, the energy of the fluid is converted into electricity using turbine or organic rankine cycle (ORC). The main feature of the system is the employment of side channels to increase the amount of thermal energy extracted. A finite difference computer model is developed to solve the heat transport equation. The numerical model was employed to evaluate the performance of the design. The major goal was to optimize the output power as a function of parameters such as thermal diffusivity of the rock, depth of the main well, number and length of lateral channels. The sustainable lifetime of the system for a target output power of 2 MW has been calculated for deep geothermal systems with drilling depths of 8000 and 10000 meters, and a financial analysis has been performed to evaluate the economic feasibility of the system for a practical range of geothermal parameters. Results show promising an outlook for deep geothermal systems for practical applications.

Low Energy X-Ray and γ-Ray Detectors Fabricated on n-Type 4H-SiC Epitaxial Layer

NASA Astrophysics Data System (ADS)

Mandal, Krishna C.; Muzykov, Peter G.; Chaudhuri, Sandeep K.; Terry, J. Russell

2013-08-01

Schottky barrier diode (SBD) radiation detectors have been fabricated on n-type 4H-SiC epitaxial layers and evaluated for low energy x- and γ-rays detection. The detectors were found to be highly sensitive to soft x-rays in the 50 eV to few keV range and showed 2.1 % energy resolution for 59.6 keV gamma rays. The response to soft x-rays for these detectors was significantly higher than that of commercial off-the-shelf (COTS) SiC UV photodiodes. The devices have been characterized by current-voltage (I-V) measurements in the 94-700 K range, thermally stimulated current (TSC) spectroscopy, x-ray diffraction (XRD) rocking curve measurements, and defect delineating chemical etching. I-V characteristics of the detectors at 500 K showed low leakage current ( nA at 200 V) revealing a possibility of high temperature operation. The XRD rocking curve measurements revealed high quality of the epitaxial layer exhibiting a full width at half maximum (FWHM) of the rocking curve 3.6 arc sec. TSC studies in a wide range of temperature (94-550 K) revealed presence of relatively shallow levels ( 0.25 eV) in the epi bulk with a density 7×1013 cm-3 related to Al and B impurities and deeper levels located near the metal-semiconductor interface.

State-of-the-Art for Assessing Earthquake Hazards in the United States. Report 19. The Evidence for Reservoir-Induced Macroearthquakes.

DTIC Science & Technology

1982-06-01

pore pressures are dissipating. 232. The question of deep fluid communication is unresolved. Koyna is situated in flow basalt known as the Deccan Traps ...The trap rock formation is about 1200 m thick near Koyna. The basalt flows are irregular and at the damsite seven flows have been mapped. Some of the...ranges from 0 to about 30 km but is generally 2 to 8 km in depth. This places the bulk of the seismicity below the trap rock in a basement rock of unknown

Planetary Perspective on Life on Early Mars and the Early Earth

NASA Technical Reports Server (NTRS)

Sleep, Norman H.; Zahnle, Kevin

1996-01-01

Impacts of asteroids and comets posed a major hazard to the continuous existence of early life on Mars as on the Earth. The chief danger was presented by globally distributed ejecta, which for very large impacts takes the form of transient thick rock vapor atmospheres; both planets suffered such impacts repeatedly. The exposed surface on both planets was sterilized when it was quickly heated to the temperature of condensed rock vapor by radiation and rock rain. Shallow water bodies were quickly evaporated and sterilized. Any surviving life must have been either in deep water or well below the surface.

The Unicorn Cave, Southern Harz Mountains, Germany: From known passages to unknown extensions with the help of geophysical surveys

NASA Astrophysics Data System (ADS)

Kaufmann, Georg; Nielbock, Ralf; Romanov, Douchko

2015-12-01

In soluble rocks (limestone, dolomite, anhydrite, gypsum, …), fissures and bedding partings can be enlarged with time by both physical and chemical dissolution of the host rock. With time, larger cavities evolve, and a network of cave passages can evolve. If the enlarged cave voids are not too deep under the surface, geophysical measurements can be used to detect, identify and trace these karst structures, e.g.: (i) gravity revealing air- and sediment-filled cave voids through negative Bouguer anomalies, (ii) electrical resistivity imaging (ERI) mapping different infillings of cavities either as high resistivities from air-filled voids or dry soft sediments, or low resistivities from saturated sediments, and (iii) groundwater flow through electrical potential differences (SP) arising from dislocated ionic charges from the walls of the underground flow paths. We have used gravity, ERI, and SP methods both in and above the Unicorn Cave located in the southern Harz Mountains in Germany. The Unicorn Cave is a show cave developed in the Werra dolomite formation of the Permian Zechstein sequence, characterised by large trunk passages interrupted by larger rooms. The overburden of the cave is only around 15 m, and passages are filled with sediments reaching infill thicknesses up to 40 m. We present results from our geophysical surveys above the known cave and its northern and southern extension, and from the cave interior. We identify the cave geometry and its infill from gravity and ERI measurements, predict previously unknown parts of the cave, and subsequently confirm the existence of these new passages through drilling. From the wealth of geophysical data acquired we derive a three-dimensional structural model of the Unicorn Cave and its surrounding, especially the cave infill.

How did the ball of rock we live on get so nice?

NASA Astrophysics Data System (ADS)

Armstrong, K.

2017-12-01

We want to understand how the big ball of rock, water, and air we live on got to be as nice as it is. Some of the things that made our world so nice are what it's made of, and what happened to those things after they were all put together. When our home ball of rock was little, it got bigger by grabbing some of the other stuff that was close by in space. So our world is made of all that space stuff, which was rocks, and that stuff that turns red if you let it get wet. Most of that red stuff is deep down in the middle of the world, covered up by a lot of rocks. But there is a lot of it inside the rocks, too. That red stuff does a lot of cool stuff when it touches other things, especially the kind of air we like to breathe- that is what makes it turn red. Just one very tiny piece of the red stuff can join up with the breathing air in different ways: it can team up with none at all, or a little bit, or a lot, or even more. If we look at how much of the breathing air is teamed up with the red stuff inside the rocks, we can learn about how the rocks got there and what happened to them a long time ago. In the rocks that we can look at, there is more of the breathing air teamed up with the red stuff than we might have thought. We think that maybe that is because when more and more stuff tries to fit in the same small space, and gets pressed down, like it does deep down in our world, it can change in ways we do not expect. When our world was almost as big as it is now, it probably grabbed some space stuff that was almost as big as it was. The space stuff would have run into our world really hard, and that would have made everything really hot, hot enough to make all the rocks in the world move like water. We have an idea that maybe, when all the rocks on the world were really hot and moved around like water, deep down the red stuff and the breathing air might have got all pressed together very hard, so that more of the breathing air would team up with the red stuff than it would if it was not all pressed together. We tried to see if this works by putting some rocks in a really big and strong pressing box and then making it very hot. We did this many times, sometimes pressing a little and sometimes pressing a lot. The more we pressed, the more breathing air was teamed up with the red stuff, so maybe we can start to understand more about how our world got so nice.

Geomicrobiology in oceanography: microbe-mineral interactions at and below the seafloor.

PubMed

Edwards, Katrina J; Bach, Wolfgang; McCollom, Thomas M

2005-09-01

Oceanography is inherently interdisciplinary and, since its inception, has included the study of microbe-mineral interactions. From early studies of manganese nodules, to the discovery of hydrothermal vents, it has been recognized that microorganisms are involved at various levels in the transformation of rocks and minerals at and below the seafloor. Recent studies include mineral weathering at low temperatures and microbe-mineral interactions in the subseafloor "deep biosphere". A common characteristic of seafloor and subseafloor geomicrobiological processes that distinguishes them from terrestrial or near-surface processes is that they occur in the dark, one or more steps removed from the sunlight that fuels the near-surface biosphere on Earth. This review focuses on geomicrobiological studies and energy flow in dark, deep-ocean and subseafloor rock habitats.

The origin and evolution of sulfur in an Archean volcano-sedimentary basin, Deer Lake area, Minnesota. M.S. Thesis

NASA Technical Reports Server (NTRS)

Nicol, D. L.

1980-01-01

Rocks of the Deer Lake area, northcentral Minnesota, consist of Archean (age greater than 2.6 billion years) metasediments and metavolcanics intruded by mafic layered sills. Geologic and sulfur isotopic data suggest that sulfides in the sediments are bacteriogenic, having formed in response to the activity of sulfate reducing bacteria during diagenesis. Deposition of the sediments appears to have occurred in a deep marine basin with restricted circulation of sea water. The bulk of the sulfur in the igneous rocks is of deep seated origin, but basal contacts of the sills show evidence of assimilation of biogenic sulfur from the intruded sediments. This assimilation of biogenic sulfur is the primary geochemical control of local Cu-Ni sulfide mineralization.

Petrology and geochemistry of lithic fragments separated from the Apollo 15 deep-drill core

NASA Technical Reports Server (NTRS)

Lindstrom, M. M.; Nielsen, R. L.; Drake, M. J.

1977-01-01

Petrological and geochemical analysis of lithic fragments separated from the Apollo 15 deep-drill core showed these fragments to fall into the essentially the same range of rock types as observed in surface soil samples and large rock samples. Three particles are singled out as being of special interest. One sample is a mare basalt containing extremely evolved phases. The particle may represent small-scale imperfect crystal/liquid separation in a lava flow. A green glass particle is not the ultramafic emerald green glass described from the Apollo 15 site, but rather an ANT-like light green color, and has a quite different chemical composition from the ultramafic variety. One mare basalt displays a positive Eu anomaly and is enriched in plagioclase relative to olivine plus pyroxene.

Length Scales and Types of Heterogeneities Along the Deep Subduction Interface: Insights From an Exhumed Subduction Complex on Syros Island, Greece

NASA Astrophysics Data System (ADS)

Kotowski, A. J.; Behr, W. M.; Tong, X.; Lavier, L.

2017-12-01

The rheology of the deep subduction interface strongly influences the occurrence, recurrence, and migration of episodic tremor and slow slip (ETS) events. To better understand the environment of deep ETS, we characterize the length scales and types of rheological heterogeneities that decorate the deep interface using an exhumed subduction complex. The Cycladic Blueschist Unit on Syros, Greece, records Eocene subduction to 60 km, partial exhumation along the top of the slab, and final exhumation along Miocene detachment faults. The CBU reached 450-580˚C and 14-16 kbar, PT conditions similar to where ETS occurs in several modern subduction zones. Rheological heterogeneity is preserved in a range of rock types on Syros, with the most prominent type being brittle pods embedded within a viscous matrix. Prograde, blueschist-facies metabasalts show strong deformation fabrics characteristic of viscous flow; cm- to m-scale eclogitic lenses are embedded within them as massive, veined pods, foliated pods rotated with respect to the blueschist fabric, and attenuated, foliation-parallel lenses. Similar relationships are observed in blueschist-facies metasediments interpreted to have deformed during early exhumation. In these rocks, metabasalts form lenses ranging in size from m- to 10s of m and are distributed at the m-scale throughout the metasedimentary matrix. Several of the metamafic lenses, and the matrix rocks immediately adjacent to them, preserve multiple generations of dilational veins and shear fractures filled with quartz and high pressure minerals. These observations suggest that coupled brittle-viscous deformation under high fluid pressures may characterize the subduction interface in the deep tremor source region. To test this further, we modeled the behavior of an elasto-plastic pod in a viscous shear zone under high fluid pressures. Our models show that local stress concentrations around the pod are large enough to generate transient dilational shear at seismic strain rates. Scaling the model up to a typical source area for deep tremor suggests these heterogeneities may yield a seismic moment similar to those calculated for tremor bursts in modern subduction zones.

Risk Analysis and Prediction of Floor Failure Mechanisms at Longwall Face in Parvadeh-I Coal Mine using Rock Engineering System (RES)

NASA Astrophysics Data System (ADS)

Aghababaei, Sajjad; Saeedi, Gholamreza; Jalalifar, Hossein

2016-05-01

The floor failure at longwall face decreases productivity and safety, increases operation costs, and causes other serious problems. In Parvadeh-I coal mine, the timber is used to prevent the puncture of powered support base into the floor. In this paper, a rock engineering system (RES)-based model is presented to evaluate the risk of floor failure mechanisms at the longwall face of E 2 and W 1 panels. The presented model is used to determine the most probable floor failure mechanism, effective factors, damaged regions and remedial actions. From the analyzed results, it is found that soft floor failure is dominant in the floor failure mechanism at Parvadeh-I coal mine. The average of vulnerability index (VI) for soft, buckling and compressive floor failure mechanisms was estimated equal to 52, 43 and 30 for both panels, respectively. By determining the critical VI for soft floor failure mechanism equal to 54, the percentage of regions with VIs beyond the critical VI in E 2 and W 1 panels is equal to 65.5 and 30, respectively. The percentage of damaged regions showed that the excess amount of used timber to prevent the puncture of weak floor below the powered support base is equal to 4,180,739 kg. RES outputs and analyzed results showed that setting and yielding load of powered supports, length of face, existent water at face, geometry of powered supports, changing the cutting pattern at longwall face and limiting the panels to damaged regions with supercritical VIs could be considered to control the soft floor failure in this mine. The results of this research could be used as a useful tool to identify the damaged regions prior to mining operation at longwall panel for the same conditions.

Rock Melt Borehole Sealing System, Final Technical Report for SBIR Phase I Grant No. DE-SC0011888

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osnes, John D.; Vining, Cody A.; Nopola, Jay R.

Purpose of Research Deep borehole disposal is one option that has received attention in recent years as a possible strategy for long-term disposal of the tens of thousands of tons of spent nuclear fuel. The feasibility of the deep borehole option relies upon designing and constructing an effective seal within the borehole to ensure that the waste package does not communicate with the shallow subsurface biosphere through the borehole itself. Some of the uncertainty associated with the long-term suitability of the deep borehole option is related to (1) the degradation of traditional sealing materials over time and (2) the inabilitymore » of traditional sealing methods to adequately seal a Disturbed Rock Zone surrounding the borehole. One possible system to address these concerns consists of encapsulating the waste in a melt generated from either the waste itself or a plug above the waste. This current project expanded on previous work to further advance the deep borehole disposal concept. Research Objectives & Findings The overarching objective of the study was to evaluate the feasibility of constructing a downhole heater that is capable of meeting the technical and logistical requirements to melt rock. This ultimate objective was accomplished by two primary approaches. The first approach was to define the heater requirements and conceptually design a system that is capable of melting rock. The second approach was to determine the feasibility of conducting an in situ, field-scale melting experiment to validate the suitability of the rock melt seal concept. The evaluation and conceptual design of the heater system resulted in the following primary findings: • Borehole wall temperatures capable of producing a partial melt are achievable under most expected thermal conductivities with a 12-kilowatt heater. • Commercially available components have been identified that meet the requirements of the heater system, including resistive elements that are capable of providing the required heat generation, container materials that can withstand the anticipated temperatures, and a system capable of providing power to the heater. Evaluating the feasibility of performing field-scale experiments resulted in the following major findings: • The Sanford Underground Research Facility (SURF) has been identified as a host site for field testing of prototype heaters. The technical and logistical requirements for performing the rock melt tests can be met by using or expanding the existing infrastructure at SURF with on-site personnel and contractors. • In situ hydraulic conductivity test using packers can test the effectiveness of the rock melt seal, while a mine back performed from a lower level can further evaluate the recrystallized melt. • Preliminary costing indicates that a field-scale melting experiment at SURF is feasible within a Phase II Small Business Innovation Research budget while allowing sufficient budget for refining the heater design, coordinating the test program, and interpreting the results. Application of Research The rock melt sealing concept has the potential to reduce uncertainty associated with the long-term storage of nuclear waste. Preliminary efforts of this study defined the requirements of a downhole heater system capable of melting rock and indicated that developing such a system is feasible using available technology. The next logical step is designing and manufacturing prototype heaters. Concurrent with prototype development is coordinating robust field-scale experiments that are capable of validating the design for marketing to potential users.« less

Specific yield: compilation of specific yields for various materials

USGS Publications Warehouse

Johnson, A.I.

1967-01-01

Specific yield is defined as the ratio of (1) the volume of water that a saturated rock or soil will yield by gravity to (2) the total volume of the rock or soft. Specific yield is usually expressed as a percentage. The value is not definitive, because the quantity of water that will drain by gravity depends on variables such as duration of drainage, temperature, mineral composition of the water, and various physical characteristics of the rock or soil under consideration. Values of specific yields nevertheless offer a convenient means by which hydrologists can estimate the water-yielding capacities of earth materials and, as such, are very useful in hydrologic studies. The present report consists mostly of direct or modified quotations from many selected reports that present and evaluate methods for determining specific yield, limitations of those methods, and results of the determinations made on a wide variety of rock and soil materials. Although no particular values are recommended in this report, a table summarizes values of specific yield, and their averages, determined for 10 rock textures. The following is an abstract of the table. [Table

Geomechanical Considerations for the Deep Borehole Field Test

NASA Astrophysics Data System (ADS)

Park, B. Y.

2015-12-01

Deep borehole disposal of high-level radioactive waste is under consideration as a potential alternative to shallower mined repositories. The disposal concept consists of drilling a borehole into crystalline basement rocks to a depth of 5 km, emplacement of canisters containing solid waste in the lower 2 km, and plugging and sealing the upper 3 km of the borehole. Crystalline rocks such as granites are particularly attractive for borehole emplacement because of their low permeability and porosity at depth, and high mechanical strength to resist borehole deformation. In addition, high overburden pressures contribute to sealing of some of the fractures that provide transport pathways. We present geomechanical considerations during construction (e.g., borehole breakouts, disturbed rock zone development, and creep closure), relevant to both the smaller-diameter characterization borehole (8.5") and the larger-diameter field test borehole (17"). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

New Site Coefficients and Site Classification System Used in Recent Building Seismic Code Provisions

USGS Publications Warehouse

Dobry, R.; Borcherdt, R.D.; Crouse, C.B.; Idriss, I.M.; Joyner, W.B.; Martin, G.R.; Power, M.S.; Rinne, E.E.; Seed, R.B.

2000-01-01

Recent code provisions for buildings and other structures (1994 and 1997 NEHRP Provisions, 1997 UBC) have adopted new site amplification factors and a new procedure for site classification. Two amplitude-dependent site amplification factors are specified: Fa for short periods and Fv for longer periods. Previous codes included only a long period factor S and did not provide for a short period amplification factor. The new site classification system is based on definitions of five site classes in terms of a representative average shear wave velocity to a depth of 30 m (V?? s). This definition permits sites to be classified unambiguously. When the shear wave velocity is not available, other soil properties such as standard penetration resistance or undrained shear strength can be used. The new site classes denoted by letters A - E, replace site classes in previous codes denoted by S1 - S4. Site classes A and B correspond to hard rock and rock, Site Class C corresponds to soft rock and very stiff / very dense soil, and Site Classes D and E correspond to stiff soil and soft soil. A sixth site class, F, is defined for soils requiring site-specific evaluations. Both Fa and Fv are functions of the site class, and also of the level of seismic hazard on rock, defined by parameters such as Aa and Av (1994 NEHRP Provisions), Ss and S1 (1997 NEHRP Provisions) or Z (1997 UBC). The values of Fa and Fv decrease as the seismic hazard on rock increases due to soil nonlinearity. The greatest impact of the new factors Fa and Fv as compared with the old S factors occurs in areas of low-to-medium seismic hazard. This paper summarizes the new site provisions, explains the basis for them, and discusses ongoing studies of site amplification in recent earthquakes that may influence future code developments.

Rocks of the early lunar crust

NASA Technical Reports Server (NTRS)

James, O. B.

1980-01-01

Data are summarized which suggest a model for the early evolution of the lunar crust. According to the model, during the final stages of accretion, the outer part of the moon melted to form a magma ocean approximately 300 km deep. This ocean fractionated to form mafic and ultramafic cumulates at depth and an overlying anorthositic crust made up of ferroan anorthosites. Subsequent partial melting in the primitive mantle underlying the crystallized magma ocean produced melts which segregated, moved upward, intruded the primordial crust, and crystallized to form layered plutons consisting of Mg-rich plutonic rocks. Intense impact bombardment at the lunar surface mixed and melted the rocks of the two suites to form a thick layer of granulated debris, granulitic breccias, and impact-melt rocks.

A framework for grand scale parallelization of the combined finite discrete element method in 2d

NASA Astrophysics Data System (ADS)

Lei, Z.; Rougier, E.; Knight, E. E.; Munjiza, A.

2014-09-01

Within the context of rock mechanics, the Combined Finite-Discrete Element Method (FDEM) has been applied to many complex industrial problems such as block caving, deep mining techniques (tunneling, pillar strength, etc.), rock blasting, seismic wave propagation, packing problems, dam stability, rock slope stability, rock mass strength characterization problems, etc. The reality is that most of these were accomplished in a 2D and/or single processor realm. In this work a hardware independent FDEM parallelization framework has been developed using the Virtual Parallel Machine for FDEM, (V-FDEM). With V-FDEM, a parallel FDEM software can be adapted to different parallel architecture systems ranging from just a few to thousands of cores.

Photoacoustic tomography of foreign bodies in soft biological tissue.

PubMed

Cai, Xin; Kim, Chulhong; Pramanik, Manojit; Wang, Lihong V

2011-04-01

In detecting small foreign bodies in soft biological tissue, ultrasound imaging suffers from poor sensitivity (52.6%) and specificity (47.2%). Hence, alternative imaging methods are needed. Photoacoustic (PA) imaging takes advantage of strong optical absorption contrast and high ultrasonic resolution. A PA imaging system is employed to detect foreign bodies in biological tissues. To achieve deep penetration, we use near-infrared light ranging from 750 to 800 nm and a 5-MHz spherically focused ultrasonic transducer. PA images were obtained from various targets including glass, wood, cloth, plastic, and metal embedded more than 1 cm deep in chicken tissue. The locations and sizes of the targets from the PA images agreed well with those of the actual samples. Spectroscopic PA imaging was also performed on the objects. These results suggest that PA imaging can potentially be a useful intraoperative imaging tool to identify foreign bodies.

Jet production and fragmentation properties in deep inelastic muon scattering

NASA Astrophysics Data System (ADS)

Arneodo, M.; Arvidson, A.; Aubert, J. J.; Badelek, B.; Beaufays, J.; Bee, C. P.; Benchouk, C.; Berghoff, G.; Bird, I.; Blum, D.; Böhm, E.; de Bouard, X.; Brasse, F. W.; Braun, H.; Broll, C.; Brown, S.; Brück, H.; Calen, H.; Chima, J. S.; Ciborowski, J.; Clifft, R.; Coignet, G.; Combley, F.; Conrad, J.; Coughlan, J.; D'Agostini, G.; Dahlgren, S.; Dengler, F.; Derado, I.; Dreyer, T.; Drees, J.; Drobnitzki, M.; Düren, M.; Eckardt, V.; Edwards, A.; Edwards, M.; Ernst, T.; Eszes, G.; Favier, J.; Ferrero, M. I.; Figiel, J.; Flauger, W.; Foster, J.; Ftàčnik, J.; Gabathuler, E.; Gajewski, J.; Gamet, R.; Gayler, J.; Geddes, N.; Grafström, P.; Grard, F.; Haas, J.; Hagberg, E.; Hasert, F. J.; Hayman, P.; Heusse, P.; Jaffre, M.; Jacholkowska, A.; Janata, F.; Jancso, G.; Johnson, A. S.; Kabuss, E. M.; Kellner, G.; Korbel, V.; Krüger, A.; Krüger, J.; Kullander, S.; Landgraf, U.; Lanske, D.; Loken, J.; Long, K.; Maire, M.; Malecki, P.; Manz, A.; Maselli, S.; Mohr, W.; Montanet, F.; Montgomery, H. E.; Nagy, E.; Nassalski, J.; Norton, P. R.; Oakham, F. G.; Osborne, A. M.; Pascaud, C.; Pawlik, B.; Payre, P.; Peroni, C.; Peschel, H.; Pessard, H.; Pettingale, J.; Pietrzyk, B.; Pietrzyk, U.; Pönsgen, B.; Pötsch, M.; Renton, P.; Ribarics, P.; Rith, K.; Rondio, E.; Sandacz, A.; Scheer, M.; Schlabböhmer, A.; Schiemann, H.; Schmitz, N.; Schneegans, M.; Scholz, M.; Schröder, T.; Schultze, K.; Sloan, T.; Stier, H. E.; Studt, M.; Taylor, G. N.; Thénard, J. M.; Thompson, J. C.; de La Torre, A.; Toth, J.; Urban, L.; Urban, L.; Wallucks, W.; Whalley, M.; Wheeler, S.; Williams, W. S. C.; Wimpenny, S. J.; Windmolders, R.; Wolf, G.; Ziemons, K.

1987-12-01

Results are presented from a study of deep inelastic 280 GeV muon-nucleon interactions on the transverse momenta and jet properties of the final state hadrons. The results are analysed in a way which attempts to separate the contributions of hard and soft QCD effects from those that arise from the fragmentation process. The fragmentation models with which the data are compared are the Lund string model, the independent jet model, the QCD parton shower model including soft gluon interference effects, and the firestring model. The discrimination between these models is discussed. Various methods of analysis of the data in terms of hard QCD processes are presented. From a study of the properties of the jet profiles a value of α s , to leading order, is determined using the Lund string model, namely α s =0.29±0.01 (stat.) ±0.02 (syst.), for Q 2˜20 GeV2.

Origin, evolution and geothermometry of the thermal waters in the Gölemezli Geothermal Field, Denizli Basin (SW Anatolia, Turkey)

NASA Astrophysics Data System (ADS)

Alçiçek, Hülya; Bülbül, Ali; Brogi, Andrea; Liotta, Domenico; Ruggieri, Giovanni; Capezzuoli, Enrico; Meccheri, Marco; Yavuzer, İbrahim; Alçiçek, Mehmet Cihat

2018-01-01

The Gölemezli Geothermal Field (GGF) is one of the best known geothermal fields in western Anatolia (Turkey). The exploited fluids are of meteoric origin, mixed with deep magmatic fluids, which interacted with the metamorphic rocks of the Menderes Massif. The geothermal fluids are channeled along Quaternary faults belonging to the main normal faults system delimiting the northern side of the Denizli Basin and their associated transfer zones. In this study, hydrochemical and isotopic analyses of the thermal and cold waters allow us to determine water-rock interactions, fluid paths and mixing processes. Two groups of thermal waters have been distinguished: (i) Group 1A, comprising Na-SO4 type and Ca-SO4 type and (ii) Group 1B, only consisting Ca-HCO3 type waters. Differently, two groups were recognized in the cold waters: (i) Group 2A, corresponding to Ca-HCO3 type and (ii) Group 2B, including Mg-HCO3 type. Their geochemical characteristics indicate interactions with the Paleozoic metamorphic rocks of the Menderes Massif and with the Neogene lacustrine sedimentary rocks. Dissolution of host rock and ion-exchange reactions modify thermal water composition in the reservoir of the GGF. High correlation in some ionic ratios and high concentrations of some minor elements suggest an enhanced water-rock interaction. None of the thermal waters has been reached a complete chemical re-equilibrium, possibly as a result of mixing with cold water during their pathways. Geothermal reservoir temperatures are calculated in the range of 130-210°C for the Gölemezli field. Very negative δ18O and δ2H isotopic ratios are respectively between -8.37 and -8.13‰ and -61.09 and -59.34‰ for the SO4-rich thermal waters, and ca. - 8.40 and -8.32‰ and - 57.80 and -57.41‰ for the HCO3-rich thermal waters. Low tritium (< 1 TU) and low oxygen isotope values reflect a deep circuit and fluids of meteoric origin. Positive δ13CDIC ratios (+ 5.11 to + 7.54‰) of all thermal waters imply a contribution of metamorphic origin. Heating is guaranteed by a deep circuit within an overheated continental crust, mainly affected by damaged rock volumes. Volatile ascent from deep magmatic sources through crustal structures can explain the occurrence of mantle volatiles at shallow depth in the Denizli Basin. The NW- and NE-trending fault systems, associated with their related fractures, played as hydraulic conduits underlining the strict link existing between fractures and fluid convection in the extensional settings. In this view, the GGF is a very good example of geothermal field associated to active tectonic setting and magmatism, as it is the case of the other geothermal fields occurring in the Denizli Basin.

Mineral resource of the month: diatomite

USGS Publications Warehouse

,

2013-01-01

The article discusses the properties and applications of the mineral diatomite. According to the author, diatomite is a soft, friable and very fine-grained siliceous sedimentary rock made of the remains of fossilized diatoms. The author adds that its properties make diatomite very useful as a filtration medium and as a component in cement.

Between a Rock and a Soft Place

ERIC Educational Resources Information Center

Denig, Stephen J.

2012-01-01

Catholic colleges and universities are caught between two competing pressures. On the one side the church hierarchy, especially the Vatican, wants to make certain that these institutions of higher learning remain faithful to the intellectual tradition and the teachings of the church. On the other side these institutions exist in a postmodern world…

A preliminary analysis of failure mechanisms in karst and man-made underground caves in Southern Italy

NASA Astrophysics Data System (ADS)

Parise, M.; Lollino, P.

2011-11-01

Natural and anthropogenic caves may represent a potential hazard for the built environment, due to the occurrence of instability within caves, that may propagate upward and eventually reach the ground surface, inducing the occurrence of sinkholes. In particular, when caves are at shallow depth, the effects at the ground surface may be extremely severe. Apulia region (southern Italy) hosts many sites where hazard associated with sinkholes is very serious due to presence of both natural karst caves and anthropogenic cavities, the latter being mostly represented by underground quarries. The Pliocene-Pleistocene calcarenite (a typical soft rock) was extensively quarried underground, by digging long and complex networks of tunnels. With time, these underground activities have progressively been abandoned and their memory lost, so that many Apulian towns are nowadays located just above the caves, due to urban expansion in the last decades. Therefore, a remarkable risk exists for society, which should not be left uninvestigated. The present contribution deals with the analysis of the most representative failure mechanisms observed in the field for such underground instability processes and the factors that seem to influence the processes, as for example those causing weathering of the rock and the consequent degradation of its physical and mechanical properties. Aimed at exploring the progression of instability of the cavities, numerical analyses have been developed by using both the finite element method for geological settings represented by continuous soft rock mass, and the distinct element method for jointed rock mass conditions. Both the effects of local instability processes occurring underground and the effects of the progressive enlargement of the caves on the overall stability of the rock mass have been investigated, along with the consequent failure mechanisms. In particular, degradation processes of the rock mass, as a consequence of wetting and weathering phenomena in the areas surrounding the caves, have been simulated. The results obtained from the numerical simulations have then been compared with what has been observed during field surveys and a satisfactory agreement between the numerical simulations and the instability processes, as detected in situ, has been noticed.

Preliminary Geophysical Investigations of the Ship Rock Diatreme, Navajo Nation, New Mexico

NASA Astrophysics Data System (ADS)

Gruen, E. M.; McCarthy, L.; Namingha, G.; Bank, C.; Noblett, J.; Semken, S.

2003-12-01

Magnetic and gravity data were collected at the Ship Rock minette neck and dikes, part of the Navajo volcanic field in the central Colorado Plateau, to investigate their subsurface structure. The deep root system of Ship Rock, an exhumed Oligocene maar-diatreme complex, has not been resolved. The diatreme is largely composed of minette tuff-breccia with a large wallrock fraction, whereas the dikes are composed of hypabyssal minette. The country rock is the Upper Cretaceous Mancos Shale. Density and magnetic contrasts between the igneous rock and surrounding shale suggest that the buried structure of Ship Rock can be imaged. Preliminary geophysical investigations were carried out in order to test this hypothesis. We collected magnetic and gravitational data along four lines selected to transect the major south and northeast dikes and to partly encircle the diatreme. Modeling differently sized, oriented and shaped intrusions, we created theoretical Free Air anomaly curves to try to match the two clearest anomalies. Modeling necessitates (i) that the major north-south dike dips west and (ii) the presence of a high-density, deep body near the diatreme. The Free Air anomaly curves show that smaller dikes might not be detected from gravity data; however, they are necessary to determine the presence of large, dense bodies. Although not modeled, the magnetics curves show that smaller dikes can easily be detected. Our study results are promising, and we plan a more thorough investigation in the future which will produce a magnetic map to determine if further buried dikes exist in the vicinity, and measure gravity along additional profiles to better constrain the location of the dense body at depth.

Microstructural, textural and thermal evolution of an exhumed strike-slip fault and insights into localization and rheological transition

NASA Astrophysics Data System (ADS)

Cao, Shuyun; Neubauer, Franz; Liu, Junlai; Bernroider, Manfred; Genser, Johann

2016-04-01

The presence of deep exhumed crustal rocks with a dominant but contrasting mineralogy results in shear concentration in the rheological weakest layer, which exhibits contrasting patterns of fabrics and thermal conditions during their formation. We tested a combination of methodologies including microstructural and textural investigations, geochronology and geothermometry on deformed rocks from exhumed strike-slip fault, Ailao Shan-Red River, SE, Asian. Results indicate that the exhumed deep crustal rocks since late Oligocene (ca. 28 Ma) to Pliocene (ca. 4 Ma) typically involve dynamic microstructural, textural and thermal evolution processes, which typically record a progressive deformation and syn-kinematic reactions from ductile to semi-ductile and brittle behavior during exhumation. This transformation also resulted in dramatic strength reduction that promoted strain localization along the strike-slip and transtensional faults. Detailed analysis has revealed the co-existence of microfabrics ranging from high-temperatures (granulite facies conditions) to overprinting low-temperatures (lower greenschist facies conditions). The high-temperature microstructures and textures are in part or entirely altered by subsequent, overprinting low-temperature shearing. In quartz-rich rocks, quartz was deformed in the dislocation creep regime and records transition of microfabrics and slip systems during decreasing temperature, which lasted until retrogression related to final exhumation. As a result, grain-size reduction associated by fluids circulating within the strike-slip fault zone at brittle-ductile transition leads to rock softening, which resulted in strain localization, weak rock rheology and the overall hot thermal structure of the crust. Decompression occurred during shearing and as a result of tectonic exhumation. All these results demonstrate that the ductile to ductile-brittle transition involves a combination of different deformation mechanisms, rheological transition features and feedbacks between deformation, decreasing temperature and fluids.

Lower Paleozoic deep-water facies of the Medfra area, central Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1997

USGS Publications Warehouse

Dumoulin, Julie A.; Bradley, Dwight C.; Harris, Anita G.; Repetski, John E.

1999-01-01

Deep-water facies, chiefly hemipelagic deposits and turbidites, of Cambrian through Devonian age are widely exposed in the Medfra and Mt. McKinley quadrangles. These strata include the upper part of the Telsitna Formation (Middle-Upper Ordovician) and the Paradise Fork Formation (Lower Silurian-Lower Devonian) in the Nixon Fork terrane, the East Fork Hills Formation (Upper Cambrian-Lower Devonian) in the East Fork subterrane of the Minchumina terrane, and the chert and argillite unit (Ordovician) and the argillite and quartzite unit (Silurian- Devonian? and possibly older) in the Telida subterrane of the Minchumina terrane.In the western part of the study area (Medfra quadrangle), both hemipelagic deposits and turbidites are largely calcareous and were derived from the Nixon Fork carbonate platform. East- ern exposures (Mt. McKinley quadrangle; eastern part of the Telida subterrane) contain much less carbonate; hemipelagic strata are mostly chert, and turbidites contain abundant rounded quartz and lesser plagioclase and potassium feldspar. Deep-water facies in the Medfra quadrangle correlate well with rocks of the Dillinger terrane exposed to the south (McGrath quadrangle), but coeval strata in the Mt. McKinley quadrangle are compositionally similar to rocks to the northeast (Livengood quadrangle). Petrographic data thus suggest that the Telida subterranes presently defined is an artificial construct made up of two distinct sequences of disparate provenance.Restoration of 90 and 150 km of dextral strike-slip on the Iditarod and Farewell faults, respectively, aligns the deep-water strata of the Minchumina and Dillinger terranes in a position east of the Nixon Fork carbonate platform. This restoration supports the interpretation that lower Paleozoic rocks in the Nixon Fork and Dillinger terranes, and in the western part of the Minchumina terrane (East Fork subterrane and western part of the Telida subterrane), formed along a single continental margin. Rocks in the eastern part of the Telida subterrane are compositionally distinct from those to the west and may have had a different origin and history.

Soft Somatosensitive Actuators via Embedded 3D Printing.

PubMed

Truby, Ryan L; Wehner, Michael; Grosskopf, Abigail K; Vogt, Daniel M; Uzel, Sebastien G M; Wood, Robert J; Lewis, Jennifer A

2018-04-01

Humans possess manual dexterity, motor skills, and other physical abilities that rely on feedback provided by the somatosensory system. Herein, a method is reported for creating soft somatosensitive actuators (SSAs) via embedded 3D printing, which are innervated with multiple conductive features that simultaneously enable haptic, proprioceptive, and thermoceptive sensing. This novel manufacturing approach enables the seamless integration of multiple ionically conductive and fluidic features within elastomeric matrices to produce SSAs with the desired bioinspired sensing and actuation capabilities. Each printed sensor is composed of an ionically conductive gel that exhibits both long-term stability and hysteresis-free performance. As an exemplar, multiple SSAs are combined into a soft robotic gripper that provides proprioceptive and haptic feedback via embedded curvature, inflation, and contact sensors, including deep and fine touch contact sensors. The multimaterial manufacturing platform enables complex sensing motifs to be easily integrated into soft actuating systems, which is a necessary step toward closed-loop feedback control of soft robots, machines, and haptic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[The Research Advancement and Conception of the Deep-underground Medicine].

PubMed

Xie, He-Ping; Liu, Ji-Feng; Gao, Ming-Zhong; Wan, Xue-Hong; Liu, Shi-Xi; Zou, Jian; Wu, Jiang; Ma, Teng-Fei; Liu, Yi-Lin; Bu, Hong; Li, Wei-Min

2018-03-01

The 21th century is the century of exploring and utilizing the underground space. In the future, more and more people will spend more and more time living or/and working in the underground space. However,we know little about the effect on the health of human caused by the underground environment. Herein,we systematically put forward the strategic conception of the deep-underground medicine,in order to reveal relative effects and mechanism of the potential factors in the deep underground space on human's physiological and psychological healthy,and to work out the corresponding countermeasures. The original deep-underground medicine includes the following items. ①To model different depth of underground environment according to various parameters (such as temperature,radiation,air pressure, rock,microorganism), and to explore their quantitative character and effects on human health and mechanism. ② To study the psychological change, maintenance of homeostasis and biothythm of organism in the deep underground space. ③ To learn the association between psychological healthy of human and the depth, structure, physical environment and working time of underground space. ④ To investigate the effect of different terrane and lithology on healthy of human and to deliberate their contribution on organism growth. ⑤ To research the character and their mechanism of growth,metabolism,exchange of energy,response of growth, aging and adaptation of cells living in deep underground space. ⑥ To explore the physiological feature,growth of microbiome and it's interaction with host in the deep underground space. ⑦ To develop deep-underground simulation space, the biologically medical technology and equipments. As a research basis,a deep-underground medical lab under a rock thickness of about 1 470 m has been built,which aims to operate the research of the effect on living organism caused by different depth of underground environment. Copyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).

Geologic map of the Chelan 30-minute by 60-minute quadrangle, Washington

USGS Publications Warehouse

Tabor, R.W.; Frizzell, V.A.; Whetten, J.T.; Waitt, R.B.; Swanson, D.A.; Byerly, G.R.; Booth, D.B.; Hetherington, M.J.; Zartman, R.E.

1987-01-01

Summary -- The Chelan quadrangle hosts a wide variety of rocks and deposits and display a long geologic history ranging from possible Precambrian to Recent. Two major structures, the Leavenworth and Entiat faults divide cross the quadrangle from southeast to northwest and bound the Chiwaukum 'graben', a structural low preserving Tertiary sedimentary rocks between blocks of older, metamorphic and igneous rocks. Pre-Tertiary metamorphic rocks in the quadrangle are subdivided into five major tectonostratigraphic terranes: (1) the Ingalls terrane, equivalent to the Jurassic Ingalls Tectonic Complex of probable mantle and deep oceanic rocks origin, (2) the Nason terrane, composed of the Chiwaukum Schist and related gneiss, (3) the Swakane terrane, made up entirely of the Swakane Biotite Gneiss, a metamorphosed, possibly Precambrian, sedimentary and/or volcanic rock, (4) the Mad River terrane composed mostly of the rocks of the Napeequa River area (Napeequa Schist), a unit of oceanic protolith now considered part of the Chelan Mountains terrane (the Mad River terrane has been abandoned, 2001), and (5) the Chelan Mountains terrane, dominated by the Chelan Complex of Hopson and Mattinson (1971) which is composed of migmatite and gneissic to tonalite of deep-seated igneous and metamorphic origin.During an episode of Late Cretaceous regional metamorphism, all the terranes were intruded by deepseated tonalite to granodiorite plutons, including the Mount Stuart batholith, Ten Peak and Dirty Face plutons, and the Entiat pluton and massive granitoid rocks of the Chelan Complex. The Duncan Hill pluton intruded rocks of the Chelan Mountains terrane in the Middle Eocene. At about the same time fluvial arkosic sediment of the Chumstick Formation was deposited in a depression. The outpouring of basalt lavas to the southeast of the quadrangle during the Miocene built up the Columbia River Basalt Group. These now slightly warped lavas lapped onto the uplifted older rocks. Deformation, uplift, and erosion recorded in the rocks and deposits of the quadrangle continued into post-Miocene time. Quaternary deposits reflect advances of glaciers down the major valleys, a complicated history of catastrophic glacial floods down the Columbia River, the formation of lakes in the Columbia and Wenatchee river valleys by landslides and flood backwaters, and hillslope erosion by large and small landslides and debris flows.

Anionic deep cavitands enable the adhesion of unmodified proteins at a membrane bilayer.

PubMed

Ghang, Yoo-Jin; Perez, Lizeth; Morgan, Melissa A; Si, Fang; Hamdy, Omar M; Beecher, Consuelo N; Larive, Cynthia K; Julian, Ryan R; Zhong, Wenwan; Cheng, Quan; Hooley, Richard J

2014-12-28

An anionic self-folding deep cavitand is capable of immobilizing unmodified proteins and enzymes at a supported lipid bilayer interface, providing a simple, soft bioreactive surface that allows enzymatic function under mild conditions. The adhesion is based on complementary charge interactions, and the hosts are capable of binding enzymes such as trypsin at the bilayer interface: the catalytic activity is retained upon adhesion, allowing selective reactions to be performed at the membrane surface.

Geology of the continental margin beneath Santa Monica Bay, Southern California, from seismic-reflection data

USGS Publications Warehouse

Fisher, M.A.; Normark, W.R.; Bohannon, R.G.; Sliter, R.W.; Calvert, A.J.

2003-01-01

We interpret seismic-reflection data, which were collected in Santa Monica Bay using a 70-in3 generator-injector air gun, to show the geologic structure of the continental shelf and slope and of the deep-water, Santa Monica and San Pedro Basins. The goal of this research is to investigate the earthquake hazard posed to urban areas by offshore faults. These data reveal that northwest of the Palos Verdes Peninsula, the Palos Verdes Fault neither offsets the seafloor nor cuts through an undeformed sediment apron that postdates the last sea level rise. Other evidence indicates that this fault extends northwest beneath the shelf in the deep subsurface. However, other major faults in the study area, such as the Dume and San Pedro Basin Faults, were active recently, as indicated by an arched seafloor and offset shallow sediment. Rocks under the lower continental slope are deformed to differing degrees on opposite sides of Santa Monica Canyon. Northwest of this canyon, the continental slope is underlain by a little-deformed sediment apron; the main structures that deform this apron are two lower-slope anticlines that extend toward Point Dume and are cored by faults showing reverse or thrust separation. Southeast of Santa Monica Canyon, lower-slope rocks are deformed by a complex arrangement of strike-slip, normal, and reverse faults. The San Pedro Escarpment rises abruptly along the southeast side of Santa Monica Canyon. Reverse faults and folds underpinning this escarpment steepen progressively southeastward. Locally they form flower structures and cut downward into basement rocks. These faults merge downward with the San Pedro Basin fault zone, which is nearly vertical and strike slip. The escarpment and its attendant structures diverge from this strike-slip fault zone and extend for 60 km along the margin, separating the continental shelf from the deep-water basins. The deep-water Santa Monica Basin has large extent but is filled with only a thin (less than 1.5-km) section of what are probably post-Miocene rocks and sediment. Extrapolating ages obtained from Ocean Drilling Program site 1015 indicates that this sedimentary cover is Quaternary, possibly no older than 600 ka. Folds and faults along the base of the San Pedro Escarpment began to form during 8-13 ka ago. Refraction-velocity data show that high-velocity rocks, probably the Catalina Schist or Miocene volcanic rocks, underlie the sedimentary section. The San Pedro Basin developed along a strike-slip fault, widens to the southeast, and is deformed by faults having apparent reverse separation and by folds near Redondo Canyon and the Palos Verdes Peninsula.

Research on construction settlement of different soft foundation under vacuum preloading condition

NASA Astrophysics Data System (ADS)

Bin, LI; Changquan, YIN

2017-11-01

Vacuum preloading, rigid foundation, raft foundation and piled raft foundation are more commonly used in soft foundation treatment. PLAXIS is large finite element software of rock and soil, which can simulate the influence of different foundation forms. After the vacuum preloading treatment, the foundation settlement is reduced by 80%, the raft foundation settlement is reduced by 60%, the pile raft foundation settlement is reduced by 40%. It is suggested that the vacuum preloading is used to deal with the foundation of the building. If the time limit, the pile raft foundation is used as the foundation form of the foundation is better than others.

How to identify and manage oak wilt in Texas

Treesearch

D. N. Appel; R. S. Cameron; A. D. Wilson; J. D. Johnson.

2008-01-01

Measures can be taken to break root connections between live oaks or dense groups of red oaks to reduce or stop root transmission of the oak wilt fungus. The most common technique is to sever roots by trenching at least 4 ft deep with trenching machines, rock saws, or ripper bars. Trenches more than 4 ft deep may be needed to assure control in deeper soils. Although...

Microseismic Monitoring of Strainburst Activities in Deep Tunnels at the Jinping II Hydropower Station, China

NASA Astrophysics Data System (ADS)

Xu, N. W.; Li, T. B.; Dai, F.; Zhang, R.; Tang, C. A.; Tang, L. X.

2016-03-01

Rockbursts were frequently encountered during the construction of deep tunnels at the Jinping II hydropower station, Southwest China. Investigations of the possibility of rockbursts during tunnel boring machine (TBM) and drilling and blasting (D&B) advancement are necessary to guide the construction of tunnels and to protect personnel and TBM equipment from strainburst-related accidents. A real-time, movable microseismic monitoring system was installed to forecast strainburst locations ahead of the tunnel faces. The spatiotemporal distribution evolution of microseismic events prior to and during strainbursts was recorded and analysed. The concentration of microseismic events prior to the occurrence of strainbursts was found to be a significant precursor to strainbursts in deep rock tunnelling. During a 2-year microseismic investigation of strainbursts in the deep tunnels at the Jinping II hydropower station, a total of 2240 strainburst location forecasts were issued, with 63 % correctly forecasting the locations of strainbursts. The successful forecasting of strainburst locations proved that microseismic monitoring is essential for the assessment and mitigation of strainburst hazards, and can be used to minimise damage to equipment and personnel. The results of the current study may be valuable for the construction management and safety assessment of similar underground rock structures under high in situ stress.

Characterization Efforts in a Deep Borehole Field Test

NASA Astrophysics Data System (ADS)

Kuhlman, K. L.; Sassani, D.; Freeze, G. A.; Hardin, E. L.; Brady, P. V.

2016-12-01

The US Department of Energy Office of Nuclear Energy is embarking on a Deep Borehole Field Test to investigate the feasibility of constructing and characterizing two boreholes in crystalline basement rock to a depth of 5 km (16,400 ft). The concept of deep borehole disposal for radioactive waste has some advantages, including incremental construction and loading and the enhanced natural barriers provided by deep continental crystalline basement. Site characterization activities will include geomechanical (i.e., hydrofracture stress measurements), geological (i.e., core and mud logging), hydrological (i.e., packer-based pulse and pumping tests), and chemical (i.e., fluids sampled in situ from packer intervals and extracted from cores) tests. Borehole-based characterization will be used to determine the variability of system state (i.e., stress, pressure, temperature, and chemistry) with depth and interpretation of material and system parameters relevant to numerical site simulation. We explore the effects fluid density and geothermal temperature gradients (i.e., thermohaline convection) have on characterization goals in light of expected downhole conditions, including a disturbed rock zone surrounding the borehole. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Estimation of Deeper Structure at the Soultz Hot Dry Rock Field by Means of Reflection Method Using 3C AE as Wave Source

NASA Astrophysics Data System (ADS)

Soma, N.; Niitsuma, H.; Baria, R.

1997-12-01

We investigate the deep subsurface structure below the artificial reservoir at the Soultz Hot Dry Rock (HDR) site in France by a reflection method which uses acoustic emission (AE) as a wave source. In this method, we can detect reflected waves by examining the linearity of a three-dimensional hodogram. Additionally for imaging a deep subsurface structure, we employ a three-dimensional inversion with a restriction of wave polarization angles and with a compensation for a heterogeneous source distribution.¶We analyzed 101 AE wave forms observed at the Soultz site during the hydraulic testing in 1993. Some deep reflectors were revealed by this method. The bottom of the artificial reservoir that is presumed from all of the AE locations in 1993 was delineated at the depth of about 3900 m as a reflector. Other deeper reflectors were detected below the reservoir, which would not have been detected using conventional methods. Furthermore these reflectors agreed with the results of the tri-axial drill-bit VSP (Asanuma et al., 1996).

Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater

USGS Publications Warehouse

Haskin, L.A.; Wang, A.; Jolliff, B.L.; McSween, H.Y.; Clark, B. C.; Des Marais, D.J.; McLennan, S.M.; Tosca, N.J.; Hurowitz, J.A.; Farmer, J.D.; Yen, A.; Squyres, S. W.; Arvidson, R. E.; Klingelhofer, G.; Schroder, C.; De Souza, P.A.; Ming, D. W.; Gellert, Ralf; Zipfel, J.; Brückner, J.; Bell, J.F.; Herkenhoff, K.; Christensen, P.R.; Ruff, S.; Blaney, D.; Gorevan, S.; Cabrol, N.A.; Crumpler, L.; Grant, J.; Soderblom, L.

2005-01-01

Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and wind-blown 'global' dust. The analyses of three rock interiors exposed by the rock abrasion tool showed that they are similar to one another, consistent with having originated from a common lava flow. Here we report the investigation of soils, rock coatings and rock interiors by the Spirit rover from sol (martian day) 1 to sol 156, from its landing site to the base of the Columbia hills. The physical and chemical characteristics of the materials analysed provide evidence for limited but unequivocal interaction between water and the volcanic rocks of the Gusev plains. This evidence includes the softness of rock interiors that contain anomalously high concentrations of sulphur, chlorine and bromine relative to terrestrial basalts and martian meteorites; sulphur, chlorine and ferric iron enrichments in multilayer coatings on the light-toned rock Mazatzal; high bromine concentration in filled vugs and veins within the plains basalts; positive correlations between magnesium, sulphur and other salt components in trench soils; and decoupling of sulphur, chlorine and bromine concentrations in trench soils compared to Gusev surface soils, indicating chemical mobility and separation.

Seismic Anisotropy of Soft Sands, Offshore Western AUstralia

NASA Astrophysics Data System (ADS)

Urosevic, M.; Gurevich, B.

2007-05-01

Seismic anisotropy is commonly measured in sand shale environment. Intrinsic polar anisotropy of the shale and its effect on seismic data processing and analysis is well established and reasonably well understood. In sandstone, azimuthal anisotropy is often detected and is typically connected to an in situ stress regime and the brittleness of the rock. This type of anisotropy, commonly referred to as fractured induced anisotropy, has been widely and extensively studied as it directly affects both permeability and the strength of the rock. Hence fracture induced anisotropy is not only important for hydrocarbon exploration but also for geotechnical studies, underground mining, etc. Interestingly, in the last few years azimuthal anisotropy has also been detected in soft, poorly consolidated clean sands, mainly by cross-dipole sonic log measurements. This is somewhat surprising as in such soft, typically highly porous and permeable rocks stress induced fractures are unlikely to be abundant. In this study we analyse the anisotropy in such sand class using well-log measurements, three-component VSP data, as well as 2D and 3D surface seismic (reflection) data. High-quality cross-dipole sonic log measurements showed significant shear wave splitting over unconsolidated, highly porous and permeable sand interval. The shear wave anisotropy was computed to be around 10-15%. This is commonly seen as an indication that the rock is fractured and that the fractures are likely to be open. However, image log data over the same sand section suggested dilute most likely non-conductive fractures. Analysis of the shear wave splitting in VSP data also suggested low fracture density. The frequency content of the direct fast and slow shear waves on the VSP data was very similar, not supporting the presence of open fluid saturated fractures. Unfortunately, the evidence from the VSP data is not very compelling because the reservoir is thin compared to the wavelength and sampling interval of the VSP data. Further analysis of the soft sand anisotropy was conducted on surface seismic data. Magnitude of the overlain shale anisotropy was first established by measurements in the dominant horizontal stress direction. Subsequently pre-stack reflection amplitudes measured along several azimuths were matched to expected amplitudes from anisotropic AVO modelling. The results indicate that the anisotropy of the reservoir sands is high (more than 10%) at sonic frequencies but weak (about 2-3%), at seismic frequencies. We think this anisotropy is caused by the preferential closure of compliant inter-granular contacts oriented perpendicular to the principal horizontal stress. The effect is weaker at seismic frequencies since the wavelength in this case involves shales as well as sand. Furthermore, sonic anisotropy could have also been affected by the local stress conditions around the wellbore.

Rock deformation models and fluid leak-off in hydraulic fracturing

NASA Astrophysics Data System (ADS)

Yarushina, Viktoriya M.; Bercovici, David; Oristaglio, Michael L.

2013-09-01

Fluid loss into reservoir rocks during hydraulic fracturing is modelled via a poro-elastoplastic pressure diffusion equation in which the total compressibility is a sum of fluid, rock and pore space compressibilities. Inclusion of pore compressibility and porosity-dependent permeability in the model leads to a strong pressure dependence of leak-off (i.e. drainage rate). Dilation of the matrix due to fluid invasion causes higher rates of fluid leak-off. The present model is appropriate for naturally fractured and tight gas reservoirs as well as for soft and poorly consolidated formations whose mechanical behaviour departs from simple elastic laws. Enhancement of the leak-off coefficient by dilation, predicted by the new model, may help explain the low percentage recovery of fracturing fluid (usually between 5 and 50 per cent) in shale gas stimulation by hydraulic fracturing.

Modeling stress/strain-dependent permeability changes for deep geoenergy applications

NASA Astrophysics Data System (ADS)

Rinaldi, Antonio Pio; Rutqvist, Jonny

2016-04-01

Rock permeability is a key parameter in deep geoenergy systems. Stress and strain changes induced at depth by fluid injection or extraction may substantially alter the rock permeability in an irreversible way. With regard to the geoenergies, some applications require the permeability to be enhanced to improve productivity. The rock permeability is generally enhanced by shearing process of faults and fractures (e.g. hydroshearing for Enhanced and Deep Geothermal Systems), or the creation of new fractures (e.g. hydrofracturing for shale gas). However, such processes may, at the same time, produce seismicity that can be felt by the local population. Moreover, the increased permeability due to fault reactivation may pose at risk the sealing capacity of a storage site (e.g. carbon sequestration or nuclear waste disposal), providing then a preferential pathway for the stored fluids to escape at shallow depth. In this work we present a review of some recent applications aimed at understanding the coupling between stress (or strain) and permeability. Examples of geoenergy applications include both EGS and CO2 sequestration. To investigate both "wanted" and "unwanted" effects, THM simulations have been carried out with the TOUGH-FLAC simulator. Our studies include constitutive equations relating the permeability to mean effective stress, effective normal stress, volumetric strain, as well as accounting for permeability variation as related to fault/fracture reactivation. Results show that the geomechanical effects have a large role in changing the permeability, hence affecting fluids leakage, reservoir enhancement, as well as the induced seismicity.

Transport of barium through dolomite rocks under the presence of guar gum and brine salinities of hydraulic fracturing wastewater

NASA Astrophysics Data System (ADS)

Ebrahimi, P.; Vilcaez, J.

2017-12-01

Hydraulic fracturing wastewater (HFW) containing high concentrations of Ba, is commonly disposed into the deep saline aquifers. We investigate the effect of brine salinity, competing cations (Ca and Mg), and guar gum (most common fracturing viscosifier) on the sorption and transport of Ba through dolomite rocks. To this aim, we have conducted batch sorption and core-flooding experiments at both ambient (22°C) and deep subsurface (60°C) temperature conditions. The effect of mineral composition is assessed by comparing batch and core-flooding experimental results obtained with sandstone and dolomite rocks. Batch sorption experiments conducted using powdered dolomite rocks (500-600 µm particle size) revealed that Ba sorption on dolomite greatly decreases with increasing brine salinity (0 - 180,000 mg-NaCl/L), and that at brine salinities of HFW, chloro-complexation reactions between Ba and Cl ions and changes in pH (that results from dolomite dissolution) are the controlling factors of Ba sorption on dolomite. Organo-complexation reactions between Ba and guar gum, and competition of Ba with common cations (Ca and Mg) for hydration sites of dolomite, play a secondary role. This finding is in accordance with core-flooding experimental results, showing that the transport of Ba through synthetic dolomite rocks of high flow properties (25-29.6% porosity, 9.6-13.7 mD permeability), increases with increasing brine salinity (0-180,000 mg-NaCl/L), while the presence of guar gum (50-500 mg/L) does not affect the transport of Ba. On the other hand, core-flooding experiments conducted using natural dolomite core plugs (6.5-8.6% porosity, 0.06-0.3 mD permeability), indicates that guar gum can clog the pore throats of tight dolomite rocks retarding the transport of Ba. Results of our numerical simulation studies indicate that the mechanism of Ba sorption on dolomite can be represented by a sorption model that accounts for both surface complexation reactions on three distinct hydration sites (>CaOHo, >MgOHo, and >CO3Ho), and the kinetic dissolution of dolomite. The presented results are important in understanding the fate of heavy metals present in HFW disposed into deep saline aquifers.

Fluids of the lower crust and upper mantle: deep is different

NASA Astrophysics Data System (ADS)

Manning, C. E.

2017-12-01

Deep fluids are important for the evolution and properties of the lower crust and upper mantle in tectonically active settings. Uncertainty about their chemistry has led past workers to use upper crustal fluids as analogues. However, recent results show that fluids at >15 km differ fundamentally from shallow fluids and help explain high-pressure metasomatism and resistivity patterns. Deep fluids are comprised of four components: H2O, non-polar gases (chiefly CO2), salts (mostly alkali chlorides), and rock-derived solutes (dominated by aluminosilicates and related components). The first three generally define the solvent properties of the fluid, and models must account for observations that H2O activity may be quite low. The contrasting behavior of H2O-gas and H2O-salt mixtures yields immiscibility in the ternary system, which can lead to separation of two phases with fundamentally different chemical and transport properties. Thermodynamic modeling of equilibrium between rocks and H2O using simple ionic species known from shallow-crustal systems yields solutions possessing total dissolved solids and ionic strength that are too low to be consistent with experiments and resistivity surveys. Addition of CO2 further lowers bulk solubility and conductivity. Therefore, additional species must be present in H2O, and H2O-salt solutions likely explain much of the evidence for fluid action in high-P settings. At low salinity, H2O-rich fluids are powerful solvents for aluminosilicate rock components that are dissolved as previously unrecognized polymerized clusters. Experiments show that, near H2O-saturated melting, Al-Si polymers comprise >80% of solutes. The stability of these species facilitates critical critical mixing in rock-H2O systems. Addition of salt (e.g., NaCl) changes solubility patterns, but aluminosilicate contents remain high. Thermodynamic models indicate that the ionic strength of fluids with Xsalt = 0.05 to 0.4 and equilibrated with model crustal rocks have predicted bulk conductivities of 10-1.5 to 100 S/m at porosity of 0.001. Such fluids are thus consistent with conductivity anomalies commonly observed in the lower crust (e.g., the "G" anomaly), and are capable of the mass transfer commonly seen in metamorphic rocks exhumed from the lower crust and subduction zones.

Crustal faults exposed in the Pito Deep Rift: Conduits for hydrothermal fluids on the southeast Pacific Rise

NASA Astrophysics Data System (ADS)

Hayman, Nicholas W.; Karson, Jeffrey A.

2009-02-01

The escarpments that bound the Pito Deep Rift (northeastern Easter microplate) expose in situ upper oceanic crust that was accreted ˜3 Ma ago at the superfast spreading (˜142 mm/a, full rate) southeast Pacific Rise (SEPR). Samples and images of these escarpments were taken during transects utilizing the human-occupied vehicle Alvin and remotely operated vehicle Jason II. The dive areas were mapped with a "deformation intensity scale" revealing that the sheeted dike complex and the base of the lavas contain approximately meter-wide fault zones surrounded by fractured "damage zones." Fault zones are spaced several hundred meters apart, in places offset the base of the lavas, separate areas with differently oriented dikes, and are locally crosscut by (younger) dikes. Fault rocks are rich in interstitial amphibole, matrix and vein chlorite, prominent veins of quartz, and accessory grains of sulfides, oxides, and sphene. These phases form the fine-grained matrix materials for cataclasites and cements for breccias where they completely surround angular to subangular clasts of variably altered and deformed basalt. Bulk rock geochemical compositions of the fault rocks are largely governed by the abundance of quartz veins. When compositions are normalized to compensate for the excess silica, the fault rocks exhibit evidence for additional geochemical changes via hydrothermal alteration, including the loss of mobile elements and gain of some trace metals and magnesium. Microstructures and compositions suggest that the fault rocks developed over multiple increments of deformation and hydrothermal fluid flow in the subaxial environment of the SEPR; faults related to the opening of the Pito Deep Rift can be distinguished by their orientation and fault rock microstructure. Some subaxial deformation increments were likely linked with violent discharge events associated with fluid pressure fluctuations and mineral sealing within the fault zones. Other increments were linked with the influx of relatively fresh seawater. The spacing of the faults is consistent with fault localization occurring every 7000 to 14,000 years, with long-term slip rates of <3 mm/a. Once spread from the ridge axis, the faults were probably not active, and damage zones likely played a more significant role in axial flank and off-axis crustal permeability.

Anorthosites and alkaline rocks from the deep crust of peninsular India

NASA Technical Reports Server (NTRS)

Leelanandam, C.; Ratnakar, J.; Reddy, M. Narsimha

1988-01-01

The anorthosite and alkaline rock localities in the Precambrian Shield of Peninsular India were reviewed. There are approximately 50 localities of such rocks, generally restricted to the Eastern Ghats mobile belt. The alkaline plutons are typically confined to the margin of the Eastern Ghats. The anorthosites are all greater than 500 sq km, but many exhibit similarities to one another. It was suggested that the anorthosites are associated with cryptic sutures, and are thought to have originated as a result of ponding of basaltic magmas. An analogy was drawn between the Eastern Ghats belt and the Grenville Province of the Canadian Shield.

High Sr/Y rocks are not all adakites!

NASA Astrophysics Data System (ADS)

Moyen, Jean-François

2010-05-01

The name of "adakite" is used to describe a far too large group of rocks, whose sole common feature is high Sr/Y and La/Yb ratios. Defining adakites only by this criterion is misleading, as the definition of this group of rocks does include many other criteria, including major elements. In itself, high (or commonly moderate!) Sr/Y ratios can be achieved via different processes: melting of a high Sr/Y (and La/Yb) source; deep melting, with abundant residual garnet; fractional crystallization or AFC; or interactions of felsic melts with the mantle, causing selective enrichment in LREE and Sr over HREE. A database of the compositions of "adakitic" rocks - including "high silica" and "low silica" adakites, "continental" adakites and Archaean adakites—was assembled. Geochemical modeling of the potential processes is used to interpret it, and reveals that (1) the genesis of high-silica adakites requires high pressure evolution (be it by melting or fractionation), in equilibrium with large amounts of garnet; (2) low-silica adakites are explained by garnet-present melting of an adakite-metasomatized mantle, i.e at depths greater than 2.5 GPa; (3) "Continental" adakites is a term encompassing a huge range of rocks, with a corresponding diversity of petrogenetic processes, and most of them are different from both low- and high- silica adakites; in fact in many cases it is a complete misnomer and the rocks studied are high-K calc-alkaline granitoids or even S-type granites; (4) Archaean adakites show a bimodal composition range, with some very high Sr/Y examples (similar to part of the TTG suite) reflecting deep melting (> 2.0 GPa) of a basaltic source with a relatively high Sr/Y, while lower Sr/Y rocks formed by shallower (1.0 GPa) melting of similar sources. Comparison with the Archaean TTG suite highlights the heterogeneity of the TTGs, whose composition spreads the whole combined range of HSA and Archaean adakites, pointing to a diversity of sources and processes contributing to the "TTG suite".

Long-term conditioning of deep-seated rockslides in deglaciated valleys: the Spriana case study

NASA Astrophysics Data System (ADS)

Agliardi, Federico; Crosta, Giovanni B.

2015-04-01

Deep-seated rockslides in alpine valleys evolve over long time under the action of multiple triggers. Early Warning based on monitoring is often the only effective approach to cope with these landslides, but it requires an improved understanding of mechanisms interplaying over long time. Deep-seated rockslides are often characterized by long-term 'creep' and seasonal displacement components, contributing to measured displacement patterns which are often modelled as rockslide responses to hydrologic perturbations. Although this hydro-mechanical modelling approach fits the behaviour of disrupted rockslide masses with well-developed shear zones, it is often insufficient to explain the initial onset and the long-term components of creep movements of deep-seated rockslides. This outlines the need to link long-term evolution of rock slopes and their sensitivity to triggers. We discuss the Spriana rockslide, affecting the steep left-hand flank of Val Malenco (italian Central Alps). Documented instabilities date back to 1912, whereas the rockslide underwent major acceleration stages in 1960 and 1977-78 and later minor reactivations. We reviewed a large amount of data collected since 1978 by extensive geotechnical site investigation (borehole drilling, exploratory adits, and seismic refraction) and monitoring activities (ground surface and deep displacements, pore pressures) motivated by potential catastrophic collapse threatening the city of Sondrio area. We performed rock mass characterization based on laboratory studies on intact rock samples, field surveys and drillcore logging. These data allowed re-evaluating the geological model of the Spriana rockslide, which is a compound slide of up to 50 Mm3 of slope debris and fractured gneiss, with multiple shear failure zones up to 90 m deep. Two main scarps developed in different stages, suggesting progressive failure processes. The rockslide creeps at slow rates of 0.4-3 cm/a, and undergoes acceleration stages (weeks to months) during increased water recharge periods. Heavily fractured rock masses occur below rockslide base up to 150 m in depth, suggesting extensive rock mass damage pre-dating rockslide onset. Groundwater monitoring shows that this fractured layer hosts a perched water table characterized by annual fluctuations up to 3 m. To gain insights in the long-term slope evolution we performed 2D Finite-Element multi-stage stress-strain and seepage modelling, accounting for post-LGM deglaciation, damage and related changes in slope strength and hydrology. Results validated using investigation data show that rockslide onset would have been unlikely without the strong preconditioning of long-term damage related to deglaciation. This led to a two-layer hydro-mechanical slope differentiation, with a fractured upper layer hosting a perched water table that favoured rockslide onset. Once structured, the rockslide became more sensitive to short-term hydrologic triggers, with displacement rates increasing in response to groundwater recharge related to critical values of antecedent (7 to 30 days) rainfall. Our results outline the importance of accounting for long-term slope evolution when dealing with rockslides evolving over 102-103 year timescales, and point to the need of modelling approaches able to relate changing hydro-mechanical properties of slopes to long-term damage processes.

Structural, electronic and vibrational properties of lanthanide monophosphide at high pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panchal, J. M., E-mail: amitjignesh@yahoo.co.in; Department of Physics, University School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat; Joshi, Mitesh

2016-05-06

A first-principles plane wave self-consistent method with the ultra-soft-pseudopotential scheme in the framework of the density functional theory (DFT) is performed to study structural, electronic and vibrational properties of LaP for Rock-salt (NaCl/Bl) and Cesium-chloride (CsCl/B2) phases. The instability of Rock-salt (NaCl/Bl) phases around the transition is discussed. Conclusions based on electronic energy band structure, density of state, phonon dispersion and phonon density of states in both phases are outlined. The calculated results are consistence and confirm the successful applicability of quasi-harmonic phonon theory for structural instability studies for the alloys.

Well-circumscribed deep-seated lipomas of the upper extremity. A report of 13 cases.

PubMed

Elbardouni, A; Kharmaz, M; Salah Berrada, M; Mahfoud, M; Elyaacoubi, M

2011-04-01

The purpose of this study is to determine if giant size is of bad prognosis in deep lipomas of the upper extremity. We report a retrospective study of 13 patients with deep-seated lipomas of the upper extremity treated during the period from April 1997 to April 2008. We evaluated the clinical and radiological characteristics, treatment and evolution profile of these patients. There were 10 women and three men, with an average age of 53 years (range 30-79 years). Seven of these lipomas were in the arm, one in the shoulder, and five in the forearm. Six lipomas were intramuscular, six intermuscular (three of them being attached to bone and labelled parosteal lipoma) and one epivaginal lipoma of the flexor tendon sheath. All patients presented a progressive slow-growing mass that was associated with radial paralysis in one case and carpal tunnel syndrome in one case. Plain radiographs showed a radiolucent soft-tissue image in all cases and an associated osteochondroma in one parosteal lipoma. Computer tomography (CT) or magnetic resonance imaging (MRI) suggested the lipomatous nature and benign characteristics of these deep lipomas that were giant in all cases (mean size: 7 cm). Lipoma marginal excision was performed and histopathological examination demonstrated features consistent with a benign lipoma. There was good function and no clinical recurrence was observed after a mean follow-up of three years. Giant deep-seated lipomas of the upper extremity are uncommon and can be intermuscular or intramuscular. A painless soft-tissue mass is the most frequent chief complaint. MRI with fat suppression suggests the diagnosis and studies the extension of deep lipoma. Marginal excision is the treatment of choice and histopathology eliminates diagnosis of well-differentiated liposarcoma. Appropriate evaluation of deep lipoma is to rule out malignancy by systematically performing MRI and biopsy. In contrast to deep-seated lipomas of the lower extremity or the retroperitoneal space, the prognosis of deep-seated lipomas of the upper extremity is good irrelevant of their size. Recurrence and the degeneration are very rare. Level 4. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Stratigraphy and paleogeographic significance of a Late Pennsylvanian to Early Permian channeled slope sequence in the Darwin Basin, southern Darwin Hills, east-central California

USGS Publications Warehouse

Stevens, Calvin H.; Stone, Paul; Magginetti, Robert T.; Ritter, Scott M.

2015-01-01

The complex stratigraphy of late Paleozoic rocks in the southern Darwin Hills consists of regionally extensive Mississippian and Early to Middle Pennsylvanian rocks overlain by latest Pennsylvanian to Early Permian rocks, herein called the Darwin Hills sequence. Deposition of this latter sequence marked the beginning of the Darwin Basin. In Mississippian time, a carbonate platform prograded westward over slightly older slope deposits. In the Late Mississippian this platform was exposed to erosion and siliciclastic sediments were deposited. In Early to Middle Pennsylvanian time the area subsided, forming a west-facing ramp that was subjected to deformation and erosion in Middle or early Late Pennsylvanian time. Later this area was tilted westward and deep-water sediments were deposited on this slope. In latest Pennsylvanian to earliest Permian time, a major channel was cut through the older Pennsylvanian rocks and into the Upper Mississippian strata. This channel was gradually filled with increasingly finer grained, deep-water sediment as the area evolved into a basin floor by Early Permian (Sakmarian) time. Expansion of the Darwin Basin in Artinskian time led to a second phase of deposition represented by strata of the regionally extensive Darwin Canyon Formation. The geology in this small area thus documents tectonic events occurring during the early development of the Darwin Basin.

Vertical cross contamination of trichloroethylene in a borehole in fractured sandstone

USGS Publications Warehouse

Sterling, S.N.; Parker, B.L.; Cherry, J.A.; Williams, J.H.; Lane, J.W.; Haeni, F.P.

2005-01-01

Boreholes drilled through contaminated zones in fractured rock create the potential for vertical movement of contaminated ground water between fractures. The usual assumption is that purging eliminates cross contamination; however, the results of a field study conducted in a trichloroethylene (TCE) plume in fractured sandstone with a mean matrix porosity of 13% demonstrates that matrix-diffusion effects can be strong and persistent. A deep borehole was drilled to 110 m below ground surface (mbgs) near a shallow bedrock well containing high TCE concentrations. The borehole was cored continuously to collect closely spaced samples of rock for analysis of TCE concentrations. Geophysical logging and flowmetering were conducted in the open borehole, and a removable multilevel monitoring system was installed to provide hydraulic-head and ground water samples from discrete fracture zones. The borehole was later reamed to complete a well screened from 89 to 100 mbgs; persistent TCE concentrations at this depth ranged from 2100 to 33,000 ??g/L. Rock-core analyses, combined with the other types of borehole information, show that nearly all of this deep contamination was due to the lingering effects of the downward flow of dissolved TCE from shallower depths during the few days of open-hole conditions that existed prior to installation of the multilevel system. This study demonstrates that transfer of contaminant mass to the matrix by diffusion can cause severe cross contamination effects in sedimentary rocks, but these effects generally are not identified from information normally obtained in fractured-rock investigations, resulting in potential misinterpretation of site conditions. Copyright ?? 2005 National Ground Water Association.

Research in rock deformation: Report of the Second Rock Deformation Colloquium, 1989 AGU Spring Meeting

NASA Astrophysics Data System (ADS)

Green, Harry

In response to the considerable interest expressed at the first Rock Deformation Colloquium held at the Fall 1988 AGU meeting in San Francisco, a second dinner meeting was held on Monday evening, May 8, 1989, at the Omni Hotel in Baltimore. The principal business items were a report by Steve Kirby (U.S. Geological Survey, Menlo Park, Calif.) concerning the meeting the previous day of the rock deformation steering committee and an after dinner presentation by Steve Freiman of the National Institute of Standards and Technology in Gaithersburg, Md., entitled “The Environmental Effects on Subcritical Crack Growth.” Kirby reported that a technical committee for rock deformation has been established within the Tectonophysics Section of AGU; the steering committee will attempt to establish constructive working relations with allied societies and disciplines, such as ceramics, metallurgy, materials science, structural geology, and surface science. Brian Evans of the Massachusetts Institute of Technology in Cambridge, Terry Tullis of Brown University in Providence, R.I., and Harry Green of the University of California at Davis agreed to be a subcommittee to propose a name for the technical committee, for discussion at the next steering committee meeting to be held before the 1989 Fall AGU meeting. Green also agreed to investigate the possibility of convening a special session at the Fall Meeting on the nature and mechanism of deep-focus earthquakes. (The session is Deep Slab Deformation and Faulting, T21B and T22A, organized by Harry and Ken Creager of the University of Washington, Seattle; it will be all day on Tuesday, December 5.)

Permeability in fractured rocks from deep geothermal boreholes in the Upper Rhine Graben

NASA Astrophysics Data System (ADS)

Vidal, Jeanne; Whitechurch, Hubert; Genter, Albert; Schmittbuhl, Jean; Baujard, Clément

2015-04-01

Permeability in fractured rocks from deep geothermal boreholes in the Upper Rhine Graben Vidal J.1, Whitechurch H.1, Genter A.2, Schmittbuhl J.1, Baujard C.2 1 EOST, Université de Strasbourg 2 ES-Géothermie, Strasbourg The thermal regime of the Upper Rhine Graben (URG) is characterized by a series of geothermal anomalies on its French part near Soultz-sous-Forêts, Rittershoffen and in the surrounding area of Strasbourg. Sedimentary formations of these areas host oil field widely exploited in the past which exhibit exceptionally high temperature gradients. Thus, geothermal anomalies are superimposed to the oil fields which are interpreted as natural brine advection occurring inside a nearly vertical multi-scale fracture system cross-cutting both deep-seated Triassic sediments and Paleozoic crystalline basement. The sediments-basement interface is therefore very challenging for geothermal industry because most of the geothermal resource is trapped there within natural fractures. Several deep geothermal projects exploit local geothermal energy to use the heat or produce electricity and thus target permeable fractured rocks at this interface. In 1980, a geothermal exploration well was drilled close to Strasbourg down to the Permian sediments at 3220 m depth. Bottom hole temperature was estimated to 148°C but the natural flow rate was too low for an economic profitability (<7 L/s). Petrophysics and reservoir investigations based on core analysis revealed a low matrix porosity with fracture zones spatially isolated and sealed in the sandstone formations. Any stimulation operation was planned and the project was abandoned. The Soultz-sous-Forêts project, initiated in 1986, explored during more than 30 years the experimental geothermal site by drilling five boreholes, three of which extend to 5 km depth. They identified a temperature of 200° C at 5 km depth in the granitic basement but with a variable flow rate. Hydraulic and chemical stimulation operations were applied in order to increase the initial low permeability by reactivating and dissolving sealed fractures in basement. The productivity was considerably improved and allows geothermal exploitation at 165° C and 20 L/s. Recent studies revealed the occurrences of permeable fractures in the limestones of Muschelkalk and the sandstones of Buntsandstein also. For the ongoing project at Rittershoffen, two deep boreholes, drilled down to 2.7 km depth target a reservoir in the sandstones of Buntsandstein and in the granitic basement interface. The thermal, hydraulic and chemical stimulations of the first well lead the project to an economic profitability with a temperature of 170° C and an industrial flow rate of 70 L/s. The deep sedimentary cover and the top of the granitic basement are the main target of the geothermal project in the URG. Permeability of fractured rocks after drilling operations or stimulation operations demonstrates the viability of French industrial deep geothermal projects in the URG was also confirmed by several geothermal projects in Germany that target the similar sediments-basement interface (Landau and Insheim) or the deep Triassic sediments (Bruchsal and Brühl). In France, future geothermal projects are planned in particular in Strasbourg suburb to exploit the permeability of deep-seated fractured sediment-basement interface.

Upper Cretaceous Shannon Sandstone reservoirs, Powder River Basin, Wyoming: evidence for organic acid diagenesis?

USGS Publications Warehouse

Hansley, P.L.; Nuccio, V.F.

1992-01-01

Comparison of the petrology of shallow and deep oil reservoirs in the Upper Cretaceous Shannon Sandstone Beds of the Steele Member of the Cody Shale strongly suggests that organic acids have had a more significant impact on the diagenetic alteration of aluminosilicate grains and carbonate cements in the deep reservoirs than in the shallow reservoirs. Vitrinite reflectance and Rock-Eval measurements, as well as the time-temperature index and kinetic modeling, indicate that deep reservoirs have been subjected to maximum temperatures of approximately 110-120??C, whereas shallow reservoirs have reached only 75??C. -from Authors

An exploration of motivations among scuba divers in north central Florida

Treesearch

Louisa A. Meyer; Brijesh Thapa; Lori Pennington-Gray

2003-01-01

There has been a boom in the adventure travel market as 98 million adults had taken an adventure vacation between 1992 and 1997, which includes soft adventure vacations (e.g., camping, hiking, biking, bird-or-animal-watching, horseback riding, sailing, skiing), and hard adventure vacations (e.g., mountain biking, whitewater rafting/kayaking, scuba diving, rock climbing...

Nature of Pre-Earthquake Phenomena and their Effects on Living Organisms

PubMed Central

Freund, Friedemann; Stolc, Viktor

2013-01-01

Simple Summary Earthquakes are invariably preceded by a period when stresses increase deep in the Earth. Animals appear to be able to sense impending seismic events. During build-up of stress, electronic charge carriers are activated deep below, called positive holes. Positive holes have unusual properties: they can travel fast and far into and through the surrounding rocks. As they flow, they generate ultralow frequency electromagnetic waves. When they arrive at the Earth surface, they can ionize the air. When they flow into water, they oxidize it to hydrogen peroxides. All these physical and chemical processes can have noticeable effects on animals. Abstract Earthquakes occur when tectonic stresses build up deep in the Earth before catastrophic rupture. During the build-up of stress, processes that occur in the crustal rocks lead to the activation of highly mobile electronic charge carriers. These charge carriers are able to flow out of the stressed rock volume into surrounding rocks. Such outflow constitutes an electric current, which generates electromagnetic (EM) signals. If the outflow occurs in bursts, it will lead to short EM pulses. If the outflow is continuous, the currents may fluctuate, generating EM emissions over a wide frequency range. Only ultralow and extremely low frequency (ULF/ELF) waves travel through rock and can reach the Earth surface. The outflowing charge carriers are (i) positively charged and (ii) highly oxidizing. When they arrive at the Earth surface from below, they build up microscopic electric fields, strong enough to field-ionize air molecules. As a result, the air above the epicentral region of an impending major earthquake often becomes laden with positive airborne ions. Medical research has long shown that positive airborne ions cause changes in stress hormone levels in animals and humans. In addition to the ULF/ELF emissions, positive airborne ions can cause unusual reactions among animals. When the charge carriers flow into water, they oxidize water to hydrogen peroxide. This, plus oxidation of organic compounds, can cause behavioral changes among aquatic animals. PMID:26487415

Cecal bacterial communities in wild Japanese rock ptarmigans and captive Svalbard rock ptarmigans.

PubMed

Ushida, Kazunari; Segawa, Takahiro; Tsuchida, Sayaka; Murata, Koichi

2016-02-01

Preservation of indigenous gastrointestinal microbiota is deemed to be critical for successful captive breeding of endangered wild animals, yet its biology is poorly understood. Here, we investigated cecal bacterial communities in wild Japanese rock ptarmigans (Lagopus muta japonica) and compared them with those in Svalbard rock ptarmigans (L. m. hyperborea) in captivity. Ultra-deep sequencing of 16S rRNA gene indicated that the community structure of cecal microbiota in wild rock ptarmigans was remarkably different from that in captive Svalbard rock ptarmigans. Fundamental differences between bacterial communities in the two groups of birds were detected at the phylum level. Firmicutes, Actinobacteria, Bacteroidetes and Synergistetes were the major phyla detected in wild Japanese rock ptarmigans, whereas Firmicutes alone occupied more than 80% of abundance in captive Svalbard rock ptarmigans. Furthermore, unclassified genera of Coriobacteriaceae, Synergistaceae, Bacteroidaceae, Actinomycetaceae, Veillonellaceae and Clostridiales were the major taxa detected in wild individuals, whereas in zoo-reared birds, major genera were Ruminococcus, Blautia, Faecalibacterium and Akkermansia. Zoo-reared birds seemed to lack almost all rock ptarmigan-specific bacteria in their intestine, which may explain the relatively high rate of pathogenic infections affecting them. We show evidence that preservation and reconstitution of indigenous cecal microflora are critical for successful ex situ conservation and future re-introduction plan for the Japanese rock ptarmigan.

Seeking: Accurate Measurement Techniques for Deep-Bone Density and Structure

NASA Technical Reports Server (NTRS)

Sibonga, Jean

2009-01-01

We are seeking a clinically-useful technology with enough sensitivity to assess the microstructure of "spongy" bone that is found in the marrow cavities of whole bones. However, this technology must be for skeletal sites surrounded by layers of soft tissues, such as the spine and the hip. Soft tissue interferes with conventional imaging and using a more accessible area -- for example, the wrist or the ankle of limbs-- as a proxy for the less accessible skeletal regions, will not be accurate. A non-radioactive technology is strongly preferred.

Qualitative and quantitative changes in detrital reservoir rocks caused by CO2-brine-rock interactions during first injection phases (Utrillas sandstones, Northern Spain)

NASA Astrophysics Data System (ADS)

Berrezueta, E.; Ordóñez-Casado, B.; Quintana, L.

2015-08-01

The aim of this article is to describe and interpret qualitative and quantitative changes at rock matrix scale of Lower-Upper Cretaceous sandstones exposed to supercritical (SC) CO2 and brine. The effects of experimental injection of SC CO2 during the first injection phases were studied at rock matrix scale, in a potential deep sedimentary reservoir in Northern Spain (Utrillas unit, at the base of the Cenozoic Duero Basin). Experimental wet CO2 injection was performed in a reactor chamber under realistic conditions of deep saline formations (P ≈ 78 bar, T ≈ 38 °C and 24 h exposure time). After the experiment, exposed and non-exposed equivalent sample sets were compared with the aim of assessing possible changes due to the effect of the CO2-brine exposure. Optical microscopy (OpM) and scanning electron microscopy (SEM) aided by optical image analysis (OIA) were used to compare the rock samples and get qualitative and quantitative information about mineralogy, texture and porous network distribution. Chemical analyses were performed to refine the mineralogical information and to obtain whole rock geochemical data. Brine composition was also analysed before and after the experiment. The results indicate an evolution of the pore network (porosity increase ≈ 2 %). Intergranular quartz matrix detachment and partial removal from the rock sample (due to CO2 input/release dragging) are the main processes that may explain the porosity increase. Primary mineralogy (≈ 95 % quartz) and rock texture (heterogeneous sand with interconnected framework of micro-channels) are important factors that seem to enhance textural/mineralogical changes in this heterogeneous system. The whole rock and brine chemical analyses after interaction with SC CO2-brine do not present important changes in the mineralogical, porosity and chemical configuration of the rock with respect to initial conditions, ruling out relevant precipitation or dissolution at these early stages. These results, simulating the CO2 injection near the injection well during the first phases (24 h) indicate that, in this environment where CO2 displaces the brine, the mixture principally generates local mineralogical/textural re-adjustments due to physical detachment of quartz grains. Consequences deriving from these changes are variable. Possible porosity and permeability increases could facilitate further CO2 injection but textural re-adjustment could also affect the rock physically. However, it is not clear yet what effect the quartz (solid suspension) could provoke in more distant areas of the rock. Quartz could be transported in the fluid flow path and probably accumulated at pore throats.

Monitoring controlled graves representing common burial scenarios with ground penetrating radar

NASA Astrophysics Data System (ADS)

Schultz, John J.; Martin, Michael M.

2012-08-01

Implementing controlled geophysical research is imperative to understand the variables affecting detection of clandestine graves during real-life forensic searches. This study focused on monitoring two empty control graves (shallow and deep) and six burials containing a small pig carcass (Sus scrofa) representing different burial forensic scenarios: a shallow buried naked carcass, a deep buried naked carcass, a deep buried carcass covered by a layer of rocks, a deep buried carcass covered by a layer of lime, a deep buried carcass wrapped in an impermeable tarpaulin and a deep buried carcass wrapped in a cotton blanket. Multi-frequency, ground penetrating radar (GPR) data were collected monthly over a 12-month monitoring period. The research site was a cleared field within a wooded area in a humid subtropical environment, and the soil consisted of a Spodosol, a common soil type in Florida. This study compared 2D GPR reflection profiles and horizontal time slices obtained with both 250 and 500 MHz dominant frequency antennae to determine the utility of both antennae for grave detection in this environment over time. Overall, a combination of both antennae frequencies provided optimal detection of the targets. Better images were noted for deep graves, compared to shallow graves. The 250 MHz antenna provided better images for detecting deep graves, as less non-target anomalies were produced with lower radar frequencies. The 250 MHz antenna also provided better images detecting the disturbed ground. Conversely, the 500 MHz antenna provided better images when detecting the shallow pig grave. The graves that contained a pig carcass with associated grave items provided the best results, particularly the carcass covered with rocks and the carcass wrapped in a tarpaulin. Finally, during periods of increased soil moisture levels, there was increased detection of graves that was most likely related to conductive decompositional fluid from the carcasses.

Continuation of down-hole geophysical testing for rock sockets.

DOT National Transportation Integrated Search

2013-11-01

Site characterization for the design of deep foundations is crucial for ensuring a reliable and economic substructure design, as unanticipated site conditions can cause significant problems and disputes during construction. Traditional invasive explo...

The Analysis of Weak Rock Using the Pressuremeter

NASA Astrophysics Data System (ADS)

Dafni, Jacob

The pressuremeter is a versatile in situ testing instrument capable of testing a large range of materials from very soft clay to weak rock. Due to limitations of other testing devices, the pressuremeter is one of the few instruments capable of capturing stiffness and strength properties of weak rock. However, data collected is only useful if the material tested is properly modeled and desirable material properties can be obtained. While constitutive models with various flows rules have been developed for pressuremeter analysis in soil, less research has been directed at model development for pressuremeter tests in weak rock. The result is pressuremeter data collected in rock is typically analyzed using models designed for soil. The aim of this study was to explore constitutive rock models for development into a pressuremeter framework. Three models were considered, with two of those three implemented for pressuremeter analysis. A Mohr-Coulomb model with a tensile cutoff developed by Haberfield (1987) and a Hoek-Brown model initiated by Yang et al (2011) and further developed by the author were implemented and calibrated against a data set of pressuremeter tests from 5 project test sites including a total of 115 pressuremeter tests in a number of different rock formations. Development of a multiscale damage model established by Kondo et al (2008) was explored. However, this model requires further development to be used for pressuremeter data analysis.

Preliminary isostatic residual gravity anomaly map of Paso Robles 30 x 60 minute quadrangle, California

USGS Publications Warehouse

McPhee, D.K.; Langenheim, V.E.; Watt, J.T.

2011-01-01

This isostatic residual gravity map is part of an effort to map the three-dimensional distribution of rocks in the central California Coast Ranges and will serve as a basis for modeling the shape of basins and for determining the location and geometry of faults within the Paso Robles quadrangle. Local spatial variations in the Earth\\'s gravity field, after accounting for variations caused by elevation, terrain, and deep crustal structure reflect the distribution of densities in the mid- to upper crust. Densities often can be related to rock type, and abrupt spatial changes in density commonly mark lithological or structural boundaries. High-density rocks exposed within the central Coast Ranges include Mesozoic granitic rocks (exposed northwest of Paso Robles), Jurassic to Cretaceous marine strata of the Great Valley Sequence (exposed primarily northeast of the San Andreas fault), and Mesozoic sedimentary and volcanic rocks of the Franciscan Complex [exposed in the Santa Lucia Range and northeast of the San Andreas fault (SAF) near Parkfield, California]. Alluvial sediments and Tertiary sedimentary rocks are characterized by low densities; however, with increasing depth of burial and age, the densities of these rocks may become indistinguishable from those of older basement rocks.

The mechanism of earthquake

NASA Astrophysics Data System (ADS)

Lu, Kunquan; Cao, Zexian; Hou, Meiying; Jiang, Zehui; Shen, Rong; Wang, Qiang; Sun, Gang; Liu, Jixing

2018-03-01

The physical mechanism of earthquake remains a challenging issue to be clarified. Seismologists used to attribute shallow earthquake to the elastic rebound of crustal rocks. The seismic energy calculated following the elastic rebound theory and with the data of experimental results upon rocks, however, shows a large discrepancy with measurement — a fact that has been dubbed as “the heat flow paradox”. For the intermediate-focus and deep-focus earthquakes, both occurring in the region of the mantle, there is not reasonable explanation either. This paper will discuss the physical mechanism of earthquake from a new perspective, starting from the fact that both the crust and the mantle are discrete collective system of matters with slow dynamics, as well as from the basic principles of physics, especially some new concepts of condensed matter physics emerged in the recent years. (1) Stress distribution in earth’s crust: Without taking the tectonic force into account, according to the rheological principle of “everything flows”, the normal stress and transverse stress must be balanced due to the effect of gravitational pressure over a long period of time, thus no differential stress in the original crustal rocks is to be expected. The tectonic force is successively transferred and accumulated via stick-slip motions of rock blocks to squeeze the fault gouge and then exerted upon other rock blocks. The superposition of such additional lateral tectonic force and the original stress gives rise to the real-time stress in crustal rocks. The mechanical characteristics of fault gouge are different from rocks as it consists of granular matters. The elastic moduli of the fault gouges are much less than those of rocks, and they become larger with increasing pressure. This peculiarity of the fault gouge leads to a tectonic force increasing with depth in a nonlinear fashion. The distribution and variation of the tectonic stress in the crust are specified. (2) The strength of crust rocks: The gravitational pressure can initiate the elasticity-plasticity transition in crust rocks. By calculating the depth dependence of elasticity-plasticity transition and according to the actual situation analysis, the behaviors of crust rocks can be categorized in three typical zones: elastic, partially plastic and fully plastic. As the proportion of plastic portion reaches about 10% in the partially plastic zone, plastic interconnection may occur and the variation of shear strength in rocks is mainly characterized by plastic behavior. The equivalent coefficient of friction for the plastic slip is smaller by an order of magnitude, or even less than that for brittle fracture, thus the shear strength of rocks by plastic sliding is much less than that by brittle breaking. Moreover, with increasing depth a number of other factors can further reduce the shear yield strength of rocks. On the other hand, since earthquake is a large-scale damage, the rock breaking must occur along the weakest path. Therefore, the actual fracture strength of rocks in a shallow earthquake is assuredly lower than the average shear strength of rocks as generally observed. The typical distributions of the average strength and actual fracture strength in crustal rocks varying with depth are schematically illustrated. (3) The conditions for earthquake occurrence and mechanisms of earthquake: An earthquake will lead to volume expansion, and volume expansion must break through the obstacle. The condition for an earthquake to occur is as follows: the tectonic force exceeds the sum of the fracture strength of rock, the friction force of fault boundary and the resistance from obstacles. Therefore, the shallow earthquake is characterized by plastic sliding of rocks that break through the obstacles. Accordingly, four possible patterns for shallow earthquakes are put forward. Deep-focus earthquakes are believed to result from a wide-range rock flow that breaks the jam. Both shallow earthquakes and deep-focus earthquakes are the energy release caused by the slip or flow of rocks following a jamming-unjamming transition. (4) The energetics and impending precursors of earthquake: The energy of earthquake is the kinetic energy released from the jamming-unjamming transition. Calculation shows that the kinetic energy of seismic rock sliding is comparable with the total work demanded for rocks’ shear failure and overcoming of frictional resistance. There will be no heat flow paradox. Meanwhile, some valuable seismic precursors are likely to be identified by observing the accumulation of additional tectonic forces, local geological changes, as well as the effect of rock state changes, etc.

The role of rock moisture on regulating hydrologic and solute fluxes in the critical zone

NASA Astrophysics Data System (ADS)

Rempe, D. M.; Druhan, J. L.; Hahm, W. J.; Wang, J.; Murphy, C.; Cargill, S.; Dietrich, W. E.; Tune, A. K.

2017-12-01

In environments where the vadose zone extends below the soil layer into underlying weathered bedrock, the water held in the weathering -generated pores can be an important source of moisture to vegetation. The heterogeneous distribution of pore space in weathered bedrock, furthermore, controls the subsurface water flowpaths that dictate how water is partitioned in the critical zone (CZ) and evolves geochemically. Here, we present the results of direct monitoring of the fluxes of water and solutes through the deep CZ using a novel vadose zone monitoring system (VMS) as well as geophysical logging and sampling in a network of deep wells across a steep hillslope in Northern California. At our study site (Eel River CZO), multi-year monitoring reveals that a significant fraction of incoming rainfall (up to 30%) is seasonally stored in the fractures and matrix of the upper 12 m of weathered bedrock as rock moisture. Intensive geochemical and geophysical observations distributed from the surface to the depth of unweathered bedrock indicate that the seasonal addition and depletion of rock moisture has key implications for hydrologic and geochemical processes. First, rock moisture storage provides an annually consistent water storage reservoir for use by vegetation during the summer, which buffers transpiration fluxes against variability in seasonal precipitation. Second, because the timing and magnitude of groundwater recharge and streamflow are controlled by the annual filling and drainage of the rock moisture, rock moisture regulates the partitioning of hydrologic fluxes. Third, we find that rock moisture dynamics—which influence the myriad geochemical and microbial processes that weather bedrock—strongly correspond with the observed vertical weathering profile. As a result of the coupling between chemical weathering reactions and hydrologic fluxes, the geochemical composition of groundwater and streamflow is influenced by the temporal dynamics of rock moisture. Our findings highlight the strong influence of water transport and storage dynamics in the weathered bedrock beneath the soil layer on catchment-scale hydrologic and geochemical fluxes, and underscore the need for further exploration of the fractured bedrock vadose zones common to many upland landscapes.

Deep-sea fan deposition of the lower Tertiary Orca Group, eastern Prince William Sound, Alaska

USGS Publications Warehouse

Winkler, Gary R.

1976-01-01

The Orca Group is a thick, complexly deformed, sparsely fossiliferous sequence of flysch-like sedimentary and tholeiitic volcanic rocks of middle or late Paleocene age that crops out over an area of. roughly 21,000 km2 in the Prince William Sound region and the adjacent Chugach Mountains. The Orca Group also probably underlies a large part of the Gulf of Alaska Tertiary province and the continental shelf south of the outcrop belt; coextensive rocks to the southwest on Kodiak Island are called the Ghost Rocks and Sitkalidak Formations. The Orca Group was pervasively faulted, tightly folded, and metamorphosed regionally to laumontite and prehnite-pumpellyite facies prior to, and perhaps concurrently with, intrusion of early Eocene granodiorite and quartz monzonite plutons. In eastern Prince William Sound, 95% of the Orca sedimentary rocks are interbedded feldspathic and lithofeldspathic sandstone, siltstone, and mudstone turbidites. Lithic components vary widely in abundance and composition, but labile sedimentary and volcanic grains dominate. A widespread yet minor amount of the mudstone is hemipelagic or pelagic, with scattered foraminifers. Pebbly mudstone with rounded clasts of exotic lithologies and locally conglomerate with angular blocks of deformed sandstone identical to the enclosing matrix are interbedded with the turbidites. Thick and thin tabular bodies of altered tholeiitic basalt are locally and regionally conformable with the sedimentary rocks, and constitute 15-20% of Orca outcrops in eastern Prince William Sound. The basalt consists chiefly of pillowed and nonpillowed flows, but also includes minor pillow breccia, tuff, and intrusive rocks. Nonvolcanic turbidites are interbedded with the basalt; lenticular bioclastic limestone, red and green mudstone, chert, and conglomerate locally overlie the basalt, but are supplanted upward by turbidites. From west to east, basalts within the Orca Group become increasingly fragmental and amygdaloidal. Such textural changes probably indicate shallower water to the east. A radial distribution of paleocurrents and distinctive associations of turbidite facies within the sedimentary rocks suggest that the Orca Group in eastern Prince William Sound was deposited on a westward-sloping, complex deep-sea fan. Detritus was derived primarily from 'tectonized' sedimentary, volcanic, and plutonic rocks. Coeval submarine volcanism resulted in intercalation of basalt within prisms of terrigenous sediment.

Aquifers survey in the context of source rocks exploitation: from baseline acquisition to long term monitoring

NASA Astrophysics Data System (ADS)

Garcia, Bruno; Rouchon, Virgile; Deflandre, Jean-Pierre

2017-04-01

Producing hydrocarbons from source rocks (like shales: a mix of clays, silts, carbonate and sandstone minerals containing matured organic matter, i.e. kerogen oil and gas, but also non-hydrocarbon various species of chemical elements including sometimes radioactive elements) requires to create permeability within the rock matrix by at least hydraulically fracturing the source rock. It corresponds to the production of hydrocarbon fuels that have not been naturally expelled from the pressurized matured source rock and that remain trapped in the porosity or/and kerogen porosity of the impermeable matrix. Azimuth and extent of developed fractures can be respectively determined and mapped by monitoring the associated induced microseismicity. This allows to have an idea of where and how far injected fluids penetrated the rock formation. In a geological context, aquifers are always present in the vicinity -or on fluid migration paths- of such shale formations: deep aquifers (near the shale formation) up to sub-surface and potable (surface) aquifers. Our purpose will be to track any unsuitable invasion or migration of chemicals specifies coming from matured shales of production fluids including both drilling and fracturing ones into aquifers. Our objective is to early detect and alarm of any anomaly to avoid any important environmental issue. The approach consists in deploying a specific sampling tool within a well to recover formation fluids and to run a panoply of appropriate laboratory tests to state on fluid characteristics. Of course for deep aquifers, such a characterization process may consider aquifer properties prior producing shale oil and gas, as they may contain naturally some chemical species present in the source rocks. One can also consider that a baseline acquisition could be justified in case of possible previous invasion of non-natural fluids in the formation under survey (due to any anthropogenic action at surface or in the underground). The paper aims at presenting the protocol and routine test we propose to make our early detection approach efficient for production of shale hydrocarbon fluids, in considering the source-rock reservoir itself, the aquifers, and also the chemical species present in the fluids that are used for hydraulic fracturing operations.

Site-specific seismic ground motion analyses for transportation infrastructure in the New Madrid seismic zone.

DOT National Transportation Integrated Search

2012-11-01

Generic, code-based design procedures cannot account for the anticipated short-period attenuation and long-period amplification of earthquake ground motions in the deep, soft sediments of the Mississippi Embayment within the New Madrid Seismic Zone (...

A large parosteal ossifying lipoma of lower limb encircling the femur

PubMed Central

2014-01-01

Introduction Lipoma is a benign soft tissue neoplasm that may contain mesenchymal elements, as a result of metaplastic process. Ossification in benign and malignant soft tissue tumors can also manifest due to metaplastic process. Case presentation A 45 year old woman presented with a large thigh mass. The mass was developed one and a half year ago which insidiously increased in size and was associated with movement restriction. Radiological findings revealed soft tissue neoplasm on antero-medial aspect of thigh encircling the femur and displacing adjacent muscles. Fine trabeculations were seen in neoplasm suggestive of ossification. Excision of the mass was performed and histopathology revealed adipocytes with mature bony trabeculae possessing prominent osteoblastic rimming suggestive of ossifying lipoma. Conclusion It is important to recognize this variant of lipoma as it is associated with a better clinical outcome in contrast to most of the deep seated soft tissue neoplasms. Secondly it should also be differentiated from myositis ossificans and heterologous differentiation in other soft tissue neoplasms. We suggest an algorithmic approach to the diagnosis of ossifying soft tissue neoplasms histopathologically. Mature bony trabeculae with prominent osteoblastic rimming in a soft tissue lesion are due to a metaplastic process and should not be confused with osteosarcoma. PMID:24433545

Opportunities for Multidisciplinary Research in Partnership with Rock Engineers at the Deep Underground Science and Engineering Laboratory

NASA Astrophysics Data System (ADS)

Laughton, C.

2008-12-01

For the last half century the physics community has increasingly turned to the use of underground space to conduct basic research. The community is currently planning to conduct a new generation of underground experiments at the Deep Underground Science and Engineering Laboratory (DUSEL). DUSEL will be constructed within the footprint of the defunct Homestake Gold Mine, located in Lead, South Dakota. Physics proposals call for the construction of new caverns in which to conduct major new experiments. Some of the proposed laboratory facilities will be significantly larger and deeper than any previously constructed. The talk will highlight possible opportunities for integrating multi-disciplinary research in to the cavern construction program, and will stress the need to work closely with design and construction contractors to ensure that research goals can be achieve with minimal impact on project work. The constructors of large caverns should be particularly receptive to, and encouraging of geoscience research that could improve the engineering characterization of the rock mass. An improved understanding of the rock mass, as the host construction material, would result in a more reliable cavern design and construction process, and a reduced construction risk to the Project.

Geophysical prospecting for the deep geothermal structure of the Zhangzhou basin, Southeast China

NASA Astrophysics Data System (ADS)

Wu, Chaofeng; Liu, Shuang; Hu, Xiangyun; Wang, Guiling; Lin, Wenjing

2017-04-01

Zhangzhou basin located at the Southeast margins of Asian plate is one of the largest geothermal fields in Fujian province, Southeast China. High-temperature natural springs and granite rocks are widely distributed in this region and the causes of geothermal are speculated to be involved the large number of magmatic activities from Jurassic to Cretaceous periods. To investigate the deep structure of Zhangzhou basin, magnetotelluric and gravity measurements were carried out and the joint inversion of magnetotelluric and gravity data delineated the faults and the granites distributions. The inversion results also indicated the backgrounds of heat reservoirs, heat fluid paths and whole geothermal system of the Zhangzhou basin. Combining with the surface geological investigation, the geophysical inversion results revealed that the faults activities and magma intrusions are the main reasons for the formation of geothermal resources of the Zhangzhou basin. Upwelling mantle provides enormous heats to the lower crust leading to metamorphic rocks to be partially melt generating voluminous magmas. Then the magmas migration and thermal convection along the faults warm up the upper crust. So finally, the cap rocks, basements and major faults are the three favorable conditions for the formation of geothermal fields of the Zhangzhou basin.

Maintenance and Control of Erosion and Sediment Along Secondary Roads and Tertiary Trails.

DTIC Science & Technology

1997-07-01

abuse. Figure 3-4. Culverts located on natural channels. 36 USACERL SR 97/108 handle the base flow of the channel. They permit 0 Slag : A byproduct of...largely on the aggregate deep used. Aggregates may be classified as talus, pit- S!F: run, quarry rock, crushed rock, or slag . The fol- MEDIUM SEVERITY... slag , or stone aggregate is then wastes of the wood-pulping process. Variations spread over the treated area. The rate of appli- include calcium ligno

Landing Trail in 3-D

NASA Technical Reports Server (NTRS)

2004-01-01

A three-dimensional color model created using data from the Mars Exploration Rover's panoramic camera shows images of airbag drag marks on the martian surface. The triangular rock in the upper left corner is approximately 20 centimeters (8 inches) tall. The meatball-shaped rock in the upper right corner is approximately 10 centimeters (4 inches) tall. The dark portion of the surface, or 'trough' is approximately 1 centimeter (0.4 inches) deep at its deepest point. This model is displayed using software developed by NASA's Ames Research Center.

Microcracking and healing in granites: new evidence from cathodoluminescence.

PubMed

Sprunt, E S; Nur, A

1979-08-03

Quartz grains in granitic rocks usually have blue cathodoluminescence (CL). Within the blue-luminescing grains, there are often red-luminescing domains which are frequently impossible to detect without CL contrast. This finding suggests that the red-luminescing quartz is sealing preexisting mnicrocracks. The presence of these now-healed microcracks has important implications with respect to the role of pore fluid pressure and fluid transfer in metamorphism, the origih of granites, longperiod crustal deformation, earthquake mechanics, physical properties of rocks, and deep-seated geothermal energy.

Deep multi-spectral ensemble learning for electronic cleansing in dual-energy CT colonography

NASA Astrophysics Data System (ADS)

Tachibana, Rie; Näppi, Janne J.; Hironaka, Toru; Kim, Se Hyung; Yoshida, Hiroyuki

2017-03-01

We developed a novel electronic cleansing (EC) method for dual-energy CT colonography (DE-CTC) based on an ensemble deep convolution neural network (DCNN) and multi-spectral multi-slice image patches. In the method, an ensemble DCNN is used to classify each voxel of a DE-CTC image volume into five classes: luminal air, soft tissue, tagged fecal materials, and partial-volume boundaries between air and tagging and those between soft tissue and tagging. Each DCNN acts as a voxel classifier, where an input image patch centered at the voxel is generated as input to the DCNNs. An image patch has three channels that are mapped from a region-of-interest containing the image plane of the voxel and the two adjacent image planes. Six different types of spectral input image datasets were derived using two dual-energy CT images, two virtual monochromatic images, and two material images. An ensemble DCNN was constructed by use of a meta-classifier that combines the output of multiple DCNNs, each of which was trained with a different type of multi-spectral image patches. The electronically cleansed CTC images were calculated by removal of regions classified as other than soft tissue, followed by a colon surface reconstruction. For pilot evaluation, 359 volumes of interest (VOIs) representing sources of subtraction artifacts observed in current EC schemes were sampled from 30 clinical CTC cases. Preliminary results showed that the ensemble DCNN can yield high accuracy in labeling of the VOIs, indicating that deep learning of multi-spectral EC with multi-slice imaging could accurately remove residual fecal materials from CTC images without generating major EC artifacts.

A case of streptococcal toxic shock syndrome due to Group G streptococci identified as Streptococcus dysgalactiae subsp. equisimilis.

PubMed

Nei, Takahito; Akutsu, Koichi; Shima, Ayaka; Tsuboi, Ippei; Suzuki, Hiroomi; Yamamoto, Takeshi; Tanaka, Keiji; Shinoyama, Akihiro; Kojima, Yoshiko; Washio, Yohei; Okawa, Sakina; Sonobe, Kazunari; Norose, Yoshihiko; Saito, Ryoichi

2012-12-01

A 79-year-old man with a 3-month history of lymphedema of the lower limbs, and diabetes mellitus, was admitted to our hospital for suspected deep venous thrombosis. Several hours after admission, leg pain and purpura-like skin color appeared. On the 2nd hospital day, he was referred to our department for possible acute occlusive peripheral artery disease (PAD) and skin necrosis with blisters; however, computed tomography with contrast showed no occlusive lesions. He had already developed shock and necrotizing deep soft-tissue infections of the left lower leg. Laboratory findings revealed renal dysfunction and coagulation system collapse. Soon after PAD was ruled out, clinical findings suggested necrotizing deep soft-tissue infections, shock state, disseminated intravascular coagulation, and multiple organ failure. These symptoms led to a high suspicion of the well-recognized streptococcal toxic shock syndrome (STSS). With a high suspicion of STSS, we detected Group G β-hemolytic streptococci (GGS) from samples aspirated from the leg bullae, and the species was identified as Streptococcus dysgalactiae subsp. equisimilis (SDSE) by 16S-ribosomal RNA sequencing. However, unfortunately, surgical debridement was impossible due to the broad area of skin change. Despite adequate antimicrobial therapy and intensive care, the patient died on the 3rd hospital day. The M-protein gene (emm) typing of the isolated SDSE was revealed to be stG6792. This type of SDSE is the most frequent cause of STSS due to GGS in Japan. We consider it to be crucial to rapidly distinguish STSS from acute occlusive PAD to achieve life-saving interventions in patients with severe soft-tissue infections.

Cannula Versus Sharp Needle for Placement of Soft Tissue Fillers: An Observational Cadaver Study.

PubMed

van Loghem, Jani A J; Humzah, Dalvi; Kerscher, Martina

2017-12-13

Soft-tissue fillers have become important products for facial rejuvenation. Deep fat compartments and facial bones lose volume during the natural aging process. For the most natural-looking results, deep volumetric injections at strategic sites are therefore preferred. Supraperiosteal placement is performed with a sharp needle or a non-traumatic cannula. The primary objective was to determine whether there is a difference in precision between supraperiosteal placement with a sharp needle compared with a non-traumatic cannula in cadaver specimens. A secondary objective was to analyze the safety profiles of both injection techniques. Cadaver heads were injected with dye material and soft-tissue fillers at multiple aesthetic facial sites on the supraperiosteum and subsequently dissected for observation of dye and filler placement. The non-traumatic cannula technique resulted in product being confined to the deep anatomic layers. In contrast, with the sharp needle technique, material was placed in multiple anatomic layers, from the periosteum to more superficial skin layers. For both techniques results were consistent for all facial sites. Although direct extrapolation from cadavers to the in vivo situation cannot be made, cannulae showed more precision in placement of product. With the sharp needle, the material was injected on the periosteum, and then migrated in a retrograde direction along the trajectory of the needle path, ending up in multiple anatomic layers. The sharp needle technique also showed a higher complication risk with intra-arterial injection occurring, even though the needle tip was positioned on the periosteum and the product was injected with the needle in constant contact with the periosteum. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

Subsurface geology of the Lusi region: preliminary results from a comprehensive seismic-stratigraphic study.

NASA Astrophysics Data System (ADS)

Moscariello, Andrea; Do Couto, Damien; Lupi, Matteo; Mazzini, Adriano

2016-04-01

We investigate the subsurface data of a large sector in the Sidoarjo district (East Java, Indonesia) where the sudden catastrophic Lusi eruption started the 26th May 2006. Our goal is to understand the stratigraphic and structural features which can be genetically related to the surface manifestations of deep hydrothermal fluids and thus allow us to predict possible future similar phenomena in the region. In the framework of the Lusi Lab project (ERC grant n° 308126) we examined a series of densely spaced 2D reflection commercial seismic lines This allowed the reconstruction of the lateral variability of key stratigraphic horizons as well as the main tectonic features. In particular, we shed light on the deep structure of the Watukosek fault system and the associated fracture corridors crossing the entire stratigraphic successions. To the South-West, when approaching the volcanic complex, we could identify a clear contrast in seismic facies between chaotic volcanoclastic wedges and clastic-prone sedimentary successions as well as between the deeper stratigraphic units consisting of carbonates and lateral shales units. The latter show possible ductile deformation associated to fault-controlled diapirism which control in turns deformation of overlying stratigraphic units and deep geo-fluids circulation. Large collapse structures recognized in the study area (e.g. well PRG-1) are interpreted as the results of shale movement at depth. Similarly to Lusi, vertical deformation zones ("pipes"), likely associated with deeply rooted strike-slip systems seem to be often located at the interface between harder carbonate rocks forming isolated build ups and the laterally nearby clastic (shale-prone)-units. The mechanisms of deformation of structural features (strike vs dip slip systems) which may affect either the basement rock or the overlying deeper stratigraphic rocks is also being investigated to understand the relationship between deep and shallower (i.e. meteoric) fluid circulation. Seismic stratigraphic study of the basin margin (closer to volcanic accumulations) will also allow reconstructing the relationships between present and past volcanic activity recorded in the deep subsurface with the genesis of piercement structures and development of vertical deformation zones

The Continental Plates are Getting Thicker.

ERIC Educational Resources Information Center

Kerr, Richard A.

1986-01-01

Reviews seismological studies that provide evidence of the existence of continental roots beneath the continents. Suggests, that through the collisions of plate tectonics, continents stabilized part of the mobile mantle rock beneath them to form deep roots. (ML)

A Blast from the Past.

ERIC Educational Resources Information Center

Sharp, Len

1998-01-01

Describes how teaching a lesson on the discovery of a crater in the Yucatan Peninsula and the rock strata deep in the ocean can help students explain the demise of dinosaurs. Discusses the impact theory and the core model. (DDR)

Study on the characteristics of coal rock electromagnetic radiation (EMR) and the main influencing factors

NASA Astrophysics Data System (ADS)

Song, Xiaoyan; Li, Xuelong; Li, Zhonghui; Zhang, Zhibo; Cheng, Fuqi; Chen, Peng; Liu, Yongjie

2018-01-01

Coal rock would produce electromagnetic radiation (EMR) in the loading process, but study on the influence factors influence on the coal rock EMR characteristics in the mesoscopic level is not insufficient. In the paper, the EMR characteristics of coal and rock samples under uniaxial loading are studied. Several typical microcosmic mechanisms affecting the characteristics of EMR are discussed, such as strength, composition and microstructure of the samples. Results show that the macroscopic structure of the outburst coal is soft, the corresponding EMR signal increases slowly with the loading increase and the EMR peak is smaller. The rockburst coal has a strong brittleness, the EMR signal increases quickly and EMR peak appears while the coal breaks is larger than the outburst coal. The EMR characteristics of rock samples are similar to the rockburst coal, but the EMR peak is the largest. When the coal rock microstructure is complete, the coal rock block is larger and the brittleness is stronger, then the corresponding strength would be larger. And the free charge generated by thermal excitation, field emission and intergranular chemical bond breakage would also be more. In the meantime, the crack propagation rate becomes greater, therefore the EMR is more stronger. The piezoelectric effect is mainly caused by the linear elastic stage of the specimen deformation and rupture, which contributes less to the EMR signals. This study is of great theoretical and practical value for assessing the mechanical state of coal rock through EMR technology, and accurately monitoring and predicting the coal rock dynamic disasters.

Virtual Walk: The Construction of the Long Baseline Neutrino Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

This 2-minute animation shows a virtual walk through the large caverns of the Long-Baseline Neutrino Facility, which will house the Deep Underground Neutrino Experiment. To create the caverns for the huge DUNE particle detectors, construction crews will excavate more than 800,000 tons of rock a mile underground at the Sanford Underground Research Facility in South Dakota. Scientists and dignitaries broke ground for this project on July 21, 2017. When construction is complete, DUNE scientists will send an intense neutrino beam through 1,300 kilometers of rock from the Department of Energy’s Fermilab to the DUNE particle detectors to understand the rolemore » that neutrinos – the most abundant matter particles in the universe – play in our cosmos. About 1,000 scientists from more than 160 institutions in 30 countries work on the Deep Underground Neutrino Experiment.« less

Reconstructing a hydrogen-driven microbial metabolic network in Opalinus Clay rock.

PubMed

Bagnoud, Alexandre; Chourey, Karuna; Hettich, Robert L; de Bruijn, Ino; Andersson, Anders F; Leupin, Olivier X; Schwyn, Bernhard; Bernier-Latmani, Rizlan

2016-10-14

The Opalinus Clay formation will host geological nuclear waste repositories in Switzerland. It is expected that gas pressure will build-up due to hydrogen production from steel corrosion, jeopardizing the integrity of the engineered barriers. In an in situ experiment located in the Mont Terri Underground Rock Laboratory, we demonstrate that hydrogen is consumed by microorganisms, fuelling a microbial community. Metagenomic binning and metaproteomic analysis of this deep subsurface community reveals a carbon cycle driven by autotrophic hydrogen oxidizers belonging to novel genera. Necromass is then processed by fermenters, followed by complete oxidation to carbon dioxide by heterotrophic sulfate-reducing bacteria, which closes the cycle. This microbial metabolic web can be integrated in the design of geological repositories to reduce pressure build-up. This study shows that Opalinus Clay harbours the potential for chemolithoautotrophic-based system, and provides a model of microbial carbon cycle in deep subsurface environments where hydrogen and sulfate are present.

Reconstructing a hydrogen-driven microbial metabolic network in Opalinus Clay rock

PubMed Central

Bagnoud, Alexandre; Chourey, Karuna; Hettich, Robert L.; de Bruijn, Ino; Andersson, Anders F.; Leupin, Olivier X.; Schwyn, Bernhard; Bernier-Latmani, Rizlan

2016-01-01

The Opalinus Clay formation will host geological nuclear waste repositories in Switzerland. It is expected that gas pressure will build-up due to hydrogen production from steel corrosion, jeopardizing the integrity of the engineered barriers. In an in situ experiment located in the Mont Terri Underground Rock Laboratory, we demonstrate that hydrogen is consumed by microorganisms, fuelling a microbial community. Metagenomic binning and metaproteomic analysis of this deep subsurface community reveals a carbon cycle driven by autotrophic hydrogen oxidizers belonging to novel genera. Necromass is then processed by fermenters, followed by complete oxidation to carbon dioxide by heterotrophic sulfate-reducing bacteria, which closes the cycle. This microbial metabolic web can be integrated in the design of geological repositories to reduce pressure build-up. This study shows that Opalinus Clay harbours the potential for chemolithoautotrophic-based system, and provides a model of microbial carbon cycle in deep subsurface environments where hydrogen and sulfate are present. PMID:27739431

Deep learning decision fusion for the classification of urban remote sensing data

NASA Astrophysics Data System (ADS)

Abdi, Ghasem; Samadzadegan, Farhad; Reinartz, Peter

2018-01-01

Multisensor data fusion is one of the most common and popular remote sensing data classification topics by considering a robust and complete description about the objects of interest. Furthermore, deep feature extraction has recently attracted significant interest and has become a hot research topic in the geoscience and remote sensing research community. A deep learning decision fusion approach is presented to perform multisensor urban remote sensing data classification. After deep features are extracted by utilizing joint spectral-spatial information, a soft-decision made classifier is applied to train high-level feature representations and to fine-tune the deep learning framework. Next, a decision-level fusion classifies objects of interest by the joint use of sensors. Finally, a context-aware object-based postprocessing is used to enhance the classification results. A series of comparative experiments are conducted on the widely used dataset of 2014 IEEE GRSS data fusion contest. The obtained results illustrate the considerable advantages of the proposed deep learning decision fusion over the traditional classifiers.

In situ seismic anisotropy around deep earthquakes in Japan subduction slabs using Japan Meteorological Agency moment tensors

NASA Astrophysics Data System (ADS)

Li, J.; Zheng, Y.; Thomsen, L.

2017-12-01

Knowing the in situ seismic anisotropy around deep earthquakes in slabs is important in understanding deep-earthquake mechanism as it may provide critically needed information about the rock fabric where deep earthquakes occur. It has been recognized for about 50 years that many deep earthquakes are not double-couple (DC) events. Previously we showed that in situ anisotropy around deep earthquakes could explain such observed non-DC events. Traditionally, the shear wave splitting method has been used to infer such anisotropy around deep earthquakes but this is challenging because it will need many crossing ray paths for the method to localize the anisotropic region (Long 2013). In this abstract, we adopt the same procedure to obtain anisotropy in the Pacific slab under Japan using moment tensors provided by the Japan Meteorological Agency using the F-net data. We directly probe the in situ anisotropy within the subducting slabs using the radiation patterns (represented by the moment tensors) of deep earthquakes (with depth greater than 60 km). By assuming a group of shear dislocation events embedded in a common tilted transversely isotropic (TTI) medium, we used the moment tensors as our input data to invert for the anisotropy in Mariana-Japan-Kuril subducting zone. The TTI medium is characterized by the P and S wave velocities along the symmetry axis (described by two free angles) and three Thomsen parameters. We divided the deep earthquake events into 9 groups by their spatial proximity using the k-means clustering method (Hartigan and Wong 1979). These 9 groups include 2 intermediate-depth groups (depth from 60 km to 300 km) and 7 deep-focus groups (depth greater than 300 km). Our inversion results show that the inverted TTI symmetry axes are perpendicular to the slab interface for two intermediate-depth groups (consistent with dehydration metamorphic reactions) and parallel to the slab interface for 7 deep-focus group. The shear wave anisotropy is best resolved by our inversion algorithm with a typical value of around 28% (ranging from 25% to 41%). Our inverted anisotropy provides direct information of stress and rock fabric inside the subducting slab and may help explain the mechanisms of deep earthquakes.

Block oscillation model for impact crater collapse

NASA Astrophysics Data System (ADS)

Ivanov, B. A.; Kostuchenko, V. N.

1997-03-01

Previous investigations of the impact crater formation mechanics have shown that the late stage, a transient cavity collapse in a gravity field, may be modeled with a traditional rock mechanics if one ascribes very specific mechanical properties of rock in the vicinity of a crater: an effective strength of rock needed is around 30 bar, and effective angle of internal friction below 5 deg. The rock media with such properties may be supposed 'temporary fluidized'. The nature of this fluidization is now poorly understood; an acoustic (vibration) nature of this fluidization has been suggested. This model now seems to be the best approach to the problem. The open question is how to implement the model (or other possible models) in a hydrocode for numerical simulation of a dynamic crater collapse. We study more relevant models of mechanical behavior of rocks during cratering. The specific of rock deformation is that the rock media deforms not as a plastic metal-like continuum, but as a system of discrete rock blocks. The deep drilling of impact craters revealed the system of rock blocks of 50 m to 200 m in size. We used the model of these block oscillations to formulate the appropriate rheological law for the subcrater flow during the modification stage.

Rock Bites into 'Bounce'

NASA Technical Reports Server (NTRS)

2004-01-01

This panoramic camera image from the Mars Exploration Rover Opportunity features the 6.44 millimeter (0.25 inch) deep hole ground into the rock dubbed 'Bounce' by the rover's rock abrasion tool. The tool took 2 hours and 15 minutes to grind the hole on sol 66 of the rover's journey. A combination of limited solar power and the rock's jagged texture led the rock abrasion tool team to set very aggressive grinding parameters to ensure that the end result was a full circle, suitable for a thorough read from the rover's spectrometers.

Bounce's markedly different appearance (when compared to the rocks that were previously examined in the Eagle Crater outcrop) made it a natural target for rover research. In order to achieve an ideal position from which to grind into the rock, Opportunity moved in very close with its right wheel next to Bounce. In this image, the panoramic camera on the rover's mast is looking down, catching the tip of the solar panel which partially blocks the full circle ground by the rock abrasion tool.

The outer ring consists of the cuttings from the rock, pushed out by the brushes on the grinding instrument. The dark impression at the top of the outer circle was caused by the instrument's contact mechanism which serves to stabilize it while grinding.

In situ trace metal analysis of Neoarchaean--Ordovician shallow-marine microbial-carbonate-hosted pyrites.

PubMed

Gallagher, M; Turner, E C; Kamber, B S

2015-07-01

Pre-Cambrian atmospheric and oceanic redox evolutions are expressed in the inventory of redox-sensitive trace metals in marine sedimentary rocks. Most of the currently available information was derived from deep-water sedimentary rocks (black shale/banded iron formation). Many of the studied trace metals (e.g. Mo, U, Ni and Co) are sensitive to the composition of the exposed land surface and prevailing weathering style, and their oceanic inventory ultimately depends on the terrestrial flux. The validity of claims for increased/decreased terrestrial fluxes has remained untested as far as the shallow-marine environment is concerned. Here, the first systematic study of trace metal inventories of the shallow-marine environment by analysis of microbial carbonate-hosted pyrite, from ca. 2.65-0.52 Ga, is presented. A petrographic survey revealed a first-order difference in preservation of early diagenetic pyrite. Microbial carbonates formed before the 2.4 Ga great oxygenation event (GOE) are much richer in pyrite and contain pyrite grains of greater morphological variability but lesser chemical substitution than samples deposited after the GOE. This disparity in pyrite abundance and morphology is mirrored by the qualitative degree of preservation of organic matter (largely as kerogen). Thus, it seems that in microbial carbonates, pyrite formation and preservation were related to presence and preservation of organic C. Several redox-sensitive trace metals show interpretable temporal trends supporting earlier proposals derived from deep-water sedimentary rocks. Most notably, the shallow-water pyrite confirms a rise in the oceanic Mo inventory across the pre-Cambrian-Cambrian boundary, implying the establishment of efficient deep-ocean ventilation. The carbonate-hosted pyrite also confirms the Neoarchaean and early Palaeoproterozoic ocean had higher Ni concentration, which can now more firmly be attributed to a greater proportion of magnesian volcanic rock on land rather than a stronger hydrothermal flux of Ni. Additionally, systematic trends are reported for Co, As, and Zn, relating to terrestrial flux and oceanic productivity. © 2015 John Wiley & Sons Ltd.

Changes in chloride concentration in water from municipal wells that tap aquifers in rocks of Cambrian and Ordovician age in northeastern Illinois, 1915-84

USGS Publications Warehouse

Balding, G.O.

1991-01-01

During the past few decades, several municipalities in northeastern Illinois have noted increases in the salinity of water from wells that tap aquifers in rocks of Cambrian and Ordovician age. The municipalities have discontinued the use of, or sealed-off sections of, those wells. The aquifers involved include the Ancell, the Ironton-Galesville, and the Elmhurst-Mt. Simon. To define the location, magnitude, and possible causes for the salinity increases in the six northeastern counties of Illinois, 17 municipal wells and 1 deep test well were selected on the basis of their proximity to major pumping centers, the availability of water-quality data, and their documented maintenance history. Well depths ranged from about 960 to 3,475 feet. One well was finished in the middle confining unit, 2 wells were finished in the Ironton-Galesville aquifer, 4 wells were finished in the Eau Claire confining unit, and 10 wells were finished in the Elmhurst-Mt. Simon aquifer. The deep test well was finished below the Elmhurst-Mt. Simon aquifer in Precambrian-age rock. Chloride concentrations in the municipal wells ranged from less than 5 to greater than 600 milligrams per liter; in the deep test well, they ranged from 13 t o 37,000 milligrams per liter. Some changes in the chloride concentration in water from the studied municipal wells can be related to physical changes to the wells, including the partial filling in of a well, bridging within a well, the cleaning out of a well, or the deepening of a well. Some changes in chloride concentration are not related to physical changes but may be caused by increased pumpage; changes in pumping rate, frequency, or duration; cessation of pumping; improper abandonment of wells; and the upconing of highly mineralized water. The data base was inadequate for a quantitative study of the changes in chloride concentration in water from individual aquifers in rocks of Cambrian and Ordovician age.

Phosphate rock formation and marine phosphorus geochemistry: the deep time perspective.

PubMed

Filippelli, Gabriel M

2011-08-01

The role that phosphorite formation, the ultimate source rock for fertilizer phosphate reserves, plays in the marine phosphorus (P) cycle has long been debated. A shift has occurred from early models that evoked strikingly different oceanic P cycling during times of widespread phosphorite deposition to current thinking that phosphorite deposits may be lucky survivors of a series of inter-related tectonic, geochemical, sedimentological, and oceanic conditions. This paradigm shift has been facilitated by an awareness of the widespread nature of phosphogenesis-the formation of authigenic P-bearing minerals in marine sediments that contributes to phosphorite formation. This process occurs not just in continental margin sediments, but in deep sea oozes as well, and helps to clarify the driving forces behind phosphorite formation and links to marine P geochemistry. Two processes come into play to make phosphorite deposits: chemical dynamism and physical dynamism. Chemical dynamism involves the diagenetic release and subsequent concentration of P-bearing minerals particularly in horizons, controlled by a number of sedimentological and biogeochemical factors. Physical dynamism involves the reworking and sedimentary capping of P-rich sediments, which can either concentrate the relatively heavy and insoluble disseminated P-bearing minerals or provide an episodic change in sedimentology to concentrate chemically mobilized P. Both processes can result from along-margin current dynamics and/or sea level variations. Interestingly, net P accumulation rates are highest (i.e., the P removal pump is most efficient) when phosphorites are not forming. Both physical and chemical pathways involve processes not dominant in deep sea environments and in fact not often coincide in space and time even on continental margins, contributing to the rarity of high-quality phosphorite deposits and the limitation of phosphate rock reserves. This limitation is becoming critical, as the human demand for P far outstrips the geologic replacement for P and few prospects exist for new discoveries of phosphate rock. Copyright © 2011 Elsevier Ltd. All rights reserved.

Deep Learning for Population Genetic Inference.

PubMed

Sheehan, Sara; Song, Yun S

2016-03-01

Given genomic variation data from multiple individuals, computing the likelihood of complex population genetic models is often infeasible. To circumvent this problem, we introduce a novel likelihood-free inference framework by applying deep learning, a powerful modern technique in machine learning. Deep learning makes use of multilayer neural networks to learn a feature-based function from the input (e.g., hundreds of correlated summary statistics of data) to the output (e.g., population genetic parameters of interest). We demonstrate that deep learning can be effectively employed for population genetic inference and learning informative features of data. As a concrete application, we focus on the challenging problem of jointly inferring natural selection and demography (in the form of a population size change history). Our method is able to separate the global nature of demography from the local nature of selection, without sequential steps for these two factors. Studying demography and selection jointly is motivated by Drosophila, where pervasive selection confounds demographic analysis. We apply our method to 197 African Drosophila melanogaster genomes from Zambia to infer both their overall demography, and regions of their genome under selection. We find many regions of the genome that have experienced hard sweeps, and fewer under selection on standing variation (soft sweep) or balancing selection. Interestingly, we find that soft sweeps and balancing selection occur more frequently closer to the centromere of each chromosome. In addition, our demographic inference suggests that previously estimated bottlenecks for African Drosophila melanogaster are too extreme.

Deep Learning for Population Genetic Inference

PubMed Central

Sheehan, Sara; Song, Yun S.

2016-01-01

Given genomic variation data from multiple individuals, computing the likelihood of complex population genetic models is often infeasible. To circumvent this problem, we introduce a novel likelihood-free inference framework by applying deep learning, a powerful modern technique in machine learning. Deep learning makes use of multilayer neural networks to learn a feature-based function from the input (e.g., hundreds of correlated summary statistics of data) to the output (e.g., population genetic parameters of interest). We demonstrate that deep learning can be effectively employed for population genetic inference and learning informative features of data. As a concrete application, we focus on the challenging problem of jointly inferring natural selection and demography (in the form of a population size change history). Our method is able to separate the global nature of demography from the local nature of selection, without sequential steps for these two factors. Studying demography and selection jointly is motivated by Drosophila, where pervasive selection confounds demographic analysis. We apply our method to 197 African Drosophila melanogaster genomes from Zambia to infer both their overall demography, and regions of their genome under selection. We find many regions of the genome that have experienced hard sweeps, and fewer under selection on standing variation (soft sweep) or balancing selection. Interestingly, we find that soft sweeps and balancing selection occur more frequently closer to the centromere of each chromosome. In addition, our demographic inference suggests that previously estimated bottlenecks for African Drosophila melanogaster are too extreme. PMID:27018908

Histologic effects of a high-repetition pulsed Nd:YAG laser on intraoral soft tissue

NASA Astrophysics Data System (ADS)

White, Joel M.; Goodis, Harold E.; Yessik, Michael J.; Myers, Terry D.

1995-05-01

High-repetition rate, fiberoptic-delivered Nd:YAG lasers have increased oral soft tissue laser applications. This study focused on three parameters: the temperature rise occurring in deeper tissue during excision, the histology of thermal coagulation during excision of oral tissue, and effects of accidental exposure to adjacent hard tissue. Thermocouples were placed 5.0 +/- 0.5 mm in bone below fresh bovine gingiva and at the same depth in tongue; temperatures in the underlying tissue were measured during laser excision. An Nd:YAG laser with 100 microsecond(s) pulse duration was used to excise the tissue using a 200 or 300 micrometers diameter fiber in contact with the tissue. The soft tissue was excised using constant force and rate with laser powers of 1.5, 3, 5, and 10 W, and a variety of pulse rates. The tissue was bioprepared, sectioned and stained with hematoxylin and eosin. The width and depth of the tissue removed as well as lateral and deep thermal coagulation were measured in histologic sections with a measuring microscope (10x). Multifactor randomized ANOVA showed that probe diameter and repetition rates were not significant variables (p

Compositional changes of reservoir rocks through the injection of supercritical CO2

NASA Astrophysics Data System (ADS)

Scherf, Ann-Kathrin; Schulz, Hans-Martin; Zetzl, Carsten; Smirnova, Irina; Andersen, Jenica; Vieth, Andrea

2010-05-01

The European project CO2SINK is the first project on the on-shore underground storage of carbon dioxide in Europe. CO2SINK is part of the ongoing efforts to understand the impact, problems, and likelihood of using deep saline aquifers for long term storage of CO2. In Ketzin (north-east Germany, 40 km west of Berlin) a saline sandstone aquifer of the younger Triassic (Stuttgart Formation) has been chosen as a reservoir for the long-term storage of carbon dioxide. Our monitoring focuses on the composition and mobility of the organic carbon pools within the saline aquifer and their changes due to the storage of carbon dioxide. Supercritical carbon dioxide is known as an excellent solvent of non- to moderately polar organic compounds, depending on temperature and pressure (Hawthorne, 1990). The extraction of organic matter (OM) from reservoir rock, using multiple extraction methods, allows insight into the composition of the OM and the biomarker inventory of the deep biosphere. The extraction of reservoir rock using supercritical CO2 may additionally simulate the impact of CO2 storage on the deep biosphere by the possible mobilisation of OM. We will present compound specific results from laboratory CO2 extraction experiments on reservoir rocks from the CO2 storage site in Ketzin, Germany. A total of five rock samples (silt and sandstones) from the injection well and two observation wells were applied to supercritical CO2 extraction. In the experimental setup, a supercritical fluid extractor is used to simulate the conditions within the saline aquifer. The results show distinct quantitative and qualitative differences in extraction yields between the rock samples. This may be due to differences in mineralogy and porosity (12 - 27%; Norden et al., 2007a, b, c), which seem to be extraction-controlling key factors. Furthermore, the results illustrate that the amount of extracted materials depends on the length of the time interval in which CO2 flows through the rock, rather than saturation of extracted compounds in the solvent when CO2 is stationary. Total extraction yields seem to be low compared to the OM present in the reservoir rock, but yields still have to be extrapolated to the large volumes of reservoir rock that are in contact with supercritical CO2 at the test site. In the future, our lab results may be combined with models to determine how much of the mobilised organic acids and non organic material will occupy the entire reservoir (pore space) or could be used by organisms and induce growth. Additionally, the rock samples were analysed after the extraction with supercritical CO2, using a variety of organic and inorganic geochemical techniques. Thus, changes in the composition of the rocks were also observed. Here, amongst others, scanning electron microscopy was done and indicated corrosion effects on mineral surfaces due to exposure to supercritical CO2. References Hawthorne, S.B. (1990) Analytical Chemistry 62, 633-642. Norden, B. (2007a) Geologischer Abschlussbericht der Bohrung CO2 Ktzi 200/2007. Norden, B. (2007b) Geologischer Abschlussbericht der Bohrung CO2 Ktzi 201/2007. Norden, B. (2007c) Geologischer Abschlussbericht der Bohrung CO2 Ktzi 202/2007.

Alteration of submarine volcanic rocks in oxygenated Archean oceans

NASA Astrophysics Data System (ADS)

Ohmoto, H.; Bevacqua, D.; Watanabe, Y.

2009-12-01

Most submarine volcanic rocks, including basalts in diverging plate boundaries and andesites/dacites in converging plate boundaries, have been altered by low-temperature seawater and/or hydrothermal fluids (up to ~400°C) under deep oceans; the hydrothermal fluids evolved from shallow/deep circulations of seawater through the underlying hot igneous rocks. Volcanogenic massive sulfide deposits (VMSDs) and banded iron formations (BIFs) were formed by mixing of submarine hydrothermal fluids with local seawater. Therefore, the behaviors of various elements, especially of redox-sensitive elements, in altered submarine volcanic rocks, VMSDs and BIFs can be used to decipher the chemical evolution of the oceans and atmosphere. We have investigated the mineralogy and geochemistry of >500 samples of basalts from a 260m-long drill core section of Hole #1 of the Archean Biosphere Drilling Project (ABDP #1) in the Pilbara Craton, Western Australia. The core section is comprised of ~160 m thick Marble Bar Chert/Jasper Unit (3.46 Ga) and underlying, inter-bedded, and overlying submarine basalts. Losses/gains of 65 elements were quantitatively evaluated on the basis of their concentration ratios against the least mobile elements (Ti, Zr and Nb). We have recognized that mineralogical and geochemical characteristics of many of these samples are essentially the same as those of hydrothermally-altered modern submarine basalts and also those of altered volcanic rocks that underlie Phanerozoic VMSDs. The similarities include, but are not restricted to: (1) the alteration mineralogy (chlorite ± sericite ± pyrophyllite ± carbonates ± hematite ± pyrite ± rutile); (2) the characteristics of whole-rock δ18O and δ34S values; (3) the ranges of depletion and enrichment of Si, Al, Mg, Ca, K, Na, Fe, Mn, and P; (4) the enrichment of Ba (as sulfate); (5) the increases in Fe3+/Fe2+ ratios; (6) the enrichment of U; (7) the depletion of Cr; and (8) the negative Ce anomalies. Literature data on other submarine volcanic rocks in Pilbara, Australia (~3.55 Ga to ~3.2 Ga in age) and the ~2.9 - 2.7 Ga submarine volcanic rocks in Ontario, Canada indicate that many of these rocks exhibit the same characteristics (1)-(8). Characteristics (4) was probably caused by the mixing of Ba-rich hydrothermal fluids and SO42--rich seawater; (5) and the abundance of hematite by reactions between ferrous-rich minerals and O2-rich seawater; (6) by reactions between ferrous-rich minerals and U-rich seawater; (7) by leaching of Cr from rocks by O2-rich seawater; and (8) by reactions with Ce-depleted oxidized seawater. These data suggest that the chemistry of ocean water, including the concentrations of major elements and many redox-sensitive elements/compounds (e.g., U, Ce, SO42-, and O2), has been basically the same since at least ~3.5 Ga, except for the higher ∑CO2 contents in Archean oceans. O2 contents of deep (>200 m) oceans would become zero when the atmospheric pO2 decreased to less than ~50% of the present level. Therefore, geochemical data on the Archean rocks further suggest that the atmospheric pO2 level, the fluxes of bio-essential elements to the oceans (e.g., K, PO43-, NO3-, Ba, Mo, W), and the biological productivity in the oceans, have been basically the same since at least ~3.5 Ga.

Water demand forecasting: review of soft computing methods.

PubMed

Ghalehkhondabi, Iman; Ardjmand, Ehsan; Young, William A; Weckman, Gary R

2017-07-01

Demand forecasting plays a vital role in resource management for governments and private companies. Considering the scarcity of water and its inherent constraints, demand management and forecasting in this domain are critically important. Several soft computing techniques have been developed over the last few decades for water demand forecasting. This study focuses on soft computing methods of water consumption forecasting published between 2005 and 2015. These methods include artificial neural networks (ANNs), fuzzy and neuro-fuzzy models, support vector machines, metaheuristics, and system dynamics. Furthermore, it was discussed that while in short-term forecasting, ANNs have been superior in many cases, but it is still very difficult to pick a single method as the overall best. According to the literature, various methods and their hybrids are applied to water demand forecasting. However, it seems soft computing has a lot more to contribute to water demand forecasting. These contribution areas include, but are not limited, to various ANN architectures, unsupervised methods, deep learning, various metaheuristics, and ensemble methods. Moreover, it is found that soft computing methods are mainly used for short-term demand forecasting.

The T-Reflection and the Deep Crustal Structure of the Vøring Margin, Offshore mid-Norway

NASA Astrophysics Data System (ADS)

Abdelmalak, M. M.; Faleide, J. I.; Planke, S.; Gernigon, L.; Zastrozhnov, D.; Shephard, G. E.; Myklebust, R.

2017-11-01

Seismic reflection data along volcanic passive margins frequently provide imaging of strong and laterally continuous reflections in the middle and lower crust. We have completed a detailed 2-D seismic interpretation of the deep crustal structure of the Vøring Margin, offshore mid-Norway, where high-quality seismic data allow the identification of high-amplitude reflections, locally referred to as the T-Reflection. Using a dense seismic grid, we have mapped the geometry of the T-Reflection in order to compare it with filtered Bouguer gravity anomalies and seismic refraction data. The T-Reflection is identified between 7 and 10 s. Sometimes it consists of one single smooth reflection. However, it is frequently associated with a set of rough multiple reflections displaying discontinuous segments with varying geometries, amplitudes, and contact relationships. The T-Reflection seems to be connected to deep sill networks and is locally identified at the continuation of basement high structures or terminates over fractures and faults. The T-Reflection presents a low magnetic signal. The spatial correlation between the filtered positive Bouguer gravity anomalies and the deep dome-shaped reflections indicates that the latter represent a high-impedance boundary contrast associated with a high-density and high-velocity body. In 50% of the outer Vøring Margin, the depth of the mapped T-Reflection is found to correspond to the depth of the top of the Lower Crustal Body (LCB), which is characterized by high P wave velocities (>7 km/s). We present a tectonic scenario, where a large part of the deep crustal structure is composed of preserved upper continental crustal blocks and middle to lower crustal lenses of inherited high-grade metamorphic rocks. Deep intrusions into the faulted crustal blocks are responsible for the rough character of the T-Reflection, whereas intrusions into the ductile lower crust and detachment faults are likely responsible for its smoother character. Deep magma intrusions can be responsible for regional metamorphic processes leading to an increasing velocity of the lower crust to more than 7 km/s. The result is a heterogeneous LCB that likely represents a complex mixture of pre- to syn-breakup mafic and ultramafic rocks (cumulates and sills) and old metamorphic rocks such as granulites and eclogites. An increasing degree of melting toward the breakup axis is responsible for an increasing proportion of cumulates and sill intrusions in the lower crust.

Physical properties of the surface materials at the Viking landing sites on Mars

USGS Publications Warehouse

Moore, H.J.; Hutton, R.E.; Clow, G.D.; Spitzer, C.R.

1987-01-01

This report summarizes the results of the Physical Properties Investigation of the Viking '75 Project, activities of the surface samplers, and relevant results from other investigations. The two Viking Landers operated for nearly four martian years after landing on July 20 (Lander 1) and Sept. 3 (Lander 2), 1976; Lander 1 acquired its last pictures on or about Nov. 5, 1982. Lander 1 rests on a smooth, cratered plain at the west edge of Chryse Planitia (22.5 ? N, 48.0? W), and Lander 2 rests 200 km west of the crater Mie in Utopia Planitia (48.0? N, 225.7? W). Lander 1 views showed that dune-like deposits of drift material were superposed on rock-strewn surfaces. Soil-like material from the rock-strewn areas was called blocky material. Lander 2 views also showed a rock-strewn surface. Polygonal to irregular features, etched by the wind, revealed crusty to cloddy material among rocks. Both landers descended to the surface along nearly vertical trajectories. Velocities at touchdown were about 2 m/s for both landers. Footpad 2 of Lander 1 penetrated drift material 0.165 m, and footpad 3 penetrated blocky material 0.036 m. The two visible footpads of Lander 2 struck rocks. Erosion by exhausts from the forward engines produced craters with rims of mixed fine-grained material and platy to equidimensional clods, crusts, and fragments. Comparison of engine-exhaust erosion on Mars with terrestrial data suggested that drift material behaved like a weakly cohesive material with a grain size less than 3-9 /-lm. Although not sand, blocky and crusty to cloddy materials eroded like sand-with grain sizes of 0.01 or 0.2 cm. The surface samplers accomplished an impressive number of tasks. All experiments that required samples received samples. Deep holes, as much as 0.22 m deep, were excavated by both landers. Lander 2 successfully pushed rocks and collected samples from areas originally beneath the rocks. Tasks specifically accomplished for the Physical Properties Investigation include: (1) acquiring motor-current data while excavating trenches, (2) performing surface-bearing tests, (3) performing backhoe touchdowns, (4) attempting to chip or scratch rocks, (5) comminuting samples, (6) measuring subsurface diurnal temperatures, and (7) constructing conical piles of materials on and among rocks. Sample trenches in the three major types of soil-like materials were different from one another. Trenches in drift material, which were typically 0.06 m deep, had steep walls along much of their lengths, lumpy tailings and floors, and smooth domed surfaces with sparse fine fractures around their tips. Trenches in blocky material, which were typically 0.03-0.04 m deep, had steep walls near their tips, and surfaces around their tips were displaced upward and some appeared blocky. Trenches in crusty to cloddy material, which were typically 0.04-0.05 m deep, had steep and often irregular slopes near their tips, clods and slabs of crust in their tailings, and disrupted areas around their tips composed of mixed fine-grained material and slabs of crust or thick polygonal clods that had been displaced upwards. Data acquired during landing, trenching, surface-bearing tests, backhoe touchdowns, and from other science experiments were used to determine the mechanical properties of drift, blocky, and crusty to cloddy materials. Drift material appeared to be very fine grained, with local planes of weakness; in general, the drift material was consistent with a material having an angle of internal friction about 18?, a cohesion ranging from 0.7 to 3.0 kPa, and a bulk density of 1,200 kg/m 3 . Blocky material was consistent with a material having an angle of internal friction about 30?, cohesions from 1.5 to 16 kPa, and a bulk density of 1,600 kg/m 3 . Crusty to cloddy material had variable properties. For chiefly crusty to cloddy material, angles of internal friction were about 35 ? , and cohesions were from 0.5 to 5.2 kPa. For mixed fines and crusts, a

Occurence and magnitude of methane - hydrate accumulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zielinski, R.E.; McIver, R.D.

1982-01-01

Solid, ice-like mixtures of natural gas and water have been found immobilized in rocks beneath the permafrost in Arctic basins, and in muds under deep water along the continental margins of the Americas. The muds in North America could contain almost 5.7 x 10/sup 14/ m/sup 3/, of gas, but probably only a small fraction, eg., 5.7 x 10/sup 12/ M/sup 3/, in rock porous enough to be considered reservoir rocks. None of this gas is recoverable with present technology. However, the very magnitude of the resource is so large that naturally occurring hydrates should be the object of continuingmore » study and research. 25 refs.« less

Finite element code FENIA verification and application for 3D modelling of thermal state of radioactive waste deep geological repository

NASA Astrophysics Data System (ADS)

Butov, R. A.; Drobyshevsky, N. I.; Moiseenko, E. V.; Tokarev, U. N.

2017-11-01

The verification of the FENIA finite element code on some problems and an example of its application are presented in the paper. The code is being developing for 3D modelling of thermal, mechanical and hydrodynamical (THM) problems related to the functioning of deep geological repositories. Verification of the code for two analytical problems has been performed. The first one is point heat source with exponential heat decrease, the second one - linear heat source with similar behavior. Analytical solutions have been obtained by the authors. The problems have been chosen because they reflect the processes influencing the thermal state of deep geological repository of radioactive waste. Verification was performed for several meshes with different resolution. Good convergence between analytical and numerical solutions was achieved. The application of the FENIA code is illustrated by 3D modelling of thermal state of a prototypic deep geological repository of radioactive waste. The repository is designed for disposal of radioactive waste in a rock at depth of several hundred meters with no intention of later retrieval. Vitrified radioactive waste is placed in the containers, which are placed in vertical boreholes. The residual decay heat of radioactive waste leads to containers, engineered safety barriers and host rock heating. Maximum temperatures and corresponding times of their establishment have been determined.

Chlorine-36 tracing of salinity sources in the Dry Valleys of Victoria Land, Antarctica

NASA Astrophysics Data System (ADS)

Carlson, Catherine A.; Phillips, Fred M.; Elmore, David; Bentley, Harold W.

1990-02-01

Chlorine-36 was used to trace the origins of salts in six saline lakes in the Dry Valleys of Southern Victoria Land, Antarctica. Characteristic 36Cl signatures were estimated for the various potential chloride sources, which include atmospheric deposition, rock weathering, seawater, and deep ground water. 36Cl /Cl ratios were measured in natural waters and salts from the Dry Valleys. Dilute lake waters (Cl - < 100 mg/l) were found to have 36Cl /Cl ratios in the range 100 × 10 -15 to 1,700 × 10 -15, whereas saline waters (Cl - > 1000 mg/l) had ratios in the range 9 × 10 -15 to 40 × 10 -15. Simple mixing models were employed to quantify the relative contributions of the various chloride sources to Lake Vanda and Don Juan Pond. These results show that Lake Vanda has received its chloride from both deep ground water and the Onyx River. Don Juan Pond has received nearly all its chloride from deep ground water, probably ultimately from rock-water interaction. Deep ground water is the principal source of chloride to the lakes of Wright Valley. However, preliminary data suggest that marine-derived salts or relict sea water may be a significant source of chloride to the lakes of Taylor Valley, implying a possible recent marine invasion that did not affect Wright Valley.

The Iceland Deep Drilling Project 4.5 km deep well, IDDP-2, in the seawater-recharged Reykjanes geothermal field in SW Iceland has successfully reached its supercritical target

NASA Astrophysics Data System (ADS)

Friðleifsson, Guðmundur Ó.; Elders, Wilfred A.; Zierenberg, Robert A.; Stefánsson, Ari; Fowler, Andrew P. G.; Weisenberger, Tobias B.; Harðarson, Björn S.; Mesfin, Kiflom G.

2017-11-01

The Iceland Deep Drilling Project research well RN-15/IDDP-2 at Reykjanes, Iceland, reached its target of supercritical conditions at a depth of 4.5 km in January 2017. After only 6 days of heating, the measured bottom hole temperature was 426 °C, and the fluid pressure was 34 MPa. The southern tip of the Reykjanes peninsula is the landward extension of the Mid-Atlantic Ridge in Iceland. Reykjanes is unique among Icelandic geothermal systems in that it is recharged by seawater, which has a critical point of 406 °C at 29.8 MPa. The geologic setting and fluid characteristics at Reykjanes provide a geochemical analog that allows us to investigate the roots of a mid-ocean ridge submarine black smoker hydrothermal system. Drilling began with deepening an existing 2.5 km deep vertical production well (RN-15) to 3 km depth, followed by inclined drilling directed towards the main upflow zone of the system, for a total slant depth of 4659 m ( ˜ 4.5 km vertical depth). Total circulation losses of drilling fluid were encountered below 2.5 km, which could not be cured using lost circulation blocking materials or multiple cement jobs. Accordingly, drilling continued to the total depth without return of drill cuttings. Thirteen spot coring attempts were made below 3 km depth. Rocks in the cores are basalts and dolerites with alteration ranging from upper greenschist facies to amphibolite facies, suggesting that formation temperatures at depth exceed 450 °C. High-permeability circulation-fluid loss zones (feed points or feed zones) were detected at multiple depth levels below 3 km depth to bottom. The largest circulation losses (most permeable zones) occurred between the bottom of the casing and 3.4 km depth. Permeable zones encountered below 3.4 km accepted less than 5 % of the injected water. Currently, the project is attempting soft stimulation to increase deep permeability. While it is too early to speculate on the energy potential of this well and its economics, the IDDP-2 is a milestone in the development of geothermal resources and the study of hydrothermal systems. It is the first well that successfully encountered supercritical hydrothermal conditions, with potential high-power output, and in which on-going hydrothermal metamorphism at amphibolite facies conditions can be observed. The next step will be to carry out flow testing and fluid sampling to determine the chemical and thermodynamic properties of the formation fluids.

Wound botulism presenting as a deep neck space infection.

PubMed

Gouveia, Christopher; Mookherjee, Somnath; Russell, Matthew S

2012-12-01

Otolaryngologists commonly evaluate patients with findings suspicious for deep space soft tissue infections of the neck. In this case, a woman with a history of injection drug use (IDU) presented with dysphagia, odynophagia, and neck pain. Multiple neck abscesses, too small to drain, were seen on imaging. Despite broad-spectrum intravenous antibiotics, she unexpectedly and rapidly developed respiratory failure requiring intubation. Further work-up diagnosed wound botulism (WB). To our knowledge, this is the first report of WB presenting as a deep neck space infection, and illustrates the importance of considering this deadly diagnosis in patients with IDU history and bulbar symptoms. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Local interaction simulation approach to modelling nonclassical, nonlinear elastic behavior in solids.

PubMed

Scalerandi, Marco; Agostini, Valentina; Delsanto, Pier Paolo; Van Den Abeele, Koen; Johnson, Paul A

2003-06-01

Recent studies show that a broad category of materials share "nonclassical" nonlinear elastic behavior much different from "classical" (Landau-type) nonlinearity. Manifestations of "nonclassical" nonlinearity include stress-strain hysteresis and discrete memory in quasistatic experiments, and specific dependencies of the harmonic amplitudes with respect to the drive amplitude in dynamic wave experiments, which are remarkably different from those predicted by the classical theory. These materials have in common soft "bond" elements, where the elastic nonlinearity originates, contained in hard matter (e.g., a rock sample). The bond system normally comprises a small fraction of the total material volume, and can be localized (e.g., a crack in a solid) or distributed, as in a rock. In this paper a model is presented in which the soft elements are treated as hysteretic or reversible elastic units connected in a one-dimensional lattice to elastic elements (grains), which make up the hard matrix. Calculations are performed in the framework of the local interaction simulation approach (LISA). Experimental observations are well predicted by the model, which is now ready both for basic investigations about the physical origins of nonlinear elasticity and for applications to material damage diagnostics.

Statistical geochemistry reveals disruption in secular lithospheric evolution about 2.5 Gyr ago.

PubMed

Keller, C Brenhin; Schoene, Blair

2012-05-23

The Earth has cooled over the past 4.5 billion years (Gyr) as a result of surface heat loss and declining radiogenic heat production. Igneous geochemistry has been used to understand how changing heat flux influenced Archaean geodynamics, but records of systematic geochemical evolution are complicated by heterogeneity of the rock record and uncertainties regarding selection and preservation bias. Here we apply statistical sampling techniques to a geochemical database of about 70,000 samples from the continental igneous rock record to produce a comprehensive record of secular geochemical evolution throughout Earth history. Consistent with secular mantle cooling, compatible and incompatible elements in basalts record gradually decreasing mantle melt fraction through time. Superimposed on this gradual evolution is a pervasive geochemical discontinuity occurring about 2.5 Gyr ago, involving substantial decreases in mantle melt fraction in basalts, and in indicators of deep crustal melting and fractionation, such as Na/K, Eu/Eu* (europium anomaly) and La/Yb ratios in felsic rocks. Along with an increase in preserved crustal thickness across the Archaean/Proterozoic boundary, these data are consistent with a model in which high-degree Archaean mantle melting produced a thick, mafic lower crust and consequent deep crustal delamination and melting--leading to abundant tonalite-trondhjemite-granodiorite magmatism and a thin preserved Archaean crust. The coincidence of the observed changes in geochemistry and crustal thickness with stepwise atmospheric oxidation at the end of the Archaean eon provides a significant temporal link between deep Earth geochemical processes and the rise of atmospheric oxygen on the Earth.

Deep-water lithofacies and conodont faunas of the Lisburne Group, western Brooks Range, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1992

USGS Publications Warehouse

Dumoulin, Julie A.; Harris, Anita G.; Schmidt, Jeanine M.

1993-01-01

Deep-water lithofacies of the Lisburne Group occur in thrust sheets in the western part of the foreland fold and thrust belt of the Brooks Range and represent at least three discrete units. The Kuna Formation (Brooks Range allochthon) consists mostly of spiculitic mudstone and lesser shale; subordinate carbonate layers are chiefly diagenetic dolomite. Predominantly shale sections of the Kuna that contain few sponge spicules occur in the western part of the study area. The Akmalik Chert (Picnic Creek allochthon) is mostly radiolarian-spiculitic chert; rare limy beds are calcitized radiolarite. The Rim Butte unit (Ipnavik River allochthon) consists chiefly of calcareous turbidites, derived from both shallow- and deep-water sources, interbedded with spiculitic mudstone. Much of the material in the turbidites came from a contemporaneous carbonate platform and margin, but some fossils and lithic clasts were eroded from older, already lithified carbonate-platform rocks. All three units appear to be roughly coeval and are chiefly Osagean (late Early Mississippian) in age in the study area.Shallow-water lithofacies of the Lisburne Group exposed in the Howard Pass area (Brooks Range allochthon) are mostly of Meramecian (early Late Mississippian) age. Thus, these carbonate-platform rocks were not the source of the calcareous turbidites in the Rim Butte unit. Rim Butte turbidites could have been derived from older platform carbonate rocks such as those of the Utukok Formation (Kelly River allochthon) exposed mainly to the west of the Howard Pass quadrangle.

Fungus-like mycelial fossils in 2.4-billion-year-old vesicular basalt.

PubMed

Bengtson, Stefan; Rasmussen, Birger; Ivarsson, Magnus; Muhling, Janet; Broman, Curt; Marone, Federica; Stampanoni, Marco; Bekker, Andrey

2017-04-24

Fungi have recently been found to comprise a significant part of the deep biosphere in oceanic sediments and crustal rocks. Fossils occupying fractures and pores in Phanerozoic volcanics indicate that this habitat is at least 400 million years old, but its origin may be considerably older. A 2.4-billion-year-old basalt from the Palaeoproterozoic Ongeluk Formation in South Africa contains filamentous fossils in vesicles and fractures. The filaments form mycelium-like structures growing from a basal film attached to the internal rock surfaces. Filaments branch and anastomose, touch and entangle each other. They are indistinguishable from mycelial fossils found in similar deep-biosphere habitats in the Phanerozoic, where they are attributed to fungi on the basis of chemical and morphological similarities to living fungi. The Ongeluk fossils, however, are two to three times older than current age estimates of the fungal clade. Unless they represent an unknown branch of fungus-like organisms, the fossils imply that the fungal clade is considerably older than previously thought, and that fungal origin and early evolution may lie in the oceanic deep biosphere rather than on land. The Ongeluk discovery suggests that life has inhabited submarine volcanics for more than 2.4 billion years.

Deep-crustal seismicity in volcanic regions by fluid-enhanced wallrock embrittlement

NASA Astrophysics Data System (ADS)

Sisson, T. W.; Power, J. A.

2013-12-01

Spatial association of deep long-period (DLP) seismicity with volcanoes [1,2], spectral frequencies resembling shallow events attributed to fluid motions, and temporal associations with some eruptions, prompt the interpretation that DLPs mark the locations of magma, or magma with percolating exsolved vapor, in the mid and lower crust. However, various factors are more consistent with the events taking place in the walls surrounding the hot aseismic cores of deep magmatic systems, due to expelled magmatic fluids elevating pore pressures and reducing wall rock brittle strengths, or possibly in largely solidified peripheral intrusions embrittled by interstitial residual melt. First, although exceptions are known, deep seismic events are typically displaced to one or more sides of the locus of volcanism. Compilation of >1000 mid to deep crustal DLP and volcano tectonic events from the Aleutian arc, plotted as radial distance from the respective volcanic locus vs. depth, shows a minimum of events beneath the volcanic loci, encased in a downward broadening halo of events, typically displaced about 6 km to the sides of the volcanic locus. Lateral offsets of deep events are also well established for volcanoes of the Washington Cascades [3], averaging 7.5×4.5(1σ) km, and for some centers in California [1]. Second, while mafic parental magmas can have high concentrations of H2O (CO2 concentrations are comparatively negligible), H2O is highly soluble at mid to lower crustal pressures and will not exsolve appreciably until advanced crystallization and second boiling. Deep vapor exsolution will proceed gradually, delayed well after replenishment events, due to slow cooling and crystallization in the hot deep crust. Exsolution dominantly at high crystallinities argues against bubbles moving through largely liquid replenishing magmas as a major cause of DLPs. Third, isotherms around the mid to deep crustal portions of magmatic systems will propagate outward with time1/2 due to dominantly conductive heat transfer at those depths. Over the ca. 1-5×105 yr durations of convergent margin volcanoes, characteristic isotherms propagate <10 km (k: 2.25 W/mK); temperature dependent thermal conductivity [4] would reduce these distances. Deep magmatic systems are therefore encased in relatively thin thermal sheaths, outboard of which temperatures drop sharply to near-ambient values, and rock strengths increase accordingly. Collectively, these factors support a scenario wherein magmas crystallize in the roots of volcanic systems, gradually exsolving and releasing vapor, some of which percolates into surrounding wallrocks. Beyond some critical isotherm, plastic rock strength increases sufficiently for fluid enhanced brittle failure when the walls are stressed by magma replenishments or by ordinary tectonic forces. If so, the statistical spatial distribution of DLPs indicates that the hot, active portions of the deep magmatic systems are relatively narrow, commonly <6 km in semi-minor radius. 1. Pitt et al., 2002, Seis Res Lett 73:144-152 2. Power et al., 2004, Jour Volc Geotherm Res 138:243-266 3. Nichols et al., 2011, Jour Volc Geotherm Res 200:116-128 4. Whittington et al., 2009, Nature 458, 319-321

Thermal Properties of West Siberian Sediments in Application to Basin and Petroleum Systems Modeling

NASA Astrophysics Data System (ADS)

Romushkevich, Raisa; Popov, Evgeny; Popov, Yury; Chekhonin, Evgeny; Myasnikov, Artem; Kazak, Andrey; Belenkaya, Irina; Zagranovskaya, Dzhuliya

2016-04-01

Quality of heat flow and rock thermal property data is the crucial question in basin and petroleum system modeling. A number of significant deviations in thermal conductivity values were observed during our integral geothermal study of West Siberian platform reporting that the corrections should be carried out in basin models. The experimental data including thermal anisotropy and heterogeneity measurements were obtained along of more than 15 000 core samples and about 4 500 core plugs. The measurements were performed in 1993-2015 with the optical scanning technique within the Continental Super-Deep Drilling Program (Russia) for scientific super-deep well Tyumenskaya SG-6, parametric super-deep well Yen-Yakhinskaya, and deep well Yarudeyskaya-38 as well as for 13 oil and gas fields in the West Siberia. Variations of the thermal conductivity tensor components in parallel and perpendicular direction to the layer stratification (assessed for 2D anisotropy model of the rock studied), volumetric heat capacity and thermal anisotropy coefficient values and average values of the thermal properties were the subject of statistical analysis for the uppermost deposits aged by: T3-J2 (200-165 Ma); J2-J3 (165-150 Ma); J3 (150-145 Ma); K1 (145-136 Ma); K1 (136-125 Ma); K1-K2 (125-94 Ma); K2-Pg+Ng+Q (94-0 Ma). Uncertainties caused by deviations of thermal conductivity data from its average values were found to be as high as 45 % leading to unexpected errors in the basin heat flow determinations. Also, the essential spatial-temporal variations in the thermal rock properties in the study area is proposed to be taken into account in thermo-hydrodynamic modeling of hydrocarbon recovery with thermal methods. The research work was done with financial support of the Russian Ministry of Education and Science (unique identification number RFMEFI58114X0008).

Ecohydrology of Deep Fractured Rocks at Homestake DUSEL

NASA Astrophysics Data System (ADS)

Kieft, T. L.; Boutt, D. F.; Murdoch, L. C.; Wang, H. F.

2009-12-01

The Deep Underground Science and Engineering Laboratory (DUSEL) at Homestake in SD will provide an unprecedented opportunity to study the terrestrial subsurface. Such a study could fundamentally change the way we view the origin and early evolution of life on Earth, the search for novel materials, and the generation of energy. Knowledge of subsurface life has come from only a few boreholes and deep mines. DUSEL will enable the first detailed study of a deep ecosystem in the context of the hydrology, geochemistry, and rock system state that sustain it. We are guided by the over-arching question: What controls the distribution and evolution of subsurface life? Our hypothesis is that these controls are dominated by processes related to geology, geochemistry, geomechanics, and hydrology. Themes of scaling and the development of facies, or zones of similar characteristics cut across all the processes. The ecohydrologic setting of DUSEL Homestake is characterized by a vast expanse of fractured metamorphic rock cut by 100s of km of tunnels and boreholes. Many km3 of the region have been highly affected by mining activities; adjacent regions are partially desaturated; and more distal regions are pristine and presumed to harbor indigenous microbial ecosystems. Simulations along with descriptions of the mine suggest division into zones, or ecohydrologic facies, where essential characteristics related to the requirements for life are expected to be similar. These ecohydrologic facies are a primary organizing principle for our investigation. The Deep EcoHydrology Experiment will consist of field studies supported by numerical simulations. The experimental activities include a particularly exciting opportunity to probe the lower limits of the biosphere using deep drilling technology deployed from the lowest reaches of the facility (2440 m below the surface). The use of the flooding/dewatering event as a tracer combined with hydrologic and mechanical stressors form a theme that cuts across many of the experimental activities. Five key experimental activities have been identified that will enable motivating hypotheses to be tested: 1) Initial Characterization, 2) Flow System, 3) Stress and Deformation, 4) Exploration, and 5) Cross-cutting activities. The International Continental Drilling Program has approved a preproposal for an ICDP ecohydrology project at DUSEL. The development of a long-term deep geosciences observatory at the Homestake DUSEL will revolutionize the field of deep sub-surface ecohydrology. The opportunities for young scientists and international participation in such a facility will be tremendous. Results from the work will have wide ranging implications as 20% of the current earth’s surface consists of a similar geologic setting. DUSEL will also facilitate experiential learning for K-12 through graduate school students working alongside world-class geoscientists.

MRI in necrotizing fasciitis of the extremities.

PubMed

Ali, S Z; Srinivasan, S; Peh, W C G

2014-01-01

Necrotizing fasciitis is a life-threatening soft-tissue infection of bacterial origin, which involves mainly the deep fascia. Early recognition of this condition may be hampered by the uncommon nature of the disease and non-specificity of initial clinical signs and symptoms in less fulminant cases, making the role of imaging important. MRI is the most useful imaging modality in the diagnosis of necrotizing fasciitis. The presence of thick (>3 mm) hyperintense signal in the deep fascia (particularly intermuscular fascia) on fat-suppressed T2 weighted or short tau inversion-recovery images is an important marker for necrotizing fasciitis. Contrast enhancement of the thickened necrotic fascia can be variable, with a mixed-pattern of enhancement being more commonly encountered. Involvement of multiple musculofascial compartments increases the likelihood of necrotizing fasciitis. It is important to remember that T2-hyperintense signal in the deep fascia is not specific to necrotizing fasciitis and can also be seen in cases such as non-infective inflammatory fasciitis or muscle tear. In this pictorial essay, we aim to review the MRI findings in necrotizing fasciitis, discuss its limitations and pitfalls and identify differentiating features from non-necrotizing soft-tissue infections, such as cellulitis and infective myositis/pyomyositis, conditions which may clinically mimic necrotizing fasciitis.

MRI in necrotizing fasciitis of the extremities

PubMed Central

Srinivasan, S; Peh, W C G

2014-01-01

Necrotizing fasciitis is a life-threatening soft-tissue infection of bacterial origin, which involves mainly the deep fascia. Early recognition of this condition may be hampered by the uncommon nature of the disease and non-specificity of initial clinical signs and symptoms in less fulminant cases, making the role of imaging important. MRI is the most useful imaging modality in the diagnosis of necrotizing fasciitis. The presence of thick (>3 mm) hyperintense signal in the deep fascia (particularly intermuscular fascia) on fat-suppressed T2 weighted or short tau inversion–recovery images is an important marker for necrotizing fasciitis. Contrast enhancement of the thickened necrotic fascia can be variable, with a mixed-pattern of enhancement being more commonly encountered. Involvement of multiple musculofascial compartments increases the likelihood of necrotizing fasciitis. It is important to remember that T2-hyperintense signal in the deep fascia is not specific to necrotizing fasciitis and can also be seen in cases such as non-infective inflammatory fasciitis or muscle tear. In this pictorial essay, we aim to review the MRI findings in necrotizing fasciitis, discuss its limitations and pitfalls and identify differentiating features from non-necrotizing soft-tissue infections, such as cellulitis and infective myositis/pyomyositis, conditions which may clinically mimic necrotizing fasciitis. PMID:24288403

Massive deep-sea sulphide ore deposits discovered on the East Pacific Rise

USGS Publications Warehouse

Francheteau, Jean; Needham, H.D.; Choukroune, P.; Juteau, Tierre; Seguret, M.; Ballard, Richard D.; Fox, P.J.; Normark, William; Carranza, A.; Cordoba, D.; Guerrero, J.; Rangin, C.; Bougault, H.; Cambon, P.; Hekinian, R.

1979-01-01

Massive ore-grade zinc, copper and iron sulphide deposits have been found at the axis of the East Pacific Rise. Although their presence on the deep ocean-floor had been predicted there was no supporting observational evidence. The East Pacific Rise deposits represent a modern analogue of Cyprus-type sulphide ores associated with ophiolitic rocks on land. They contain at least 29% zinc metal and 6% metallic copper. Their discovery will provide a new focus for deep-sea exploration, leading to new assessments of the concentration of metals in the upper layers of the oceanic crust. ?? 1979 Nature Publishing Group.

Deep-focus earthquakes and recycling of water into the earth's mantle

NASA Technical Reports Server (NTRS)

Meade, Charles; Jeanloz, Raymond

1991-01-01

For more than 50 years, observations of earthquakes to depths of 100 to 650 kilometers inside earth have been enigmatic: at these depths, rocks are expected to deform by ductile flow rather than brittle fracturing or frictional sliding on fault surfaces. Laboratory experiments and detailed calculations of the pressures and temperatures in seismically active subduction zones indicate that this deep-focus seismicity could originate from dehydration and high-pressure structural instabilities occurring in the hydrated part of the lithosphere that sinks into the upper mantle. Thus, seismologists may be mapping the recirculation of water from the oceans back into the deep interior of the planet.

Numerical Experiments on the Role of the Lower Crust in the Development of Extension-driven Gneiss Domes

NASA Astrophysics Data System (ADS)

Korchinski, M.; Rey, P. F.; Teyssier, C. P.; Mondy, L. S.; Whitney, D.

2016-12-01

Flow of orogenic crust is a critical geodynamic process in the chemical and physical evolution of continents. Deeply sourced rocks are transported to the near surface within gneiss domes, which are ubiquitous features in orogens and extensional regions. Exhumation of material within a gneiss dome can occur as the result of tectonic stresses, where material moves into space previously occupied by the shallow crust as the result of extension localized along a detachment system. Gravitationally driven flow may also contribute to exhumation. This research addresses how physical parameters (density, viscosity) of the deep crust (base of brittle crust to Moho) impact (1) the localization of extension in the shallow crust, and (2) the flow of deep crust by tectonic and non-tectonic stresses. We present 2D numerical experiments in which the density (2900-3100 kg m-3) and viscosity (1e19-1e21 Pa s) of the deep crust are systematically varied. Lateral and vertical transport of deep crustal rocks toward the gneiss dome occurs across the entire parameter space. A low viscosity deep crust yields localized extension in the upper crust and crustal-scale upward flow; this case produces the highest exhumation. A high viscosity deep crust results in distributed thinning of the upper crust, which suppresses upward mass transport. The density of the deep crust has only a second-order effect on the shallow crust extension regime. We capture the flow field generated after the cessation of extension to evaluate mass transport that is not driven by tectonic stresses. Upward transport of material within the gneiss dome is present across the entire parameter space. In the case of a low-viscosity deep crust, horizontal flow occurs adjacent to the dome above the Moho; this flow is an order of magnitude higher than that within the dome. Density variations do not drastically alter the flow field in the low viscosity lower crust. However, a high density and high viscosity deep crust results in boudinage of the whole crust, which generates significant upward flow from the buoyant asthenosphere.

The Regolith of 4 Vesta - Inferences from Howardites

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.; Herrin, J. S.; Cartwright, J. A.

2011-01-01

Asteroid 4 Vesta is quite likely the parent asteroid of the howardite, eucrite and diogenite meteorites - the HED clan. Eucrites and diogenites are the products of igneous processes; the former are basaltic composition rocks from flows, and shallow and deep intrusive bodies, whilst the latter are cumulate orthopyroxenites thought to have formed deep in the crust. Impact processes have excavated these materials and mixed them into a suite of polymict breccias. Howardites are polymict breccias composed mostly of clasts and mineral fragments of eucritic and diogenitic parentage, with neither end-member comprising more than 90% of the rock. Early work interpreted howardites as representing the lithified regolith of their parent asteroid. Recently, howardites have been divided into two subtypes; fragmental howardites, being a type of non-regolithic polymict breccia, and regolithic howardites, being lithified remnants of the active regolith of 4 Vesta. We are in the thralls of a collaborative investigation of the record of impact mixing contained within howardites, which includes studies of their mineralogy, petrology, bulk rock compositions, and bulk rock and clast noble gas contents. One goal of our investigation is to test the hypothesis that some howardites represent breccias formed from an ancient, well-mixed regolith on Vesta. Another is to use our results to further understand regolith processing on differentiated asteroids as compared to what has been learned from the Moon. We have made petrographic observations and electron microprobe analyses on 21 howardites and 3 polymict eucrites. We have done bulk rock analyses using X-ray fluorescence spectrometry and are completing inductively coupled plasma mass spectrometry analyses. Here, we discuss our petrologic and bulk compositional results in the context of regolith formation. Companion presentations describe the noble gas results and compositional studies of low-Ca pyroxene clasts.

Morphological preservation of carbonaceous plant fossils in blueschist metamorphic rocks from New Zealand.

PubMed

Galvez, M E; Beyssac, O; Benzerara, K; Bernard, S; Menguy, N; Cox, S C; Martinez, I; Johnston, M R; Brown, G E

2012-03-01

Morphological and chemical evidence of ancient life is widespread in sedimentary rocks retrieved from shallow depths in the Earth's crust. Metamorphism is highly detrimental to the preservation of biological information in rocks, thus limiting the geological record in which traces of life might be found. Deformation and increasing pressure/temperature during deep burial may alter the morphology as well as the composition and structure of both the organic and mineral constituents of fossils. However, microspore fossils have been previously observed in intensely metamorphosed rocks. It has been suggested that their small size, and/or the nature of the polymer composing their wall, and/or the mineralogy of their surrounding matrix were key parameters explaining their exceptional preservation. Here, we describe the remarkable morphological preservation of plant macrofossils in blueschist metamorphic rocks from New Zealand containing lawsonite. Leaves and stems can be easily identified at the macroscale. At the microscale, polygonal structures with walls mineralized by micas within the leaf midribs and blades may derive from the original cellular ultrastructure or, alternatively, from the shrinkage during burial of the gelified remnants of the leaves in an abiotic process. Processes and important parameters involved in the remarkable preservation of these fossils during metamorphism are discussed. Despite the excellent morphological preservation, the initial biological polymers have been completely transformed to graphitic carbonaceous matter down to the nanometer scale. This occurrence demonstrates that plant macrofossils may experience major geodynamic processes such as metamorphism and exhumation involving deep changes and homogenization of their carbon chemistry and structure but still retain their morphology with remarkable integrity even if they are not shielded by any hard-mineralized concretion. © 2012 Blackwell Publishing Ltd.

Geological and geochemical investigations of uranium occurrences in the Arrastre Lake area of the Medicine Bow Mountains, Wyoming

USGS Publications Warehouse

Miller, W. Roger; Houston, R.S.; Karlstrom, K.E.; Hopkins, D.M.; Ficklin, W.H.

1977-01-01

Metasedimentary rocks of Precambrian X age in and near the Snowy Range wilderness study area of southeastern Wyoming are lithologically and chronologically similar to those on the north shore of Lake Huron in Canada. The rocks in Canada contain major deposits of uranium in quartz-pebble conglomerates near the base of the metasedimentary sequence. Similar conglomerates in the Deep Lake Formation in the Medicine Bow Mountains of southeastern Wyoming are slightly radioactive and may contain deposits of uranium and other valuable heavy metals. During the summer of 1976, a geological and geochemical pilot study was conducted in the vicinity of Arrastre Lake in the Medicine Bow Mountains to determine the most effective exploration methods for evaluating the uranium potential of the Snowy Range wilderness study area. The area around Arrastre Lake was selected because of the presence of a radioactive lens within a quartz-pebble conglomerate of the Deep Lake Formation. The results of the survey indicate possible uranium mineralization in the subsurface rocks of this formation. The radon content of the dilute waters of the area is much higher than can be accounted for by the uranium content of the surface rocks. Two sources for the high content of the radon are possible. In either case, the high values of radon obtained in this study are a positive indication of uranium mineralization in the subsurface rocks. The determination of the radon content of water samples is the recommended geochemical technique for uranium exploration in the area. The determination of uranium in water and in organic-rich bog material is also recommended.

Influence of stretching and density contrasts on the chemical evolution of continental magmas: An example from the Ivrea-Verbano Zone

USGS Publications Warehouse

Sinigoi, S.; Quick, J.E.; Mayer, A.; Budahn, J.

1996-01-01

The southern Ivrea-Verbano Zone of the Italian Western Alps contains a huge mafic complex that intruded high-grade metamorphic rocks while they were resident in the lower crust. Geologic mapping and chemical variations of the igneous body were used to study the evolution of underplated crust. Slivers of crustal rocks (septa) interlayered with igneous mafic rocks are concentrated in a narrow zone deep in the complex (Paragneiss-bearing Belt) and show evidence of advanced degrees of partial melting. Variations of rare-earth-element patterns and Sr isotope composition of the igneous rocks across the sequence are consistent with increasing crustal contamination approaching the septa. Therefore, the Paragneiss-bearing Belt is considered representative of an "assimilation region" where in-situ interaction between mantle- and crust-derived magmas resulted in production of hybrid melts. Buoyancy caused upwards migration of the hybrid melts that incorporated the last septa and were stored at higher levels, feeding the Upper Mafic Complex. Synmagmatic stretching of the assimilation region facilitated mixing and homogenization of melts. Chemical variations of granitoids extracted from the septa show that deep septa are more depleted than shallow ones. This suggests that the first incorporated septa were denser than the later ones, as required by the high density of the first-injected mafic magmas. It is inferred that density contrasts between mafic melts and crustal rocks play a crucial role for the processes of contamination of continental magmas. In thick under- plated crust, the extraction of early felsic/hybrid melts from the lower crust may be required to increase the density of the lower crust and to allow the later mafic magmas to penetrate higher crustal levels.

10. VIEW SHOWING TWO BUTTRESSES ON THE NORTH ELEVATION, WHICH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. VIEW SHOWING TWO BUTTRESSES ON THE NORTH ELEVATION, WHICH SUPPORT A DEEP CURVE IN THE LONGEST SECTION OF THE WALL, LOOKING SOUTH-SOUTHWEST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

A Cone Shaped Hill

NASA Image and Video Library

2015-10-14

There are many hills and knobs on Mars that reveal aspects of the local geologic history. Typically, the hills in the relatively-smooth region surrounding this image are flat topped erosional remnants or mesas with irregular or even polyhedral margins. These landforms suggest wide spread erosion of the soft or weakly-cemented sedimentary layers. This hill stands out because of is circular inverted-cone shape and apparent dark streaks along its flanks visible in lower resolution images. Close inspection from HiRISE reveals that the fine soils sloping down from the peak are intersected with radiating lines of rock and eroding rubble. This formation is similar to lava intrusions that form in the core of a volcano. As lava is squeezed up into a central conduit, radiating fractures fill with lava forming rock units called dikes. As the lava cools inside the ground and in the fractures, it forms into a harder rock that is more resistant to erosion. Later, as the surrounding sediments and soils erode, the resistant volcanic rock remains standing to tell a story of what happened underground long ago. http://photojournal.jpl.nasa.gov/catalog/PIA20003

Insight into the geology of the East Antarctic hinterland: a study of sediment inclusions from ice cores of the Lake Vostok borehole

USGS Publications Warehouse

Leitchenkov, G.L.; Belyatsky, B.V.; Rodionov, N.V.; Sergeev, S.A.

2007-01-01

refrozen from the lake water. This ice layer contains random sediment inclusions, eight of which have been studied using state-of the-art analytical techniques. Six inclusions comprise soft aggregates consisting mainly of clay-mica minerals and micron-sized quartz grains while two others are solid clasts of fine-grained cemented rocks. The largest rock clast consists of poorly-rounded quartz and minor amounts of accessory minerals and is classified as quartzose siltstone. More than twenty grains of zircon and monazite have been identified in this siltstone and dated by SIMS SHRIMP-II. Two age clusters have been recognized for these detrital grains, in the ranges 0.8−1.2 Ga and 1.6−1.8 Ga. The compositions of the rock clasts suggest that the bedrock situated to the west of Lake Vostok is sedimentary. The age data on the detrital accessory minerals suggest that the provenance of these sedimentary rocks − the Gamburtsev Mountains and Vostok Subglacial Highlands, is mainly represented by Paleoproterozoic and MesoproterozoicNeoproterozoic crustal provinces

Contrasted glass-whole rock compositions and phenocryst re-distribution, IPOD Sites 417 and 418

NASA Astrophysics Data System (ADS)

Staudigel, H.; Bryan, W. B.

1982-01-01

Major element composition ranges of closely associated basalt glass-whole rock pairs from individual small cooling units approach the total known range of basalt glass and whole rock compositions at IPOD sites 417 and 418. The whole rock samples fall into two groups: one is depleted in MgO and distinctly enriched in plagioclase but has lost some olivine and/or pyroxene relative to its corresponding glass; and the other is enriched in MgO and in phenocrysts of olivine and pyroxene as well as plagioclase compared to its corresponding glass. By analogy with observed phenocryst distributions in lava pillows, tubes, and dikes, and with some theoretical studies, we infer that bulk rock compositions are strongly affected by phenocryst redistribution due to gravity settling, flotation, and dynamic sorting after eruption, although specific models are not well constrained by the one-dimensional geometry of drill core. Compositional trends or groupings in whole rock data resulting from such late-stage processes should not be confused with more fundamental compositional effects produced in deep chambers or during partial melting.

Rock Abrasion Tool Exhibits the Deep Red Pigment of Mars

NASA Technical Reports Server (NTRS)

2006-01-01

During recent soil-brushing experiments, the rock abrasion tool on NASA's Mars Exploration Rover Spirit became covered with dust, as shown here. An abundance of iron oxide minerals in the dust gave the device a reddish-brown veneer. Investigators were using the rock abrasion tool to uncover successive layers of soil in an attempt to reveal near-surface stratigraphy. Afterward, remnant dirt clods were visible on both the bit and the brush of the tool. Designers of the rock abrasion tool at Honeybee Robotics and engineers at the Jet Propulsion Laboratory developed a plan to run the brush on the rock abrasion tool in reverse to dislodge the dirt and return the tool to normal operation. Subsequent communications with the rover revealed that the procedure is working and the rock abrasion tool remains healthy.

Spirit acquired this approximately true-color image with the panoramic camera on the rover's 893rd sol, or Martian day (July 8, 2006). The image combines exposures taken through three of the camera's filters, centered on wavelengths of 750 nanometers, 530 nanometers, and 430 nanometers.

Elastic geobarometry: uncertainties arising from the geometry of the host-inclusion system

NASA Astrophysics Data System (ADS)

Mazzucchelli, Mattia L.; Burnley, Pamela; Angel, Ross J.; Chiara Domeneghetti, M.; Nestola, Fabrizio; Alvaro, Matteo

2017-04-01

Ultra-high-pressure metamorphic (UHPM) rocks are the only rocks that can provide insights into the detailed processes of deep and ultra-deep subduction. The application of conventional geobarometry to these rocks can be extremely challenging. Elastic geobarometry is an alternative and complementary method independent of chemistry and chemical equilibria. Minerals trapped as inclusions within other host minerals develop residual pressure (Pinc) on exhumation as a result of the differences between the thermo-elastic properties of the host and the inclusion. If correctly interpreted, measurement of the Pinc allows for a good estimate of the entrapment pressure. The solution for isotropic non-linear elasticity has been recently incorporated into the classic host-inclusion model [1; 2] and is now available in the EoSFit7c software [3]. However, this solution assumes a simple geometry for the host inclusion system with a small spherical inclusion located at the center of an infinite host. To verify the results of the analytical solution and to extend the analysis beyond the existing geometrical assumptions we performed numerical calculations using Finite Element Modelling (FEM). This approach has allowed us to evaluate the deviation from the pressure calculated with the isotropic solution if applied to real host-inclusion systems where the geometry is far from ideal, for example when the inclusion is not small, not at the center of the host and not spherical. In order to determine the effects of shape alone, we performed calculations with isotropic elasticity. Our results show that the deviations from the analytical solution arising from the geometry of the system are smaller than 1% if a spherical inclusion has a radius smaller than 1/4 of that of the host and is located at more than two inclusion radii from the external surface of the host. Deviations produced by changes in the shape of the inclusions include two contributions. First, the effect of edges and corners is small and introduces deviations of less than 2%. Second, the aspect ratio of the inclusion gives rise to large deviations in Pinc with shifts in the calculated pressures of more than 10% for platy inclusions (i.e. aspect ratio 1:5:5). The exact effect on Pinc is a complex function of both the values of the bulk and shear moduli of both host and inclusion, and the contrast in these values. For a soft quartz-like inclusion, the influence of the aspect ratio and of the presence of edges and corners becomes greater as the host is made softer and approaches the bulk modulus of the inclusion, provided a contrast in shear moduli remains. These deviations from the analytical solution induced by the shape are smaller than 1% only when inclusions are approximately spherical (i.e. ellipsoids with aspect ratios of less than 1:2:2) and the host is significantly stiffer than the inclusion. This work is supported by MIUR-SIR grant "MILE DEEp" (RBSI140351) to M. Alvaro, and ERC starting grant 307322 to F. Nestola. References: [1] Angel, R.J et al. (2014a) Am Mineral,99, 2146-2149 [2] Angel R.J et al. (2015) J. Metamorph. Geol.33, 801-813. [3] Angel RJ et al. (2014b) Z Kristallogr,229, 405-419.

Ion beam analyses of radionuclide migration in heterogeneous rocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alonso, Ursula; Missana, Tiziana; Garcia-Gutierrez, Miguel

2013-07-18

The migration of radionuclides (RN) in the environment is a topic of general interest, for its implications on public health, and it is an issue for the long-term safety studies of deep geological repositories (DGR) for high-level radioactive waste. The role played by colloids on RN migration is also of great concern. Diffusion and sorption are fundamental mechanisms controlling RN migration in rocks and many experimental approaches are applied to determine transport parameters for low sorbing RN in homogeneous rocks. However, it is difficult to obtain relevant data for high sorbing RN or colloids, for which diffusion lengths are extremelymore » short, or within heterogeneous rocks, where transport might be different in different minerals. The ion beam techniques Rutherford Backscattering Spectrometry (RBS) and micro-Particle Induced X-Ray Emission ({mu}PIXE), rarely applied in the field, were selected for their micro-analytical potential to study RN diffusion and surface retention within heterogeneous rocks. Main achievements obtained during last 12 years are highlighted.« less

Early lunar petrogenesis, oceanic and extraoceanic

NASA Technical Reports Server (NTRS)

Warren, P. H.; Wasson, J. T.

1980-01-01

An attempt is made to ascertain which (if any) pristine nonmare rocks, other than KREEPy ones, are not cumulates from the magma ocean. It is noted that the only pristine rocks having bulk densities low enough to have formed by floating above the magma ocean are the ferroan anorthosites, which are easily recognizable as a discrete subset of pristine rocks in general, on the basis of mineral composition relationships. The other class of pristine nonmare rocks, the Mg-rich rocks, did not form from the same magma that produced the ferroan anorthosites. It is suggested that they were formed in layered noritic-troctolitic plutons. These plutons, it is noted, were apparently intruded at, or slightly above, the boundary between the floated ferroan anorthosite crust and the underlying complementary mafic cumulates. It is thought that the parental magmas of the plutons may have arisen by partial melting of either deep mafic cumulates from the magma ocean or a still deeper, undifferentiated primordial layer that was not molten during the magma ocean period.

Petrology of gabbroic rocks from the Mid-Cayman rise spreading center

NASA Technical Reports Server (NTRS)

Elthon, Don

1987-01-01

Mineral analyses of oxide and silicate phases from a suite (collected with the DSRV Alvin in January 1976 and July 1977) of 48 gabbroic rocks collected from the vicinity of the Mid-Cayman Rise spreading center are reported. Mineral compositions of these anorthosites, leuco-troctolite, leuco-olivine gabbros, olivine gabbros, leuco-gabbros, and gabbros indicate the cumulate rocks have been produced by the crystal fractionation of basaltic liquids. Certain features of these rocks are inconsistent with the occurrence of this fractionation at low pressures (1 atm to 2 kbar). Although the experimental data are not available to conclusively demonstrate that the effects seen were produced at moderate pressures (5-10 kbar), the effects are similar to those predicted thermodynamically and to those observed in limited experimental studies within this pressure range. It is therefore suggested that the most likely scenario for the production of these gabbroic rocks is the moderate-pressure crystallization of basaltic magmas within deep-seated magma chambers underneath this slow-spreading center.

Evidence for Seismogenic Hydrogen Gas, a Potential Microbial Energy Source on Earth and Mars.

PubMed

McMahon, Sean; Parnell, John; Blamey, Nigel J F

2016-09-01

The oxidation of molecular hydrogen (H2) is thought to be a major source of metabolic energy for life in the deep subsurface on Earth, and it could likewise support any extant biosphere on Mars, where stable habitable environments are probably limited to the subsurface. Faulting and fracturing may stimulate the supply of H2 from several sources. We report the H2 content of fluids present in terrestrial rocks formed by brittle fracturing on fault planes (pseudotachylites and cataclasites), along with protolith control samples. The fluids are dominated by water and include H2 at abundances sufficient to support hydrogenotrophic microorganisms, with strong H2 enrichments in the pseudotachylites compared to the controls. Weaker and less consistent H2 enrichments are observed in the cataclasites, which represent less intense seismic friction than the pseudotachylites. The enrichments agree quantitatively with previous experimental measurements of frictionally driven H2 formation during rock fracturing. We find that conservative estimates of current martian global seismicity predict episodic H2 generation by Marsquakes in quantities useful to hydrogenotrophs over a range of scales and recurrence times. On both Earth and Mars, secondary release of H2 may also accompany the breakdown of ancient fault rocks, which are particularly abundant in the pervasively fractured martian crust. This study strengthens the case for the astrobiological investigation of ancient martian fracture systems. Deep biosphere-Faults-Fault rocks-Seismic activity-Hydrogen-Mars. Astrobiology 16, 690-702.

Resilience vs soft crisis: dynamic risk assessment in complex hybrid systems. Case history of Ginosa (Taranto, Southern Italy)

NASA Astrophysics Data System (ADS)

Parisi, Alessandro; Argentiero, Ilenia; Fidelibus, Maria Dolores; Pellicani, Roberta; Spilotro, Giuseppe

2017-04-01

Considering a natural system without human-induced modifications, its resilience can be altered by many natural drivers (e.g. geological characteristics, climate) and their spatial modifications over time. Therefore, natural hazardous phenomena could shift natural system over tipping points in an easier or more difficult way. So long as natural system does not involve human settlements or transport infrastructures, natural system risk assessment could not be a basic topic. Nowadays, human activities have modified many natural systems forming, as a result, hybrid systems (both human and natural), in which natural and human-induced drivers modify hybrid systems vulnerability in order to decrease or increase their resilience: scientists define this new age Anthropocene. In this context, dynamic risk assessment of hybrid systems is required in order to avoid disaster when hazardous phenomena occur, but it is a quite complex issue. In fact, soft crisis emerging signals are difficult to identify because of wrong risk perception and lack of communication. Furthermore, natural and human-induced modifications are rarely registered and supervised by governments, so it is fairly difficult defining how systems resilience changes over time. Inhabitants of Ginosa (Taranto, South of Italy) had modified many old rock dwellings over thousand years since the Middle Ages. Indeed, they had built up three-storey houses on three hypogeum levels of rock dwellings along the ravine. The Matrice street collapse in Ginosa is an example of how natural and human-induced spatial modifications over time had led a soft crisis to evolve in a disaster, fortunately without fatalities. This research aim is to revisit events before the Matrice street collapse on the 21st January 2014. The will is to define the relationship between the hybrid system resilience and soft crisis variation over time and how human and natural drivers were involved in the shift.

Use of the Fracture Continuum Model for Numerical Modeling of Flow and Transport of Deep Geologic Disposal of Nuclear Waste in Crystalline Rock

NASA Astrophysics Data System (ADS)

Hadgu, T.; Kalinina, E.; Klise, K. A.; Wang, Y.

2015-12-01

Numerical modeling of disposal of nuclear waste in a deep geologic repository in fractured crystalline rock requires robust characterization of fractures. Various methods for fracture representation in granitic rocks exist. In this study we used the fracture continuum model (FCM) to characterize fractured rock for use in the simulation of flow and transport in the far field of a generic nuclear waste repository located at 500 m depth. The FCM approach is a stochastic method that maps the permeability of discrete fractures onto a regular grid. The method generates permeability fields using field observations of fracture sets. The original method described in McKenna and Reeves (2005) was designed for vertical fractures. The method has since then been extended to incorporate fully three-dimensional representations of anisotropic permeability, multiple independent fracture sets, and arbitrary fracture dips and orientations, and spatial correlation (Kalinina et al. 20012, 2014). For this study the numerical code PFLOTRAN (Lichtner et al., 2015) has been used to model flow and transport. PFLOTRAN solves a system of generally nonlinear partial differential equations describing multiphase, multicomponent and multiscale reactive flow and transport in porous materials. The code is designed to run on massively parallel computing architectures as well as workstations and laptops (e.g. Hammond et al., 2011). Benchmark tests were conducted to simulate flow and transport in a specified model domain. Distributions of fracture parameters were used to generate a selected number of realizations. For each realization, the FCM method was used to generate a permeability field of the fractured rock. The PFLOTRAN code was then used to simulate flow and transport in the domain. Simulation results and analysis are presented. The results indicate that the FCM approach is a viable method to model fractured crystalline rocks. The FCM is a computationally efficient way to generate realistic representation of complex fracture systems. This approach is of interest for nuclear waste disposal models applied over large domains.

Elastic wave velocities, chemistry and modal mineralogy of crustal rocks sampled by the Outokumpu scientific drill hole: Evidence from lab measurements and modeling

NASA Astrophysics Data System (ADS)

Kern, H.; Mengel, K.; Strauss, K. W.; Ivankina, T. I.; Nikitin, A. N.; Kukkonen, I. T.

2009-07-01

The Outokumpu scientific deep drill hole intersects a 2500 m deep Precambrian crustal section comprising a 1300 m thick biotite-gneiss series (mica schists) at top, followed by a 200 m thick meta-ophiolite sequence, underlain again by biotite gneisses (mica schists) (500 m thick) with intercalations of amphibolite and meta-pegmatoids (pegmatitic granite). From 2000 m downward the dominating rock types are meta-pegmatoids (pegmatitic granite). Average isotropic intrinsic P- and S-wave velocities and densities of rocks were calculated on the basis of the volume fraction of the constituent minerals and their single crystal properties for 29 core samples covering the depth range 198-2491 m. The modal composition of the rocks is obtained from bulk rock (XRF) and mineral chemistry (microprobe), using least squares fitting. Laboratory seismic measurements on 13 selected samples representing the main lithologies revealed strong anisotropy of P- and S-wave velocities and shear wave splitting. Seismic anisotropy is strongly related to foliation and is, in particular, an important property of the biotite gneisses, which dominate the upper and lower gneiss series. At in situ conditions, velocity anisotropy is largely caused by oriented microcracks, which are not completely closed at the pressures corresponding to the relatively shallow depth drilled by the borehole, in addition to crystallographic preferred orientation (CPO) of the phyllosilicates. The contribution of CPO to bulk anisotropy is confirmed by 3D velocity calculations based on neutron diffraction texture measurements. For vertical incidence of the wave train, the in situ velocities derived from the lab measurements are significantly lower than the measured and calculated intrinsic velocities. The experimental results give evidence that the strong reflective nature of the ophiolite-derived rock assemblages is largely affected by oriented microcracks and preferred crystallographic orientation of major minerals, in addition to the lithologic control.

Dynamics of metasomatic transformation of lithospheric mantle rocks under Siberian Craton

NASA Astrophysics Data System (ADS)

Sharapov, Victor; Perepechko, Yury; Tomilenko, Anatoly; Chudnenko, Konstantin; Sorokin, Konstantin

2014-05-01

Numerical problem for one- and two-velocity hydrodynamics of heat and mass transfer in permeable zones over 'asthenospheric lenses' (with estimates for dynamics of non-isothermal metasomatosis of mantle rocks, using the approximation of flow reactor scheme) was formulated and solved based on the study of inclusion contents in minerals of metamorphic rocks of the lithosphere mantle and earth crust, estimates of thermodynamic conditions of inclusions appearance, and the results of experimental modeling of influence of hot reduced gases on rocks and minerals of xenoliths in mantle rocks under the cratons of Siberian Platform (SP): 1) the supply of fluid flows of any composition from upper mantle magma sources results in formation of zonal metasomatic columns in ultrabasic lithosphere mantle in permeable zones of deep faults; 2) when major element or petrogenetic components are supplied from magma source, depleted ultrabasic rocks of the lithosphere mantle are transformed into substrates which can be regarded as deep analogs of crust rodingites; 3) other fluid compositions cause deep calcinations and noticeable salination of metasomated substrate, or garnetization (eclogitization) of primary ultrabasic matrix develops; 4) above these zones the zone of basification appears; it is changed by the area of pyroxenitization, amphibolization, and biotitization; 5) modeling of thermo and mass exchange for two-velocity hydrodynamic problem showed that hydraulic approximation increases velocities of heat front during convective heating and decreases pressure in fluid along the flow. It was shown that grospydites, regarded earlier as eclogites, in permeable areas of lithosphere mantle, are typical zones draining upper mantle magma sources of metasomatic columns. As a result of the convective melting the polybaric magmatic sources may appear. Thus the formation of the (kimberlites?) melilitites or carbonatites is possible at the base of the lithospheric plates. It is shown that the physico - chemical conditions of the carbonation of the depleted mantle peridotites refer to the narrow interval of the possible fluid compositions. The bulk fluid content near 4 weight % with the SiO2 CaO 0.5 - 0.1 molar volumes the 1) the Si/Ca molar ratio is < 1; 2) in the C-H-O system the molar ration should be 1/2/3 - 2/1/2; 3) the pO2 variations should be -8 < lg pO2 < -11; 4) in the fluid the CO2 content is twice higher than H2O and Cl essentially prevail under F. In the system with smaller fraction of the fluid phase less increased by the major element rock components the carbonation is more intensive when the Ca content decrease. The fusions of the basic magmas are possible within the wehrlitization zones. The work is supported by RFBR grant 12-05-00625.

Geochronology and geochemistry of deep-seated crustal xenoliths in the northern North China Craton: Implications for the evolution and structure of the lower crust

NASA Astrophysics Data System (ADS)

Su, Yuping; Zheng, Jianping; Griffin, William L.; Huang, Yan; Wei, Ying; Ping, Xianquan

2017-11-01

The age and composition of the lower crust are critical in understanding the processes of continental formation and evolution, and deep-seated granulite xenoliths can offer direct information on the lower crust. Here, we report mineral chemistry, whole-rock major and trace elements, Sr-Nd isotopes and zircon U-Pb-Hf results for a suite of deep-seated crustal xenoliths, recently discovered in the Cenozoic basalts of the Nangaoya area in the northern part of the North China Craton (NCC). Based on the P-T estimates, these xenoliths including mafic, intermediate and felsic granulites and hornblendites were sampled from different levels of the lower crust. While a hornblendite has a flat REE pattern, all other xenoliths display LREE enrichment and depletion of Nb, Ta, Th and Ti. The mafic granulite xenolith has relatively high whole-rock εNd(t) value of - 13.37, and yields Mesozoic (188-59 Ma) zircons ages with high εHf(t) values from - 15.3 to - 9.2. The garnet-bearing intermediate granulite-facies rocks show low εNd(t) values from - 16.92 to - 17.48, and reveal both Paleoproterozoic (1948 Ma) and Mesozoic (222-63 Ma) zircon U-Pb ages. Their Mesozoic zircons have lower εHf(t) values (from - 18.4 to - 13.8) than those from the mafic xenolith. The remaining intermediate to felsic xenoliths show Paleoproterozoic zircon ages, and the lowest εNd(t) values (from - 20.78 to - 24.03). The mafic-intermediate granulites with Mesozoic zircons originated from the interaction of lower crust-derived magmas with mantle melts, with higher proportions of mantle magmas involved in the generation of mafic granulite, whereas intermediate to felsic xenoliths without Mesozoic zircons represent ancient Paleoproterozoic to Neoarchean deep crust. These deep-seated xenoliths reveal complicated crustal evolution processes, including crustal growth during Neoarchean (2.5-2.7 Ga), middle Paleoproterozoic (2.2-2.1 Ga) and Mesozoic, and reworking during early Paleoproterozoic, late Paleoproterozoic and Mesozoic related to magmatic underplating. The integrated analyses of lithological, geochemical and age data for a suite of deep-seated xenoliths show that the lower crust in the Nangaoya area is temporally and compositionally zoned. The upper part of the lower crust mainly comprises Neoarchean to Paleoproterozoic intermediate-felsic rocks with intercalated hornblendites, the majority of which record 1950 and 1850 Ma metamorphism; the middle part is dominated by a Paleoproterozoic and Mesozoic intermediate garnet-bearing granulite-facies hybrid layer; and the lowermost crust is represented by a Mesozoic mafic granulite layer, which was significantly modified by episodic magmatic underplating. Such a modification induced by crust-mantle interaction can result in Mesozoic ages and more mafic components for xenolith granulites, and thus is an effective mechanism to explain the differences between exposed and xenolithic granulites.

Eustatic control of turbidites and winnowed turbidites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shanmugam, G.; Moiola, R.J.

1982-05-01

Global changes in sea level, primarily the results of tectonism and glaciation, control deep-sea sedimentation. During periods of low sea level the frequency of turbidity currents is greatly increased. Episodes of low sea level also cause vigorous contour currents, which winnow away the fines of turbidites. In the rock record, the occurrence of most turbidites and winnowed turbidities closely corresponds to global lowstands of paleo-sea level. This observation may be useful in predicting the occurrence of deep-sea reservoir facies in the geologic record.

Survival, blood osmolality, and gill morphology of juvenile yellow perch, rock bass, black crappie, and largemouth bass exposed to acidified soft water

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, J.H.; Jensen, K.M.; Leino, R.L.

1989-01-01

When exposed to a range of pH from 7.0 to 4.0 in soft water (1 mg Ca(2+)/L), juvenile rock bass Ambloplites rupestris, black crappie Pomoxis nigromaculatus, and largemouth bass Micropterus salmoides showed a capacity to osmoregulate and survive for up to 30 d at pH 4.5 and above. Juvenile yellow perch Perca flavescens maintained osmoregulatory control through 58 d at pH 5.0. All four species lost osmoregulatory control at pH 4.0, and death of fish ensued within a few days after blood osmolality declined to about 200 mosmol/kg or less (normal values, about 300 mosmol/kg). After 58 d of exposuremore » of pH 4.0, mean blood osmolality of yellow perch was 218 mosmol/kg, and these fish were severely emaciated and moribund. Rock bass, black crappie, and largemouth bass all died by days 29, 16, and 9, respectively, when exposed to pH 4.0. Examination of gills showed progressively increased pathology with longer exposures to lower than normal pH. Among fish exposed to low pH, gill hyperplasia was present most often, but epithelial hypertrophy, chloride-cell proliferation, chloride-cell degeneration, edema, and vacuolization of the tissues also were observed. Morphological changes that were observed in the three centrarchids at pH values above pH 4.0 suggested that gill pathology may be a more sensitive indicator of potentially lethal acid stress than blood osmolality.« less

Ultra-Deep Drilling Cost Reduction; Design and Fabrication of an Ultra-Deep Drilling Simulator (UDS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindstrom, Jason

2010-01-31

Ultra-deep drilling, below about 20,000 ft (6,096 m), is extremely expensive and limits the recovery of hydrocarbons at these depths. Unfortunately, rock breakage and cuttings removal under these conditions is not understood. To better understand and thus reduce cost at these conditions an ultra-deep single cutter drilling simulator (UDS) capable of drill cutter and mud tests to sustained pressure and temperature of 30,000 psi (207 MPa) and 482 °F (250 °C), respectively, was designed and manufactured at TerraTek, a Schlumberger company, in cooperation with the Department of Energy’s National Energy Technology Laboratory. UDS testing under ultra-deep drilling conditions offers anmore » economical alternative to high day rates and can prove or disprove the viability of a particular drilling technique or fluid to provide opportunity for future domestic energy needs.« less

Trends and Future Challenges in Sampling the Deep Terrestrial Biosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilkins, Michael J.; Daly, Rebecca; Mouser, Paula J.

2014-09-12

Research in the deep terrestrial biosphere is driven by interest in novel biodiversity and metabolisms, biogeochemical cycling, and the impact of human activities on this ecosystem. As this interest continues to grow, it is important to ensure that when subsurface investigations are proposed, materials recovered from the subsurface are sampled and preserved in an appropriate manner to limit contamination and ensure preservation of accurate microbial, geochemical, and mineralogical signatures. On February 20th, 2014, a workshop on “Trends and Future Challenges in Sampling The Deep Subsurface” was coordinated in Columbus, Ohio by The Ohio State University and West Virginia University faculty,more » and sponsored by The Ohio State University and the Sloan Foundation’s Deep Carbon Observatory. The workshop aims were to identify and develop best practices for the collection, preservation, and analysis of terrestrial deep rock samples. This document summarizes the information shared during this workshop.« less

Trends and future challenges in sampling the deep terrestrial biosphere.

PubMed

Wilkins, Michael J; Daly, Rebecca A; Mouser, Paula J; Trexler, Ryan; Sharma, Shihka; Cole, David R; Wrighton, Kelly C; Biddle, Jennifer F; Denis, Elizabeth H; Fredrickson, Jim K; Kieft, Thomas L; Onstott, Tullis C; Peterson, Lee; Pfiffner, Susan M; Phelps, Tommy J; Schrenk, Matthew O

2014-01-01

Research in the deep terrestrial biosphere is driven by interest in novel biodiversity and metabolisms, biogeochemical cycling, and the impact of human activities on this ecosystem. As this interest continues to grow, it is important to ensure that when subsurface investigations are proposed, materials recovered from the subsurface are sampled and preserved in an appropriate manner to limit contamination and ensure preservation of accurate microbial, geochemical, and mineralogical signatures. On February 20th, 2014, a workshop on "Trends and Future Challenges in Sampling The Deep Subsurface" was coordinated in Columbus, Ohio by The Ohio State University and West Virginia University faculty, and sponsored by The Ohio State University and the Sloan Foundation's Deep Carbon Observatory. The workshop aims were to identify and develop best practices for the collection, preservation, and analysis of terrestrial deep rock samples. This document summarizes the information shared during this workshop.

Preparatory Drilling Test on Martian Target Windjana

NASA Image and Video Library

2014-04-30

NASA Curiosity Mars rover completed a shallow mini drill test April 29, 2014, in preparation for full-depth drilling at a rock target called Windjana. The hole results from the test is 0.63 inch across and about 0.8 inch deep.

Barbados: Architecture and implications for accretion

NASA Astrophysics Data System (ADS)

Speed, R. C.; Larue, D. K.

1982-05-01

The island of Barbados exposes the crestal zone of the remarkably broad accretionary prism of the Lesser Antilles foreacrc. The architecture of Barbados is three-tiered: an upper arched cap of Pleistocene reefs that record rapid and differential uplift of the island, an intermediate zone of nappes of mainly abyssal or deep bathyal pelagic rocks, and a basal complex whose lithotypes extend to substantial depth and may be representative of the bulk of the western or inner accretionary prism. The exposed basal complex consists of generally steeply dipping ENE to NE-striking fault-bounded packets which contain rocks of one of three lithic suites: terrigenous (quartzose turbidite and mudstone), debris flow, and hemipelagic (chiefly radiolarite). Present but imcomplete rock dating indicates that the terrigenous and hemipelagic suites and the pelagic rocks of the intermediate zone are age overlapping in Early and Middle Eocene time. Deformation within packets of the basal complex is systematic, pre- or synfault, and indicative of shortening that is generally normal to packet boundaries. A unit of terrigenous materials that probably underwent local resedimentation in the Miocene is recognized in wells, but its relationship to exposed rocks is uncertain. The packet-bounding faults of the basal complex are interpreted to have been primary accretionary surfaces which may have been reactivated by later intraprism movements. Exposed sedimentary rocks of Barbados can be successfully assigned to contemporaneous depositional sites associated with an accretionary prism: terrigenous beds to a trench wedge that was connected to South American sediment sources, debris flow to trench floor or slope basin accumulations of material derived from the lower slope, hemipelagic to Atlantic plain strata, and pelagic rocks of the intermediate zone to deep outer forearc basin sites. The decollement at the base of the intermediate zone is probably due to uplift and arcward motion of the crestal zone of the accretionary prism with respect to the forearc basin during progressive prism growth. Principal uplift of the prism seems to have started, apparently abruptly, in the Miocene. Quaternary uplift of Barbados may be due partly to local diapirism. Paleogene subduction that created the arcward region of the prism probably occurred in a differently configured zone from the present one.

Maastrichtian sedimentation and palaeoenvironments of the Saratov Volga region

NASA Astrophysics Data System (ADS)

Iakovishina, Elena; Blinova, Irina; Kopaevich, Ludmila; Vishnevskaya, Valentina; Bordunov, Sergey

2016-04-01

The Saratov Volga region was a shallow-marine epicontinental basin North-Eastern shelf zone of the Tethys Ocean in the Maastrichtian. The basis for the modeling conditions of sedimentation was the detection mineral composition of rocks, as well as the contents of various chemical elements in rocks in three reference sections: Lower Bannovka, quarries "Bolshevik" and "Kommunar". Rocks of quarries "Bolshevik" and "Kommunar" characterized by quartz-calcite mineral association. The main rock-forming mineral is calcite, small amounts in rocks contain quartz. Other mineral composition characterized section Lower Bannovka. At the base of the section in the rock marked the presence of the opal. The source of silica are radiolarians. Favorable conditions for the existence of which is cold deep water enriched with SiO2. Above the section marked authigenic glauconite, which are confined to zones of skip in sedimentation.Further up begins to dominate the accumulation of calcite with rich bentic foraminifera. Clay minerals in rocks of the section Lower Bannovka presented montmorillonite and illite. The relationship of chemical elements and their alkali modules allow to detail the conditions of sedimentation. The ratio of Fe/Mn in them varies from 44 to 5729. Higher values are characteristic of glauconite sandstones. Up the section marked decrease in the Ti/Zr, indicating that the increase in the distance from the source area to the place of deposition. The similarity values of the ratio Ti/Zr samples indicates a community source area. Sedimentation Model revealed the impact of the PreUral strait connecting Tethys and Paleoarktic. Through the Strait of deep cold water saturated with SiO2, penetrated into the of the Saratov Volga region, were accumulated clay. The closing of the PreUral Strait changed the conditions of sedimentation, the associated fall in sea levels due to global cooling reflected in the crisis of radiolarians, increase in the number of glauconite. Subsequent warming and warm-water transgression caused dominance of carbonates. The work was supported by grants 15-05-04990, 15-05-04700 Russian Foundation for Basic Research and IGCP project 609.

Plutonism at Different Crustal Levels of an Arc: Insights From the 5 to 40 km (Paleodepth) North Cascades Crustal Section, Washington

NASA Astrophysics Data System (ADS)

Miller, R. B.; Paterson, S. R.; Matzel, J. P.

2008-12-01

The crystalline core of the North Cascades preserves a Cretaceous crustal section that facilitates evaluation of pluton construction, emplacement, geometry, composition, and deformation at widely variable crustal levels (~5 to 40 km paleodepth) in a thick (> 55 km) continental magmatic arc. The oldest and largest pulse of plutonism was focused between 96-89 Ma when fluxes were a minimum of 3.9x10-6km3/yr/km of arc length, but the coincidence with regional crustal thickening and underthrusting of a cool outboard terrane resulted in relatively low mid- to deep-crustal temperatures for an arc. A second, smaller peak of magmatism at 78-71 Ma (minimum of 8.2x10-7km3/yr/km of arc length) occurred during regional transpression. Tonalite dominates at all levels of the section. Intrusions range from large plutons to thin (< 50 m) dispersed sheets encased in metamorphic rocks that record less focused magmatism. The percentage of igneous rocks increases systematically from shallow to middle to deep levels; from approximately 37% to 55% to 65% of the total rock volume. Unfocused magmas comprise much higher percentages (approximately 19%) of the total plutonic rock at deep- and mid-crustal depths, but only 1% at shallower levels, whereas the largest intrusions were emplaced into shallow crust. Plutons have a range of shapes, including: asymmetric wedges to funnels; subhorizontal tabular sheets; steep-sided, blade-shaped bodies with high aspect ratios in map view; and steep-sided, vertically extensive (> 8 km) bodies shaped like thick disks and/or hockey pucks. Sheeted intrusions and gently dipping tabular bodies are more common with depth. Some of these plutons fit the model that most intrusions are subhorizontal and tabular, but many do not, reflecting the complex changes in lithology and rheology in arc crust undergoing regional shortening. The steep sheeted plutons partly represent magma transfer zones that fed the large shallow plutons, which were sites of intermittent magma accumulation for up to 5.5 m.y. Downward movement of host rocks by multiple processes occurred at all crustal levels during pluton emplacement. Ductile flow and accompanying rigid rotation were the dominant processes; stoping played an important secondary role, and magma wedging and regional deformation also aided emplacement. Overall, there are some striking changes with increasing depth, but many features and processes in the arc are similar throughout the crustal section, probably reflecting the relatively small differences in peak temperatures between the mid- and deep crust. Such patterns may be representative of thick continental magmatic arcs constructed during regional shortening.

Geologic influence on induced seismicity: Constraints from potential field data in Oklahoma

USGS Publications Warehouse

Shah, Anjana K.; Keller, G. Randy

2017-01-01

Recent Oklahoma seismicity shows a regional correlation with increased wastewater injection activity, but local variations suggest that some areas are more likely to exhibit induced seismicity than others. We combine geophysical and drill hole data to map subsurface geologic features in the crystalline basement, where most earthquakes are occurring, and examine probable contributing factors. We find that most earthquakes are located where the crystalline basement is likely composed of fractured intrusive or metamorphic rock. Areas with extrusive rock or thick (>4 km) sedimentary cover exhibit little seismicity, even in high injection rate areas, similar to deep sedimentary basins in Michigan and western North Dakota. These differences in seismicity may be due to variations in permeability structure: within intrusive rocks, fluids can become narrowly focused in fractures and faults, causing an increase in local pore fluid pressure, whereas more distributed pore space in sedimentary and extrusive rocks may relax pore fluid pressure.

Deposition and deformation of stratified rocks in the northern Nia Mensa region of Valles Marineris, Mars

NASA Astrophysics Data System (ADS)

Okubo, C. H.

2016-12-01

Large-scale structural and geologic mapping based on HiRISE (High Resolution Imaging Science Experiment) digital elevation models reveals new details of the depositional environment for the stratified rocks in the northern Nia Mensa region of eastern Candor Chasma, Valles Marineris, Mars. The map area encompasses the contact between massive sedimentary rocks that comprise most of Nia Mensa and the stratified sedimentary and mass-wasting deposits exposed between Nia Mensa and the north wall of eastern Candor Chasma. The area contains a stratified fan-like deposit on the lower slopes of Nia Mensa. The strata within this deposit dip outward at < 10°, away from its morphologic apex, consistent with an origin as a depositional fan (rather than being carved into a fan shape by erosion). Whether this fan has a subaerial or submarine origin has not yet been determined. Additionally, the fan and surrounding stratified rocks exhibit evidence of soft-sediment deformation in the form of clastic dikes and contorted bedding, indicating that these deposits were water-saturated at the time of deformation. Finally, the northern section of the map area encompasses part of a fractured rise, and deposits interpreted as mud flows mantle the top of this rise. Inferred flow directions suggest that the mud erupted out of these fractures. These findings place constraints on the depositional environment of the local stratified bedrock. The presence of the fan deposit indicates that lateral transport was a component in the depositional history of these sediments. Therefore the sediments did not form entirely as a mantling deposit, such as air fall ash or sediments settled out of a water column. The soft-sediment deformation and subsurface mobilized sediments indicate that groundwater was present in the area after emplacement of the stratified deposits, but before its lithification. These findings point to a wet-playa to lacustrine depositional environment.

Preliminary view of geotechnical properties of soft rocks of Semanggol formation at Pokok Sena, Kedah

NASA Astrophysics Data System (ADS)

Ahmad, N. R.; Jamin, N. H.

2018-04-01

The research was inspired by series of geological studies on Semanggol formation found exposed at North Perak, South Kedah and North Kedah. The chert unit comprised interbedded chert-shale rocks are the main lithologies sampled in a small-scale outcrop of Pokok Sena area. Black shale materials were also observed associated with these sedimentary rocks. The well-known characteristics of shale that may swell when absorb water and leave shrinkage when dried make the formation weaker when load is applied on it. The presence of organic materials may worsen the condition apart from the other factors such as the history of geological processes and depositional environment. Thus, this research is important to find the preliminary relations of the geotechnical properties of soft rocks and the geological reasoning behind it. Series of basic soil tests and 1-D compression tests were carried out to obtain the soil parameters. The results obtained gave some preliminary insight to mechanical behaviour of these two samples. The black shale and weathered interbedded chert-shale were classified as sandy-clayey-SILT and clayey-silty-SAND respectively. The range of specific gravity of black shale and interbedded chert/shale 2.3 – 2.6 and fall in the common range of shale and chert specific gravity value. In terms of degree of plasticity, the interbedded chert/shale samples exhibit higher plastic degree compared to the black shale samples. Results from oedometer tests showed that black shale samples had higher overburden pressure (Pc) throughout its lifetime compare to weathered interbedded chert-shale, however the compression index (Cc) of black shale were 0.15 – 0.185 which was higher than that found in interbedded chert-shale. The geotechnical properties of these two samples were explained in correlation with their provenance and their history of geological processes involved which predominantly dictated the mechanical behaviour of these two samples.

Biodiversity and community composition of sediment macrofauna associated with deep-sea Lophelia pertusa habitats in the Gulf of Mexico

USGS Publications Warehouse

Demopoulos, Amanda W.J.; Bourque, Jill R.; Frometa, Janessy

2014-01-01

Scleractinian corals create three-dimensional reefs that provide sheltered refuges, facilitate sediment accumulation, and enhance colonization of encrusting fauna. While heterogeneous coral habitats can harbor high levels of biodiversity, their effect on the community composition within nearby sediments remains unclear, particularly in the deep sea. Sediment macrofauna from deep-sea coral habitats (Lophelia pertusa) and non-coral, background sediments were examined at three sites in the northern Gulf of Mexico (VK826, VK906, MC751, 350–500 m depth) to determine whether macrofaunal abundance, diversity, and community composition near corals differed from background soft-sediments. Macrofaunal densities ranged from 26 to 125 individuals 32 cm−2 and were significantly greater near coral versus background sediments only at VK826. Of the 86 benthic invertebrate taxa identified, 16 were exclusive to near-coral habitats, while 14 were found only in background sediments. Diversity (Fisher’s α) and evenness were significantly higher within near-coral sediments only at MC751 while taxon richness was similar among all habitats. Community composition was significantly different both between near-coral and background sediments and among the three primary sites. Polychaetes numerically dominated all samples, accounting for up to 70% of the total individuals near coral, whereas peracarid crustaceans were proportionally more abundant in background sediments (18%) than in those near coral (10%). The reef effect differed among sites, with community patterns potentially influenced by the size of reef habitat. Taxon turnover occurred with distance from the reef, suggesting that reef extent may represent an important factor in structuring sediment communities near L. pertusa. Polychaete communities in both habitats differed from other Gulf of Mexico (GOM) soft sediments based on data from previous studies, and we hypothesize that local environmental conditions found near L. pertusa may influence the macrofaunal community structure beyond the edges of the reef. This study represents the first assessment of L. pertusa-associated sediment communities in the GOM and provides baseline data that can help define the role of transition zones, from deep reefs to soft sediments, in shaping macrofaunal community structure and maintaining biodiversity; this information can help guide future conservation and management activities.

Monitoring of waste disposal in deep geological formations

NASA Astrophysics Data System (ADS)

German, V.; Mansurov, V.

2003-04-01

In the paper application of kinetic approach for description of rock failure process and waste disposal microseismic monitoring is advanced. On base of two-stage model of failure process the capability of rock fracture is proved. The requests to monitoring system such as real time mode of data registration and processing and its precision range are formulated. The method of failure nuclei delineation in a rock masses is presented. This method is implemented in a software program for strong seismic events forecasting. It is based on direct use of the fracture concentration criterion. The method is applied to the database of microseismic events of the North Ural Bauxite Mine. The results of this application, such as: efficiency, stability, possibility of forecasting rockburst are discussed.

The south-central United States magnetic anomaly

NASA Technical Reports Server (NTRS)

Hinze, W. J.; Braile, L. W. (Principal Investigator); Starich, P. J.

1984-01-01

The South-Central United States Magnetic Anomaly is the most prominent positive feature in the MAGSAT scalar magnetic field over North America. The anomaly correlates with increased crustal thickness, above average crustal velocity, negative free air gravity anomalies and an extensive zone of Middle Proterozoic anorogenic felsic basement rocks. Spherical dipole source inversion of the MAGSAT scalar data and subsequent calculation of reduced to pole and derivative maps provide constraints for a crustal magnetic model which corresponds geographically to the extensive Middle Proterozoic felsic rocks trending northeasterly across the United States. These felsic rocks contain insufficient magnetization or volume to produce the anomaly, but are rather indicative of a crustal zone which was disturbed during a Middle Proterozoic thermal event which enriched magnetic material deep in the crust.

CITICO CREEK WILDERNESS STUDY AREA, TENNESSEE.

USGS Publications Warehouse

Slack, John F.; Behum, Paul T.

1984-01-01

A mineral-resource survey of the Citico Creek Wilderness Study Area, in easternmost Tennessee, indicated that the area offers little promise for the occurrence of metallic mineral resources. Geochemical sampling found traces of gold, copper, cobalt, barium, arsenic, lead, zinc, and thorium in rocks, stream sediments, and panned concentrates, but not in sufficient quantities to indicate the presence of metallic mineral deposits. The only apparent resources are nonmetallic commodities including rock suitable for construction materials, and small amounts of sand and gravel; however, these commodities are found in abundance outside the study area. The potential for oil and natural gas at great depths could not be evaluated by this study. Deep drilling would test the potential for hydrocarbon resources underlying the metamorphic rocks.

Angiofibroma of soft tissue: clinicopathologic study of 2 cases of a recently characterized benign soft tissue tumor.

PubMed

Zhao, Ming; Sun, Ke; Li, Changshui; Zheng, Jiangjiang; Yu, Jingjing; Jin, Jie; Xia, Wenping

2013-01-01

Angiofibroma of soft tissue is a very recently characterized, histologically distinctive benign mesenchymal neoplasm of unknown cellular origin composed of 2 principal components, the spindle cell component and very prominent stromal vasculatures. It usually occurs in middle-aged adults, with a female predominance. Herein, we describe the clinical and pathologic details of 2 other examples of this benign tumor. Both patients were middle-aged male and presented with a slow-growing, painless mass located in the deep-seated soft tissue of thigh and left posterior neck region, respectively. Grossly, both tumors were well-demarcated, partial encapsulated of a grayish-white color with firm consistence. Histologically, one case showed morphology otherwise identical to those have been described before, whereas the other case showed in areas being more cellular than most examples of this subtype tumor had, with the lesional cells frequently exhibiting short fascicular, vaguely storiform and occasionally swirling arrangements, which posed a challenging differential diagnosis. Immunostains performed on both tumors did not confirm any specific cell differentiation with lesional cells only reactive for vimentin and focally desmin and negative for all the other markers tested. This report serves to broaden the morphologic spectrum of angiofibroma of soft tumor. Awareness of this tumor is important to prevent misdiagnosis as other more aggressive soft tissue tumor.

The use of differential scintigraphy in the clinical diagnosis of osseous and soft tissue changes affecting the diabetic foot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Visser, H.J.; Jacobs, A.M.; Oloff, L.

Prompt recognition of cellulitis, osteomyelitis, diabetic osteolysis, Charcot neuroarthropathy, septic synovitis, and deep plantar abscesses in the diabetic foot is essential because the therapy is drastically different. Differential diagnosis has been greatly facilitated by recently developed scanning techniques.

Physical properties of sidewall cores from Decatur, Illinois

USGS Publications Warehouse

Morrow, Carolyn A.; Kaven, Joern; Moore, Diane E.; Lockner, David A.

2017-10-18

To better assess the reservoir conditions influencing the induced seismicity hazard near a carbon dioxide sequestration demonstration site in Decatur, Ill., core samples from three deep drill holes were tested to determine a suite of physical properties including bulk density, porosity, permeability, Young’s modulus, Poisson’s ratio, and failure strength. Representative samples of the shale cap rock, the sandstone reservoir, and the Precambrian basement were selected for comparison. Physical properties were strongly dependent on lithology. Bulk density was inversely related to porosity, with the cap rock and basement samples being both least porous (

Laboratory experiments duplicate conditions in the Earth’s crust

USGS Publications Warehouse

Peselnick, L.; Dieterich, J.H.; Stewart, R.M.

1974-01-01

An experimental device that simulates conditions in the Earth's crust at depths of up to 30 kilometers has been constructed by geophysicists working at the U.S Geological Survey laboratories in Menlo Park, California. A high pressure "bomb" is being used to experimentally measure the velocity of seismic waves in different types of rock at various confining pressures and temperatures. The principal purpose of these measurements is to determine the elastic and non-elastic properties of rocks and minerals under conditions of high-pressure such as exist deep in the Earth's crust. 

GANSEKI: JAMSTEC Deep Seafloor Rock Sample Database Emerging to the New Phase

NASA Astrophysics Data System (ADS)

Tomiyama, T.; Ichiyama, Y.; Horikawa, H.; Sato, Y.; Soma, S.; Hanafusa, Y.

2013-12-01

Japan Agency for Marine-Earth Science and Technology (JAMSTEC) collects a lot of substantial samples as well as various geophysical data using its research vessels and submersibles. These samples and data, which are obtained by spending large amounts of human and physical resources, are precious wealth of the world scientific community. For the better use of these samples and data, it is important that they are utilized not only for initial purpose of each cruse but also for other general scientific and educational purposes of second-hand users. Based on the JAMSTEC data and sample handling policies [1], JAMSTEC has systematically stored samples and data obtained during research cruises, and provided them to domestic/foreign activities on research, education, and public relation. Being highly valued for second-hand usability, deep seafloor rock samples are one of the most important types of samples obtained by JAMSTEC, as oceanic biological samples and sediment core samples are. Rock samples can be utilized for natural history sciences and other various purposes; some of these purposes are connected to socially important issues such as earthquake mechanisms and mineral resource developments. Researchers and educators can access to JAMSTEC rock samples and associated data through 'GANSEKI [2]', the JAMSTEC Deep Seafloor Rock Sample Database. GANSEKI was established on the Internet in 2006 and its contents and functions have been continuously enriched and upgraded since then. GANSEKI currently provides 19 thousands of sample metadata, 9 thousands of collection inventory data and 18 thousands of geochemical data. Most of these samples are recovered from the North-western Pacific Ocean, although samples from other area are also included. The major update of GANSEKI held in May 2013 involved a replacement of database core system and a redesign of user interface. In the new GANSEKI, users can select samples easily and precisely using multi-index search, numerical constraints on geochemical data and thumbnail browsing of sample and thin-section photos. 'MyList' function allows users to organize, compare and download the data of selected samples. To develop a close network among online databases, the new GANSEKI allows multiple URL entries for individual samples. Now the curatorial staffs are working for maintaining references to other JAMSTEC databases such as 'DARWIN [3]' and 'J-EDI [4]'.

Oxygen isotope evidence for submarine hydrothermal alteration of the Del Puerto ophiolite, California

USGS Publications Warehouse

Schiffman, P.; Williams, A.E.; Evarts, R.C.

1984-01-01

The oxygen isotope compositions and metamorphic mineral assemblages of hydrothermally altered rocks from the Del Puerto ophiolite and overlying volcaniclastic sedimentary rocks at the base of the Great Valley sequence indicate that their alteration occurred in a submarine hydrothermal system. Whole rock ??18O compositions decrease progressively down section (with increasing metamorphic grade): +22.4??? (SMOW) to +13.8 for zeolite-bearing volcaniclastic sedimentary rocks overlying the ophiolite; +19.6 to +11.6 for pumpellyite-bearing metavolcanic rocks in the upper part of the ophiolite's volcanic member; +12.3 to +8.1 for epidote-bearing metavolcanic rocks in the lower part of the volcanic member; +8.5 to +5.7 for greenschist facies rocks from the ophiolite's plutonic member; +7.6 to +5.8 for amphibolite facies or unmetamorphosed rocks from the plutonic member. Modelling of fluid-rock interaction in the Del Puerto ophiolite indicates that the observed pattern of upward enrichment in whole rock ??18O can be best explained by isotopic exchange with discharging 18O-shifted seawater at fluid/rock mass ratios near 2 and temperatures below 500??C. 18O-depleted plutonic rocks necessarily produced during hydrothermal circulation were later removed as a result of tectonism. Submarine weathering and later burial metamorphism at the base of the Great Valley sequence cannot by itself have produced the zonation of hydrothermal minerals and the corresponding variations in oxygen isotope compositions. The pervasive zeolite and prehnite-pumpellyite facies mineral assemblages found in the Del Puerto ophiolite may reflect its origin near an island arc rather than deep ocean spreading center. ?? 1984.

Badlands in humid regions - redbed desertification in Nanxiong Basin, China

NASA Astrophysics Data System (ADS)

Yan, Luobin; Hua, Peng; Simonson, Scott

2016-04-01

The redbed badlands in Nanxiong City, China, well represent badlands in humid regions. The erosion rate in humid regions is much higher than that in arid regions and can reach 1 cm per month during the summer. The purpose of this study is to introduce the research of badlands in China, which have not been extensively studied so far, and to compare the badlands between arid and humid regions. Furthermore, the aim is to study the impact of mineralogical and chemical composition on the disintegration of soft rock in Nanxiong Basin badlands. For the purpose of this study field observations, sampling, and digging profiles were done. The mineralogical and chemical compositions of the Nanxiong Basin badland lithologies were determined by XRD, XRF and thin sections. Weathering resistance, process of weathering, and disintegration features were studied by weathering experiments under natural conditions. Weathering profiles can be easily divided into four layers: regolith, a strongly weathered layer, a poorly weathered layer, and an unweathered sediment. The depth of the weathering profile is influenced by the weathering resistance of the soft rock. Weathering resistance affects the erosion rate and evolution of landforms in badlands by influencing the rate from unweathered rock to regolith. Analyzed sediments have high content of illite and illite-smectite interstratifications. This composition of clay minerals together with poor sediment consolidation jointly leads to weathering prone sediment. The weathering and disintegration of soft rock in Nanxiong Basin badlands has a close relationship with rainfall. Sheet erosion, a kind of solid-liquid phase flow, formed in the regolith of the badland during rainfall events and can be the most instrumental to erosion. The mineral composition and liquidity plasticity index were also analyzed, and the results show that the regolith are low liquid limit silts with liquid limit of 21%-25%, plastic limit of 13%-18% and plasticity index of 6.5%-11%. Sheet erosion will occur when rainfall splash destroys the original structure of the badland slopes with the impermeable siltstone underneath and with the high porosity regolith. In China, the badlands in redbed areas have been called the extreme "redbed desertification". Our preliminary research concerning Nanxiong Basin badlands puts forward the concepts of "redbed deserts" and "redbed desertification". Based on the field work, the mechanism of redbed desertification depends on the lithological features, natural impacts, and human activities. The trigger for formation of the redbed badlands desertification are complex, but mainly influenced by activities such as severe reclamation, forest fires, tree planting disturbances, dry-land degradation, acquirement of topsoil, etc.

Changes in Alaskan soft-bottom prey communities along a gradient in sea otter predation

USGS Publications Warehouse

Kvitek, R.G.; Oliver, J.S.; DeGange, A.R.; Anderson, B.S.

1992-01-01

Sea Otter (Enhydra lutris), well documented as "keystone" predators in rocky marine communities, were found to exert a strong influence on infaunal prey communities in soft-sediment habitats. Direct and indirect effects of sea otter predation on subtidal soft-bottom prey communities were evaluated along a temporal gradient of sea otter occupancy around the Kodiak Archipelago. The results indicate that Kodiak otters forage primarily on bivalve prey and dramatically reduce infaunal bivalve and green sea urchin (Strongylocentrotus droebachiensis) prey populations. Bivalve prey abundance, biomass, and size were inversely related to duration of sea otter occupancy. The relative conditions of shells discarded by otters in shallow (<10 m) vs. deep (> 20 m) water at the same sites indicate that otters first exploited Saxidomus in shallow-water feeding areas, and later switched to Macoma spp. in deeper water. Otter-cracked shells of the deep-burrowing clam Tresus capax were rarely found, even at otter foraging sites where the clam accounted for the majority of available prey biomass, suggesting that it has a partial depth refuge from otter predation. The indirect effects of otter predation included substratum disturbance and the facilitation of sea star predation on infaunal prey. Sea stars, Pycnopodia helianthoides, were attracted to experimentally dug excavations as well as natural sea otter foraging pits, where the sea stars foraged on smaller size classes of infaunal bivalves than those eaten by otters. Otters also discard clam shells on the sediment surface and expose old, buried shells during excavation. Surface shells were found to provide attachment sites for large anemones and kelp. Our study shows that sea otters can affect soft-sediment communities, not only through predation, as in rocky habitats, but also through disturbance, and thus retain a high degree of influence in two very different habitat types.

Lithology and mineralogy recognition from geochemical logging tool data using multivariate statistical analysis.

PubMed

Konaté, Ahmed Amara; Ma, Huolin; Pan, Heping; Qin, Zhen; Ahmed, Hafizullah Abba; Dembele, N'dji Dit Jacques

2017-10-01

The availability of a deep well that penetrates deep into the Ultra High Pressure (UHP) metamorphic rocks is unusual and consequently offers a unique chance to study the metamorphic rocks. One such borehole is located in the southern part of Donghai County in the Sulu UHP metamorphic belt of Eastern China, from the Chinese Continental Scientific Drilling Main hole. This study reports the results obtained from the analysis of oxide log data. A geochemical logging tool provides in situ, gamma ray spectroscopy measurements of major and trace elements in the borehole. Dry weight percent oxide concentration logs obtained for this study were SiO 2 , K 2 O, TiO 2 , H 2 O, CO 2 , Na 2 O, Fe 2 O 3 , FeO, CaO, MnO, MgO, P 2 O 5 and Al 2 O 3 . Cross plot and Principal Component Analysis methods were applied for lithology characterization and mineralogy description respectively. Cross plot analysis allows lithological variations to be characterized. Principal Component Analysis shows that the oxide logs can be summarized by two components related to the feldspar and hydrous minerals. This study has shown that geochemical logging tool data is accurate and adequate to be tremendously useful in UHP metamorphic rocks analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Organic geochemistry of sediments of deep Gulf of Mexico basin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, J.; Sassen, R.; Nunn, J.

1989-09-01

An analysis of 716 core samples from DSDP (Deep Sea Drilling Project) Leg 96 in the Mississippi submarine fan and the Orca and Pigmy basins in the Louisiana continental slope was done using a Rock-Eval pyrolysis unit with TOC (total organic carbon) module. The analysis allows computation of the hydrogen index (HI), TOC, and kerogen type, and assessment of the oil-generative capacity of the sediments in the Louisiana continental slope. No samples are obviously oil prone. TOC content ranges from 0.12 to 2.29%, with an overall average of 0.82%. HI values are generally less than 150 mg HC/g TOC. T{submore » max} (temperature of the maximum of the S{sub 2} peak) values (425{degree}C average) show the sediments are immature throughout the study area. Hydrocarbon-generative potential of the sediments ranges from 492 to 1,107 ppm, with an average of 854 ppm. Because of organic lean, thermally immature, and gas-prone terrestrial organic matter, there is little reason to assume that the sediments from the Mississippi fan can provide oil source rock for the Gulf Coast basin, and that sediments of anoxic basins in the Louisiana continental slope are analogs to the past environments where source rocks for crude oil have been deposited.« less

Kamenetsk—A new impact structure in the Ukrainian Shield

NASA Astrophysics Data System (ADS)

Gurov, Eugene; Nikolaenko, Nikolay; Shevchuk, Helena; Yamnichenko, Anatoly

2017-12-01

The Kamenetsk impact structure is a deeply eroded simple crater that formed in crystalline rocks of the Ukrainian Shield. This study presents structural, lithologic, and shock metamorphic evidence for an impact origin of the Kamenetsk structure, which was previously described as a paleovolcano. The Kamenetsk structure is an oval depression that is 1.0-1.2 km in diameter and 130 m deep. The structure is deeply eroded, and only the lower part of the sequence of lithic breccia has been preserved in the deepest part of the crater to recent time, while the predominant part of impact rocks and postimpact sediments was eroded. Manifestations of shock metamorphism of minerals, especially planar deformation features in quartz and feldspars, were determined by petrographic investigations of lithic breccia that allowed us to determine the impact origin of the Kamenetsk structure. The erosion of the crater and surrounding target to a minimal depth of 220 m preceded the deposition of the postimpact sediments. The time of the formation of the Kamenetsk structure is bracketed within a wide interval from 2.0 to 2.1 Ga, the age of the crystalline target rocks, to the Late Miocene age of the sediments overlaying the crater. The deep erosion of the structure suggests it is probably Paleozoic in age.

Gravity modeling finds a large magma body in the deep crust below the Gulf of Naples, Italy.

PubMed

Fedi, M; Cella, F; D'Antonio, M; Florio, G; Paoletti, V; Morra, V

2018-05-29

We analyze a wide gravity low in the Campania Active Volcanic Area and interpret it by a large and deep source distribution of partially molten, low-density material from about 8 to 30 km depth. Given the complex spatial-temporal distribution of explosive volcanism in the area, we model the gravity data consistently with several volcanological and petrological constraints. We propose two possible models: one accounts for the coexistence, within the lower/intermediate crust, of large amounts of melts and cumulates besides country rocks. It implies a layered distribution of densities and, thus, a variation with depth of percentages of silicate liquids, cumulates and country rocks. The other reflects a fractal density distribution, based on the scaling exponent estimated from the gravity data. According to this model, the gravity low would be related to a distribution of melt pockets within solid rocks. Both density distributions account for the available volcanological and seismic constraints and can be considered as end-members of possible models compatible with gravity data. Such results agree with the general views about the roots of large areas of ignimbritic volcanism worldwide. Given the prolonged history of magmatism in the Campania area since Pliocene times, we interpret the detected low-density body as a developing batholith.

Lot A2 test, THC modelling of the bentonite buffer

NASA Astrophysics Data System (ADS)

Itälä, Aku; Olin, Markus; Lehikoinen, Jarmo

Finnish spent nuclear fuel is planned to be disposed of deep in the crystalline bedrock of the Olkiluoto island. In such a repository, the role of the bentonite buffer is considered to be central. The initially unsaturated bentonite emplaced around a spent-fuel canister will become fully saturated by the groundwater from the host rock. In order to assess the long-term safety of a deep repository, it is essential to determine how temperature influences the chemical stability of bentonite. The aim of this study was to achieve an improved understanding of the factors governing the thermo-hydro-chemical evolution of the bentonite buffer subject to heat generation from the disposed fuel and in contact with a highly permeable rock fracture intersecting a canister deposition hole. TOUGHREACT was used to model a test known as the long-term test of buffer material adverse-2, which was conducted at the Äspö hard rock laboratory in Sweden. The results on the evolution of cation-exchange equilibria, bentonite porewater chemistry, mineralogy, and saturation of the buffer are presented and discussed. The calculated model results show similarity to the experimental results. In particular, the spatial differences in the saturation and porewater chemistry of the bentonite buffer were clearly visible in the model.

Burial History, Thermal Maturity, and Oil and Gas Generation History of Source Rocks in the Bighorn Basin, Wyoming and Montana

USGS Publications Warehouse

Roberts, Laura N.R.; Finn, Thomas M.; Lewan, Michael D.; Kirschbaum, Mark A.

2008-01-01

Burial history, thermal maturity, and timing of oil and gas generation were modeled for seven key source-rock units at eight well locations throughout the Bighorn Basin in Wyoming and Montana. Also modeled was the timing of cracking to gas of Phosphoria Formation-sourced oil in the Permian Park City Formation reservoirs at two well locations. Within the basin boundary, the Phosphoria is thin and only locally rich in organic carbon; it is thought that the Phosphoria oil produced from Park City and other reservoirs migrated from the Idaho-Wyoming thrust belt. Other petroleum source rocks include the Cretaceous Thermopolis Shale, Mowry Shale, Frontier Formation, Cody Shale, Mesaverde and Meeteetse Formations, and the Tertiary (Paleocene) Fort Union Formation. Locations (wells) selected for burial history reconstructions include three in the deepest parts of the Bighorn Basin (Emblem Bench, Red Point/Husky, and Sellers Draw), three at intermediate depths (Amoco BN 1, Santa Fe Tatman, and McCulloch Peak), and two at relatively shallow locations (Dobie Creek and Doctor Ditch). The thermal maturity of source rocks is greatest in the deep central part of the basin and decreases to the south, east, and north toward the basin margins. The Thermopolis and Mowry Shales are predominantly gas-prone source rocks, containing a mix of Type-III and Type-II kerogens. The Frontier, Cody, Mesaverde, Meeteetse, and Fort Union Formations are gas-prone source rocks containing Type-III kerogen. Modeling results indicate that in the deepest areas, (1) the onset of petroleum generation from Cretaceous rocks occurred from early Paleocene through early Eocene time, (2) peak petroleum generation from Cretaceous rocks occurred during Eocene time, and (3) onset of gas generation from the Fort Union Formation occurred during early Eocene time and peak generation occurred from late Eocene to early Miocene time. Only in the deepest part of the basin did the oil generated from the Thermopolis and Mowry Shales start generating gas from secondary cracking, which occurred in the late Eocene to Miocene. Also, based on modeling results, gas generation from the cracking of Phosphoria oil reservoired in the Park City Formation began in the late Eocene in the deep part of the basin but did not anywhere reach peak generation.

Chlorine-36 tracing of salinity sources in the dry valleys of Victoria land, Antarctica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, C.A.; Phillips, F.M.; Elmore, D.

1990-02-01

Chlorine-36 was used to trace the origins of salts in six saline lakes in the Dry Valleys of Southern Victoria Land, Antarctica. Characteristic {sup 36}Cl signatures were estimated for the various potential chloride sources, which include atmospheric deposition, rock weathering, seawater, and deep ground water. {sup 36}Cl/Cl ratios were measured in natural waters and salts from the Dry Valleys. Dilute lake waters (Cl{sup {minus}} < 100 mg/l) were found to have {sup 36}Cl/Cl ratios in the range 100 {times} 10{sup {minus}15} to 1,700 {times} 10{sup {minus}15}, whereas saline waters (Cl{sup {minus}} > 1000 mg/l) had ratios in the range 9more » {times} 10{sup {minus}15} to 40 {times} 10{sup {minus}15}. Simple mixing models were employed to quantify the relative contributions of the various chloride sources to Lake Vanda and Don Juan Pond. These results show that Lake Vanda has received its chloride from both deep ground water and the Onyx River. Don Juan Pond has received nearly all its chloride from deep ground water, probably ultimately from rock-water interaction. Deep ground water is the principal sources of chloride to the lakes of Wright Valley. However, preliminary data suggest that marine-derived salts or relict sea water may be a significant sources of chloride to the lakes of Taylor Valley, implying a possible recent marine invasion that did not affect Wright Valley.« less

Impact disruption and recovery of the deep subsurface biosphere

USGS Publications Warehouse

Cockell, Charles S.; Voytek, Mary A.; Gronstal, Aaron L.; Finster, Kai; Kirshtein, Julie D.; Howard, Kieren; Reitner, Joachim; Gohn, Gregory S.; Sanford, Ward E.; Horton, J. Wright; Kallmeyer, Jens; Kelly, Laura; Powars, David S.

2012-01-01

Although a large fraction of the world's biomass resides in the subsurface, there has been no study of the effects of catastrophic disturbance on the deep biosphere and the rate of its subsequent recovery. We carried out an investigation of the microbiology of a 1.76 km drill core obtained from the ~35 million-year-old Chesapeake Bay impact structure, USA, with robust contamination control. Microbial enumerations displayed a logarithmic downward decline, but the different gradient, when compared to previously studied sites, and the scatter of the data are consistent with a microbiota influenced by the geological disturbances caused by the impact. Microbial abundance is low in buried crater-fill, ocean-resurge, and avalanche deposits despite the presence of redox couples for growth. Coupled with the low hydraulic conductivity, the data suggest the microbial community has not yet recovered from the impact ~35 million years ago. Microbial enumerations, molecular analysis of microbial enrichment cultures, and geochemical analysis showed recolonization of a deep region of impact-fractured rock that was heated to above the upper temperature limit for life at the time of impact. These results show how, by fracturing subsurface rocks, impacts can extend the depth of the biosphere. This phenomenon would have provided deep refugia for life on the more heavily bombarded early Earth, and it shows that the deeply fractured regions of impact craters are promising targets to study the past and present habitability of Mars.

Impact disruption and recovery of the deep subsurface biosphere.

PubMed

Cockell, Charles S; Voytek, Mary A; Gronstal, Aaron L; Finster, Kai; Kirshtein, Julie D; Howard, Kieren; Reitner, Joachim; Gohn, Gregory S; Sanford, Ward E; Horton, J Wright; Kallmeyer, Jens; Kelly, Laura; Powars, David S

2012-03-01

Although a large fraction of the world's biomass resides in the subsurface, there has been no study of the effects of catastrophic disturbance on the deep biosphere and the rate of its subsequent recovery. We carried out an investigation of the microbiology of a 1.76 km drill core obtained from the ∼35 million-year-old Chesapeake Bay impact structure, USA, with robust contamination control. Microbial enumerations displayed a logarithmic downward decline, but the different gradient, when compared to previously studied sites, and the scatter of the data are consistent with a microbiota influenced by the geological disturbances caused by the impact. Microbial abundance is low in buried crater-fill, ocean-resurge, and avalanche deposits despite the presence of redox couples for growth. Coupled with the low hydraulic conductivity, the data suggest the microbial community has not yet recovered from the impact ∼35 million years ago. Microbial enumerations, molecular analysis of microbial enrichment cultures, and geochemical analysis showed recolonization of a deep region of impact-fractured rock that was heated to above the upper temperature limit for life at the time of impact. These results show how, by fracturing subsurface rocks, impacts can extend the depth of the biosphere. This phenomenon would have provided deep refugia for life on the more heavily bombarded early Earth, and it shows that the deeply fractured regions of impact craters are promising targets to study the past and present habitability of Mars.

Use of groundwater lifetime expectancy for the performance assessment of a deep geologic radioactive waste repository: 2. Application to a Canadian Shield environment

NASA Astrophysics Data System (ADS)

Park, Y.-J.; Cornaton, F. J.; Normani, S. D.; Sykes, J. F.; Sudicky, E. A.

2008-04-01

F. J. Cornaton et al. (2008) introduced the concept of lifetime expectancy as a performance measure of the safety of subsurface repositories, on the basis of the travel time for contaminants released at a certain point in the subsurface to reach the biosphere or compliance area. The methodologies are applied to a hypothetical but realistic Canadian Shield crystalline rock environment, which is considered to be one of the most geologically stable areas on Earth. In an approximately 10 × 10 × 1.5 km3 hypothetical study area, up to 1000 major and intermediate fracture zones are generated from surface lineament analyses and subsurface surveys. In the study area, mean and probability density of lifetime expectancy are analyzed with realistic geologic and hydrologic shield settings in order to demonstrate the applicability of the theory and the numerical model for optimally locating a deep subsurface repository for the safe storage of spent nuclear fuel. The results demonstrate that, in general, groundwater lifetime expectancy increases with depth and it is greatest inside major matrix blocks. Various sources and aspects of uncertainty are considered, specifically geometric and hydraulic parameters of permeable fracture zones. Sensitivity analyses indicate that the existence and location of permeable fracture zones and the relationship between fracture zone permeability and depth from ground surface are the most significant factors for lifetime expectancy distribution in such a crystalline rock environment. As a consequence, it is successfully demonstrated that the concept of lifetime expectancy can be applied to siting and performance assessment studies for deep geologic repositories in crystalline fractured rock settings.

Apatite fission-track evidence of widespread Eocene heating and exhumation in the Yukon-Tanana Upland, interior Alaska

USGS Publications Warehouse

Dusel-Bacon, C.; Murphy, J.M.

2001-01-01

We present an apatite fission-track (AFT) study of five plutonic rocks and seven metamorphic rocks across 310 km of the Yukon-Tanana Upland in east-central Alaska. Samples yielding ???40 Ma AFT ages and mean confined track lengths > 14 ??m with low standard deviations cooled rapidly from >120??C to 40 Ma suggest partial annealing and, therefore, lower maximum temperatures (???90-105??C). A few samples with single-grain ages of ???20 Ma apparently remained above ???50??C after initial cooling. Although the present geothermal gradient in the western Yukon-Tanana Upland is ???32??C/km, it could have been as high as 45??C/km during a widespread Eocene intraplate magmatic episode. Prior to rapid exhumation, samples with ???40 Ma AFT ages were >3.8-2.7 km deep and samples with >50 Ma AFT ages were >3.3-2.0 km deep. We calculate a 440-320 m/Ma minimum rate for exhumation of all samples during rapid cooling. Our AFT data, and data from rocks north of Fairbanks and from the Eielson deep test hole, indicate up to 3 km of post-40 Ma vertical displacement along known and inferred northeast-trending high-angle faults. The predominance of 40-50 Ma AFT ages throughout the Yukon-Tanana Upland indicates that, prior to the post-40 Ma relative uplift along some northeast-trending faults, rapid regional cooling and exhumation closely followed the Eocene extensional magmatism. We propose that Eocene magmatism and exhumation were somehow related to plate movements that produced regional-scale oroclinal rotation, northward translation of outboard terranes, major dextral strike-slip faulting, and subduction of an oceanic spreading ridge along the southern margin of Alaska.

Reservoir Identification: Parameter Characterization or Feature Classification

NASA Astrophysics Data System (ADS)

Cao, J.

2017-12-01

The ultimate goal of oil and gas exploration is to find the oil or gas reservoirs with industrial mining value. Therefore, the core task of modern oil and gas exploration is to identify oil or gas reservoirs on the seismic profiles. Traditionally, the reservoir is identify by seismic inversion of a series of physical parameters such as porosity, saturation, permeability, formation pressure, and so on. Due to the heterogeneity of the geological medium, the approximation of the inversion model and the incompleteness and noisy of the data, the inversion results are highly uncertain and must be calibrated or corrected with well data. In areas where there are few wells or no well, reservoir identification based on seismic inversion is high-risk. Reservoir identification is essentially a classification issue. In the identification process, the underground rocks are divided into reservoirs with industrial mining value and host rocks with non-industrial mining value. In addition to the traditional physical parameters classification, the classification may be achieved using one or a few comprehensive features. By introducing the concept of seismic-print, we have developed a new reservoir identification method based on seismic-print analysis. Furthermore, we explore the possibility to use deep leaning to discover the seismic-print characteristics of oil and gas reservoirs. Preliminary experiments have shown that the deep learning of seismic data could distinguish gas reservoirs from host rocks. The combination of both seismic-print analysis and seismic deep learning is expected to be a more robust reservoir identification method. The work was supported by NSFC under grant No. 41430323 and No. U1562219, and the National Key Research and Development Program under Grant No. 2016YFC0601

A Proposed Borehole Scientific Laboratory in Quay County, New Mexico, USA

NASA Astrophysics Data System (ADS)

Nielson, Dennis; Eckels, Marc; Mast, Peter; Zellman, Mark; Creed, Robert

2017-04-01

Our team has received funding from the US Department of Energy to initiate a Deep Borehole Field Test that will develop a subsurface test site to evaluate the drilling and scientific aspects of deep borehole disposal of nuclear waste in crystalline rock. Phase 1 of the project will focus on Public Outreach and land acquisition whereas Phase 2 will generate a drilling and testing plan and secure regulatory approvals. Phase 3 will complete the Drilling and Testing Plan and Phase 4 will include the drilling and testing. Phase 5 will be devoted to borehole science and experiments with emplacement technology. Although we are specifically considering issues associated with the disposal of waste, this project is a proof of concept, and no waste will be emplaced at our site. In brief, the concept envisions an 8-1/2 inch open-hole completion at a depth of 5000 m in crystalline rock. There will be an extensive program of sample collection (including core) and analysis as well as geophysical logging and borehole testing. Critical issues will be low permeability in the crystalline rock as well as the ability to manage borehole quality. Our team has proposed a site in Quay County, New Mexico that has an 850 meter thick Paleozoic section overlying homogeneous Precambrian granite. A subsequent phase of the project may drill a second hole with a 17-1/2 inch completion located about 200 m from the first. Our long-term plan is that this site will be managed as a deep scientific observatory that also provides a facility for scientific experiments and testing of borehole infrastructure and drilling equipment.

A gas sampling system for withdrawing humid gases from deep boreholes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rousseau, J.P.; Thordarson, W.; Kurzmack, M.A.

A gas sampling system, designed to withdraw nearly vapor-saturated gases (93 to 100% relative humidity) from deep, unsaturated zone boreholes, was developed by the U.S. Geological Survey for use in the unsaturated zone borehole instrumentation and monitoring program at Yucca Mountain, Nye County, Nevada. This gas sampling system will be used to: (1) sample formation rock gases in support of the unsaturated zone hydrochemical characterization program; and (2) verify downhole, thermocouple psychrometer measurements of water potential in support of the unsaturated zone borehole instrumentation and monitoring program. Using this sampling system, nearly vapor-saturated formation rock-gases can be withdrawn from deepmore » boreholes without condensing water vapor in the sampling tubes, and fractionating heavy isotopes of oxygen, hydrogen, and carbon. The sampling system described in this paper uses a dry carrier-gas (nitrogen) to lower the dew point temperature of the formation rock-gas at its source. Mixing of the dry carrier gas with the source gas takes place inside a specially designed downhole instrument station apparatus (DISA). Nitrogen inflow is regulated in a manner that lowers the dew point temperature of the source gas to a temperature that is colder than the coldest temperature that the mixed gas will experience in moving from warmer, deeper depths, to colder, shallower depths near the land surface. A test of this gas sampling system was conducted in December, 1992, in a 12.2 meter deep borehole that was instrumented in October, 1991. The water potential calculated using this system reproduced in-situ measurements of water potential to within five percent of the average value, as recorded by two thermocouple psychrometers that had been in operation for over 12 months.« less

Qualitative and quantitative changes in detrital reservoir rocks caused by CO2-brine-rock interactions during first injection phases (Utrillas sandstones, northern Spain)

NASA Astrophysics Data System (ADS)

Berrezueta, E.; Ordóñez-Casado, B.; Quintana, L.

2016-01-01

The aim of this article is to describe and interpret qualitative and quantitative changes at rock matrix scale of lower-upper Cretaceous sandstones exposed to supercritical (SC) CO2 and brine. The effects of experimental injection of CO2-rich brine during the first injection phases were studied at rock matrix scale, in a potential deep sedimentary reservoir in northern Spain (Utrillas unit, at the base of the Cenozoic Duero Basin).

Experimental CO2-rich brine was exposed to sandstone in a reactor chamber under realistic conditions of deep saline formations (P ≈ 7.8 MPa, T ≈ 38 °C and 24 h exposure time). After the experiment, exposed and non-exposed equivalent sample sets were compared with the aim of assessing possible changes due to the effect of the CO2-rich brine exposure. Optical microscopy (OpM) and scanning electron microscopy (SEM) aided by optical image analysis (OIA) were used to compare the rock samples and get qualitative and quantitative information about mineralogy, texture and pore network distribution. Complementary chemical analyses were performed to refine the mineralogical information and to obtain whole rock geochemical data. Brine composition was also analyzed before and after the experiment.

The petrographic study of contiguous sandstone samples (more external area of sample blocks) before and after CO2-rich brine injection indicates an evolution of the pore network (porosity increase ≈ 2 %). It is probable that these measured pore changes could be due to intergranular quartz matrix detachment and partial removal from the rock sample, considering them as the early features produced by the CO2-rich brine. Nevertheless, the whole rock and brine chemical analyses after interaction with CO2-rich brine do not present important changes in the mineralogical and chemical configuration of the rock with respect to initial conditions, ruling out relevant precipitation or dissolution at these early stages to rock-block scale. These results, simulating the CO2 injection near the injection well during the first phases (24 h) indicate that, in this environment where CO2 enriches the brine, the mixture principally generates local mineralogical/textural re-adjustments on the external area of the samples studied.

The application of OpM, SEM and optical image analysis have allowed an exhaustive characterization of the sandstones studied. The procedure followed, the porosity characterization and the chemical analysis allowed a preliminary approximation of the CO2-brine-rock interactions and could be applied to similar experimental injection tests.

Xe isotopic constraints on cycling of deep Earth volatiles

NASA Astrophysics Data System (ADS)

Parai, R.; Mukhopadhyay, S.

2017-12-01

The modern deep Earth volatile budget reflects primordial volatiles delivered during accretion, radiogenic ingrowth of volatile species (e.g., 40Ar produced by 40K decay), outgassing in association with mantle processing, and regassing via subduction. The noble gases are unique volatile tracers in that they are chemically inert, but are thought to be trapped within hydrous alteration phases in downwelling lithologies. Noble gases thus provide a tracer of volatile transport between the deep Earth and surface reservoirs. Constraints on the fluxes of noble gases between deep Earth and surface reservoirs over time can accordingly be used to provide insight into temperature conditions at subduction zones, limits on volatile cycling, and the evolving distribution of major volatile species in terrestrial reservoirs over time. Xe isotope systematics in mantle-derived rocks show that 80-90% of the mantle Xe budget is derived from recycling of atmospheric Xe, indicating that atmospheric Xe is retained in subducting slabs beyond depths of magma generation in subduction zones over Earth history. We present an integrated model of Xe cycling between the mantle and atmosphere in association with mantle processing over Earth history. We test a wide variety of outgassing and regassing rates and take the evolution of the atmospheric Xe isotopic composition [e.g., 1] into account. Models in which the deep Earth transitions from a net outgassing to net regassing regime best satisfy Xe isotopic constraints from mantle-derived rocks [2-6]. [1] Avice et al., 2017; Nature Communications, 8; [2] Mukhopadhyay, 2012, Nature 486, 101-104; [3] Parai et al., 2012, EPSL 359-360, 227-239; [4] Parai and Mukhopadhay, 2015, G-cubed 16, 719-735; [5] Peto et al., 2013, EPSL 369-370, 13-23; [6] Tucker et al., 2012, EPSL 355-356, 244-254.

Formation of ore minerals in metamorphic rocks of the German continental deep drilling site (KTB)

NASA Astrophysics Data System (ADS)

Kontny, A.; Friedrich, G.; Behr, H. J.; de Wall, H.; Horn, E. E.; Möller, P.; Zulauf, G.

1997-08-01

The German Continental Deep Drilling Program (KTB) drilled a 9.1 km deep profile through amphibolite facies metamorphic rocks and reached in situ temperatures of 265°C. Each lithologic unit is characterized by typical ore mineral assemblages related to the regional metamorphic conditions. Paragneisses contain pyrrhotite + rutile + ilmenite ± graphite, metabasic units bear ilmenite + rutile + pyrrhotite ± pyrite, and additionally, the so-called variegated units yield pyrrhotite + titanite assemblages. In the latter unit, magnetite + ilmenite + rutile + titanite assemblages related to the lower amphibolite facies breakdown of ilmenite-hematite solid solution also occur locally. Retrograde hydrothermal mineralization which commenced during Upper Carboniferous times is characterized by the following geochemical conditions: (1) low saline Na-K-Mg-Cl fluids with sulfur and oxygen fugacities at the pyrite-pyrrhotite buffer and temperatures of 400-500°C, (2) fluids with CO2, CH4±N2, andpH, Eh, sulfur, and oxygen fugacity in the stability field of graphite + pyrite at temperatures of 280-350° and (3) moderate to high saline Ca-Na-Cl fluids with CH4+ N2; sulfur and oxygen fugacity are in the stability field of pyrrhotite at temperatures <300°C. The latter environment is confirmed by in situ conditions found at the bottom of the deep drilling. Monoclinic, ferrimagnetic pyrrhotite is the main carrier of magnetization which disappears below about 8.6 km, corresponding to in situ temperatures of about 250°C. Below this depth, hexagonal antiferromagnetic pyrrhotite with a Curie temperature of 260°C is the stable phase. Temperature-dependent transformation of pyrrhotite and the reaching of its Curie isotherm within the Earth crust are one of the striking results of the KTB deep drilling project.

Does the Deep Layer of the Deep Temporalis Fascia Really Exist?

PubMed

Li, Hui; Li, Kaide; Jia, Wenhao; Han, Chaoying; Chen, Jinlong; Liu, Lei

2018-04-14

It has been widely accepted that a split of the deep temporal fascia occurs approximately 2 to 3 cm above the zygomatic arch and extends into the superficial and deep layers. The deep layer of the deep temporal fascia is between the superficial temporal fat pad and the temporal muscle. However, during procedures, the authors noted the absence of the deep layer of the deep temporal fascia between the superficial temporal fat pad and the temporal muscle. This prospective study was conducted to clarify the presence or absence of a deep layer of the deep temporal fascia. Anatomic layers of the soft tissues of the temporal region, with reference to the deep temporal fascia, were investigated in 130 cases operated on for zygomaticofacial fractures using the supratemporal approach from June 2013 to June 2017. Of 130 surgeries, the authors found the absence of a thick, obviously identifiable, fascial layer between the superficial temporal fat pad and the temporal muscle. In fact, the authors found nothing above the temporal muscle in most cases. In a few cases, the authors observed only a small amount of scattered loose connective tissue between the superficial temporal fat pad and the temporal muscle. This clinical study showed the absence of a thick, obviously identifiable, fascial layer between the superficial temporal fat pad and the temporal muscle, which suggests that a "deep layer of the deep temporal fascia" might not exist. Copyright © 2018. Published by Elsevier Inc.

Nonlinear and linear site response and basin effects in Seattle for the M 6.8 Nisqually, Washington, earthquake

USGS Publications Warehouse

Frankel, A.D.; Carver, D.L.; Williams, R.A.

2002-01-01

We used recordings of the M 6.8 Nisqually earthquake and its ML 3.4 aftershock to study site response and basin effects for 35 locations in Seattle, Washington. We determined site amplification from Fourier spectral ratios of the recorded horizontal ground motions, referenced to a soft-rock site. Soft-soil sites (generally National Earthquake Hazard Reduction Program [NEHRP] class E) on artificial fill and young alluvium have the largest 1-Hz amplifications (factors of 3-7) for both the mainshock and aftershock. These amplifications are correlated with areas of higher damage from the mainshock to major buildings and liquefaction. There are several indications of nonlinear response at the soft-soil sites for the mainshock ground motions, despite relatively modest peak accelerations in the S waves of 15%-22%g. First, the mainshock spectral ratios do not show amplification at 2-8 Hz as do the aftershock spectral ratios. Spectral peaks at frequencies below 2 Hz generally occur at lower frequencies for the mainshock spectral ratios than for the aftershock ratios. At one soft-soil site, there is a clear shift of the resonant frequency to a lower frequency for the mainshock compared with the aftershock. The frequency of this resonance increases in the coda of the mainshock record, indicating that the site response during the weaker motions of the coda is more linear than that of the initial S wave. Three of the soft-soil sites display cusped, one-sided mainshock accelerograms after the S wave. These soft-soil sites also show amplification at 10-20 Hz in the S wave, relative to the rock site, that is not observed for the aftershock. The cusped waveforms and 10-20-Hz amplification are symptomatic of nonlinear response at the soft-soil sites. These sites had nearby liquefaction. The largest amplifications for 0.5 Hz occur at soft-soil sites on the southern portion of the Seattle Basin. Stiff-soil sites (NEHRP classes D and C) on Pleistocene-age glacial deposits display similar spectral amplification for the mainshock and aftershock, indicating approximately linear response. The stiff-soil sites generally have moderate amplification (factors of 1.1-2.4) at 0.5 and 1 Hz. Amplifications at 1 and 5 Hz for all sites generally increase with decreasing shear-wave velocity measured in the top 30 m (Vs 30). However, larger amplifications at 0.5 and 1 Hz for sites with similar Vs 30 values are observed for sites in the Seattle Basin, illustrating the amplification from the deeper (>30 m) sediments and the contribution from basin surface waves. Record sections for the mainshock and aftershock show that basin surface waves produce the peak velocities for many of the sites in the Seattle Basin and often dominate the amplitude at 1 Hz and lower frequencies.

Investigation and development of an effective, economical and efficient concrete pile splice.

DOT National Transportation Integrated Search

2015-06-01

Structures such as bridges or tall buildings often require deep foundations in order to reach soil or rock strata capable of resisting the associated high loads. In Florida, concrete elements such as driven piles, drilled shafts or other cast-in-plac...

Analysis of deep seismic reflection and other data from the southern Washington Cascades. Final report, September 15, 1992--December 31, 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanley, W.D.; Johnson, S.Y.; Nuccio, V.F.

1993-12-01

This report describes results of a synthesis of geological, geological, geophysical and geochemical data from a largely volcanic rock covered region in southwestern Washington that has been identified as a underlain by thick marine sedimentary rocks. The work was funded by the Deep Source Gas projects at the Morgantown Energy Technology Center (METC). The subproject which resulted in this report is centered in the Branch of Geophysics, US Geological Survey (USGS) has involved one task focused on the application of geophysical methods to the study of phenomena associated with fossil and active subduction zones and non-subduction suture zones that maymore » have deeply emplaced sedimentary rocks. This report represents a summary synthesis of several geophysical and geological data sets. The Southern Washington Cascades Conductor (SWCC) has been examined using several types of data in addition to MT, seismic, magnetic, and gravity Specific geological mapping tasks have been completed trough funding by the Department of Energy and the USGS in the western part of the proposed basin near Morton, WA. Other regional geological studies using wells and outcrops done as part of the USGS Evolution of Sedimentary Basins programs have added information that constraint the possible nature of the SWCC rocks and their tectonic setting. Recently, evaluation of patterns of seismicity in the SWCC region has demonstrated the likelihood of several parallel and step-over strike-slip faults that may have produced the proposed basin or altered its geometry. In addition, the seismicity patterns trace the axis of key anticlinal structures and thrusts.« less

Magnetism at Depth: A View from an Ancient Continental Subduction and Collision Zone

NASA Astrophysics Data System (ADS)

McEnroe, Suzanne A.; Robinson, Peter; Church, Nathan; Purucker, Michael

2018-04-01

Recent sophisticated global data compilations and magnetic surveys have been used to investigate the nature of magnetization in the lower crust and upper mantle. Two approaches to constraining magnetizations are developed, providing minimum (0.01 SI) and maximum (0.04 SI) susceptibility estimates, given some assumed thickness (15+ km here). These values are higher than are found in many continental rocks. Are there rocks deeper in the crust or upper mantle that are more magnetic than expected, or are the model assumptions incomplete? What is the magnetic behavior of deep-crustal and upper mantle rocks, when slightly cooler than the Curie or Néel temperatures of their magnetic minerals, after being exhumed from locations of high-grade metamorphism at greater depth? Different sets of equilibrium metamorphic minerals can be considered that would form under different conditions. Results on 1,501 samples from the Western Gneiss Region (WGR) Norway, mainly from mafic and ultramafic bodies subducted to depths of 60-200 km and temperatures of 750 up to 950°C at the very highest pressures, show that rocks did not fully equilibrate to the dominant metamorphic-facies conditions. There is a large variation in petrophysical properties, oxide minerals, and mineral assemblages in WGR samples, though they cannot explain the broad high-amplitude (deep-seated) anomalies measured in this region. The presence of magnetite, and exsolved titanohematite and hemoilmenite in samples, shows those magnetic phases are preserved even at eclogite-facies conditions, in part because complete eclogite-facies equilibrium was rarely achieved.

Rock Slide Monitoring by Using TDR Inclinometers

NASA Astrophysics Data System (ADS)

Drusa, Marián; Bulko, Roman

2016-12-01

The geotechnical monitoring of the slope deformations is widespread at present time. In many geological localities and civil engineering construction areas, monitoring is a unique tool for controlling of negative factors and processes, also inform us about actual state of rock environment or interacting structures. It is necessary for risk assessment. In our case, geotechnical monitoring is controlling rockslide activity around in the future part of motorway. The construction of new highway route D1 from Bratislava to Košice crosses the territory which is affected by a massive rockslide close to Kraľovany village. There was a need to monitor the activity of a large unstable rockslide with deep shear planes. In this case of underground movement activity, the Department of Geotechnics of the University of Žilina installed inclinometers at the unstable area which worked on Time Domain Reflectometry (TDR) principle. Based on provided measurements, effectivity and suitability of TDR inclinometers for monitoring of deep underground movement activity is demonstrated.

Sodium storage in deep paleoweathering profiles beneath the Paleozoic-Triassic unconformity

NASA Astrophysics Data System (ADS)

Thiry, M.; Parcerisa, D.; Ricordel-Prognon, C.; Schmitt, J.-M.

2009-04-01

A major sodium accumulation has been recognized for long and by numerous authors in the Permo-Triassic salt deposits (Hay et al., 2006). Beside these basinal deposits, important masses of sodium were stored on the continents within deep palaeoweathering profiles in form of albite. Indeed, wide surfaces and huge volumes of granito-gneissic basements of the Hercynian massifs are albitized from North-Africa up to Scandinavia. These albitized rocks have usually been considered as related to tardi-magmatic metasomatic processes (Cathelineau 1986; Petersson and Eliasson 1997). Geometrical arrangement and dating of these alterations point out that these albitizations, or at least a part of them, developed under low temperature subsurface conditions in relation with the Triassic palaeosurface (Ricordel et al., 2007; Parcerisa et al., 2009). Petrology The albitized igneous rocks show a strong alteration with pseudomorphic replacement of the primary plagioclases into albite, replacement of primary biotite by chlorite and minor precipitation of neogenic minerals like albite, chlorite, apatite, haematite, calcite and titanite. Albitized rocks are characterized by their pink coloration due to the presence of minute haematite inclusions in the albite. The development and distribution of the albitization and related alterations above the unaltered basement occurs in three steps that define a vertical profile, up to 100-150 m depth. 1) In the lower part of the profile, albitization occurs within pink-colored patches in the unaltered rock, giving a pink-spotted aspect to the rock. 2) In the middle part of the profile, rocks have an overall pink coloration due to the albitization of the primary Ca-bearing igneous plagioclases. Usually, this facies develops in a pervasive manner, affecting the whole rock, but it may also be restricted to joints, giving a sharp-pink coloration to the fracture wall. 3) Finally, the top of the profile is defined by the same mineral paragenesis as in the pink stage, with an increase in the amount and size of sericite and hematite inclusions. The latter causes the red coloration of the altered rocks. Regional layout Regional distribution of the alterations which affect the Carboniferous igneous and volcanic formations beneath the Jurassic sedimentary cover lead to associate these alterations to the Triassic unconformity. Besides, albitized facies show generally both topographic and regional arrangements, with more altered facies occurring in the mountain highs and in the external parts of the massifs and unaltered facies occurring in the river valleys and in the central parts of the massifs. Moreover, the haematite associated with these albitized basement rocks has been dated from Early Trias by means of paleomagnetism (Ricordel et al, 2007). From this layout and dating, it is deduced that albitization is related to the development of a deep weathering profile (up to 150 m deep) during a long-lasting exposure of the Triassic erosional unconformity (regolith). Geochemistry and paleoenvironmental setting It has to be highlighted that, this alteration may not behave like an "ordinary" weathering profile and occurred under unusual, or at least very specific, geological settings. The scale of the profiles (over 100 m depth) relates this alteration rather to a groundwater environment. The weak mobility of most chemical elements may point to a groundwater with very low outflows and deep water table. This may occur in very subdued landscape and in arid climatic conditions. It has also to be pointed that this alteration may have lasted for several 10's of Ma. Albite formation at low temperature may be envisioned consequently in alkaline, confined waters with sufficient concentrations of sodium and silica. Early attempts of modeling (Schmitt, 1994) have also indicated that a high Na+/K+ ratio is as well probably required. Petrographic data also indicate an import of sodium by the weathering solutions, without any clear enrichment in potassium. The Na+ enrichment is most likely linked with the peculiar geochemical setting of the Triassic environment where for instance halite moulds are very common in transgressive epicontinental deposits. The leaching of such salts, the role of salty marine aerosols, or a periodic/episodic contribution of seawater or evaporative solutions may be equally invoked. Mass balance Taking into account the surpergene origin of albitization and its widespread development on the Paleozoic basement rocks (from Morocco to Scandinavia) means that high amounts of Na+ have been stored in the deep paleoweathering profiles of the Triassic continents. This sodium storage in weathering profiles has to be taken in consideration in addition to the major sodium chloride accumulation in the basins during the Permo-Triassic times. Further investigations are needed to demonstrate the extent of these paleoweathering profiles and then to estimate the amount of this continental sodium storage. References Cathelineau M (1986) The hydrothermal alkali metasomatism effects on granitic rocks: Quartz dissolution and related sub-solidus changes. Jour. Petrol., 27: 945-965. Hay, W.W.; Migdisov, A.; Balukhovsky, A.N.; Wold, C.N.; Flogel, S., Soding, E. (2006) Evaporites and the salinity of the ocean during the Phanerozoic: Implications for climate, ocean circulation and life. Palaeogeography, Palaeoclimatology, Palaeoecology, 240/1-2: 3-46. Parcerisa D., Thiry M., Schmitt J.-M. (2009) Albitisation related to the Triassic unconformity in igneous rocks of the Morvan Massif (France), International Journal of Earth Sciences, DOI: 10.1007/s00531-008-0405-1. Petersson J, Eliasson T (1997) Mineral evolution and element mobility during episyenitization (dequartzification) and albitization in the postkinematic Bohus granite, southwest Sweden. Lithos, 42: 123-146. Ricordel C, Parcerisa D, Thiry M, Moreau M-G, Gómez-Gras D (2007) Triassic magnetic overprints related to albitization in granites from the Morvan massif (France). Palaeogeography Palaeoclimatology Palaeoecology, 251: 268-282. Schmitt JM (1994) Geochemical modelling and origin of the Triassic albitized regolith in southern France. 14th International Sedimentological Congress, Recife, Brazil. Abstracts book S8: 19-21.

A survey of lunar rock types and comparison of the crusts of earth and moon

NASA Technical Reports Server (NTRS)

Wood, J. A.

1977-01-01

The principal known types of lunar rocks are briefly reviewed, and their chemical relationships discussed. In the suite of low-KREEP highland rocks, Fe/(Fe + Mg) in the normative mafic minerals increases and the albite content of normative plagio-clase decreases as the total amount of normative plagioclase increases, the opposite of the trend predicted by the Bowen reaction principle. The distribution of compositions of rocks from terrestrial layered mafic intrusives is substantially different: here the analyses fall in several discrete clusters (anorthositic rocks, norites, granophyres and ferrogabbros, ultramafics), and the chemical trends noted above are not reproduced. It is suggested that the observed trends in lunar highland rocks could be produced by crystal fractionation in a deep global surface magma system if (1) plagiociase tended to float, upon crystallization, and (2) the magma was kept agitated and well mixed (probably by thermal convection) until crystallization was far advanced and relatively little residual liquid was left. After the crustal system solidified, but before extensive cooling had developed a thick, strong lithosphere, mantle convection was able to draw portions of the lunar anorthositic crust down into the mantle.

Biostratigraphy and petrography of upper Paleozoic rocks of Sierra Las Pintas, northern Baja California

NASA Astrophysics Data System (ADS)

Navas-Parejo, Pilar; Lara-Peña, R. Aaron; Torres-Martínez, Miguel Angel; Martini, Michelangelo

2018-07-01

A transported crinoid fauna is herein described for the first time in the Paleozoic succession cropping out in the Sierra Las Pintas, northern Baja California, northwestern Mexico. The fossil association includes Heterostelechus texanus Moore and Jeffords, Preptopremnum laeve? Moore and Jeffords, and Mooreanteris perforatus Moore and Jeffords, which indicates a Middle Pennsylvanian-early Permian time-averaged age. The studied area corresponds with the northernmost outcrop of definitely late Paleozoic deep-water facies in northwestern Mexico and the southern United States. Petrographic analyses indicate that the studied metasandstones were primarily derived from high-grade metamorphic rocks and from a shallow-water platform environment dominated by crinoid meadows. These results allow the correlation of the studied metasedimentary rocks with the Carboniferous Rancho Nuevo Formation of the Sonora allochthon, which crops out in central Sonora. The Sonora allochthon includes an Early Ordovician-Late Pennsylvanian sedimentary succession that was deposited in the oceanic basin located south of the Laurentian craton. Therefore, upper Paleozoic metasedimentary rocks of the Sierra Las Pintas were deposited along the same continental margin of Laurentia as those rocks in the Sonora allochthon, and were mostly derived from metamorphic rocks of the continental craton and by the typical Carboniferous encrinites, which characterize the shallow-water rocks of central and northern Sonora.

Hydrogeology of the vicinity of Homestake mine, South Dakota, USA

NASA Astrophysics Data System (ADS)

Murdoch, Larry C.; Germanovich, Leonid N.; Wang, Herb; Onstott, T. C.; Elsworth, Derek; Stetler, Larry; Boutt, David

2012-02-01

The former Homestake mine in South Dakota (USA) cuts fractured metamorphic rock over a region several km2 in plan, and plunges to the SE to a depth of 2.4 km. Numerical simulations of the development and dewatering of the mine workings are based on idealizing the mine-workings system as two overlapping continua, one representing the open drifts and the other representing the host rock with hydrologic properties that vary with effective stress. Equating macroscopic hydrologic properties with characteristics of deformable fractures allows the number of parameters to be reduced, and it provides a physically based justification for changes in properties with depth. The simulations explain important observations, including the co-existence of shallow and deep flow systems, the total dewatering flow rate, the spatial distribution of in-flow, and the magnitude of porosity in the mine workings. The analysis indicates that a deep flow system induced by ~125 years of mining is contained within a surface-truncated ellipsoid roughly 8 km by 4 km in plan view and 5.5 km deep with its long-axis aligned to the strike of the workings. Groundwater flow into the southern side of the workings is characterized by short travel times from the ground surface, whereas flow into the northern side and at depth consists of old water removed from storage.

The onset of fabric development in deep marine sediments

NASA Astrophysics Data System (ADS)

Maffione, Marco; Morris, Antony

2017-09-01

Post-depositional compaction is a key stage in the formation of sedimentary rocks that results in porosity reduction, grain realignment and the production of sedimentary fabrics. The progressive time-depth evolution of the onset of fabric development in deep marine sediments is poorly constrained due to the limited quantity and resolution of existing data. Here we present high-resolution anisotropy of magnetic susceptibility (AMS) results from clay-rich deep marine sediments recovered at International Ocean Discovery Program Site U1438 (Philippine Sea). AMS is a petrofabric tool sensitive to the preferred orientation of grains in rocks. Down-section variations of AMS parameters, density, porosity and the inclination of magnetic remanences demonstrate that fabrics develop in response to compaction and dewatering but also that they do not develop progressively with depth below the mudline. Instead, a horizontal foliation first forms at 83 mbsf once the sediment load reaches an effective stress threshold for the onset of compaction and is then continuously enhanced down to 113 mbsf, defining a 30 m-thick 'initial compaction window'. The magnetostratigraphic age model for IODP Site U1438 indicates a delay of 5.7 Ma in initial fabric formation following sediment deposition, with strongly defined fabrics then taking an additional 6.5 Ma to develop.

GLIMPCE Seismic reflection evidence of deep-crustal and upper-mantle intrusions and magmatic underplating associated with the Midcontinent Rift system of North America

USGS Publications Warehouse

Behrendt, John C.; Hutchinson, D.R.; Lee, M.; Thornber, C.R.; Tréhu, A.; Cannon, W.; Green, A.

1990-01-01

Deep-crustal and Moho reflections, recorded on vertical incidence and wide angle ocean bottom Seismometer (OBS) data in the 1986 GLIMPCE (Great Lakes International Multidisciplinary Program on Crustal Evolution) experiment, provide evidence for magmatic underplating and intrusions within the lower crust and upper mantle contemporaneous with crustal extension in the Midcontinent Rift system at 1100 Ma. The rift fill consists of 20-30 km (7-10 s) of basalt flows, secondary syn-rift volcaniclastic and post-basalt sedimentary rock. Moho reflections recorded in Lake Superior over the Midcontinent Rift system have times from 14-18 s (about 46 km to as great as 58 km) in contrast to times of about 11-13 s (about 36-42 km crustal thickness) beneath the surrounding Great Lakes. The Seismically complex deep-crust to mantle transition zone (30-60 km) in north-central Lake Superior, which is 100 km wider than the rift half-graben, reflects the complicated products of tectonic and magmatic interaction of lower-crustal and mantle components during evolution or shutdown of the aborted Midcontinent Rift. In effect, mantle was changed into crust by lowering Seismic velocity (through intrusion of lower density magmatic rocks) and increasing Moho (about 8.1 km s-1 depth. 

'Home Plate' Evidence for an Explosive Past

NASA Technical Reports Server (NTRS)

2006-01-01

This view of layers around the edge of a low plateau called 'Home Plate' inside Mars' Gusev Crater includes a feature that may be what geologists call a 'bomb sag' and interpret as evidence of an explosive event, such as a volcanic eruption.

The layers seen here are generally straight and parallel except in the lower right, where they dip around a greyish rock that is about 4 centimeters (about 1.5 inches) in diameter. When layered deposits are struck by a falling rock while the layers are still soft, this type of pattern can be created. The rock might have been lofted by a volcanic burst or as part of the material ejected by the crater-forming impact of a meteorite.

The panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit acquired the exposures for this image on Spirit's 754th Martian day (Feb. 15, 2006). This view is an approximately true-color rendering mathematically generated from separate images taken through all of the left Pancam's 432-nanometer to 753-nanometer filters.

Seismic Hazard Assessment for the Baku City and Absheron Peninsula, Azerbaijan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babayev, Gulam R.

2006-03-23

This paper deals with the seismic hazard assessment for Baku and the Absheron peninsula. The assessment is based on the information on the features of earthquake ground motion excitation, seismic wave propagation (attenuation), and site effect. I analyze active faults, seismicity, soil and rock properties, geological cross-sections, the borehole data of measured shear-wave velocity, lithology, amplification factor of each geological unit, geomorphology, topography, and basic rock and surface ground motions. To estimate peak ground acceleration (PGA) at the surface, PGA at the basic rock is multiplied by the amplification parameter of each surface layers. Quaternary soft deposits, representing a highmore » risk due to increasing PGA values at surface, are studied in detail. For a near-zone target earthquake PGA values are compared to intensity at MSK-64 scale for the Absheron peninsula. The amplification factor for the Baku city is assessed and provides estimations for a level of a seismic motion and seismic intensity of the studied area.« less

Microseismicity of Blawan hydrothermal complex, Bondowoso, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Maryanto, S.

2018-03-01

Peak Ground Acceleration (PGA), hypocentre, and epicentre of Blawan hydrothermal complex have been analysed in order to investigate its seismicity. PGA has been determined based on Fukushima-Tanaka method and the source location of microseismic estimated using particle motion method. PGA ranged between 0.095-0.323 g and tends to be higher in the formation that containing not compacted rocks. The seismic vulnerability index region indicated that the zone with high PGA also has a high seismic vulnerability index. This was because the rocks making up these zones were inclined soft and low-density rocks. For seismic sources around the area, epicentre and hypocentre, have estimated base on seismic particle motion method of single station. The stations used in this study were mobile stations identified as BL01, BL02, BL03, BL05, BL06, BL07 and BL08. The results of the analysis particle motion obtained 44 points epicentre and the depth of the sources about 15 – 110 meters below ground surface.

[Arthroscopy-guided fracture management. Ankle joint and calcaneus].

PubMed

Schoepp, C; Rixen, D

2013-04-01

Arthroscopic fracture management of the ankle and calcaneus requires a differentiated approach. The aim is to minimize surgical soft tissue damage and to visualize anatomical fracture reduction arthroscopically. Moreover, additional cartilage damage can be detected and treated. The arthroscopic approach is limited by deep impressions of the joint surface needing cancellous bone grafting, by multiple fracture lines on the articular side and by high-grade soft tissue damage. An alternative to the minimally invasive arthroscopic approach is open arthroscopic reduction in conventional osteosynthesis. This facilitates correct assessment of surgical reduction of complex calcaneal fractures, otherwise remaining non-anatomical reduction might not be fluoroscopically detected during surgery.

Solar activity during the deep minimum of 2009

NASA Astrophysics Data System (ADS)

Sylwester, Janusz; Siarkowski, Marek; Gburek, Szymon; Gryciuk, Magdalena; Kepa, Anna; Kowaliński, Mirosław; Mrozek, Tomek; Phillips, Kenneth J. H.; Podgórski, Piotr; Sylwester, Barbara

2014-12-01

We discuss the character of the unusually deep solar activity minimum of 2009 between Solar Cycles 23 and 24. Levels of solar activity in various parts of the solar atmosphere -- photosphere, chromosphere, transition region, and corona -- were observed to be at their lowest for a century. The soft X-ray emission from the corona (hot outer part of the Sun's atmosphere) was measured throughout most of 2009 with the Polish-built SphinX spectrophotometer. Unlike other X-ray monitoring spacecraft, this sensitive spacecraft-borne instrument was able to continue measurements throughout this extended period of low activity.

Battling Obesity

ERIC Educational Resources Information Center

Kennedy, Mike

2007-01-01

At the Gates Chili High School near Rochester, New York, the cafeteria and kitchen are getting an overdue overhaul. Deep fryers and the fat-soaked foods that come dripping out of them are no longer welcome in the kitchens and dining halls of a growing number of the nation's schools and universities. Likewise, heavily marketed sugary soft drinks…

Propeller flap reconstruction of abdominal defects: review of the literature and case report.

PubMed

Scaglioni, Mario F; Giuseppe, Alberto Di; Chang, Edward I

2015-01-01

The abdominal wall is perfused anteriorly by the superior and deep epigastric vessels with a smaller contribution from the superficial system. The lateral abdominal wall is perfused predominantly from perforators arising from the intercostal vessels. Reconstruction of soft tissue defects involving the abdomen presents a difficult challenge for reconstructive surgeons. Pedicle perforator propeller flaps can be used to reconstruct defects of the abdomen, and here we present a thorough review of the literature as well as a case illustrating the perforasome propeller flap concept. A patient underwent resection for dermatofibrosarcoma protuberans resulting in a large defect of the epigastric soft tissue. A propeller flap was designed based on a perforator arising from the superior deep epigastric vessels and was rotated 90° into the defect allowing primary closure of the donor site. The patient healed uneventfully and was without recurrent disease 37 months following reconstruction. Perforator propeller flaps can be used successfully in reconstruction of abdominal defects and should be incorporated into the armamentarium of reconstructive microsurgeons already facile with perforator dissections. © 2014 Wiley Periodicals, Inc.

Excavation-caused extra deformation of existing masonry residence in soft soil region

NASA Astrophysics Data System (ADS)

Tang, Y.; Franceschelli, S.

2017-04-01

Growing need for construction of infrastructures and buildings in fast urbanization process creates challenges of interaction between buildings under construction and adjacent existing buildings. This paper presents the mitigation of contradiction between two parties who are involved the interaction using civil engineering techniques. Through the in-depth analysis of the results of monitoring surveys and enhanced accuracy and reliability of surveys, a better understanding of the behavior of deformable buildings is achieved. Combination with the original construction documents, the two parties agree that both of them are responsible for building damages and a better understanding for the rehabilitation of the existing buildings is focused on. Two cases studies are used to demonstrate and describe the importance of better understanding of the behavior of existing buildings and their rehabilitations. The objective of this study is to insight into mechanisms of soil-structure interaction for buildings adjacent to deep excavations, which can result in a damage in existing masonry residence, and to take the optimized measures to make deep excavations safety and economic and adjacent buildings keep good serviceability in urban areas with soft soil conditions.

A Deep Near-Infrared Survey of the N 49 Region around the Soft Gamma-Ray Repeater 0526-66

NASA Technical Reports Server (NTRS)

Klose, S.; Henden, A. A.; Geppert, U.; Greiner, J.; Guetter, H. H.; Hartmann, D. H.; Kouveliotou, C.; Luginbuhl, C. B.; Stecklurn, B.; Vrba, F. J.

2004-01-01

We report the results of a deep near-infrared survey of the vicinity of supernova remnant N49 in the Large Magellanic Cloud (LMC), which contains the soft gamma-ray repeater (SGR) 0526-66. Two of the four confirmed SGRs are potentially associated with compact stellar clusters. We thus searched for a similar association of SGR0526-66, and find the unexplored young stellar cluster SL 463 at a projected distance of approx. 30 pc from the SGR. This constitutes the third cluster-SGR link, and lends support to scenarios in which SGR progenitors originate in young, embedded clusters. If real, the cluster-SGR association constrains the age and thus the initial mass of these stars. In addition, our high-resolution images of the super- nova remnant N49 reveal an area of excess K-band flux in the southeastern part of the SNR. This feature coincides with the maximum flux area at 8.28 microns as detected by the Midcourse Space Experiment (MSX satellite), which we identify with IRAS 052594607.

'Bounce' Exposed

NASA Technical Reports Server (NTRS)

2004-01-01

This approximate true-color image, acquired by the Mars Exploration Rover Opportunity's panoramic camera, features the hole ground by the rover's rock abrasion tool into 'Bounce' rock. The hole measures approximately 35 centimeters (14 inches) long and 10 centimeters (4 inches) high. The depression measures 6.44 millimeters (0.25 inch) deep and about 4.5 centimeters (1.7 inches) across. The grinding procedure took place on the rover's 66th sol on Mars and lasted 2 hours and 15 minutes. A combination of limited solar power, added safety measures and the rock's jagged texture led the rock abrasion tool team to set more aggressive grinding parameters to ensure that the end result was a full circle, suitable for a thorough read from the rover's spectrometers.

Bounce's outer ring consists of the cuttings from the rock, pushed out by the brushes on the grinding instrument. The small impressions filled with red dust on the outer ring were caused by the instrument's contact mechanism, which serves to stabilize it while grinding.

This image was created using the panoramic camera's blue, green and red filters.

Availability and quality of ground water in the Piedmont Province of Virginia

USGS Publications Warehouse

Powell, John Duane; Abe, Joseph M.

1985-01-01

The Piedmont Province of Virginia has an ample supply of groundwater, (perhaps as much as 1.5 billion gallons are in storage per sq mi) generally suitable for domestic and small supply needs. The source of this groundwater is precipitation, which is stored in the pore spaces of the regolith and in fractures in the underlying bedrock of crystalline rocks. Water within the sedimentary rocks of the sedimentary basins is stored in bedding planes, fractures, and in pore spaces in the rock, and in the regolith. Well yields can be minimized in both terrains by constructing wells along lineaments and in valleys. Groundwater in the crystalline rock is generally slightly mineralized and acidic (pH is greater than 7.0). Dissolved solids concentration in deep wells ( < 500 ft) in sedimentary rock may exceed tolerable limits. Land disposal of solid wastes and sewage for domestic septic systems present the major threat to groundwater quality. A greater understanding of the groundwater system in the Virginia Piedmont could be used to anticipate future shortages so that preventive measures could be implemented to protect the groundwater reservoir. (Author 's abstract)

Forecasting giant, catastrophic slope collapse: lessons from Vajont, Northern Italy

NASA Astrophysics Data System (ADS)

Kilburn, Christopher R. J.; Petley, David N.

2003-08-01

Rapid, giant landslides, or sturzstroms, are among the most powerful natural hazards on Earth. They have minimum volumes of ˜10 6-10 7 m 3 and, normally preceded by prolonged intervals of accelerating creep, are produced by catastrophic and deep-seated slope collapse (loads ˜1-10 MPa). Conventional analyses attribute rapid collapse to unusual mechanisms, such as the vaporization of ground water during sliding. Here, catastrophic collapse is related to self-accelerating rock fracture, common in crustal rocks at loads ˜1-10 MPa and readily catalysed by circulating fluids. Fracturing produces an abrupt drop in resisting stress. Measured stress drops in crustal rock account for minimum sturzstrom volumes and rapid collapse accelerations. Fracturing also provides a physical basis for quantitatively forecasting catastrophic slope failure.

From P-T-age to secular change and global tectonic regimes (or Essene in reverse - from granulites to blueschists and eclogites over time)

NASA Astrophysics Data System (ADS)

Brown, M.

2006-12-01

Essene's contributions began pre-plate tectonics more than 40 years ago; they range from mineralogy to tectonics, from experiments and thermobarometry to elements and isotopes, and from the Phanerozoic to the Precambrian. Eric is a true polymath! Assessing the P-T conditions and age distribution of crustal metamorphism is an important step in evaluating secular change in tectonic regimes and geodynamics. In general, Archean rocks exhibit moderate-P - moderate-to-high-T facies series metamorphism (greenstone belts and granulite terranes); neither blueschists nor any record of deep continental subduction and return are documented and only one example of granulite facies ultrahigh-temperature metamorphism is reported. Granulite facies ultrahigh temperature metamorphism (G-UHTM) is documented in the rock record predominantly from Neoarchean to Cambrian, although G-UHTM facies series rocks may be inferred at depth in younger orogenic systems. The first occurrence of G-UHTM in the rock record signifies a change in geodynamics that generated transient sites of very high heat flow. Many G-UHTM belts may have developed in settings analogous to modern continental backarcs. On a warmer Earth, the formation and breakup of supercontinents, particularly by extroversion, which involved destruction of ocean basins floored by thinner lithosphere, may have generated hotter continental backarcs than those around the modern Pacific rim. Medium-temperature eclogite - high-pressure granulite metamorphism (E-HPGM) also is first recognized in the Neoarchean rock record, and occurs at intervals throughout the Proterozoic and Paleozoic rock record. E- HPGM belts are complementary to G-UHTM belts, and are generally inferred to record subduction-to-collision orogenesis. Blueschists become evident in the Neoproterozoic rock record; lawsonite blueschists and eclogites (high-pressure metamorphism, HPM), and ultrahigh pressure metamorphism (UHPM) characterized by coesite or diamond are predominantly Phanerozoic phenomena. HPM-UHPM registers low thermal gradients and deep subduction of continental crust during the early stage of the collision process in Phanerozoic subduction-to-collision orogens. Although counterintuitive, many HPM-UHPM belts appear to have developed by closure of small ocean basins in the process of accretion of a continental terrane during a period of supercontinent introversion (Wilson cycle ocean basin opening and closing). A duality of metamorphic belts - reflecting a duality of thermal regimes - appears in the record only since the Neoarchean Era. A duality of thermal regimes is the hallmark of modern plate tectonics and the duality of metamorphic belts is the characteristic imprint of plate tectonics in the rock record. The occurrence of both G- UHTM and E-HPGM belts since the Neoarchean manifests the onset of a `Proterozoic plate tectonics regime', although the style of tectonics likely involved differences from modern Earth. Although the style of Proterozoic subduction remains cryptic, the change in tectonic regime whereby interactions between discrete lithospheric plates generated tectonic settings with contrasting thermal regimes was a landmark event in Earth history. The `Proterozoic plate tectonics regime' evolved during a Neoproterozoic transition to the `modern plate tectonics regime' characterized by colder subduction, and subduction of continental crust deep into the mantle and its (partial) return from depths of up to 300 km, as chronicled by the appearance of blueschists and HPM-UHPM in the rock record.

Myoepithelial carcinoma on the right shoulder: Case report with published work review.

PubMed

Yokose, Chiharu; Asai, Jun; Kan, Saori; Nomiyama, Tomoko; Takenaka, Hideya; Konishi, Eiichi; Goto, Keisuke; Ansai, Shin-Ichi; Katoh, Norito

2016-09-01

Myoepithelial carcinoma is a malignant tumor that can differentiate towards myoepithelial cells and commonly occur in the salivary glands. There have been only a few reports of primary cutaneous myoepithelial carcinoma; however, most cases showed subcutaneous involvement and could also be diagnosed as soft tissue myoepithelial carcinoma arising from the subcutis with dermal involvement. It may thus be impossible to distinguish a primary cutaneous from a soft tissue myoepithelial carcinoma. Herein, we describe a case of myoepithelial carcinoma on the shoulder in an 85-year-old Japanese woman. The tumor was located in the whole dermis and subcutis; therefore, it could be diagnosed as either a cutaneous or soft tissue myoepithelial carcinoma. We reviewed previous cases of primary cutaneous and soft tissue myoepithelial carcinomas and compared their clinical and immunohistological features. We found no obvious differences in anatomical distribution or immunohistochemical findings. However, the recurrence rate of cutaneous myoepithelial carcinomas seems to be lower than that of soft tissue carcinomas. Such a difference may be attributable to the adequate surgical margin in cutaneous carcinomas compared with the deep-seated soft tissue carcinomas. The metastatic frequency did not significantly differ between the two types. Although we could summarize from only a small number of cases, these results indicate the difficulty in distinguishing between cutaneous and soft tissue myoepithelial carcinomas; furthermore, it may not be suitable to distinguish them on the basis of aggressive behavior. © 2016 Japanese Dermatological Association.

[Epidemiological characteristics and mortality risk factors in patients admitted in hospitals with soft tissue infections. A multicentric STIMG (Soft Tissue Infections Malacitan Group) study results].

PubMed

Salgado Ordóñez, F; Villar Jiménez, J; Hidalgo Conde, A; Villalobos Sánchez, A; de la Torre Lima, J; Aguilar García, J; da Rocha Costa, I; García Ordóñez, M A; Nuño Alvarez, E; Ramos Cantes, C; Martín Pérez, M

2006-07-01

To describe the characteristics of patients admitted in hospitals with soft tissue infections, and analyse the variables whose died, in order to define risk groups. retrospective analysis of medical reports of all patient admitted during 2002 year for soft tissue infections in public malacitans hospitals. We excluded the patient with soft tissue infections associated with burns, surgery, pressure ulcers, and orbit cellulitis. We analysed clinical, biochemical variables and indications for yields and imaging tests, so the empiric antibiotic treatment established and its correlations with practice guidelines. We analysed 391 admissions of 374 patients. Cellulitis was the most frequent diagnosis (69.3%). We did imaging tests in 51.6%. In 94.3% of cases were treated with empirics antibiotics. The most prescribed drug was amoxiciline plus clavulanate (39%). 27 patients died, 40.7% of them for septic cause. All deceased patients had chronic diseases. The only biochemical parameters associated with mortality were serum proteins and albumina (55 +/- 9 g/L vs. 63 +/- 8 g/L; p = 0.0231) and (22 +/- 7 g/L vs. 29 +/- 7 g/L; p = 0.0125) respectively. Cellullitis are the most frequent soft tissue infections that requires admissions in hospitals. We overuse imaging test and don t follow the practice guidelines recommendations in antibiotic therapy. Primary soft issue infection s mortality is low and it s restricted to people with chronic illness, deep infections and bad nutritional status.

Deep Geothermal Drilling Using Millimeter Wave Technology. Final Technical Research Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oglesby, Kenneth; Woskov, Paul; Einstein, Herbert

2014-12-30

Conventional drilling methods are very mature, but still have difficulty drilling through very deep,very hard and hot rocks for geothermal, nuclear waste entombment and oil and gas applications.This project demonstrated the capabilities of utilizing only high energy beams to drill such rocks,commonly called ‘Direct Energy Drilling’, which has been the dream of industry since the invention of the laser in the 1960s. A new region of the electromagnetic spectrum, millimeter wave (MMW) wavelengths at 30-300 giga-hertz (GHz) frequency was used to accomplish this feat. To demonstrate MMW beam drilling capabilities a lab bench waveguide delivery, monitoring and instrument system wasmore » designed, built and tested around an existing (but non-optimal) 28 GHz frequency, 10 kilowatt (kW) gyrotron. Low waveguide efficiency, plasma generation and reflected power challenges were overcome. Real-time monitoring of the drilling process was also demonstrated. Then the technical capability of using only high power intense millimeter waves to melt (with some vaporization) four different rock types (granite, basalt, sandstone, limestone) was demonstrated through 36 bench tests. Full bore drilling up to 2” diameter (size limited by the available MMW power) was demonstrated through granite and basalt samples. The project also demonstrated that MMW beam transmission losses through high temperature (260°C, 500oF), high pressure (34.5 MPa, 5000 psi) nitrogen gas was below the error range of the meter long path length test equipment and instruments utilized. To refine those transmission losses closer, to allow extrapolation to very great distances, will require a new test cell design and higher sensitivity instruments. All rock samples subjected to high peak temperature by MMW beams developed fractures due to thermal stresses, although the peak temperature was thermodynamically limited by radiative losses. Therefore, this limited drill rate and rock strength data were not able to be determined experimentally. New methods to encapsulate larger rock specimens must be developed and higher power intensities are needed to overcome these limitations. It was demonstrated that rock properties are affected (weakening then strengthened) by exposure to high temperatures. Since only MMW beams can economically reach rock temperatures of over 1650°C, even exceeding 3000°C, that can cause low viscosity melts or vaporization of rocks. Future encapsulated rock specimens must provide sufficiently large sizes of thermally impacted material to provide for the necessary rock strength, permeability and other analyzes required. Multiple MMW field systems, tools and methods for drilling and lining were identified. It was concluded that forcing a managed over-pressure drilling operation would overcome water influx and hot rock particulates handling problems, while simultaneously forming the conditions necessary to create a strong, sealing rock melt liner. Materials that contact hot rock surfaces were identified for further study. High power windows and gases for beam transmission under high pressures are critical paths for some of the MMW drilling systems. Straightness/ alignment can be a great benefit or a problem, especially if a MMW beam is transmitted through an existing, conventionally drilled bore.« less