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Sample records for drillholes ol-kr40 ol-kr42

  1. Drillhole results to be discussed

    NASA Astrophysics Data System (ADS)

    Katzoff, Judith A.

    Vattenfall, the Swedish State Power Board, is searching for a predicted reservoir of abiogenic methane beneath the floor of a meteorite crater in central Sweden. Some of the early scientific results from the drilling project at the Siljan Ring impact structure will be presented on Thursday, May 21, at the 1987 AGU Spring Meeting in Baltimore, Md.Thomas Gold of Cornell University (Ithaca, N.Y.) has predicted that large amounts of methane from deep within the earth may move closer to the surface beneath sites where large meteorites have hit the earth, such as the Siljan Ring structure (Eos, July 9, 1985, p. 537). The site is known for its gas seeps, according to Paul Westcott of the Gas Research Institute (GRI, in Chicago, Ill.). The institute is putting up 15% of the costs of the drillhole in return for access to samples and data. Seismic surveys at the site revealed horizontal structures in the granite, which may suggest the presence of gas-liquid interfaces, Westcott said.

  2. Basic Data Report for Drillhole SNL-2 (C-2948)

    SciTech Connect

    Powers, Dennis W.

    2005-01-19

    SNL-2 was drilled in the northwest quarter of Section 12, T22S, R30E, in eastern Eddy County, New Mexico (Figure 2-1). It is located 574 ft from the north line (fnl) and 859 ft from the west line (fwl) of the section (Figure 2-2). This location places the drillhole east of the Livingston Ridge escarpment among oil wells of the Cabin Lake field. SNL-2 will be used to test hydraulic properties and to monitor ground water levels of the Culebra Dolomite Member of the Permian Rustler Formation. SNL-2 was permitted by the New Mexico State Engineer as C-2948. [Official correspondence regarding permitting and regulatory information must reference this permit number.] In the plan describing the integrated groundwater hydrology program (Sandia National Laboratories, 2003), SNL-2 is also codesignated WTS-1 because the location also satisfies needs for long-term monitoring of water quality and movement in the Culebra Dolomite for RCRA permitting; this program is under the management of Washington TRU Solutions LLC (WTS). In the event that additional wells are established on the SNL-2 drillpad to monitor other hydrological units (e.g., the Magenta Dolomite Member of the Permian Rustler Formation), the current drillhole will likely be referred to as SNL-2C because it is completed in the Culebra. Most drillholes at WIPP have been described after completion to provide an account of the geology, hydrology, or other basic data acquired during drilling and immediate completion of the drillhole. In addition, the basic data report provides an account of the drilling procedures and activities that may be helpful to later interpretations of data or for further work in the drillhole, including test activities and eventual plugging and abandoning activities. The basic data report also provides a convenient means of reporting information about administrative activities necessary to drill the hole.

  3. Permeability and porosity of the Illinois UPH 3 drillhole granite and a comparison with other deep drillhole rocks

    USGS Publications Warehouse

    Morrow, C.A.; Lockner, D.A.

    1997-01-01

    Permeability, porosity, and volumetric strain measurements were conducted on granite cores obtained at depths of 0.7 to 1.6 km from the Illinois UPH 3 drillhole at effective confining pressures from 5 to 100 MPa. Initial permeabilities were in the range of 10-17 to 10-19 m2 and dropped rapidly with applied pressure to values between 10-20 and 10-24 m2 at 100 MPa, typical of other deep granite core samples. These values are several decades lower than equivalent weathered surface granites at comparable effective confining pressures, where weathering products in cracks and pores inhibit crack closure with applied pressure. Permeabilities of the Illinois cores were inversely related to sample depth, suggesting that stress relief and thermal microfractures induced during core retrieval dominated the fluid flow. Thus these samples provide an upper bound on in situ matrix permeability values. A comparison of core permeability from UPH 3 and other deep drillholes shows that stress relief damage can often dominate laboratory permeability measurements. We conclude that it may be difficult to make meaningful estimates of in situ permeability based on either borehole samples (possible damage during retrieval) or surface-derived analogs (altered by weathering). Volumetric strain determined from porosity measurements was compared with differential strain analysis (DSA) data reported by other investigators on samples from the same depths in the drillhole. Our strain measurements (0.002 to 0.005 at 100 MPa) were nearly twice as large as the DSA values, probably because of the crack-enhancing effects of fluids present in our samples that are absent in the dry DSA cores, as well as other time-dependent deformation effects. This difference in observed strain magnitudes between the two measurement methods may be an important consideration if strain and/or porosity data from deep core samples are used in models of stress, fluid circulation, and excess fluid pressure generation in the

  4. Permeability and porosity of the Illinois UPH 3 drillhole granite and a comparison with other deep drillhole rocks

    NASA Astrophysics Data System (ADS)

    Morrow, C. A.; Lockner, D. A.

    1997-02-01

    Permeability, porosity, and volumetric strain measurements were conducted on granite cores obtained at depths of 0.7 to 1.6 km from the Illinois UPH 3 drillhole at effective confining pressures from 5 to 100 MPa. Initial permeabilities were in the range of 10-17 to 10-19 m2 and dropped rapidly with applied pressure to values between 10-20 and 10-24 m2 at 100 MPa, typical of other deep granite core samples. These values are several decades lower than equivalent weathered surface granites at comparable effective confining pressures, where weathering products in cracks and pores inhibit crack closure with applied pressure. Permeabilities of the Illinois cores were inversely related to sample depth, suggesting that stress relief and thermal microfractures induced during core retrieval dominated the fluid flow. Thus these samples provide an upper bound on in situ matrix permeability values. A comparison of core permeability from UPH 3 and other deep drillholes shows that stress relief damage can often dominate laboratory permeability measurements. We conclude that it may be difficult to make meaningful estimates of in situ permeability based on either borehole samples (possible damage during retrieval) or surface-derived analogs (altered by weathering). Volumetric strain determined from porosity measurements was compared with differential strain analysis (DSA) data reported by other investigators on samples from the same depths in the drillhole. Our strain measurements (0.002 to 0.005 at 100 MPa) were nearly twice as large as the DSA values, probably because of the crack-enhancing effects of fluids present in our samples that are absent in the dry DSA cores, as well as other time-dependent deformation effects. This difference in observed strain magnitudes between the two measurement methods may be an important consideration if strain and/or porosity data from deep core samples are used in models of stress, fluid circulation, and excess fluid pressure generation in the

  5. Basic Data Report for Drillhole SNL-5 (C-3002)

    SciTech Connect

    Dennis W. Powers; Washington Regulatory and Environmental Services

    2005-01-18

    SNL-5 (permitted by the New Mexico State Engineer as C-3002) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation in an area north of the Waste Isolation Pilot Plant (WIPP) site where data are sparse and where a pumping or monitoring well for the northern pumping test is needed. SNL-5 is located in the southeast quarter of section 6, T22S, R31E, in eastern Eddy County, New Mexico. SNL-5 was drilled to a total depth of 687 ft below ground level (bgl), based on driller's measurements. Below the caliche pad, SNL-5 encountered the Mescalero caliche, Gatu?a, Dewey Lake, and Rustler Formations. Two intervals of the Rustler were cored: (1) from the lower Forty-niner Member through the Magenta Dolomite and into the upper Tamarisk Member; and (2) from the lower Tamarisk Member through the Culebra Dolomite and into the upper Los Meda?os Members. Geophysical logs were acquired from the open hole to a depth of ~672 ft. No water was observed to flow into the open drillhole until the Culebra was penetrated. includes horizontal beds and laminae near the base, and the uppermost part shows some inclined bedding. The mudstone unit shows mostly reddish brown claystone and siltstone with some gray mottling. Clasts or intraclasts are also included in the unit. The upper Tamarisk sulfate is somewhat brecciated near the base.

  6. Basic Data Report for Drillhole SNL-9 (C-2950)

    SciTech Connect

    Dennis W. Powers; Washington Regulatory and Environmental Services

    2005-01-19

    SNL-9 (permitted by the State Engineer as C-2950) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation within a proposed re-entrant of the margin of halite dissolved from the upper part of the Salado near Livingston Ridge. SNL-9 is located in the southeast quarter of section 23, T22S, R30E, in eastern Eddy County, New Mexico. SNL-9 was drilled to a total depth of 845 ft below the ground surface. Below surface dune sand and the Berino soil, SNL-9 encountered, in order, the Mescalero caliche, Gatuna, Dewey Lake, Rustler, and uppermost Salado Formations. Two intervals were cored: 1) from the lower Forty-niner Member through the Magenta Dolomite and into the upper Tamarisk Member; and 2) from the lower Tamarisk Member through the Culebra Dolomite and Los Meda?os Members and into the uppermost Salado Formation. Geophysical logs were acquired from the open hole to total depth, and the drillhole was successfully completed with a screened interval open across the Culebra.

  7. Basic Data Report for Drillhole SNL-12 (C-2954)

    SciTech Connect

    Dennis W. Powers

    2005-01-20

    SNL-12 (permitted by the New Mexico State Engineer as C-2954) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation near the margin of dissolution of halite in the upper part of the Salado south of the Waste Isolation Pilot Plant (WIPP). SNL-12 is located in the southeast quarter of section 20, T23S, R31E, in eastern Eddy County, New Mexico. SNL-12 was drilled to a total depth of 905 ft below the ground level. Below surface dune sand and the Berino soil, SNL-12 encountered, in order, the Mescalero caliche, Gatu?a, Dewey Lake, Rustler, and uppermost Salado Formations. Two intervals were cored: (1) from the lower Forty-niner Member through the Magenta Dolomite and into the upper Tamarisk Member; and (2) from the lower Tamarisk Member through the Culebra Dolomite and Los Meda?os Members and into the uppermost Salado Formation. Geophysical logs were acquired from the open hole to total depth, and the drillhole was successfully completed with a screened interval open across the Culebra. At SNL-12, the uppermost Salado cores display displacive halite crystals in clastic-rich units below an amalgamated sulfate at the top of the formation. There is no indication of thinning of the upper Salado due to postdepositional dissolution, and this is consistent with predrilling expectations.

  8. Stratigraphy, geochemistry and mineralogy of Eocene rocks from the Toa Baja drillhole

    SciTech Connect

    Smith, A.L.; Severin, K.; Larue, D.K. )

    1991-03-01

    The stratigraphy of the Eocene rocks of the Toa Baja drillhole is dominated by volcaniclastic sediments which are interbedded with marly pelagic limestones, especially in the lower part of the hole, and lava flows. Petrological, geochemical and paleontological evidence suggest that the site of deposition was a deep marine basin and the source of the volcanics were subaerial or shallow submarine island arc volcanoes.

  9. Basic data report for drilling and hydrologic testing of drillhole DOE-2 at the Waste Isolation Pilot Plant (WIIP) site

    SciTech Connect

    Mercer, J.W.; Beauheim, R.L.; Snyder, R.P.; Fairer, G.M.

    1987-04-01

    Drillhole DOE-2 was drilled to investigate a structural depression marked by the downward displacement of stratigraphic markers in the Salado Formation. Contrary to several hypotheses, halite layers were thicker in the lower part of the Salado, not thinner as a result of any removal of halite. The upper Castile anhydrite in Drillhole DOE-2 is anomalously thick and is strongly deformed relative to the anhydrite in adjacent drillholes. In contrast, the halite was <8 ft thick and significantly thinner than usually encountered. The lower Castile anhydrite appears to be normal. The depression within the correlated marker beds in the Salado Formation in Drillhole DOE-2 is interpreted as a result of gravity-driven deformation of the underlying Castile Formation. Several stratigraphic units were hydrologically tested in Drillhole DOE-2. Testing of the unsaturated lower portion of the Dewey Lake Red Beds was unsuccessful because of exceptionally small rates of fluid intake. Drill-stem tests were conducted in five intervals in the Rustler Formation, over the Marker Bed 138-139 interval in the Salado formation, and over three sandstone members of the Bell Canyon Formation. A pumping test was conducted in the Culebra Dolomite Member of the Rustler Formation. Pressure-pulse tests were conducted over the entire Salado Formation. Fluid samples were collected from the Culebra Dolomite Member and from the Hays Member of the Bell Canyon Formation. 31 refs., 31 figs., 5 tabs.

  10. A study of the mineralogy and lithology of cuttings from the U.S. Bureau of Reclamation MESA 6-2 Drillhole, Imperial County, California, including comparisons with MESA 6-1 Drillhole

    USGS Publications Warehouse

    Fournier, R.B.

    1976-01-01

    The Mesa 6-2 drillhole penetrates 6,000 feet of sediments in Imperial County, California. The cuttings material from the upper part of the drillhole is chiefly unconsolidated mud and silt. Soft siltstone fragments occur at about 1,400 feet and increase in amount down to 2,400 feet. Some pebbles are found above 2,400 feet, but the pebble-rich horizons are less distinctive than the pebble zone in the Mesa 6-1 drillhole. Below 2,400 feet, cuttings ape composed of about two-thirds siltstone and one-third sandstones, ranging from very fine to very coarse sand, plus loose Sand grains. Although below 2,400 feet there is no systematic change in color of siltstones, grain size, or cementation with depth, horizons composed predominantly of loose sand are more common at deeper levels. Fragments of igneous and metamorphic rocks are less common than in the Mesa 6-1 drillhole. Quartz, calcite, K-feldspar, plagioclase (albite), illite, and mixed layer clays are identified by X-ray diffractograms of whole-rock samples throughout the hole. Chlorite occurs in all samples from below 2,100 feet, and probably also occurs at shallower depths. In most siltstones, montmorillonite occurs only down to the interval 2,200-2,300 feet, but in the buff siltstone it is found to the bottom of the drillhole. Kaolinite occurs at least down to 4,700 feet. Dolomite is found down to at least 5,970 feet, but is generally absent from horizons composed mostly of loose sand. Pyrite occurs in many samples. No zeolites, ankerite, or amorphous sulfur were detected. Theme is no horizon that may be used fop conclusive correlation with the Mesa 6-1 drillhole.

  11. Potential contributions of metamorphic petrology studies in an ultra-deep drillhole in the southern Appalachians

    SciTech Connect

    Speer, J.A.

    1985-01-01

    The proposed, ultra-deep hole in the southeast U.S. will penetrate allochthonous, medium- to high-grade metamorphic rocks of the Inner Piedmont and Blue Ridge thrust sheets. It is anticipated that the hole will then encounter autochthonous low-grade, metasedimentary cover rocks before bottoming out in crystalline Precambrian basement rocks. Metamorphic petrology in the recent past has concentrated on unraveling the physical and chemical history (P, T, X/sub fluid/, etc.) of metamorphic rocks. The techniques that have been developed are ideally suited to the study of relatively limited samples from drill core. Detailed studies of the allochthonous and autochthonous rocks from the drillhole, combined with comparable studies of the surface rocks, by metamorphic petrologists experimented with these approaches, would give a 3-dimensional picture of the PTX evolution in the region of the ultra-deep hole, and thus an idea of the geometrical, chemical, and physical changes the rocks experienced. This would place constraints on conditions of the rocks before and after thrusting and thus any tectonic models of thrusting in the southern Appalachians. With limited sampling this could be a problem, with more complete sampling it will be an advantage. The metamorphic petrology of the rocks will provide basic support for the other studies of the drill core and drillhole, most notably geochronology and stable isotopes. It should not be forgotten that in addition to the historical metamorphism, the expected, present-day conditions in the drillhole are those of burial metamorphism. The hole will present an excellent opportunity to study such active metamorphic conditions.

  12. Experimental Investigation on the Basic Law of the Fracture Spatial Morphology for Water Pressure Blasting in a Drillhole Under True Triaxial Stress

    NASA Astrophysics Data System (ADS)

    Huang, Bingxiang; Li, Pengfeng

    2015-07-01

    The present literature on the morphology of water pressure blasting fractures in drillholes is not sufficient and does not take triaxial confining stress into account. Because the spatial morphology of water pressure blasting fractures in drillholes is not clear, the operations lack an exact basis. Using a large true triaxial water pressure blasting experimental system and an acoustic emission 3-D positioning system, water pressure blasting experiments on cement mortar test blocks (300 mm × 300 mm × 300 mm) were conducted to study the associated basic law of the fracture spatial morphology. The experimental results show that water pressure blasting does not always generate bubble pulsation. After water pressure blasting under true triaxial stress, a crushed compressive zone and a blasting fracture zone are formed from the inside, with the blasting section of the naked drillhole as the center, to the outside. The shape of the outer edges of the two zones is ellipsoidal. The range of the blasting fracture is large in the radial direction of the drillhole, where the surrounding pressure is large, i.e., the range of the blasting fracture in the drillhole radial cross-section is approximately ellipsoidal. The rock near the drillhole wall is affected by a tensile stress wave caused by the test block boundary reflection, resulting in more flake fractures appearing in the fracturing crack surface in the drillhole axial direction and parallel to the boundary surface. The flake fracture is thin, presenting a small-range flake fracture. The spatial morphology of the water pressure blasting fracture in the drillhole along the axial direction is similar to a wide-mouth Chinese bottle: the crack extent is large near the drillhole orifice, gradually narrows inward along the drillhole axial direction, and then increases into an approximate ellipsoid in the internal naked blasting section. Based on the causes of the crack generation, the blasting cracks are divided into three

  13. Basic data report for drillholes at the H-11 complex (Waste Isolation Pilot Plant-WIPP)

    SciTech Connect

    Mercer, J.W. ); Snyder, R.P. )

    1990-05-01

    Drillholes H-11b1, H-11b2, and H-11b3 were drilled from August to December 1983 for site characterization and hydrologic studies of the Culebra Dolomite Member of the Upper Permian Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico. In October 1984, the three wells were subjected to a series of pumping tests designed to develop the wells, provide information on hydraulic communication between the wells, provide hydraulic properties information, and to obtain water samples for quality of water measurements. Based on these tests, it was determined that this location would provide an excellent pad to conduct a convergent-flow non-sorbing tracer test in the Culebra dolomite. In 1988, a fourth hole (H-11b4) was drilled at this complex to provide a tracer-injection hole for the H-11 convergent-flow tracer test and to provide an additional point at which the hydraulic response of the Culebra H-11 multipad pumping test could be monitored. A suite of geophysical logs was run on the drillholes and was used to identify different lithologies and aided in interpretation of the hydraulic tests. 4 refs., 6 figs., 6 tabs.

  14. Correlation of drillhole and shaft logs. Waste Isolation Pilot Plant (WIPP) project, southeastern New Mexico

    SciTech Connect

    Jarolimek, L.; Timmer, M.J.; Powers, D.W.

    1983-03-01

    This report on stratigraphic correlations from drillhole and shaft data along a generally north-south section across the potential extent of underground excavations of the Waste Isolation Pilot Plant (WIPP) facility was prepared as part of the Site Validation Field Program Plan. The results provide (1) input for the report entitled ''Results of Site Validation Experiments,'' (2) input for other WIPP-related investigations, including the Design Validation Program, and (3) a framework for further underground activities at WIPP. In general, this correlation study confirmed previous findings, including: relatively high consistency of thickness and lateral continuity of all beds within the Salado Formation, especially in the host rock interval; gentle, generally south and southeastward dips/slopes of the host rock interval strata; close correspondence between stratigraphic data obtained from the present underground excavations and data derived from the previous investigative drillholes and shafts; and depositional origin of the undulations on the top of Marker Bed (MB) 139 and relatively small variation in its thickness (1.2 to 4.1 feet).

  15. A note on drillhole depths required for reliable heat flow determinations

    USGS Publications Warehouse

    Chapman, D.S.; Howell, J.; Sass, J.H.

    1984-01-01

    In general, there is a limiting depth in a drillhole above which the reliability of a single determination of heat flow decreases rapidly with decreasing depth and below which the statistical uncertainty of a heat flow determination does not change perceptibly with increasing depth. This feature has been established empirically for a test case comprising a group of twelve heat flow sites in the Republic of Zambia. The technique consists of constructing heat flow versus depth curves for individual sites by progressively discarding data from the lower part of the hole and recomputing heat flow from the remaining data. For the Zambian test case, the curves converge towards a uniform value of 67 ?? 3 mW m-2 when all available data are used, but values of heat flow calculated for shallow(< 100 m) parts of the same holes range from 45 to 95 mW m-2. The heat flow versus depth curves are enclosed by a perturbation envelope which has an amplitude of 40 mW m-2 at the surface and decreases linearly to the noise level at 190 m. For the test region of Zambia a depth of 170 m is needed to guarantee a heat flow measurement within ?? 10% of the background regional value. It is reasonable to expect that this depth will be shallower in some regions and deeper in others. Features of heat flow perturbation envelopes can be used as quantitative reliability indices for heat flow studies. ?? 1984.

  16. Flow testing of the Newberry 2 research drillhole, Newberry volcano, Oregon

    USGS Publications Warehouse

    Ingebritsen, S.E.; Carothers, W.W.; Mariner, R.H.; Gudmundsson, J.S.; Sammel, E.A.

    1986-01-01

    A 20 hour flow test of the Newberry 2 research drillhole at Newberry Volcano produced about 33,000 kilograms of fluid. The flow rate declined from about 0.8 kilograms per sec to less than 0.3 kilograms per sec during the course of the test. The mass ratio of liquid water to vapor was about 3:2 at the separator and stayed fairly constant throughout the test. The vapor phase was about half steam and half CO2 by weight. The average enthalpy of the steam/water mixture at the separator was about 1 ,200 kilojoules per kilogram. Because of the low flow rate and the large temperature gradient into the surrounding rocks, heat loss from the wellbore was high; a simple conductive model gives overall losses of about 1,200 kilojoules per kilogram of H2O produced. The actual heat loss may have been even higher due to convective effects, and it is likely that the fluid entering the bottom of the wellbore was largely or entirely steam and CO2. (Author 's abstract)

  17. Physical-Property Measurements on Core samples from Drill-Holes DB-1 and DB-2, Blue Mountain Geothermal Prospect, North-Central Nevada

    USGS Publications Warehouse

    Ponce, David A.; Watt, Janet T.; Casteel, John; Logsdon, Grant

    2009-01-01

    From May to June 2008, the U.S. Geological Survey (USGS) collected and measured physical properties on 36 core samples from drill-hole Deep Blue No. 1 (DB-1) and 46 samples from drill-hole Deep Blue No. 2 (DB-2) along the west side of Blue Mountain about 40 km west of Winnemucca, Nev. These data were collected as part of an effort to determine the geophysical setting of the Blue Mountain geothermal prospect as an aid to understanding the geologic framework of geothermal systems throughout the Great Basin. The physical properties of these rocks and other rock types in the area create a distinguishable pattern of gravity and magnetic anomalies that can be used to infer their subsurface geologic structure. Drill-holes DB-1 and DB-2 were spudded in alluvium on the western flank of Blue Mountain in 2002 and 2004, respectively, and are about 1 km apart. Drill-hole DB-1 is at a ground elevation of 1,325 m and was drilled to a depth of 672 m and drill-hole DB-2 is at a ground elevation of 1,392 m and was drilled to a depth of 1522 m. Diameter of the core samples is 6.4 cm. These drill holes penetrate Jurassic and Triassic metasedimentary rocks predominantly consisting of argillite, mudstone, and sandstone; Tertiary diorite and gabbro; and younger Tertiary felsic dikes.

  18. "Intelligent design" of a 3D reflection survey for the SAFOD drill-hole site

    NASA Astrophysics Data System (ADS)

    Alvarez, G.; Hole, J. A.; Klemperer, S. L.; Biondi, B.; Imhof, M.

    2003-12-01

    SAFOD seeks to better understand the earthquake process by drilling though the San Andreas fault (SAF) to sample an earthquake in situ. To capitalize fully on the opportunities presented by the 1D drill-hole into a complex fault zone we must characterize the surrounding 3D geology at a scale commensurate with the drilling observations, to provide the structural context to extrapolate 1D drilling results along the fault plane and into the surrounding 3D volume. Excellent active-2D and passive-3D seismic observations completed and underway lack the detailed 3D resolution required. Only an industry-quality 3D reflection survey can provide c. 25 m subsurface sample-spacing horizontally and vertically. A 3D reflection survey will provide subsurface structural and stratigraphic control at the 100-m level, mapping major geologic units, structural boundaries, and subsurface relationships between the many faults that make up the SAF fault system. A principal objective should be a reflection-image (horizon-slice through the 3D volume) of the near-vertical fault plane(s) to show variations in physical properties around the drill-hole. Without a 3D reflection image of the fault zone, we risk interpreting drilled anomalies as ubiquitous properties of the fault, or risk missing important anomalies altogether. Such a survey cannot be properly costed or technically designed without major planning. "Intelligent survey design" can minimize source and receiver effort without compromising data-quality at the fault target. Such optimization can in principal reduce the cost of a 3D seismic survey by a factor of two or three, utilizing the known surface logistic constraints, partially-known sub-surface velocity field, and the suite of scientific targets at SAFOD. Our methodology poses the selection of the survey parameters as an optimization process that allows the parameters to vary spatially in response to changes in the subsurface. The acquisition geometry is locally optimized for

  19. Analysis of borehole televiewer measurements in the Vorotilov drillhole, Russia - First results

    USGS Publications Warehouse

    Huber, K.; Fuchs, K.; Palmer, J.; Roth, F.; Khakhaev, B.N.; Van-Kin, L. E.; Pevzner, L.A.; Hickman, S.; Moos, D.; Zoback, M.D.; Schmitt, D.

    1997-01-01

    In the Eurasian part of the World Stress Map almost the whole region east of the Tornquist-Teisseyre line is terra incognita. The closure of this information gap is of fundamental importance to the understanding of the geodynamics of the Eurasian continent. A detailed analysis of stress-induced wellbore breakouts has been performed over a 4.1-km-long depth interval in the Vorotilov drillhole (VGS). The borehole is located in the central part of the Russian platform, right in the center of the Vorotilov meteorite impact crater 60 km to the NNE of the city of Nizni Novgorod. An ultrasonic borehole televiewer (BHTV) was used to obtain high-resolution acoustical images from the borehole wall. With an interactive system for analyzing BHTV data the azimuth and shape of borehole breakouts occurring in the depth range of 1.3-4.8 km were analyzed. A statistical analysis of the resulting orientation profile of the breakout azimuths yields an overall direction of the maximum horizontal principal stress SH of N 137??E ?? 15??. Variations of breakout orientation with depth ranging from a few degrees up to more than 90?? are seen on various depth scales. The observed stress direction of N 137??E agrees very well with the average SH orientation of N 145??E in Central Europe. If this measurement is taken as representative for the Russian platform, the stress field in Russia is only slightly rotated in comparison to Central Europe. This can possibly be interpreted as indicative for the stress field to be governed by broad scale tectonic forces, such as a strong contribution from the forces exerted by the collision zone in the Alpine-Himalayan belt and by the Mid-Atlantic ridge.

  20. High-resolution temperature logging in shallow drillholes for the determination of terrestrial heat flow: field examples and analysis

    NASA Astrophysics Data System (ADS)

    Pfister, Martin; Rybach, Ladislaus

    1996-05-01

    The first 200 m of the Earth's crust is the depth range most investigated by drilling. Temperature profiles in such shallow drillholes generally show severe influences of groundwater flow; therefore they are rarely used for heat flow determinations. But regardless how severely the temperature logs are influenced by advective heat transfer the "background" conductive heat flow signal is still present in the data. It is shown how to handle distorted temperature profiles by means of simple one-dimensional, steady-state models. The undisturbed ("background") heat flow is estimated by model calculations; the comparison of the modelled temperature profiles with the measured logs is a test for the credibility of the modelling approach. Examples from northwestern Switzerland and northwestern Turkey with irregular temperature profiles are given for the following situations: conductive-convective regime with vertical groundwater movement over the entire observation depth; vertical flow in a certain layer located between purely conductive layers; and water flow inside of the drillhole. Measured temperature profiles can be approximated by modelling within ±0.2°C. Repeated, high-precision digital temperature logging is needed to prove the temporal stability of the convective disturbances in order to use steady-state models.

  1. Basic Data Report for Drillholes on the H-19 Hydropad (Waste Isolation Pilot Plant--WIPP)

    SciTech Connect

    Mercer, J.W.; Cole, D.L.; Holt, R.M.

    1998-10-09

    Seven holes were drilled and wells (H-19b0, H-19b2, H-19b3, H-19b4, H-19b5, H-19b6, and H-19b7) were constructed on the H-19 hydropad to conduct field activities in support of the Culebra Transport Program. These wells were drilled and completed on the Waste Isolation Pilot Plant (WIPP) site during February to September 1995. An eighth hole, H-19b1, was drilled but had to be abandoned before the target depth was reached because of adverse hole conditions. The geologic units penetrated at the H-19 location include surficial deposits of Holocene age, rocks from the Dockum Group of Upper Triassic age, the Dewey Lake Redbeds, and Rustler Formation of the Permian age. The Rustler Formation has been further divided into five informal members which include the Forty-niner Member, Magenta Member, Tamarisk Member, Culebra Dolomite Member, and an unnamed lower member. The Rustler Formation, particularly the Culebra Dolomite Member, is considered critical for hydrologic site characterization. The Culebra is the most transmissive saturated unit above the WIPP repository and, as such, is considered to be the most likely pathway for radionuclide transport to the accessible environment in the unlikely event the repository is breached. Seven cores from the Culebra were recovered during drilling activities at the H-19 hydropad and detailed descriptions of these cores were made. On the basis of geologic descriptions, four hydrostratigraphic units were identified in the Culebra cores and were correlated with the mapping units from the WFP air intake shaft. The entire length of H-19b1 was cored and was described in detail. During coring of H-19b1, moisture was encountered in the upper part of the Dewey Lake Redbeds. A 41-ft-thick section of this core was selected for detailed description to qualify the geologic conditions related to perched water in the upper Dewey Lake. In addition to cuttings and core, a suite of geophysical logs run on the drillholes was used to identify and

  2. Geologic Characterization of Young Alluvial Basin-Fill Deposits from Drill-Hole Data in Yucca Flat, Nye County, Nevada

    USGS Publications Warehouse

    Sweetkind, Donald S.; Drake II, Ronald M.

    2007-01-01

    Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site in Nye County, Nevada, that has been the site of numerous underground nuclear tests; many of these tests occurred within the young alluvial basin-fill deposits. The migration of radionuclides to the Paleozoic carbonate aquifer involves passage through this thick, heterogeneous section of Tertiary and Quaternary rock. An understanding of the lateral and vertical changes in the material properties of young alluvial basin-fill deposits will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating ground-water flow in the Yucca Flat area. This report by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, presents data and interpretation regarding the three-dimensional variability of the shallow alluvial aquifers in areas of testing at Yucca Flat, data that are potentially useful in the understanding of the subsurface flow system. This report includes a summary and interpretation of alluvial basin-fill stratigraphy in the Yucca Flat area based on drill-hole data from 285 selected drill holes. Spatial variations in lithology and grain size of the Neogene basin-fill sediments can be established when data from numerous drill holes are considered together. Lithologic variations are related to different depositional environments within the basin such as alluvial fan, channel, basin axis, and playa deposits.

  3. Ethanolic extract of Dalbergia sissoo promotes rapid regeneration of cortical bone in drill-hole defect model of rat.

    PubMed

    Khedgikar, Vikram; Kushwaha, Priyanka; Ahmad, Naseer; Gautam, Jyoti; Kumar, Padam; Maurya, Rakesh; Trivedi, Ritu

    2017-02-01

    Leaves of Dalbergia sissoo is known to have protective actions against postmenopausal bone loss in rat. In this study, we have evaluated the fracture healing properties of ethanolic extract (EE) of Dalbergia sissoo leaves. To observe the fracture healing property in the drill-hole injury model, we randomly divided total 32 adult female Sprague Dawley rats (180±200g) into 4 groups: (i) Control operated group; (ii) EE (250mg/kg/day); (iii) EE (500mg/kg/day) and (iv) EE (1000mg/kg/day). The right femora were fractured at the mid-diaphysis region and each group of rats received their respective treatment for 15days. Ethanol extract dose dependently induced bone regeneration at the fracture site assessed by fluorochrome labeling. All of three doses, 250mg/kg/day dose significantly increased bone volume fraction, trabecular thickness, trabecular number, and connectivity density and decreased trabecular separation in bone. Furthermore, the extract induced the expression of osteogenic genes including BMP-2, BMP-4, RunX-2 and COL-1 compared to the control group. The EE improved fracture healing much earlier (day 15) than the normal healing process, as assessed by the increased callus volumes and mineralized nodule formation. This extract is found beneficial in fracture healing of rat.

  4. High-resolution hydro- and geo-stratigraphy at Atlantic Coastal Plain drillhole CR-622 (Strat 8)

    USGS Publications Warehouse

    Wrege, B.M.; Isely, J.J.

    2009-01-01

    We interpret borehole geophysical logs in conjunction with lithology developed from continuous core to produce high-resolution hydro- and geo-stratigraphic profiles for the drillhole CR-622 (Strat 8) in the Atlantic Coastal Plain of North Carolina. The resulting hydrologic and stratigraphic columns show a generalized relation between hydrologic and geologic units. Fresh-water aquifers encountered are the surficial, Yorktown, Pungo River and Castle Hayne. Geologic units present are of the middle and upper Tertiary and Quaternary periods, these are the Castle Hayne (Eocene), Pungo River (Miocene), Yorktown (Pliocene), James City and Flanner Beach (Pleistocene), and the topsoil (Holocene). The River Bend Formation (Oligocene) is missing as a distinct unit between the Pungo River Formation and the Castle Hayne Formation. The confining unit underlying the Yorktown Aquifer corresponds to the Yorktown Geologic Unit. The remaining hydrologic units and geologic units are hydrologically transitional and non-coincident. The lower Pungo River Formation serves as the confining unit for the Castle Hayne Aquifer, rather than the River Bend Aquifer, and separates the Pungo River Aquifer from the upper Castle Hayne Aquifer. All geologic formations were bound by unconformities. All aquifers were confined by the anticipated hydrologic units. We conclude that CR-622 (Strat 8) represents a normal sequence in the Atlantic Coastal Plain.

  5. Shallow coal exploration drill-hole data--Alabama, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, South Carolina, Tennessee, and Texas

    USGS Publications Warehouse

    Valentine, Brett J.; Dennen, Kristin O.

    2012-01-01

    Coal exploration drill-hole data from over 24,000 wells in 10 States are discussed by State in the chapters of this report, and the data are provided in an accompanying spreadsheet. The drill holes were drilled between 1962 and 1984 by Phillips Coal Company, a division of Phillips Petroleum Company (Phillips). The data were donated to the U.S. Geological Survey (USGS) in 2001 by the North American Coal Corporation, which purchased the Phillips assets as part of a larger dataset. Under the terms of the agreement with North American Coal Corporation, the data were deemed proprietary until February 2011, a period of 10 years after the donation (Appendix of Chapter A). Now that the required period of confidentiality has passed, the data have been digitized from tabulated data files to create unified and spatially consistent coal exploration drill-hole maps and reports for the States of Alabama, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, South Carolina, Tennessee, and Texas. The data are made publically available by this report.

  6. Monazite, iron oxide and barite exsolutions in apatite aggregates from CCSD drillhole eclogites and their geological implications

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoming; Tang, Qian; Sun, Weidong; Xu, Li; Zhai, Wei; Liang, Jinlong; Liang, Yeheng; Shen, Kun; Zhang, Zeming; Zhou, Bing; Wang, Fangyue

    2007-06-01

    We have identified abundant exsolutions in apatite aggregates from eclogitic drillhole samples of the Chinese Continental Scientific Drilling (CCSD) project. Electron microscope and laser Raman spectroscopy analyses show that the apatite is fluorapatite, whereas exsolutions that can be classified into four types: (A) platy to rhombic monazite exsolutions; (B) needle-like hematite exsolutions; (C) irregular magnetite and hematite intergrowths; and (D) needle-like strontian barite exsolutions. The widths and lengths of type A monazite exsolutions range from about 6-10 μm (mostly 6 μm) and about 50-75 μm, respectively. Type B exsolutions are parallel with the C axis of apatite, with widths ranging from 0.5 to 2 μm, with most around 1.5 μm, and lengths that vary dramatically from 6 to 50 μm. Type C exsolutions are also parallel with the C axis of apatite, with lengths of ˜30-150 μm and widths of ˜10 to 50 μm. Type D strontian barite exsolutions coexist mostly with type B hematite exsolutions, with widths of about 9 μm and lengths of about 60-70 μm. Exsolutions of types B, C and D have never been reported in apatites before. Most of the exsolutions are parallel with the C axis of apatite, implying that they were probably exsolved at roughly the same time. Dating by the chemical Th-U-total Pb isochron method (CHIME) yields an U-Pb isochron age of 202 ± 28 Ma for monazite exsolutions, suggesting that these exsolutions were formed during recrystallization and retrograde metamorphism of the exhumed ultrahigh pressure (UHP) rocks. Quartz veins hosting apatite aggregates were probably formed slightly earlier than 202 Ma. Abundant hematite exsolutions, as well as coexistence of magnetite/hematite and barite/hematite in the apatite, suggest that the oxygen fugacity of apatite aggregates is well above the sulfide-sulfur oxide buffer (SSO). Given that quartz veins host these apatite aggregates, they were probably deposited from SiO 2-rich hydrous fluids formed during

  7. True Triaxial Strength and Brittle Fracture of the Granodiorite at the SAFOD Drillhole Wall, and the Potential for Estimating the Maximum Horizontal Principal Stress

    NASA Astrophysics Data System (ADS)

    Lee, H.; Haimson, B.

    2007-12-01

    Salinian granodiorite core from the 1462-1470m segment of the SAFOD drillhole was used to derive its critical mechanical properties under true triaxial stress conditions, analyze shear localization and brittle fracture characteristics, and establish the strength criterion under dry conditions (Eos Trans. AGU, 87/52, Abstract T32C- 03). Here we report on a series of true triaxial tests on 'unjacketed' specimens simulating stress conditions prevailing at the drillhole wall and responsible for borehole failure in the form of breakouts. Owing to numerous random cracks inherent in the core, only 11 rectangular prismatic specimens (19×19×38 mm3) were successfully tested, employing the University of Wisconsin polyaxial cell. The two larger principal stresses, σ1 and σ2, were transmitted through metal pistons, while σ3 was applied by confining fluid pressure. Specimen sides facing σ3 were left 'unjacketed', i.e. in direct contact with the confining fluid, to simulate the condition of drilling-mud pressure applying the principal radial stress (σ3) to the exposed borehole wall. The loading path called for first bringing σ2 and σ3 to preset levels and then increasing σ1 at a constant strain rate (5x10-6/sec) until brittle failure occurred. Invariably, failure occurred at σ1 levels that were only about half as high as those in previously tested dry samples under the same σ2 and σ3 magnitudes. Instead of a shear fracture, or fault, steeply inclined in the direction of σ3, as previously observed in the dry specimens, brittle failure took the form of a localized cluster of through-going extensile cracks parallel and adjacent to the faces subjected to σ3. Since failure occurred at σ1 values close to those at dilatancy onset in dry specimens, we infer that as soon as microcracks reopened, confining fluid rushed into those daylighting at the σ3 faces and extended them along a path of least resistance, i.e. along a plane normal to σ3. Thus brittle failure under

  8. Interactive interpretation of airborne gravity, magnetic, and drill-hole data within the crustal framework of the northern Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Mohamed, Haby S.; Senosy, Mahmoud. M.; Abdel Zaher, Mohamed

    2016-11-01

    The northern part of Western Desert represents the second most important oil-producing and gas provinces in Egypt. The aim of the present study is to highlight the subsurface structures, tectonic framework, and variation of the crust and upper mantle of the northern Western Desert. Geophysical data in the form of airborne gravity and magnetic maps as well as drill-hole data were used to achieve the objectives of the study. 2D interactive sequential modeling of aerogravity and aeromagnetic data was done along some selected profiles with constraints of the existing deep drill-holes at the study area. From these models, three maps for the depths to Precambrian basement, Conrad, and Moho surfaces were constructed. The results of this study indicate that the depth to the basement surface (thickness of the sedimentary section) ranges between 900 m at the southern parts and more than 5500 m at the northern parts. Meanwhile, the depth of Conrad discontinuity which reflect thickness of the upper crust; varies approximately between 10,000 m at the central and northern parts and 17,000 m at the southern parts of the area. While the Moho depth which represents the crustal thickness ranges from 27,000 m at the northern parts to 39,000 m southward. Integrating the results shows that the main compressive stress which influenced the studied area is in N55°W direction that supposed to cause primary shear in N25°W and N85°W directions with right and left lateral movements, respectively.

  9. New evidence from the Tengawai-1 drillhole, South Canterbury, New Zealand, for Oligocene erosion and deposition associated with early development of the Antarctic Circumpolar Current.

    NASA Astrophysics Data System (ADS)

    Tinto, K.; Wilson, G.; Morgans, H.; Dagg, R.

    2009-04-01

    Oligocene limestone strata along the southeastern seaboard of New Zealand are punctuated by a mid-Oligocene hiatus (Marshall Paraconformity) superposed a relatively condensed greensand horizon. The hiatus is widely recognised throughout New Zealand and has been interpreted to represent a period of non-deposition variously associated with ocean currents and sea level fall coincident with mid-Oligocene intensification of the cryosphere. The Tengawai-1 drillhole recovered a 273 m core across the Marshall Paraconformity only 40 km from the type section at Squires Farm in South Canterbury. At the Tengawai-1 site, the hiatus is underlain by fine sand which includes a mid-inner shelf, upper Bortonian-Kaiatan (> 36 Ma) fauna and overlain by a 15 m thick greensand containing a shelfal Duntroonian (25 - 27 Ma) fauna which gives way to a Waitakian (< 25 Ma) glauconitic limestone. Magnetostratigraphy from the core indicates that deposition of the greensand was relatively rapid as at least 6 m of this interval is correlated with Chron C7r (25.496-25.183). The duration of the hiatus in the core, the absence of the underlying Holme Station (Amuri) Limestone, which is present at the nearby Squires Farm section, combined with the character of the surface in a 3 km seismic line across the drill site, suggest significant erosion associated with the Marshall Paraconformity. We infer that this resulted from intense inshore currents persisting for an extended period between 36 and 25 Ma. Post 25.2 Ma, several metres of reworked glaucony were deposited under a waning current. Resumption of deposition at the Tengawai-1 site corresponds to both the lowest δ018 recorded for the mid Oligocene (Oi-2b) as well as suggested initiation of the Antarctic Circumpolar Current.

  10. Small drill-hole, gas mini-permeameter probe

    DOEpatents

    Molz, III, Fred J.; Murdoch, Lawrence C.; Dinwiddie, Cynthia L.; Castle, James W.

    2002-12-03

    The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.

  11. Small drill-hole, gas mini-permeameter probe

    DOEpatents

    Molz, III, Fred J.; Murdoch, Lawrence C.; Dinwiddie, Cynthia L.; Castle, James W.

    2002-01-01

    The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.

  12. Basic Data Report for Drillhole SNL-3 (C-2949)

    SciTech Connect

    Dennis W. Powers; Washington Regulatory and Environmental Services

    2005-01-20

    SNL-3 (permitted by the New Mexico State Engineer as C-2949) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation within a dissolution reentrant north of the WIPP site and well east of Livingston Ridge. SNL-3 is located in the southeast quarter of section 34, T21S, R31E, in eastern Eddy County, New Mexico. SNL-3 was drilled to a total depth of 970 ft below ground level (bgl). Below surface dune sand, SNL-3 encountered, in order, the Mescalero caliche, Gatuna, Dewey Lake, Rustler, and upper Salado Formations. Two intervals were cored: (1) from the lower Forty-niner Member through the Magenta Dolomite and into the upper Tamarisk Member; and (2) from the lower Tamarisk Member through the Culebra Dolomite and Los Meda?os Members and into the uppermost Salado.

  13. Basic Data Report for Drillhole SNL-1 (C-2953)

    SciTech Connect

    Dennis W. Powers; Washington Regulatory and Environmental Services

    2005-01-19

    SNL-1 (permitted by the New Mexico State Engineer as C-2953) was drilled to provide geological data and hydrological testing of the Culebra Dolomite Member of the Permian Rustler Formation near the margin of dissolution of halite in the upper Permian Salado Formation in the northeast arm of Nash Draw. SNL-1 is located in the northwest quarter of section 16, T21S, R31E, in eastern Eddy County, New Mexico, and it is adjacent to the tailings pile of Mississippi Potash Incorporated (now Intrepid) East mine to test for the presence of shallow zones that might include brine infiltrated from the tailings pile. SNL-1 was drilled to a total depth of 644 ft below ground level (bgl). Below surface wash, SNL-1 encountered, in order, the Mescalero caliche, Dewey Lake, and Rustler Formations.

  14. A SMALL-ANGLE DRILL-HOLE WHIPSTOCK

    DOEpatents

    Nielsen, D.E.; Olsen, J.L.; Bennett, W.P.

    1963-01-29

    A small angle whipstock is described for accurately correcting or deviating a drill hole by a very small angle. The whipstock is primarily utilized when drilling extremely accurate, line-of-slight test holes as required for diagnostic studies related to underground nuclear test shots. The invention is constructed of a length of cylindrical pipe or casing, with a whipstock seating spike extending from the lower end. A wedge-shaped segment is secured to the outer circumference of the upper end of the cylinder at a position diametrically opposite the circumferential position of the spike. Pin means are provided for affixing the whipstock to a directional drill bit and stem to alloy orienting and setting the whipstock properly in the drill hole. (AEC)

  15. Basic data report for drillhole WIPP 30 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    Not Available

    1980-04-01

    WIPP 30 was drilled in east-central Eddy County, New Mexico, in NW 1/4, Sec. 33, T21S, R31E, to obtain drill core for the study of dissolution of near-surface rocks. The borehole encountered from top to bottom, the Dewey Lake Red Beds (449' including artificial fill for drill pad), Rustler Formation (299'), and the upper 160' of the Salado Formation. Continuous core was cut from the surface to total depth. Geophysical logs were taken the full length of the borehole to measure acoustic velocities, density, and distribution of potassium and other radioactive elements. Information from this borehole will be included in an interpretive report on dissolution in Nash Draw based on combined borehole data, surface mapping and laboratory analyses of rocks and fluids. The WIPP is to demonstrate (through limited operations) disposal technology for transuranic defense wastes and to then be converted to a repository. The WIPP will also provide research facilities for interactions between high-level waste and salt. Administration policy as of February 1980 is to hold the WIPP site in reserve until the first disposal site can be chosen from several potential sites, including the WIPP.

  16. Basic data report for drillhole WIPP 32 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    1980-11-01

    WIPP 32 is an exploratory borehole drilled to examine the subsurface at a small topographic high in Nash Draw. The borehole is located in east-central Eddy County, New Mexico, in NE 1/4 SE 1/4 Sec. 33, T.22S., R.29E. and was drilled in August, 1979. The hole was drilled to a depth of 390 feet, and encountered, from top to bottom, the Rustler Formation (166') and the upper Salado Formation (224'). Core was taken from 4 to 353 feet. Geophysical logs were run the full length of the hole to measure formation properties. The WIPP is to demonstrate (through limited operations) disposal technology for transuranic defense wastes. The WIPP will also provide facilities to research interactions between high-level waste and salt.

  17. Permeability of Whole Core Samples of Chelungpu Fault, Taiwan TCDP Scientific Drillhole

    NASA Astrophysics Data System (ADS)

    Lockner, D. A.; Morrow, C.; Song, S.; Tembe, S.; Wong, T.

    2005-12-01

    We are measuring material properties of core samples from the 2000 meter Taiwan Continental Drilling Program (TCDP) borehole crossing the Chelungpu fault (activated during the 1999 M7.6 Chi-Chi earthquake). Measurements include permeability, intact strength, frictional sliding strength and poroelastic storativity. Initial tests are concentrating on permeability and storativity of undisturbed whole core samples spanning approximately 60 m including the main shear zones identified at depths of 1111 m and 1151 m. The 1111 m shear zone is believed to have slipped nearly 10 meters during the Chi-Chi earthquake. Formation rock types vary from shales to mudstones to graywacke. Pervasively high clay content throughout the core suggested that samples would be sensitive to salinity of the pore fluid used during testing. This was confirmed by spot tests of strength and permeability versus pore water salinity. (Increased salinity increased strength, Young's modulus and permeability.) Consequently, all TCDP samples were tested with 1 molar KCl pore fluid. Permeability results are therefore expected to represent upper bounds on in-situ values. Whole core permeabilities measured at 15.5 MPa effective confining pressure (appropriate for 1111 m depth) ranged from 0.4 to 7 x 10-20 m2, with the lowest values near the axis of the 1111 m shear zone. At this same effective pressure, storativity was in the range 1.3 to 7 x 10-11 Pa-1 and preliminary measurements of coefficient of friction were 0.55 to 0.75. Apparently, even fault `core' samples contain sufficient quartz and other hard grains to sustain moderate to high frictional strength. The northern segment of the Chi-Chi earthquake which slid on the Chelungpu fault showed an unusual combination of suppressed high frequency seismic radiation and large total slip, leading to the suggestion that deformation was enhanced by high transient pore fluid pressure. Our observations of low permeability, low storativity and high frictional strength make this section of the Chelungpu fault a good candidate for thermally-induced fluid pressurization and dynamic weakening during the Chi-Chi earthquake.

  18. Basic data report for drillhole WIPP 15 (Waste Isolation Pilot Plant-WIPP)

    SciTech Connect

    Not Available

    1981-11-01

    WIPP 15 is a borehole drilled in Marformation.h, 1978, in section 18, T.23S., R. 35E. of south-central Lea County. The purpose of WIPP 15 was to examine fill in San Simon Sink in order to extract climatic information and to attempt to date the collapse of the sink. The borehole was cored to total depth (810.5 feet) and encountered, from top to bottom, Quaternary calcareous clay, marl and sand, the claystones and siltstones of the Triassic Santa Rosa Formation. Neutron and gamma ray geophysical logs were run to measure density and radioactivity. The sink was about 547 feet of Quaternary fill indicating subsidence and deposition. Diatomaceous beds exposed on the sink margin yielded samples dated by /sup 14/C at 20,570 +- 540 years BP and greater than 32,000 years BP; these beds are believed stratigraphically equivalent to ditomaceous beds at 153 to 266 feet depth in the core. Aquatic fauna and flora from the upper 98 feet of core indicate a pluvial period (probably Tohokan) followed by an arid or very arid time before the present climate was established. Aquifer pump tests performed in the Quaternary sands and clays show transmissivities to be as high as 600 feet squared per day. As the water quality was good, the borehole was released to the lessee as a potential water well.

  19. Basic data report for drillhole AEC 8 (Waste Isolation Pilot Plant - WIPP). [Eddy County, New Mexico

    SciTech Connect

    Not Available

    1983-01-01

    AEC 8 was originally drilled in 1974 to a depth of 3028 ft by Oak Ridge National Laboratory as part of the initial investigations of a site for radioactive waste disposal. In 1976, Sandia National Laboratories deepened the borehole from the top of the Castile Formation into the Bell Canyon Formation to test the hydraulic properties of the Bell Canyon. The borehole encountered in descending order Holocene sands (20 ft), Mescalero caliche (6 ft), Santa Rosa Sandstone (143 ft), Dewey Lake Redbeds (491 ft), Rustler Formation (322 ft), Salado Formation (1990 ft), Castile Formation (1335 ft), and the upper Bell Canyon Formation (603 ft). The borehole stratigraphy is in normal order and there is no significant deformation. An extensive suite of geophysical logs provides information on the lithology and stratigraphy. The potentiometric surfaces of Bell Canyon fluid-bearing zones are 550 ft (for the zone at 4821 ft to 4827 ft) and 565 ft below land surface (for the zone at 4844 to 4860 ft). The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level wastes.

  20. Analysis of temperature-time data from 3 m drillholes at Crystal Hot Springs, Utah

    SciTech Connect

    Howell, J.; Chapman, D.S.

    1986-01-01

    A method for determining the background geothermal gradient values through the analysis of temperature measurements at multiple depths to 3 m and recorded over a time span of several days is presented. The analysis is based on the amplitude decay and phase shift of temperature waves with depth. Diurnal and other high frequency temperature variations are used to compute thermal diffusivities which in turn are used to model and remove the effect of the annual temperature wave. The analysis considers both a homogeneous half space and a two layer medium consisting of an overburden of finite thickness overlying a semi-infinite substratum. The method was tested in three holes in the Crystal Hot Springs geothermal field. Temperatures in each hole were recorded once a minute over a period of three days with a probe containing thermistors at eight different depths. Five of the thermistors were positioned at shallow depths (less than or equal to 0.5 m) to monitor diurnal and other high frequency waves and three at greater depths (greater than or equal to 1 m) to measure lower frequency variations. Since measurements were recorded at only three sites, the accuracy and reliability of the method is not fully evaluated. Potential problems to the method resulting from inaccurate model parameters and convective heat transport are investigated.

  1. Basic data report for Drillhole WIPP 33 (Waste Isolation Pilot Plant-WIPP)

    SciTech Connect

    1981-02-01

    WIPP 33 is an exploratory borehole to investigate the nature of unusually thick fill material in the northwest portion of the WIPP site; a breccia pipe was considered a possible, though unlikely, cause of the fill. The borehole is located in Section 13, T22S, R30E, in east central Eddy County, New Mexico and was drilled during July, 1979. The hole was drilled to a depth of 840 feet, and encountered, from top to bottom, surficial Holocene deposits (44 ft including artificial fill for drill pad), the Dewey Lake Red Beds (457 ft), the Rustler Formation (276 ft) and the upper portion of the Salado Formation (163 ft). Selected intervals were cored, and cuttings were taken for examination by geologists. Geophysical logs were taken the full length of the borehole to measure radioactivity, resistivity and density. The stratigraphic profile was found to be normal, and no breccia was observed.

  2. Basic data report for drillhole WIPP 11 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    Not Available

    1982-02-01

    Seismic reflection data from petroleum industry sources showed anomalous reflectors in the Castile Formation over a small area about 3 miles north of the center of the Waste Isolation Pilot Plant (WIPP) site. Additional corroborative seismic reflection data were collected as part of WIPP investigations, and WIPP 11 was drilled to investigate the anomaly. WIPP 11 was drilled near the northwest corner of Section 9, T.22.S., R.31E. it penetrated, in descending order, sand dune deposits and the Gatuna Formation (29'), Santa Rosa Sandstone (132'), Dewey Lake Red Beds (502'), Rustler Formation (288'), Salado Formation (1379'), and most of the Castile Formation (1240'). Beds within the lower part of the Salado, and the upper anhydrite of the Castile, are thinner than normal; these beds are displaced upward structurally by the upper Castile halite which is highly thickened (about 968'). The lowest halite is thin (51') and the basal anhydrite was not completely penetrated. Subsequent seismic and borehole data has shown WIPP 11 to be in a structural complex now identified as the disturbed zone. The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level waste, though there are no plans at this time to dispose of high level waste or spent fuel at WIPP.

  3. Basic data report for drillhole ERDA 9 (Waste Isolation Pilot Plant WIPP)

    SciTech Connect

    Not Available

    1983-01-01

    ERDA 9 was drilled in eastern Eddy County, New Mexico, to investigate and test salt beds for the disposal of nuclear wastes. The hole was placed near the SE corner of section 20, T22S,R31E. It was drilled between April 28 and June 4, 1976, to a depth of 2889 ft (measured from a kelly bushing altitude of 3,420.4 ft MSL). The borehole encountered, from top to bottom, Holocene deposits (including artificial fill) of 22 ft, the Pleistocene Mescalero Caliche (5 ft) and Gatuna Formation (27 ft), 9 ft of the Triassic Santa Rosa Sandstone, and 487 ft of the Dewey Lake Red Beds, 290 ft of the Rustler Formation, 1976 ft of the Salado Formation and 53 ft of the Castile Formation, all of Permian age. Cuttings were collected at 5-ft intervals for the land surface to a depth of 1090 ft, and consecutive cores were taken to a depth of 2876.6 ft. A suite of wireline geophysical logs was run the full length of the borehole to measure distribution of radioactive elements and hydrogen, and variations in rock density and elastic velocity. On the basis of the borehole findings and related hydrological and geophysical programs, the site was judged suitable to pursue the extensive geological characterization program which followed. The core from ERDA 9 provided a suite of samples extensively tested for rock mechanics, physical properties, and mineralogy. Drill-stem tests in ERDA 9 indicated no significant fluids or permeability in the Salado beds of interest. The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level wastes.

  4. Basic data report for drillhole ERDA 6 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    Not Available

    1983-01-01

    ERDA 6 was drilled in eastern Eddy County, New Mexico, to investigate a candidate site for a nuclear waste repository. The site was subsequently rejected on the basis of geological data. ERDA 6 was drilled in the NE 1/4 SE 1/4, section 35, T21S,R31E. The borehole encountered, from top to bottom, 17 ft of Quaternary deposits, 55 ft of the Triassic Santa Rosa Sandstone, 466 ft of the Dewey Lake Red Beds, 273 ft of the Rustler Formation, 1785.5 ft of the Salado Formation and 374.5 ft of the upper Castile Formation, all of Permian age. Cores or drill cuttings were taken throughout the hole. A suite of wireline geophysical logs was run to a depth of 883 ft to facilitate the recognition and correlation of rock units, to assure identification of major lithologies and to provide depth determinations independent of drill-pipe measurements. The site at ERDA 6 was rejected because the structure of the lower Salado and the Castile is too severe to develop a repository along a single set of beds. The borehole also intersected a reservoir of pressurized brine and gas at about 2710'. The pore volume for the reservoir was estimated to be in the range from about 200,000 to about 2 million barrels. ERDA 6 was re-entered in 1981 by the Department of Energy (DOE) for the purpose of further testing the brine reservoir. Those tests are described in separate reports by the DOE and its contractors. The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level wastes.

  5. Frictional strength of cuttings and core from SAFOD drillhole phases 1 and 2

    USGS Publications Warehouse

    Tembe, S.; Lockner, D.A.; Solum, J.G.; Morrow, C.A.; Wong, T.-F.; Moore, Diane E.

    2006-01-01

    We investigated the frictional properties of drill cuttings and core obtained from 1.85-3.1 km true vertical depth in the SAFOD scientific borehole in central California. Triaxial frictional sliding experiments were conducted on samples from primary lithologic traits and significant shear zones, including the inferred active trace of the San Andreas fault. The samples were deformed at room temperature under constant effective normal stresses of 10, 40, and 80 MPa with axial shortening rates of 0.01-1.0 ??m s-1. The weakest samples were from shale, claystone, and siltstone units with friction coefficient ?? = 0.4-0.55. Stronger samples were from quartzo-feldspathic rocks with ?? ??? 0.6. Materials tested from two shear, zones at 2560 and 3067 m measured depth had ?? = 0.4-0.55 and velocity strengthening behavior consistent with fault creep at depths <4 km. The coefficient of friction for bulk samples from the inferred trace of the San Andreas fault was ???0.6. Copyright 2006 by the American Geophysical Union.

  6. Geothermal research on the 2.5 km deep COSC-1 drillhole, Central Sweden

    NASA Astrophysics Data System (ADS)

    Pascal, Christophe; Beltrami, Hugo; Daly, Stephen; Juhlin, Christopher; Kukkonen, Ilmo; Long, Mike; Rath, Volker; Renner, Joerg; Schwarz, Gerhard; Sundberg, Jan

    2015-04-01

    The scientific drilling project "Collisional Orogeny in the Scandinavian Caledonides" (COSC), supported by ICDP and the Swedish Research Council, involves the drilling of two boreholes through carefully selected sections of the Paleozoic Caledonian orogen in Central Sweden. COSC-1, the first of the two planned boreholes, was drilled and fully cored down to 2.5 km depth during spring and summer 2014 near the town of Åre. The COSC working group is organised around six thematic teams including us, the geothermal team. The major objectives of the COSC geothermal team are: a) to contribute to basic knowledge about the thermal regime of Palaeozoic orogenic belts, ancient shield areas and high heat-producing plutons; b) to refine knowledge on climate change at high latitudes (i.e. Scandinavia), including historical global changes, recent palaeoclimate development (since last ice age) and expected future trends; c) to determine the vertical variation of the geothermal gradient, heat flow and thermal properties down to 2.5 km, and to determine the required corrections for shallow (< 1 km) heat flow data; d) to explore the geothermal potential of the Åre-Järpen area; e) to explore to what degree the conductive heat transfer is affected by groundwater flow in the uppermost crust and f) to evaluate the heat generation input and impact from the basement and the alum shales. To reach these targets the following tasks were carried out or are planned: 1) heat flow predictions from shallow boreholes; 2) geophysical logging; 3) analyses of logs and well tests; (3) determination of rock thermal properties on core samples; 4) determination of heat generation rates from radiometric and geochemical studies; 5) fracture characterisation for permeability and convective heat flow estimations; 6) analysis of convective signals; 7) analysis of paleoclimatic signals; 8) heat flow modelling and evaluation of geothermal potential and 9) Fennoscandia heat flow map compilation. The purpose of the present contribution is to summarise the tasks completed so far and to present the on-going research by the COSC geothermal team.

  7. Basic data report for Drillhole AEC 7 (Waste Isolation Pilot Plant - WIPP). [Lea County, New Mexico

    SciTech Connect

    Not Available

    1983-01-01

    AEC 7 is a borehole drilled in western Lea County, New Mexico, in section 31, T.21S.,R.32E. AEC 7 was drilled to 3918 feet in 1974 by Oak Ridge National Laboratory; Sandia deepened the hole to 4732 ft in 1979. The borehole provided stratigraphic and lithologic information in the initial and final drilling. The borehole was used extensively for tests of borehole plugs and plugging operations. AEC 7 penetrated, in descending order, Holocene sands and Mescalero caliche (8 ft), Santa Rosa Sandstone (109 ft), Dewey Lake Red Beds (542 ft), Rustler Formation (325 ft), Salado Formation (2014 ft), Castile Formation (1521 ft), and the upper Bell Canyon Formation (197 ft). Cores were obtained from much of the borehole. An extensive suite of geophysical logs provides information on stratigraphy, lithology, and structure. Beds were in normal stratigraphic sequence and without structural deformation except in the lower Castile. Anhydrite II and Halite II appear to be repeated in the borehole. This section was penetrated during deepening by Sandia; the structural complication is consistent with deformation found nearby in ERDA 6. The potential site on which AEC 7 is located was abandoned in 1976 after ERDA 6 was drilled. The WIPP is a demonstration facility for the disposal of transuranic (TRU) waste from defense programs. The WIPP will also provide a research facility to investigate the interactions between bedded salt and high level wastes.

  8. Basic data report for drillhole WIPP 19 (Waste Isolation Pilot Plant-WIPP)

    SciTech Connect

    Not Available

    1980-03-01

    WIPP 19 is an exploratory borehole whose objective was to determine the nature of the near-surface formations after seismic information indicated a possible fault. The borehole is located in section 20, T.22S., R.31E., in eastern Eddy County, New Mexico, and was drilled between April 6 and May 4, 1978. The hole was drilled to a depth of 1038.2 feet and encountered, from top to bottom, surficial Holocene deposits (7', including artificial fill for drill pad), the Mescalero caliche (7'), the Santa Rosa Sandstone (82'), the Dewey Lake Red Beds (494'), the Rustler Formation (315'), and the upper portion of the Salado Formation (143'). Cuttings were collected at 10-foot intervals. A suite of geophysical logs was run to measure acoustic velocities, density, and radioactivity. On the basis of comparison with other geologic sections drilled in the area, the WIPP 19 section is a normal stratigraphic sequence and it does not show structural disruption. The WIPP is to demonstrate (through limited operations) disposal technology for transuranic defense wastes. The WIPP will also provide facilities to research interactions between high-level waste and salt.

  9. Basic data report for drillhole WIPP 21 (Waste Isolation Pilot Plant - WIPP)

    SciTech Connect

    Not Available

    1980-03-01

    WIPP 21 is an exploratory borehole whose objective is to determine the nature of the near-surface formations after seismic information indicated a possible fault. The borehole is located in section 20, T.22S., R.31E., in eastern Eddy County, New Mexico, and was drilled between May 24 and 26, 1978. The hole was drilled to a depth of 1046 feet and encountered, from top to bottom, surficial Holocene deposits (6', including artificial fill for drill pad), the Mescalero caliche (6'), the Santa Rosa Sandstone (34'), the Dewey Lake Red Beds (487'), the Rustler Formation (308'), and the upper portion of the Salado Formation (178'). Cuttings were collected at 10-foot intervals. A suite of goephysical logs was run to measure acoustic velocities, density, and radioactivity. On the basis of comparison with other geologic sections drilled in the area, the WIPP 21 section is a normal stratigraphic sequence and it does not show structural disruption. The WIPP is to demonstrate (through limited operations) disposal technology for transuranic defense wastes. The WIPP will also provide facilities to research interactions between high-level waste and salt.

  10. The Silent Canyon caldera complex: a three-dimensional model based on drill-hole stratigraphy and gravity inversion

    USGS Publications Warehouse

    McKee, Edwin H.; Hildenbrand, Thomas G.; Anderson, Megan L.; Rowley, Peter D.; Sawyer, David A.

    1999-01-01

    The structural framework of Pahute Mesa, Nevada, is dominated by the Silent Canyon caldera complex, a buried, multiple collapse caldera complex. Using the boundary surface between low density Tertiary volcanogenic rocks and denser granitic and weakly metamorphosed sedimentary rocks (basement) as the outer fault surfaces for the modeled collapse caldera complex, it is postulated that the caldera complex collapsed on steeply- dipping arcuate faults two, possibly three, times following eruption of at least two major ash-flow tuffs. The caldera and most of its eruptive products are now deeply buried below the surface of Pahute Mesa. Relatively low-density rocks in the caldera complex produce one of the largest gravity lows in the western conterminous United States. Gravity modeling defines a steep sided, cup-shaped depression as much as 6,000 meters (19,800 feet) deep that is surrounded and floored by denser rocks. The steeply dipping surface located between the low-density basin fill and the higher density external rocks is considered to be the surface of the ring faults of the multiple calderas. Extrapolation of this surface upward to the outer, or topographic rim, of the Silent Canyon caldera complex defines the upper part of the caldera collapse structure. Rock units within and outside the Silent Canyon caldera complex are combined into seven hydrostratigraphic units based on their predominant hydrologic characteristics. The caldera structures and other faults on Pahute Mesa are used with the seven hydrostratigraphic units to make a three-dimensional geologic model of Pahute Mesa using the "EarthVision" (Dynamic Graphics, Inc.) modeling computer program. This method allows graphic representation of the geometry of the rocks and produces computer generated cross sections, isopach maps, and three-dimensional oriented diagrams. These products have been created to aid in visualizing and modeling the ground-water flow system beneath Pahute Mesa.

  11. Geohydrologic and drill-hole data for test well USW H-1, adjacent to Nevada Test Site, Nye County, Nevada

    USGS Publications Warehouse

    Rush, F. Eugene; Thordarson, William; Bruckheimer, Laura

    1983-01-01

    This report presents data collected to determine the hydraulic characteristics of rocks penetrated in test well USW H-1. The well is one of a series of test wells drilled in and near the southwestern part of the Nevada Test Site, Nye County, Nevada, in a program conducted on behalf of the U.S. Department of Energy. These investigations are part of the Nevada Nuclear Waste Storage Investigations to identify suitable sites for storage of high-level radioactive wastes. Data on drilling operations, lithology, borehole geophysics, hydrologic monitoring, core analysis, ground-water chemistry and pumping and injection tests for well USW H-1 are contained in this report.

  12. Geohydrologic and drill-hole data for test well USW H-4, Yucca Mountain, Nye County, Nevada

    USGS Publications Warehouse

    Whitfield, M.S.; Thordarson, William; Eshom, E.P.

    1984-01-01

    Data are presented on drilling operations, lithology, geophysical well logs, sidewall-core samples, water-level monitoring, pumping tests, injection tests, radioactive-tracer borehole flow survey, and water chemistry for test well USW H-4. The well is one of a series of test wells drilled in the southwestern part of the Nevada Test Site, Nye County, Nevada, in cooperation with the U.S. Department of Energy. These test wells are part of the Nevada Nuclear Waste Storage Investigations to identify sites for storage of high-level radioactive wastes. Test well USW H-4 was drilled in ash-flow tuff to a total depth of 1,219 meters. Depth to water below land surface was 519 meters or at an altitude of 730 meters above sea level. After test pumping at a rate of 17.4 liters per second for approximately 9 days, the drawdown was 4.85 meters. A radioactive borehole-flow survey indicated that the Bullfrog Member was the most productive geologic unit, producing 36.5 percent of the water in the well. The second most productive geologic unit was the Tram Member, which produced 32 percent of the water. The water in test well USW H-4 is predominantly a soft, sodium bicarbonate type of water typical of water produced in tuffaceous rocks in southern Nevada. (USGS)

  13. Description of drill-hole VIIIV core from the Jabiluka unconformity-type uranium deposit, Northern Territory, Australia

    SciTech Connect

    Nutt, C.J.

    1984-01-01

    The Jabiluka unconformity-type uranium deposit is one of four large unconformity-type deposits in the Alligator Rivers Uranium Field in the eastern part of the Pine Creek geosyncline, Northern Territory, Australia. These unconformity-type uranium deposits occur as veins, disseminations, and breccia matrix in metasedimentary rocks of the Lower Proterozoic Cahill Formation and are near a regional unconformity that separates the Cahill from the sedimentary rocks of the Middle Proterozoic Kombolgie Formation. The study of unconformity-type deposits - a new type of uranium deposit typified by deposits discovered in the past 15 years in Australia and Canada - is part of the US Geological Survey uranium program; funding was also provided by the US Department of Energy National Uranium Resource Evaluation (NURE) program. Pancontinental Mining Limited kindly gave us access to Jabiluka core and made their geological and geophysical data available for inclusion in our reports. Data and interpretations from the mineralogy and stratigraphy of Jabiluka should aid in defining characteristics and setting of these world class deposits and guide exploration for similar deposits in the United States. 3 refs., 6 figs., 1 tab.

  14. The Silent Canyon Caldera Complex--A three-dimensional model based on drill-hole stratigraphy and gravity inversion

    SciTech Connect

    Sawyer, D.A.; Anderson, M.L.; Hildenbrand, T.G; McKee, E.H.; Rowley, P.R.

    1999-12-13

    The structural framework of Pahute Mesa, nevada, is dominated by the Silent Canyon caldera complex, a buried, multiple collapse caldera complex. Using the boundary surface between low density Tertiary volcanogenic rocks and denser granitic and weakly metamorphosed sedimentary rocks (basement) as the outer faults surfaces for the modeled collapse caldera complex, it is postulated that the caldera complex collapsed on steeply dipping arcuate faults two, possibly three, times following eruption of at least two major ash-flow tuffs. The caldera and most if its eruptive products are now deeply buried below the surface of Pahute Mesa. Relatively low-density rocks in the caldera complex produce one of the largest gravity lows in the western conterminous United States.

  15. Thermochronometry using red TL of quartz - a feasibility study from in-situ drill-hole samples

    NASA Astrophysics Data System (ADS)

    Schmidt, Christoph; Zöller, Ludwig

    2015-04-01

    Thermochronometry - the revelation of the temperature history of rock related to subsidence or uplift and erosion - relies on methods with closure temperatures >40-70 °C, such as (U-Th-Sm)/He or fission track analysis on apatite. These methods are applicable to young and tectonically active mountain ranges, but results of calculated mean denudation rates are too imprecise for older orogens. Several studies attested the quartz luminescence signal (325 °C TL peak, OSL fast component) isothermal decay at ambient temperatures as low as 56 °C (Prokein and Wagner, 1994; Herman et al., 2010; de Sarkar et al., 2013). The so far determined closure temperatures of the quartz luminescence thermochronometry system vary between ~35 °C for the OSL fast component (Herman et al., 2010) and ~70 °C for red thermoluminescence (RTL; Tsuchiya and Fujino, 2000) and are dependent on the cooling rate and the charge trap parameters. Although featuring a favourably low closure temperature - thus allowing to study the geologically most recent temperature history -, especially quartz OSL suffers from low dose saturation, limiting the application to highly erosive orogens. Saturation doses of RTL exceed those of OSL by a factor of 10 or more (Fattahi and Stokes, 2000), what opens up new perspectives in low-temperature thermochronometry. We here present experimental results on the general suitability of RTL for thermochronometry, obtained for samples from a drilling hole in the granitic basement of the Variscan Fichtelgebirge (Franconia, Germany). The samples allowed studying the RTL signal saturation level in-situ at different ambient temperatures up to ~55 °C (at 1831 m depth). Measurements confirmed depletion of the 325 °C RTL peak for ambient temperatures >25 °C, most probably for even lower temperatures. Irradiation experiments showed that the RTL signal is not in saturation for ambient temperatures >25 °C, even for this 'old' mountain range. We could further demonstrate that the luminescence sensitivity of samples strongly increases with rising ambient temperature, opposite to the findings of Ypma and Hochman (1991) for samples from sedimentary basins. References Fattahi, M., Stokes, S., 2000. Extending the time range of luminescence dating using red TL (RTL) from volcanic quartz. Radiation Measurements 32, 479-485. Herman, F., Rhodes, E.J., Braun, J., Heiniger, L., 2010. Uniform erosion rates and relief amplitude during glacial cycles in the Southern Alps of New Zealand, as revealed from OSL-thermochronology. Earth and Planetary Science Letters 297, 183-189. Prokein, J., Wagner, G.A., 1994. Analysis of thermoluminescent glow peaks in quartz derived from the KTB-drill hole. Radiation Measurements 23, 85-94. de Sarkar, S., Mathew, G., Pande, K., Chauhan, N., Singhvi, A.K., 2013. Rapid denudation of Higher Himalaya during late Pleistocence, evidence from OSL thermochronology. Geochronometria 40, 304-310. Tsuchiya, N., Fujino, K., 2000. Evaluation of cooling history of the Quaternary Takidani pluton using thermoluminescence technique. Proceedings World Geothermal Congress, Kyushu-Tohoku, Japan. Ypma, P.J., Hochman, M.B., 1991. Thermoluminescence geothermometry - a case study of the Otway basin. APEA Journal, 312-324.

  16. Mineral occurrence and drill-hole location map of the International Falls 1 degree by 2 degrees Quadrangle, Minnesota and Ontario

    USGS Publications Warehouse

    Klein, Terry L.

    1989-01-01

    A project to assess the mineral potential of the U.S. part of the International Fall 1° x 2° quadrangle was undertaken by the U.S. Geological Survey (USGS) in the early 1984, as part of the Conterminous United States Mineral Assessment Program (CUSMAP).  Because glacial drift covers most of the basement rocks south of the U.S.-Canada border and mineral production in this part of Minnesota has been virtually nonexistent, data from the adjacent part of Ontario has been used to understand the geologic framework and to evaluate mineral-deposit models relevant to the assessment of the U.S. part of the International Falls quadrangle.  This map and accompanying tables show the locations of mineral occurrences, prospects and mines in both Canada and the United States, and summarize their lithologic association and the characteristic metals found in them.  Locations of drill holes within the United States and completed before 1987 are also included on the map.

  17. Map showing drill-hole depths, lithologic intercepts, and partial isopachs of basin fill in the Winnemucca 1 degree by 2 degrees Quadrangle, Nevada

    USGS Publications Warehouse

    Moring, B.C.

    1990-01-01

    Wells logs used for this map of the Winnemucca quadrangle are from the following sources: (1) logs of more than 1,000 water wells reported to the State of Nevada Division of Water Resources, which are on file with them in Reno and at the with U.S. Geological Survey in Carson City, (2) 44 petroleum wells collected by the Nevada Bureau of Mines (Lintz, 1957; Schilling and Garside, 1968; Garside and Schilling, 1977, Garside and others, 1977; 1988), and (3) Two geothermal wells reported in Zoback (1979) and Flynn and others (1982). Data from isostatic residual and Bouguer gravity maps by Wagini (1985) contributed to the interpretation of basin configuration. Gravity models of Dixie Valley (Schaefer, 1982, and Speed, 1976) and Grass Valley (Grannell and Noble, 1977) and seismic profiles of Grass and Pine Valleys (Potter and others, 1987) helped refine basis interpretations in those areas. The geologic base map of Paleozoic and Mesozoic igneous and sedimentary rocks, Tertiary volcanic and sedimentary rocks, and Cenozoic structures was simplified from Stewart and Carlson (1976b).

  18. The Iceland Deep Drilling Project, a 5 km Deep Drillhole Underway to Investigate Deep Geothermal Resources on the Mid-Atlantic Ridge.

    NASA Astrophysics Data System (ADS)

    Elders, W. A.; Fridleifsson, G. O.; Bird, D. K.; Pope, E. C.; Freedman, A. J.; Schiffmann, P.; Zierenberg, R. A.; Reed, M. H.; Palandri, J.

    2005-12-01

    The Iceland Deep Drilling Project (IDDP) is a long-term study of high-temperature hydrothermal systems on the Reykjanes Peninsula, where the Mid-Atlantic Ridge emerges on to the SW tip of Iceland. The IDDP is a collaborative effort, by a consortium of Icelandic power companies and the Icelandic government, to investigate if utilizing supercritical geothermal fluids would improve the economics of power production from geothermal fields. Over the next decade this will involve drilling a series of wells >4 km deep, to reach temperatures ~450°C. The deepest of these wells so far was completed at 3.1 km in February 2005. The rocks penetrated consist of Holocene basaltic lavas, subglacial hyaloclastites, marine sediments, submarine pillow basalts, and diabase dikes. In 2006, the IDDP will rotary drill and spot core this, or another candidate well, to 4.0 km, and in 2007, the IDDP will deepen the borehole from 4.0 km to 5.0 km, using continuous wireline coring. Such deep, hot wells present both technical challenges and opportunities for important scientific studies. For example, preliminary analyses of rock samples and fluids from the existing geothermal wells indicate that the shallow geothermal system is complex, as indicated by paragenetic relations and strong compositional zoning in calc-silicate minerals, such as epidote. Calculation of local equilibria between calc-silicates and calcite suggests that the CO2 content of the geothermal fluids increased during the evolution of this geothermal system. Zoned hydrothermal amphiboles at 3.1 km depth include tschermakitic hornblende (~13 wt. % Al2O3), suggesting temperatures in the upper 300°C range. Similarly, analyses of hydrogen isotopic ratios of epidotes and amphiboles currently underway indicate that meteoric water has mixed with seawater during the evolution of the Reykjanes geothermal system. The Reykjanes Peninsula is a superb location for scientific investigations of the deeper levels of a high enthalpy geothermal resource. Coring below 4.0 km is designed to penetrate into supercritical fluids which couple black smoker hydrothermal systems with their magmatic heat sources. Supercritical fluids have greatly enhanced rates of mass transfer and chemical reaction. Such environments have never before been available for comprehensive direct study and sampling. These investigations will be a very important contribution to global science and have clear connections to the studies of ridge-hotspot interactions by the Integrated Ocean Drilling Program. The broader implications of the IDDP are twofold; scientifically it will permit a quantum leap in our understanding of active hydrothermal processes that are important on a global scale, and secondly, if the industrial aims are successful, the resulting technology could have a major impact on improving the economics of high-temperature geothermal resources worldwide. The IDDP has welcomed participation by an international group of scientists that will investigate and test models of the coupling of hydrothermal and magmatic processes. The status of the project is reported at http://www.iddp.is.

  19. Tools used in mineral exploration for measuring the conductivity and the resistivity in drillholes and on drill core: observations on their range of sensitivity

    NASA Astrophysics Data System (ADS)

    Parry, Devon; Smith, Richard S.; Mahmoodi, Omid

    2016-07-01

    A study has been undertaken to acquire conductivity data using the EM39 low-induction-number conductivity tool. Measurements were taken in three holes in the Sudbury, Ontario, area: at Victoria in the south-west part of the Sudbury structure; at Levack, in the north range; and at the Lady Violet deposit near Copper Cliff. These data were compared with pre-existing data acquired using four other tools and measurements taken on core extracted from the holes. The four tools are the DGI galvanic downhole resistivity tool, the IFG downhole conductivity tool, and the handheld KT-10 and GDD meters. The comparison shows that each tool has a finite range of sensitivity. The resistivity tool used by DGI Geoscience is sensitive to conductivities primarily in the range 0.01 to 100 mS/m; the EM39 tool is sensitive to conductivities in the range of ~30 mS/m to 3000 mS/m and the IFG tool to conductivities greater than 30 mS/m. In the sub-ranges where the ranges of two instruments overlap, one might expect a good correlation between the measurements derived from the two tools. However, this is not always the case, as the instruments can have a different volume of sensitivity: the EM39 has a coil separation of 50 cm and will see material greater than 20 cm away from the hole; whereas the IFG conductivity tool seems to have a smaller spatial scale of sensitivity due to its 10 cm coil size. The handheld instruments used to log the conductivity of the core are sensitive to more conductive material (greater than ~1 S/m). The scale of the sensors of these handheld instruments is a few cm, so they are focussing on a very local estimate. The spatial characteristics of the handheld instruments are similar to the IFG tool, so there is a reasonable linear correlation between the conductivities derived from these three different instruments. However, the slopes are not unity; for example, the GDD instrument gives values three times greater than the KT-10. When selecting tools for measuring the resistivity and conductivity, ensure that the values that you expect to measure fall within the range of sensitivity of the instrument and that the features sought are comparable in size to the volume of sensitivity.

  20. Drill-hole data, drill-site geology, and geochemical data from the study of Precambrian uraniferous conglomerates of the Medicine Bow Mountains and Sierra Madre of southeastern Wyoming

    SciTech Connect

    Karlstrom, K.E.; Houston, R.S.; Schmidt, T.G.; Inlow, D.; Flurkey, A.J.; Kratochvil, A.L.; Coolidge, C.M.; Sever, C.K.; Quimby, W.F.

    1981-02-01

    This volume is presented as a companion to Volume 1: The Geology and Uranium Potential of Precambrian Conglomerates in the Medicine Bow Mountains and Sierra Madre of Southeastern Wyoming; and to Volume 3: Uranium Assessment for Precambrian Pebble Conglomerates in Southeastern Wyoming. Volume 1 summarized the geologic setting and geologic and geochemical characteristics of uranium-bearing conglomerates in Precambrian metasedimentary rocks of southeastern Wyoming. Volume 3 is a geostatistical resource estimate of U and Th in quartz-pebble conglomerates. This volume contains supporting geochemical data, lithologic logs from 48 drill holes in Precambrian rocks of the Medicine Bow Mountains and Sierra Madre, and drill site geologic maps and cross-sections from most of the holes.

  1. Examining the feasibility of modeling the subsurface structure of two volcanic units in drill-holes UE18r and ER-EC-2a using existing magnetic data

    USGS Publications Warehouse

    Phelps, G.A.

    2010-01-01

    The magnetic properties of two volcanic units encountered in two drill holes, ER-EC-2a and UE18r, located in the vicinity of the Nevada Test Site, were investigated to determine if the units were significantly more magnetic than overlying units and, thus, detectable by using aeromagnetic data. Magnetic-susceptibility measurements were made on cuttings from the drill holes and were combined with published data on remanent magnetism to generate two-dimensional magnetic models, based on an interpreted geologic cross-section. The resulting magnetic anomaly calculated from the models was compared with the observed aeromagnetic anomaly and was found to differ significantly from it. Furthermore, the calculated magnetic anomalies were found to be relatively insensitive to changes in the two units of interest.

  2. Mineral Dilution and Shallow Groundwater Dynamics as Motor to Drive Fluid Migration in the Deep Crystalline Crust - Interpretation of Hydraulic Investigations From the 9,101 m Super Deep German Continental Drillhole -

    NASA Astrophysics Data System (ADS)

    Kessels, W.; Graesle, W.

    2002-12-01

    The results of 16 years of research at the scientific drilling test site KTB Oberpfalz show that fluid flow and open hydraulic fractures exist down to 9,101m (Kessels, 1991; Huenges et. al., 1997). This means that in this seismically low active area, crustal dynamics produces stress accumulation and related fracturing (Zoback et. al. 1993). Two major fractured fault zones cross the KTB main hole at about 4,000 m and 7,100m depth. Hydraulic communication between the KTB main hole and the 4,000 m deep pilot hole shows that the upper 400 m thick fracture zone has a good transmissivity and a very low fracture porosity (Kessels and KÂ\\x81ck, 1995). The distance between both holes was 200m. The isotopic components of the fluid recovered from this zone indicate a west - east fluid flow from a topographic lower sedimentary area to the higher hilly area of the KTB site (M”ller et. al. 1997). To explain this phenomenon, the existence of a permanent, density driven dilution motor pushing such a flow is suggested. With such a system it is possible to explain fluid flow in the deep crust against the higher potential of the groundwater surface. By means of a simple convection model it can be shown that the density driven dilution motor can create a more effective hydraulic potential than a motor driven by precipitation and the related hydraulic head of the groundwater surface. Furthermore, with common geothermal gradients, the geothermal convection motor is weak compared with the fluid density effects discussed here. References: KESSELS, W. (1991): Objectives and execution of hydraulic experiments in the KTB-Oberpfalz borehole within the long-term measurement and test programme, Scientific Drilling 2, S. 287-298. ZOBACK, D., APEL, R., BAUMGÂŽRTNER, J., BRUDY, M., EMMERMANN, R, ENGESER, B., FUCHS, K., KESSELS, W., RISCHMšLLER, H., RUMMEL, F., VERNIK, L. (1993): Upper-crustal strength inferred from stress measurements to 6 km depth in the KTB borehole, Nature, 365, S. 633-635. KESSELS, W. and KšCK, J (1995): Hydraulic Communication in the Crystalline Rock Between the two Boreholes of the Continental Deep Drilling Programme in Germany, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., 32, S. 37-47. M™LLER, P., WEISE, S., ALTHAUS, E., BACH, W., BEHR, H. J., BORCHARDT, R, BRŽUER, K., DRESCHER, J., ERZINGER, J., FABER, E., HORN, E., HUENGES, E., KŽMPF, W., KESSELS, W., KIRSTEN, T., LANDWEHR, D., LODEMANN, M., MACHON, L., PEKDEGER, A., PIELOW, H.-U., REUTEL, C., SIMON, K., WALTER, J., WEINLICH, F. H., ZIMMER, M. (1997): Paleo- and Recent Fluids in the Upper Continental Crust - Results from the German Continental Deep Drilling Projekt (KTB), Journal of Geophysical Resarch, 102, B8, S 18223 - 18254. HUENGES, E., ENGESER, B., ERZINGER, J., KESSELS, W., KšCK, J. (1997): The Permeable Crust: Geohydraulic Properties Down to 9000 m Depth - Results from the German Continental Deep Drilling Project (KTB), Journal of Geophysical Resarch, 102, B8, S 18 255 -18 265.

  3. Can Re-Use of Demil Explosives and Propellants in Commercial Blasting be Made Environmentally Acceptable

    DTIC Science & Technology

    1994-08-01

    emulsion explosives in small cartridge diameters have prices approaching those of low grade dynamites. Emulsion/ ANFO Mix Explosives, Heavy ANFO The...bubble- sensitized emulsion blasting agent is used by itself in very wet drillholes, or in drillholes with running water, where ANFO would be unusable...slow, so-called heavy ANFO is used, consisting of a mix of ANFO and emulsion, containing more emulsion the more water there is in the drillholes

  4. Drilling Predation on Serpulid Polychaetes (Ditrupa arietina) from the Pliocene of the Cope Basin, Murcia Region, Southeastern Spain

    PubMed Central

    Martinell, Jordi; Kowalewski, Michał; Domènech, Rosa

    2012-01-01

    We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ∼5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 to 13.4 mm in length and displayed allometric growth patterns, with larger specimens being relatively slimmer. Drilled Ditrupa tubes were observed in all samples. Drillholes, identified as Oichnus paraboloides, were characterized by circular to elliptical outline (drillhole eccentricity increased with its diameter), parabolic vertical profile, outer diameter larger than inner diameter, penetration of one tube wall only, narrow range of drill-hole sizes, and non-random (anterior) distribution of drillholes. A total of 233 drilled specimens were identified, with drilling frequencies varying across horizons from 2.7% to 21% (3.9% for pooled data). Many tube fragments were broken across a drillhole suggesting that the reported frequencies are conservative and that biologically-facilitated (drill-hole induced) fragmentation hampers fossil preservation of complete serpulid tubes. No failed or repaired holes were observed. Multiple complete drillholes were present (3.9%). Drilled specimens were significantly smaller than undrilled specimens and tube length and drill-hole diameter were weakly correlated. The results suggest that drillholes were produced by a size-selective, site-stereotypic predatory organism of unknown affinity. The qualitative and quantitative patterns reported here are mostly consistent with previous reports on recent and fossil Ditrupa and reveal parallels with drilling patterns documented for scaphopod mollusks, a group that is ecologically and morphologically similar to Ditrupa. Consistent with previous studies, the results suggest that free-dwelling serpulid

  5. Results of site validation experiments. Volume II. Supporting documents 5 through 14

    SciTech Connect

    Not Available

    1983-01-01

    Volume II contains the following supporting documents: Summary of Geologic Mapping of Underground Investigations; Logging of Vertical Coreholes - ''Double Box'' Area and Exploratory Drift; WIPP High Precision Gravity Survey; Basic Data Reports for Drillholes, Brine Content of Facility Internal Strata; Mineralogical Content of Facility Interval Strata; Location and Characterization of Interbedded Materials; Characterization of Aquifers at Shaft Locations; and Permeability of Facility Interval Strate.

  6. 30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... by the regulatory authority. Use of a drilled hole or monitoring well as a water well must meet the... underground openings: General requirements. Each exploration hole, other drillhole or borehole, shaft, well..., fish and wildlife, and machinery in the permit area and adjacent area. Each exploration hole,...

  7. 30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... by the regulatory authority. Use of a drilled hole or monitoring well as a water well must meet the... underground openings: General requirements. Each exploration hole, other drillhole or borehole, shaft, well..., fish and wildlife, and machinery in the permit area and adjacent area. Each exploration hole,...

  8. 30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... by the regulatory authority. Use of a drilled hole or monitoring well as a water well must meet the... underground openings: General requirements. Each exploration hole, other drillhole or borehole, shaft, well..., fish and wildlife, and machinery in the permit area and adjacent area. Each exploration hole,...

  9. 30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... by the regulatory authority. Use of a drilled hole or monitoring well as a water well must meet the... underground openings: General requirements. Each exploration hole, other drillhole or borehole, shaft, well..., fish and wildlife, and machinery in the permit area and adjacent area. Each exploration hole,...

  10. A Placer-Gold Evaluation Exercise.

    ERIC Educational Resources Information Center

    Tunley, A. Tom

    1984-01-01

    A laboratory exercise allowing students to use drillhole data to simulate the process of locating a placer gold paystreak is presented. As part of the activity students arithmetically compute the value of their gold, mining costs, and personal profits or losses, and decide on development plans for the claim. (BC)

  11. Geology of Medicine Lake Volcano, Northern California Cascade Range

    USGS Publications Warehouse

    Donnelly-Nolan, Julie

    1990-01-01

    Medicine Lake volcano (MLV) is located in an E-W extensional environment on the Modoc Plateau just east of the main arc of the Cascades. It consists mainly of mafic lavas, although drillhole data indicate that a larger volume of rhyolite is present than is indicated by surface mapping. The most recent eruption was rhyolitic and occurred about 900 years ago. At least seventeen eruptions have occurred since 12,000 years ago, or between 1 and 2 eruptions per century on average, although activity appears to be strongly episodic. The calculated eruptive rate is about 0.6 km3 per thousand years during the entire history of the volcano. Drillhole data indicate that the plateau surface underlying the volcano has been downwarped by 0.5 km under the center of MLV. The volcano may be even larger than the estimated 600 km3, already the largest volcano by volume in the Cascades.

  12. Inversion of potential field data with prior information constraints: examples from mining areas in China

    NASA Astrophysics Data System (ADS)

    Liu, Shuang; Hu, Xiangyun; Fedi, Maurizio

    2017-04-01

    To decrease the ambiguity of potential field data inversion it is important to add some constraints based on prior information. We use a constrained inversion method with different kinds of prior information from drill-hole loggings, geological cross-sections and other kind of geophysical data. We use such information as a starting model or as a reference model and compare the obtained inverted models. The source properties are given by rock and ore samples, and are used as constraints to build the starting and reference models. The method firstly is tested by use of magnetic data on an iron deposit with drillhole logging information and the test reveals that inversion results adding prior information are in better agreement with the true models.

  13. Preliminary geologic investigation of the West Glendive lignite deposits, Dawson County, Montana

    USGS Publications Warehouse

    Banet, Arthur C.

    1979-01-01

    Four major lignite beds, all in the Fort Union Formation (Paleocene), occur in the West Glendive area, Dawson County, Montana. The Newton Ranch and Poverty Flats beds are in the Lebo Member and the Peuse and Kolberg Ranch beds are in the Tongue River Member. Correlation of the lignite beds across the area shows that the Peuse bed is the thickest and most extensive. Field mapping and drill-hole data indicate that folding and faulting are more common than previously reported.

  14. Taphonomic pathways and environmental differentiation based on the clypeasteroid echinoid Echinocyamus

    NASA Astrophysics Data System (ADS)

    Grun, Tobias; Nebelsick, James

    2015-04-01

    Taphonomic pathways that dictate the preservation of skeletal components differ along environmental gradients. Understanding preservation potentials within different habitats are key factors in reconstructing paleoenvironments. Actualistic studies allow for direct correlation of taphonomic features with environmental parameters serving as models for fossil analogies. This study concentrates on a single genus of clypeasteroid echinoids thus alleviating the influence of differential skeletal architectures on taphonomic pathways. The goal of this study is to gain detailed information on the alteration and preservation of recent examples and their variations with respect to environmental conditions with the goal of applying this knowledge to fossil populations. Numerous tests of the minute clypeasteroid echinoid Echinocyamus pusillus were collected from the Island of Giglio (Mediterranean Sea) from various depths and environments. The tests were analyzed for taphonomic alteration including the abrasion of the (1) tubercles, (2) stereom and (3) genital and ambulacral pores. The preservation of the (4) ambitus and the (5) test were also analyzes as well as the degree of (5) encrustation and (6) fragmentation. When drillholes of predatory gastropods were present, these were analyzed for the (7) drillhole outline and (8) cross-section. These features were analyzed both qualitatively and quantitatively and subjected to statistical analysis. Results indicate that most tests show a rather good preservation with individuals from sheltered areas featuring a low grade of tubercle and stereom abrasion. Pores are mostly not affected and the encrustation rate is low. Areas with higher wave activities yield individuals which features higher abrasion grades. Pores are more often affected than in sheltered areas, while the encrustation rate is significantly lower. Drillholes are generally robust to abrasion, since almost all drillhole outlines and the concave cross-sections are well

  15. Uranium assessment for the Precambrian pebble conglomerates in southeastern Wyoming

    SciTech Connect

    Borgman, L.E.; Sever, C.; Quimby, W.F.; Andrew, M.E.; Karlstrom, K.E.; Houston, R.S.

    1981-03-01

    This volume is a geostatistical resource estimate of uranium and thorium in quartz-pebble conglomerates, and is a companion to Volume 1: The Geology and Uranium Potential to Precambrian Conglomerates in the Medicine Bow Mountains and Sierra Madre of Southeastern Wyoming; and to Volume 2: Drill-Hole Data, Drill-Site Geology, and Geochemical Data from the Study of Precambrian Uraniferous Conglomerates of the Medicine Bow Mountains and the Sierra Madre of Southeastern Wyoming.

  16. Application of a feedforward neural network in the search for kuroko deposits in the hokuroku district, Japan

    USGS Publications Warehouse

    Singer, D.A.; Kouda, R.

    1996-01-01

    A feedforward neural network with one hidden layer and five neurons was trained to recognize the distance to kuroko mineral deposits. Average amounts per hole of pyrite, sericite, and gypsum plus anhydrite as measured by X-rays in 69 drillholes were used in train the net. Drillholes near and between the Fukazawa, Furutobe, and Shakanai mines were used. The training data were selected carefully to represent well-explored areas where some confidence of the distance to ore was assured. A logarithmic transform was applied to remove the skewness of distance and each variable was scaled and centered by subtracting the median and dividing by the interquartile range. The learning algorithm of annealing plus conjugate gradients was used to minimise the mean squared error of the sealed distance to ore. The trained network then was applied to all of the 152 drillholes that had measured gypsum, sericite, and pyrite. A contour plot of the neural net predicted distance to ore shows fairly wide areas of 1 km or less to ore; each of the known deposit groups is within the 1 km contour. The high and htw distances on the margins of the contoured distance plot are in part the result of boundary effects of the contouring algorithm. For example, the short distances to ore predicted west of the Shakanai (Hanaoka) deposits are in basement. However, the short distances to ore predicted northeast of Furotobe, just off the figure, coincide with the location of the Nurukawa kuroko deposit and the Omaki deposit, south of the Shakanai-Hanaoka deposits, seems to be on an extension of short distance to ore contour, but is beyond the 3 km limit from drillholes. Also of interest are some areas only a few kilometers from the Fukazawa and Shakanai groups of deposits that are estimated to be many kilometers from ore, apparently reflecting the network's recognition of the extreme local variability of the geology near some deposits. 1996 International Association for Mathematical Geology.

  17. Element mobility studies of two drill-cores from the Götemar Granite (Kråkemåla test site), southeast Sweden

    USGS Publications Warehouse

    Smellie, John A.T.; Stuckless, John S.

    1985-01-01

    The pervasive alteration and the more recent mobilisation of U are evident to a depth of at least 600 m. The effects are most prevalent along major fracture zones and within the upper 250–300 m of one drill-hole where a high frequency of crush zones has been noted. Higher Fe oxidation ratios, higher Rb contents, lower U contents and correspondingly higher Th/U ratios, all characterise this zone.

  18. Geochemistry of Salado Formation brines recovered from the Waste Isolation Pilot Plant (WIPP) repository

    SciTech Connect

    Abitz, R.; Myers, J.; Drez, P.; Deal, D.

    1990-01-01

    Intergranular brines recovered from the repository horizon of the Waste Isolation Pilot Plant (WIPP) have major- and trace-element compositions that reflect seawater evaporation and diagenetic processes. Brines obtained from repository drill holes are heterogenous with respect to composition, but their compositional fields are distinct from those obtained from fluid inclusions in WIPP halite. The heterogeneity of brine compositions within the drill-hole population indicates a lack of mixing and fluid homogenization within the salt at the repository level. Compositional differences between intergranular (drill hole) and intragranular (fluid inclusions) brines is attributed to isolation of the latter from diagenetic fluids that were produced from dehydration reactions involving gypsum and clay minerals. Modeling of brine-rock equilibria indicates that equilibration with evaporite minerals controls the concentrations of major elements in the brine. Drill-hole brines are in equilibrium with the observed repository minerals halite, anhydrite, magnesite, polyhalite and quartz. The equilibrium model supports the derivation of drill-hole brines from near-field fluid, rather than large-scale vertical migration of fluids from the overlying Rustler or underlying Castile Formations. 13 refs., 6 figs., 6 tabs.

  19. Comparison of sea-ice thickness measurements under summer and winter conditions in the Arctic using a small electromagnetic induction device

    SciTech Connect

    Haas, C.; Eicken, H.; Miller, H.; Gerland, S.

    1997-05-01

    Drillhole-determined sea-ice thickness was compared with values derived remotely using a portable small-offset loop-loop steady state electromagnetic (EM) induction device during expeditions to Fram Strait and the Siberian Arctic, under typical winter and summer conditions. Simple empirical transformation equations are derived to convert measured apparent conductivity into ice thickness. Despite the extreme seasonal differences in sea-ice properties as revealed by ice core analysis, the transformation equations vary little for winter and summer. Thus, the EM induction technique operated on the ice surface in the horizontal dipole mode yields accurate results within 5 to 10% of the drillhole determined thickness over level ice in both seasons. The robustness of the induction method with respect to seasonal extremes is attributed to the low salinity of brine or meltwater filling the extensive pore space in summer. Thus, the average bulk ice conductivity for summer multiyear sea ice derived according to Archie`s law amounts to 23 mS/m compared to 3 mS/m for winter conditions. These mean conductivities cause only minor differences in the EM response, as is shown by means of 1-D modeling. However, under summer conditions the range of ice conductivities is wider. Along with the widespread occurrence of surface melt ponds and freshwater lenses underneath the ice, this causes greater scatter in the apparent conductivity/ice thickness relation. This can result in higher deviations between EM-derived and drillhole determined thicknesses in summer than in winter.

  20. Seismic reflection structure of intracratonic palmyride fold-thrust belt and surrounding Arabian platform, Syria

    SciTech Connect

    McBride, J.H.; Barazangi, M.; Best, J. ); Al-Saad, D.; Sawaf, T.; Al-Otri, M.; Gebran, A. )

    1990-03-01

    Seismic reflection and drill-hole data from central Syria provide a detailed view of the subsurface structure (10-15 km depth) of the relatively little-studied intracratonic Palmyride fold and thrust belt. The data set, together with surface geologic mapping, constrains a structural/stratigraphic section spanning the northeast sector of the belt and the surrounding subprovinces of the Arabian platform. The seismic reflection and drill-hole data show Mesozoic stratigraphic sequences thickening abruptly into the Palmyrides from the adjacent, arched Paleozoic platforms Neogene (alpine) folding and thrusting of the Mesozoic basin, as documented on the seismic data, are sharply restricted to the narrow width of the belt ({approximately}100 km), in contrast to the relatively undeformed Phanerozoic strata of the platforms to the north and south. The seismic and drill-hole data support the hypothesis that the palmyrides began as a Permian-Triassic failed rift connected to the Levantine passive continental margin, which was inverted and complexly deformed by the interfering effects of Cenozoic movements along the Dead Sea transform fault system and the Turkish Bitlis convergent zone. The seismic data provide a first view into the extent and depth of the early basin formation and subsequent compressional deformation, and as such represent a necessary element for constraining reconstructions of northern Middle East plate motions. 20 figs.

  1. Using drill cutting separates to estimate the strength of narrow shear zones at SAFOD

    USGS Publications Warehouse

    Morrow, C.; Solum, J.; Tembe, S.; Lockner, D.; Wong, T.-F.

    2007-01-01

    A technique is presented for estimating frictional strength of narrow shear zones based on hand selection of drillhole cuttings separates. Tests were conducted on cuttings from the SAFOD scientific drillhole near Parkfield, California. Since cuttings are mixed with adjacent material as they travel up the drillhole, these fault-derived separates give a better representation of the frictional properties of narrow features than measurements from the bulk material alone. Cuttings from two shear zones (one an active trace of the San Andreas fault) contain a significant weight percent of clay-rich grains that exhibit deformation-induced slickensides. In addition, cuttings from the active SAF trace contain around 1% serpentine. Coefficients of friction for clay-rich and serpentine grains were 0.3-0.5 and 0.4-0.45, respectively. These values are around 0.12 lower than the friction coefficient of the corresponding bulk cuttings, providing an improved estimate of the frictional strength of the San Andreas fault. Copyright 2007 by the American Geophysical Union.

  2. Imaging of unconformity related uranium ore zones by crosshole ERT

    NASA Astrophysics Data System (ADS)

    Yi, M.; Kim, C.; Son, J.

    2011-12-01

    For the exploration of unconformity type uranium deposits in the Athabasca basin, Canada, electrical resistiivty survey is commonly used to define graphtic conductors in the basement. The method, however, can not provide enough resolution since the exploration target is seated in depth greater than 300 m while the width is less than 50 m. To overcome this inherent problem and introduce new exploration technology, we applied the crosshole ERT(Electrical Resistivity Tomography) technology in the Athabasca basin. Since the drillholes are not vertical and randomly oriented, 3D ERT inversion algorithm, accommodating arbitray electrode locations, was used to reconstruct 2D surbsurface resistivity image. For the 2D inversion in 3D inversion code, subsurface was assumed to be two-dimensional. We also applied the full 3D inversion to the field data set from several drillholes. In the ERT images, we could observe the graphitic pelite zone with very low resistivity which is our exploration target. By defining the accurate location of graphtic conductor, we could understand the basic setting of the site. Moreover, in the 3D ERT image, we could define anomalous zone in 3D space which can be related to the uranium target. By this introductory ERT survey, we could show that ERT can be used as a new geophysical exploration method in the Athabasca basin. In the current exploration procedure, barren drillholes are abandoned and further geophysical surveys using thes holes are rare in most cases. Since ERT technique can provide very high resolution image of the subsurface, we can have more detailed information to design the drilling program and this can lead to the cost reduction of exploration program. We expect crosshole ERT will become a standard geophysical methods in the exploration projects in the Athabasca basin.

  3. Mechanical anisotropy of the Yucca Mountain tuffs

    SciTech Connect

    Price, R.H.; Boyd, P.J.; Martin, R.J.; Haupt, R.W.; Noel, J.S.

    1991-12-31

    Three series of measurements were performed on oriented cores of several Yucca Mountain tuffs to determine the importance of mechanical anisotropy in the intact rock. Outcrop and drillhole samples were tested for acoustic velocities, linear compressibilities, and strengths in different orientations. The present data sets are preliminary, but suggest the tuffs are transversely anisotropic for these mechanical properties. The planar fabric that produces the anisotropy is believed to be predominantly the result of the preferred orientation of shards and pumice fragments. The potential of significant anisotropy has direct relevance to the formulation of constitutive formulation and the analyses of an underground opening within the Yucca Mountain.

  4. Diapiric origin of the Blytheville and Pascola arches in the Reelfoot rift, east-central United States: Relation to New Madrid seismicity

    SciTech Connect

    McKeown, F.A.; Diehl, S.F.; Glick, E.E. ); Hamilton, R.M. )

    1990-11-01

    Most of the earthquakes in the New Madrid seismic zone correlate spatially with the Blytheville arch and part of the Pascoal arch, which are interpreted to be the same structure. Both arches may have formed by diapirism along the axis of the Reelfoot rift. Seismic, geophysical, and drill-hole data indicate that the rocks in the arches are highly deformed and fractured and have gross lithologic properties that make them weaker than rocks adjacent to the arches. The weaker rocks are inferred to fail seismically more readily than the stronger rocks adjacent to the arches.

  5. Modeling the growth plates in the pediatric knee: implications for anterior cruciate ligament reconstruction.

    PubMed

    Guarino, J; Tennyson, S; Barrios, Y; Shea, K; Pfeiffer, R; Sabick, M

    2004-10-01

    The authors develop 3-D models of the pediatric knee from magnetic resonance imaging (MRI) image files, with the goal of minimizing injury to the pediatric growth plate during surgery. Computerized tomography (CT) scans have better resolution and contrast between bone and soft tissue than MRI scans; however, surgeons rely upon MRI scans to plan knee-joint surgeries such as anterior cruciate ligament (ACL) reconstruction. Surgeons can use the virtual models to plan and verify surgical procedures such as hole drilling and ligament attachments, and to determine volume removed from a growth plate due to different drill-hole placements with various drill sizes.

  6. API tubular ovality and stresses in horizontal wells with a finite-element method

    SciTech Connect

    Akgun, F. ); Mitchell, B.J.; Huttelmaier, H.P. )

    1994-06-01

    A finite-element program, ANSYS, was used to determine the change in physical dimensions of oilfield tubulars and the growth of stresses in their walls as these tubulars were run and landed into a drillhole. Ovalities and axial and tangential stresses modeled with a finite-element method (FEM) are presented in easy-to-use charts for 7- and 9 5/8-in.-OD API casing. Axial bending stresses with the FEM are compared with those under Lubinski's bending equation and the classic beam-bending equation.

  7. Coal reserves of the Pittsburgh (No.8) bed in Belmont County, Ohio

    USGS Publications Warehouse

    Berryhill, Henry L.

    1955-01-01

    Remaining coal reserves totaling 1,929 million tons have been appraised in the Pittsburgh (No. 8) coal bed in Belmont County, Ohio. Of these, 508 million tons are classified as measured and 1,421 million tons are classified as indicated. All the coal has less than 1,000 feet of overburden, and most of it is of high volatile A bituminous rank. This estimate is based on field work by the United States Geological Survey, supplemented by data from the fries of the Ohio Geological Survey and from mine and drill-hole records provided by mining companies.

  8. ROCK PILE MOUNTAIN WILDERNESS STUDY AREA, MISSOURI.

    USGS Publications Warehouse

    Pratt, Walden P.; Ellis, Clarence

    1984-01-01

    A geologic and mineral-occurrence survey of the Rock Pile Mountain Wilderness study area in southeastern Missouri indicates the area has little promise for the occurrence of energy and mineral resources. Exploratory drill holes on private land along the west side of the area encountered no mineralization, and none of the rocks or sediments exposed in the area contain any detectable evidence of significant mineralization. Drilling through the Bonneterre Formation, supplemented by geochemical studies of the drill-hole samples, would test the remote possibility of lead mineralization close to the contact with Precambrian rocks.

  9. [External fixation of wood as an example of an adapted technic].

    PubMed

    Domres, B; Klöss, T

    1984-01-01

    Logistic reasons gave rise to construction, production and application of an external fixation made of the wood of the rubber-tree (ficus elastica) during the treatment of Cambodian war-injured patients at the field hospital of Khao I Dang. Round pieces of wood 1.5 cm respectively 2 cm in diameter, with drill-holes (diameter 3.2 mm) for the "Steinmann"-nails were planed from well-seasoned planks of the Jang-tree. For the treatment of 25 open fractures - the wooden fixation proved to be the best solution.

  10. Uniaxial compression test series on Bullfrog Tuff

    SciTech Connect

    Price, R H; Jones, A K; Nimick, K G

    1982-04-01

    Nineteen uniaxial compressive experiments were performed on samples of the Bullfrog Member of the Crater Flat Tuff, obtained from drillhole USW-G1 at Yucca Mountain on the Nevada Test Site. The water saturated samples were deformed at a nominal strain rate of 10{sup -5} sec{sup -1}, atmospheric pressure and room temperature. Resultant unconfined compressive strengths, axial strains to failure, Young`s moduli and Poisson`s ratios ranged from 4.63 to 153. MPa, .0028 to .0058, 2.03 to 28.9 GPa and .08 to .16, respectively.

  11. Precambrian basement geology of North and South Dakota.

    USGS Publications Warehouse

    Klasner, J.S.; King, E.R.

    1986-01-01

    Combined analysis of drill-hole, gravity and magnetic data indicates that the Precambrian rocks in the basement of the Dakotas may be divided into a series of lithotectonic terrains. On the basis of an analysis of geological and geophysical data in the Dakotas and from the surrounding states and Canada, it is shown how the exposed Precambrian rocks of the adjacent shield areas project into the study area. Brief comments are made on the tectonic implications of this study. Geological and geophysical characteristics of 11 terrains are tabulated. -P.Br.

  12. Thickness of Cenozoic deposits of Yucca Flat inferred from gravity data, Nevada Test Site, Nevada

    SciTech Connect

    Jachens, R.C.; Langenheim, V.E.; Phelps, G.A.

    1999-05-25

    The basin-basement contact for Yucca Flat was modeled using isostatic gravity data, a linear density-depth function for the basin deposits, and drill-hole constraints to produce a digital database of both the depth to basement and gravitational anomaly associated with the basement rocks. The model predicts a depth of roughly 2,500 m in the deepest, southern part of the basin. The model shows offsets in the basement rocks along both the Carpetbag and Yucca faults. The basement rocks of Yucca Flat have a higher gravity anomaly west of the N-S trending Carpetbag fault, suggesting higher density rocks on the west side of the valley.

  13. The effect of stratigraphic uncertainty on repository performance

    SciTech Connect

    Wilson, M.L.; Robey, T.H.

    1994-08-01

    One source of uncertainty in calculating radionuclide releases from a potential radioactive-waste at Yucca Mountain, Nevada, is uncertainty in the unsaturated-zone stratigraphy. Uncertainty stratigraphy results from sparse drillhole data; possible variations in stratigraphy are modeled using the geostatistical method of indicator simulation. One-dimensional stratigraphic columns are generated and used for calculations of groundwater flow and radionuclide transport. There are indications of a dependence of release on hydrogeologic-unit thicknesses, but the resulting variation in release is smaller than variations produced by other sources of uncertainty.

  14. Thermal waters of the Yemen Arab Republic

    SciTech Connect

    Dowgiallo, J.

    1986-01-01

    Thermal waters (30-61/sup 0/C) occur in springs and shallow drill-holes (max. 300 m) in several areas of the Yemen Arab Republic. Their mineral content is generally low ( < 1000-2000 ppm TDS) except for waters with high CO/sub 2/ content and those directly influenced by the evaporitic Baid formation (Tertiary) in the Western Lowlands along the Red Sea. The temperature anomalies occur in areas of Quaternary basaltic volcanism (Aden formation) and in fault zones connected with the eastern margin of the Red Sea graben. In the latter zones radiogenic heat may be contributed by Tertiary granitic intrusions.

  15. Fluid-inclusion evidence for past temperature fluctuations in the Kilauea East Rift Zone geothermal area, Hawaii

    USGS Publications Warehouse

    Bargar, K.E.; Keith, T.E.C.; Trusdell, F.A.

    1995-01-01

    Heating and freezing data were obtained for fluid inclusions in hydrothermal quartz, calcite, and anhydrite from several depths in three scientific observation holes drilled along the lower East Rift Zone of Kilauea volcano, Hawaii. Comparison of measured drill-hole temperatures with fluid-inclusion homogenization-temperature (Th) data indicates that only about 15% of the fluid inclusions could have formed under the present thermal conditions. The majority of fluid inclusions studied must have formed during one or more times in the past when temperatures fluctuated in response to the emplacement of nearby dikes and their subsequent cooling. -from Authors

  16. Preliminary results on the characterization of Cretaceous and lower Tertiary low-permeability (tight) gas-bearing rocks in the Wind River Basin, Wyoming

    SciTech Connect

    Fouch, T.D.; Keefer, W.R.; Finn, T.M.

    1993-12-31

    The Wind River Basin is a structural and sedimentary basin in central Wyoming (Figure 1) that was created during the Laramide orogeny from Late Cretaceous through Eocene time. The objectives of the Wind River Basin tight gas sandstone project are to define the limits of the tight gas accumulation in the basin and to estimate in-place and recoverable gas resources. The approximate limits of the tight gas accumulation are defined from available drillhole information. Geologic parameters, which controlled the development of the accumulation, are studied in order to better understand the origins of tight gas accumulations, and to predict the limits of the accumulation in areas where little drillhole information is available. The architecture of sandstone reservoirs are studied in outcrop to predict production characteristics of similar reservoirs within the tight gas accumulation. Core and cuttings are used to determine thermal maturities, quality of source rocks, and diagenetic histories. Our work thus far has concentrated in the Wind River Indian Reservation in the western part of the basin.

  17. Template-guided vs. non-guided drilling in site preparation of dental implants.

    PubMed

    Scherer, Uta; Stoetzer, Marcus; Ruecker, Martin; Gellrich, Nils-Claudius; von See, Constantin

    2015-07-01

    Clinical success of oral implants is related to primary stability and osseointegration. These parameters are associated with delicate surgical techniques. We herein studied whether template-guided drilling has a significant influence on drillholes diameter and accuracy in an in vitro model. Fresh cadaveric porcine mandibles were used for drilling experiments of four experimental groups. Each group consisted of three operators, comparing guide templates for drilling with free-handed procedure. Operators without surgical knowledge were grouped together, contrasting highly experienced oral surgeons in other groups. A total of 180 drilling actions were performed, and diameters were recorded at multiple depth levels, with a precision measuring instrument. Template-guided drilling procedure improved accuracy on a very significant level in comparison with free-handed drilling operation (p ≤ 0.001). Inaccuracy of free-handed drilling became more significant in relation to measurement depth. High homogenic uniformity of template-guided drillholes was significantly stronger than unguided drilling operations by highly experienced oral surgeons (p ≤ 0.001). Template-guided drilling procedure leads to significantly enhanced accuracy. Significant results compared to free-handed drilling actions were achieved, irrespective of the clinical experience level of the operator. Template-guided drilling procedures lead to a more predictable clinical diameter. It shows that any set of instruments has to be carefully chosen to match the specific implant system. The current in vitro study is implicating an improvement of implant bed preparation but needs to be confirmed in clinical studies.

  18. The monzogabbroic intrusion in the island of Vulcano, Aeolian Archipelago, Italy

    NASA Astrophysics Data System (ADS)

    Faraone, D.; Silvano, A.; Verdiani, G.

    1986-10-01

    Two drill-holes were carried out during 1983 84 by the “Joint Venture” AGIP-EMS-ENEL on the island of Vulcano southwest of the Cratere della Fossa. After passing through pyroclastics and lavas of the young volcanic centres of Vulcano the drill-holes penetrated an intrusion of monzogabbro to leuco-monzogabbro composition. In one of the holes the top of the intrusion occurs at 1360 m and the intrusive rocks are found to the bottom of the well at 2050 m. At this depth the temperature exceeds 419 °C and the temperature gradients are sufficiently steep that magma could well be reached only a few hundred metres deeper. Lava of the South Vulcano centre is metamorphosed by the intrusion. A massive pyroclastic bed, underlying the welded scoriae deposits associated with collapse of the Caldera del Piano system, contains blocks of the intrusion. Radiometric data suggest an intrusion age of 30 000 years. Geophysical data indicate that the main intrusion is a shallow level and is located in the stretch of sea west of Mt. Lentìa.

  19. Tests for resistivity boundary changes at Ohaaki, New Zealand

    SciTech Connect

    Risk, G.F.

    1994-01-20

    Close-spaced resistivity measurements along ten traverse lines crossing the resistivity boundary of the Ohaaki Geothermal Field, New Zealand, were first measured in 1975 and remeasured in 1992. The 1992 resistivity profiles were similar in shape to the original ones. On both occasions very sharp resistivity boundaries were delineated along the southern and southwestern edges of the field where apparent resistivity rises sharply over a horizontal distance of a few hundred metres from 2-5 ohm m on the inside of the field to 20-50 ohm m on the outside. On two of the southern lines the resistivity boundary appears to have moved outwards by about 100 m, which may be caused by southward movement of reinjected waste water from nearby drillholes. On the other southern lines the outward movement appears to be less than about 25 m, which is the limit of resolution of the survey. Over the 17 year interval apparent resistivity values have dropped slightly at most measurement sites. The decrease is more pronounced on the inside of the field boundary where apparent resistivities have declined by up to about 40 percent. Some of this decrease is attributed to reinjection of conductive waste water near the field boundary causing a drop in ground resistivity. Part of this change may be due to calibration errors and measurement difficulties, including the disturbing effects of the new drillholes, steam pipes and an earthing mat that have been installed since 1975.

  20. Heat flow of the Norwegian continental shelf

    NASA Astrophysics Data System (ADS)

    Pascal, Christophe

    2015-04-01

    Terrestrial heat flow influences a large collection of geological processes. Its determination is a requirement to assess the economic potential of deep sedimentary basins. Published heat flow calculations from e.g. major oil provinces are however seldom. Robust heat flow determinations in drillholes require logging of undisturbed temperatures and intensive sampling of core material for petrophysical measurements. Temperature logging in exploration drillholes is traditionally conducted during drill breaks or shortly after drilling, resulting in temperatures severely disturbed by mud circulation and coring is restricted to selected intervals. Alternatively, test temperatures, information from electric logs and lithological descriptions of drill cuttings can be used to overcome these limitations. The present contribution introduces new heat flow determinations based on 63 exploration drillholes from the Norwegian North Sea, the Mid Norway Margin and the Barents Shelf. Our analyses are based on released DST temperatures, precise lithological descriptions of drill cuttings, previously measured rock matrix thermal conductivities and established porosity laws. Our results suggest median heat flow values of 64 mW/m2, 65 mW/m2 and 72 mW/m2 for the North Sea, the Mid Norway Margin (mainly the Trøndelag Platform) and the SW Barents Shelf respectively. The Barents Shelf shows significantly high heat flow, suggesting lateral transfer of heat from the mantle of the adjacent young ocean. In detail, heat flow increases by ~ 10 mW/m2 from the southern Norwegian North Sea towards the Mid Norway Margin. This result appears to be in very good agreement with seismic tomographic studies suggesting northward thinning of the underlying mantle lithosphere. Our results together with published marine heat flow data from the Mid Norway Margin suggest a gradual decrease in heat flow levels from both the North Sea and the Trøndelag Platform towards the centres of the deep Møre and V

  1. Heat Flow of the Norwegian Continental Shelf

    NASA Astrophysics Data System (ADS)

    Pascal, C.

    2015-12-01

    Terrestrial heat flow determination is of prime interest for oil industry because it impacts directly maturation histories and economic potential of oil fields. Published systematic heat flow determinations from major oil provinces are however seldom. Robust heat flow determinations in drillholes require logging of undisturbed temperatures and intensive sampling of core material for petrophysical measurements. Temperature logging in exploration drillholes is traditionally conducted during drill breaks or shortly after drilling, resulting in temperatures severely disturbed by mud circulation and coring is restricted to selected intervals. Alternatively, test temperatures, information from electric logs and lithological descriptions of drill cuttings can be used to overcome these limitations. The present contribution introduces new heat flow determinations based on 63 exploration drillholes from the Norwegian North Sea, the Mid Norway Margin and the Barents Shelf. Our analyses are based on released DST temperatures, precise lithological descriptions of drill cuttings, previously measured rock matrix thermal conductivities and established porosity laws. For the sake of comparison, we carefully review previous heat flow studies carried out both onshore and offshore Norway. Our results suggest median heat flow values of 64 mW/m2, 65 mW/m2 and 72 mW/m2 for the North Sea, the Mid Norway Margin (mainly the Trøndelag Platform) and the SW Barents Shelf respectively. In detail, heat flow increases by ~ 10 mW/m2 from the southern Norwegian North Sea towards the Mid Norway Margin. This result appears to be in very good agreement with seismic tomographic studies suggesting northward thinning of the underlying mantle lithosphere. Our results together with published marine heat flow data from the Mid Norway Margin suggest a gradual decrease in heat flow levels from both the North Sea and the Trøndelag Platform towards the centres of the deep Møre and Vøring basins. This latter

  2. The Silent Canyon caldera: a three-dimensional model as part of a Pahute Mesa-Oasis Valley, Nevada, hydrogeologic model

    USGS Publications Warehouse

    McKee, Edwin H.; Phelps, Geoffery A.; Mankinen, Edward A.

    2001-01-01

    A 3-dimensional caldera model based on gravity inversion, drill-hole data, and geologic mapping offers the framework for a hydrogeologic evaluation of the Silent Canyon caldera in the central part of Pahute Mesa, Nevada. It has been recognized for several decades that the central part of Pahute Mesa is the site of a buried caldera called the Silent Canyon caldera. Conceptually, the structural framework of the Silent Canyon caldera is based on the idea of collapse of the caldera roof over a shallow magma chamber to form a structural basin following violent volcanic eruptions. Calderas are common in certain volcanic regions of the world, and most well-exposed calderas are broadly similar to each other, particularly the arcuate or circular shape of their collapse depression. There are other reasons for modeling the Silent Canyon caldera as a circular feature in addition to knowledge that calderas throughout the world are generally circular features. The Silent Canyon caldera is the site of one of the largest gravity lows in the Western United States, indicating a thick accumulation of low-density rocks such as lavas and tuffs—a fact confirmed by drilling on Pahute Mesa. This gravity low is bowl-shaped, and the uppermost volcanic units on Pahute Mesa form a circular outcrop pattern of inward-dipping tuff interpreted to be the result of their filling the upper part of the bowl-shaped depression. Together, these features are consistent with, and indicative of, a circular collapse structural model for the Silent Canyon caldera. The collapse depression of the Silent Canyon caldera, bounded by arcuate faults, is filled with as much as 6 km (19,800 ft) of volcanic and sedimentary rocks that are considerably less dense than the underlying and surrounding basement rocks. The boundary surface between less dense caldera fill and more dense basement is modeled as the caldera ring fault. Rocks in the upper part of the caldera fill are penetrated by drilling, and the drill-hole

  3. National coal resource assessment non-proprietary data: Location, stratigraphy, and coal quality for selected tertiary coal in the Northern Rocky Mountains and Great Plains region

    USGS Publications Warehouse

    Flores, Romeo M.; Ochs, A.M.; Stricker, G.D.; Ellis, M.S.; Roberts, S.B.; Keighin, C.W.; Murphy, E.C.; Cavaroc, V.V.; Johnson, R.C.; Wilde, E.M.

    1999-01-01

    One of the objectives of the National Coal Resource Assessment in the Northern Rocky Mountains and Great Plains region was to compile stratigraphic and coal quality-trace-element data on selected and potentially minable coal beds and zones of the Fort Union Formation (Paleocene) and equivalent formations. In order to implement this objective, drill-hole information was compiled from hard-copy and digital files of the: (1) U.S. Bureau of Land Management (BLM) offices in Casper, Rawlins, and Rock Springs, Wyoming, and in Billings, Montana, (2) State geological surveys of Montana, North Dakota, and Wyoming, (3) Wyoming Department of Environmental Quality in Cheyenne, (4) U.S. Office of Surface Mining in Denver, Colorado, (5) U.S. Geological Survey, National Coal Resource Data System (NCRDS) in Reston, Virginia, (6) U.S. Geological Survey coal publications, (7) university theses, and (8) mining companies.

  4. Selected stratigraphic data for drill holes located in Frenchman Flat, Nevada Test Site. Rev. 1

    SciTech Connect

    Drellack, S.L. Jr.

    1997-02-01

    Stratigraphic data are presented in tabular form for 72 holes drilled in Frenchman Flat, Nevada Test Site, between 1950 and 1993. Three pairs of data presentations are included for each hole: depth to formation tops, formation thicknesses, and formation elevations are presented in both field (English) and metric units. Also included for each hole, where available, are various construction data (hole depth, hole diameter, surface location coordinates) and certain information of hydrogeologic significance (depth to water level, top of zeolitization). The event name is given for holes associated with a particular nuclear test. An extensive set of footnotes is included, which indicates data sources and provides other information. The body of the report describes the stratigraphic setting of Frenchman Flat, gives drill-hole naming conventions and database terminology, and provides other background and reference material.

  5. Structural evolution of the Nojima fault (Awaji Island, Japan) revisited from the GSJ drill hole at Hirabayashi

    NASA Astrophysics Data System (ADS)

    Boullier, Anne-Marie; Fujimoto, Koichiro; Ito, Hisao; Ohtani, Tomoyuki; Keulen, Nynke; Fabbri, Olivier; Amitrano, David; Dubois, Michel; Pezard, Philippe

    2004-12-01

    Following the Hyogoken Nanbu earthquake (January 17, 1995, Mw=7.2), three drillholes were sunk through the Nojima Fault (Awaji Island, Japan). Textural and petrographic studies of the Geological Survey of Japan (GSJ) drill cores allow recognition of two deformation episodes. The first one is older than the deposition of the Middle to Late Eocene Kobe Group, corresponds to a left-lateral movement on the Nojima fault and is expressed by pseudotachylytes, kinking of biotite crystals in the low-strain rocks and an intense laumontite hydrothermal alteration. The second one displaces the basal unconformity of the Kobe group, corresponds to a right-lateral reverse displacement and is expressed at least by carbonate-filled hydraulic fractures and thin gouge zones. Different important deformation mechanisms are recorded by the fault rocks, but questions relating to the attribution of deformation and alteration features to one or other deformation episodes remain unresolved.

  6. National uranium resource evaluation, Rawlins quadrangle, Wyoming and Colorado

    SciTech Connect

    Dribus, J.R.; Nanna, R.F.

    1982-06-01

    The Rawlins Quadrangle (2/sup 0/), Wyoming and Colorado, was evaluated to identify areas that contain environments favorable for the occurrence of uranium deposits. Data from reconnaissance and detailed surface studies, aerial radiometric surveys, hydrogeochemical and stream-sediment reconnaissance surveys, and subsurface drill-hole log studies were collected and compared to favorability criteria developed for the National Uranium Resource Evaluation program. The authors delineated 15 areas containing 10 favorable environments as the result of the evaluation. Sandstone uranium environments occur in 11 areas. Two areas contain favorable carbonate uranium environments, and one is favorable for uraniferous lignites. Favorable plutonic environments occur in two areas, and favorable quartz-pebble conglomerates occur in two areas. Unevaluated environments include the Baggot Rocks Granite, the Frontier Formation, the Hanna Formation east of Elk Mountain, and the Medicine Bow and Mesaverde Formations in the Laramie Basin. All remaining areas in the quadrangle are considered unfavorable.

  7. Cranberry Wilderness study area, West Virginia

    SciTech Connect

    Meissner, C.R. Jr.; Mory, P.C.

    1984-01-01

    The Cranberry Wilderness study area contains a large demonstrated resource of bituminous coal of coking quality according to studies made in 1977. Demonstrated coal resources in beds more than 14 in. thick are about 110 million short tons of which 56.5 million tons are in beds more than 28 in. thick in areas of substantiated coal resource potential. Other mineral resources in the study area include peat, shale and clay suitable for building brick and lightweight aggregate, sandstone suitable for low-quality glass sand, and sandstone suitable for construction material. These commodities are found in abundance in other areas throughout the State. Study of the drill-hole data did not reveal indications of a potential for oil and gas resources in the study area. Evidence of metallic mineral potential was not found during this investigation.

  8. Geology, hydrothermal petrology, stable isotope geochemistry, and fluid inclusion geothermometry of LASL geothermal test well C/T-1 (Mesa 31-1), East Mesa, Imperial Valley, California, USA

    SciTech Connect

    Miller, K.R.; Elders, W.A.

    1980-08-01

    Borehole Mesa 31-1 (LASL C/T-1) is an 1899-m (6231-ft) deep well located in the northwestern part of the East Mesa Geothermal Field. Mesa 31-1 is the first Calibration/Test Well (C/T-1) in the Los Alamos Scientific Laboratory (LASL), Geothermal Log Interpretation Program. The purpose of this study is to provide a compilation of drillhole data, drill cuttings, well lithology, and formation petrology that will serve to support the use of well LASL C/T-1 as a calibration/test well for geothermal logging. In addition, reviews of fluid chemistry, stable isotope studies, isotopic and fluid inclusion geothermometry, and the temperature log data are presented. This study provides the basic data on the geology and hydrothermal alteration of the rocks in LASL C/T-1 as background for the interpretation of wireline logs.

  9. Results of investigation at the Ahuachapan Geothermal Field, El Salvador. Part 2, Electrical-methods geophysics: Final report

    SciTech Connect

    Fink, J.B.

    1990-04-01

    The Ahuachapan Geothermal Field (AGF) is a 95 megawatt geothemal-sourced power-plant operated by the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) of El Salvador. During the past decade, as part of an effort to increase in situ thermal reserves in order to realize the full generation capacity of the AGF, extensive surface geophysical coverage has been obtained over the AGF and the prospective Chipilapa area to the east. The geophysical surveys were performed to determine physical property characteristics of the known reservoir and then to search for similar characteristics in the Chipilapa area. A secondary objective was to evaluate the surface recharge area in the highlands to the south of the AGF. The principal surface electrical geophysical methods used during this period were DC resistivity and magnetotellurics. Three available data sets have been reinterpreted using drillhole control to help form geophysical models of the area. The geophysical models are compared with the geologic interpretations.

  10. Evaluation of a Topical Herbal Agent for the Promotion of Bone Healing

    PubMed Central

    Siu, Wing-Sum; Ko, Chun-Hay; Lam, Ka-Wing; Shum, Wai-Ting; Lau, Clara Bik-San; Ko, Kam-Ming; Hung, Leung-Kim; Lau, David Tai-Wai; Leung, Ping-Chung

    2015-01-01

    A topically used Chinese herbal paste, namely, CDNR, was designed to facilitate fracture healing which is usually not addressed in general hospital care. From our in vitro studies, CDNR significantly inhibited the release of nitric oxide from RAW264.7 cells by 51 to 77%. This indicated its anti-inflammatory effect. CDNR also promoted the growth of bone cells by stimulating the proliferation of UMR106 cells up to 18%. It also increased the biomechanical strength of the healing bone in a drill-hole defect rat model by 16.5% significantly. This result revealed its in vivo efficacy on facilitation of bone healing. Furthermore, the detection of the chemical markers of CDNR in the skin and muscle of the treatment area demonstrated its transdermal properties. However, CDNR did not affect the bone turnover markers in serum of the rats. With its anti-inflammatory and bone formation properties, CDNR is found effective in promoting bone healing. PMID:25810746

  11. A refined characterization of the alluvial geology of yucca flat and its effect on bulk hydraulic conductivity

    USGS Publications Warehouse

    Phelps, G.A.; Halford, K.J.

    2011-01-01

    In Yucca Flat, on the Nevada National Security Site in southern Nevada, the migration of radionuclides from tests located in the alluvial deposits into the Paleozoic carbonate aquifer involves passage through a thick, heterogeneous section of late Tertiary and Quaternary alluvial sediments. An understanding of the lateral and vertical changes in the material properties of the alluvial sediments will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating groundwater flow in the Yucca Flat area. Previously published geologic models for the alluvial sediments within Yucca Flat are based on extensive examination and categorization of drill-hole data, combined with a simple, data-driven interpolation scheme. The U.S. Geological Survey, in collaboration with Stanford University, is researching improvements to the modeling of the alluvial section, incorporating prior knowledge of geologic structure into the interpolation method and estimating the uncertainty of the modeled hydrogeologic units.

  12. Constraints on magma ascent, emplacement, and eruption: geochemical and mineralogical data from drill-core samples at Obsidian dome, Inyo chain, California

    SciTech Connect

    Vogel, T.A.; Younker, L.W.; Schuraytz, B.C.

    1987-05-01

    Systematic chemical and mineralogical variability occurs in samples from drill holes through Obsidian dome, the conduit to the dome, and a nearby associated feeder dike. The drill-hole samples from the margins of the conduit and most of the lower part of the dome are high-Ba, low-silica rhyolites; they contain two populations of phenocrysts and represent commingled magmas, whereas samples from the dike and upper parts of the dome are low-Ba, higher silica rhyolites that do not reflect commingled magmas. Samples from the center of the conduit are low-Ba, higher silica rhyolites that are only slightly mixed. A major part of the variability within the drill-core samples of the dome and conduit reflects the juxtaposition and commingling of two distinct magmas during their passage through the conduit.

  13. Anomalous gold, antimony, arsenic, and tungsten in ground water and alluvium around disseminated gold deposits along the Getchell Trend, Humboldt County, Nevada

    USGS Publications Warehouse

    Grimes, D.J.; Ficklin, W.H.; Meier, A.L.; McHugh, J.B.

    1995-01-01

    Ground-water, alluvium, and bedrock samples were collected from drill holes near the Chimney Creek, Preble, Summer Camp, and Rabbit Creek disseminated gold deposits in northern Nevada. Results of chemical analyses of drill-hole water samples show the presence of hydromorphic dispersion anomalies of Au, As, Sb, and W in the local ground-water systems associated with these deposits. In addition, analysis of sequential dissolution and extraction solutions of drill cuttings of alluvium and bedrock indicate geochemical anomalies of gold and ore-related metals in the overburden at depths corresponding to the location of the present-day water table. This relationship suggests that water-rock reactions around these buried deposits are active. -from Authors

  14. Geophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications

    USGS Publications Warehouse

    Grauch, V.J.; Sawyer, David A.; Fridrich, Chris J.; Hudson, Mark R.

    1999-01-01

    Gravity and magnetic data, when integrated with other geophysical, geological, and rock-property data, provide a regional framework to view the subsurface geology in the southwestern Nevada volcanic field. The region has been loosely divided into six domains based on structural style and overall geophysical character. For each domain, the subsurface tectonic and magmatic features that have been inferred or interpreted from previous geophysical work has been reviewed. Where possible, abrupt changes in geophysical fields as evidence for potential structural lithologic control on ground-water flow has been noted. Inferred lithology is used to suggest associated hydrogeologic units in the subsurface. The resulting framework provides a basis for investigators to develop hypotheses from regional ground-water pathways where no drill-hole information exists.

  15. Site selection for manned Mars landings: A geological perspective

    NASA Technical Reports Server (NTRS)

    Spudis, Paul D.

    1986-01-01

    Issues relating to the selection of initial landing sites for manned Mars missions are discussed from a geological viewpoint. The two prime objectives for initial manned exploration should be the youngest unambiguous lava flows (to tie down the late end of the cratering history curve for Mars) and old highland crust, which is best sampled and studied through the use of large impact basins as natural, planetary drill-holes. Exploration of these two sites will provide data on Martian chronology, volcanism, impact processes and gross chemical structure that will enable a first-order global synthesis through integration of these results with the global remote-sensing data already in hand from Viking and that to be provided by the Mars Observer Mission.

  16. Tectonic and karstic effects on the western Taurus region, southwestern Turkey: Relations to the present temperature gradients and total organic carbon content

    SciTech Connect

    Demirel, I.H.; Gunay, Y.

    2000-06-01

    The western Taurus region is one of the promising hydrocarbon provinces and the largest karstic terrain of Turkey. The Mesozoic Beydaglari units deposited in the study area are composed mainly of a carbonate succession which has potential hydrocarbon source rocks of various ages. To confirm the tectonic and karstic influence on the regional temperature gradient and total organic carbon content, subsurface data obtained from four drillholes, and the results of the surface samples and water samples analyses, were used. The low salinity values (less than 2,500 mg/liter) of the formation water, and the measured hole temperatures, indicate the presence of the meteoric water circulation in the geologic section. Since the Late Miocene, intensive tectonic deformations and karstification have provided the development of the aquifer characteristics of the Beydaglari units. Water circulation in the aquifer system has influenced the total organic carbon content and karstic conduits within carbonates.

  17. A note on the frictional strength of laumontite from Cajon Pass, California

    USGS Publications Warehouse

    Morrow, C.A.; Byerlee, J.D.

    1991-01-01

    Laumontite mineralization is pervasive in joints and shear zones encountered in the Cajon Pass drillhole in southern California. In order to determine whether a gouge composed of this hydrated mineral affects shear strength in a manner similar to low-strength, clay-rich fault gouges, frictional sliding experiments were performed under dry, saturated and high pore pressure conditions at effective pressures up to 450 MPa. Coefficients of friction ranged between 0.66 and 0.84, consistent with most crustal rocks and well above the values typical of clay-rich San Andreas fault gouges. Saturation state had no effect on strength or sliding stability. These results suggest that the presence of laumontite in shear zones at Cajon Pass will not affect the shear strength of the rock in a way that can account for the inferred low ambient shear stresses. -Authors

  18. Geophysical investigations of a geothermal anomaly at Wadi Ghadir, eastern Egypt

    NASA Technical Reports Server (NTRS)

    Morgan, P.; Boulos, F. K.; Hennin, S. F.; El-Sherif, A. A.; El-Sayed, A. A.; Basta, N. Z.; Melek, Y. S.

    1984-01-01

    During regional heat flow studies a geothermal anomaly was discovered approximately 2 km from the Red Sea coast at Wadi Ghadir, in the Red Sea Hills of Eastern Egypt. A temperature gradient of 55 C/km was measured in a 150 m drillhole at this location, indicating a heat flow of approximately 175 mw/sqm, approximately four times the regional background heat flow for Egypt. Gravity and magnetic data were collected along Wadi Ghadir, and combined with offshore gravity data, to investigate the source of the thermal anomaly. Magnetic anomalies in the profile do not coincide with the thermal anomaly, but were observed to correlate with outcrops of basic rocks. Other regional heat flow and gravity data indicate that the transition from continental to oceanic type lithosphere occurs close to the Red Sea margin, and that the regional thermal anomaly is possibly related to the formation of the Red Sea.

  19. Gravity survey and interpretation of Fort Irwin and vicinity, Mojave Desert, California: Chapter H in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

    USGS Publications Warehouse

    Jachens, Robert C.; Langenheim, V.E.; Buesch, David C.

    2014-01-01

    In support of a hydrogeologic study of the groundwater resources on Fort Irwin, we have combined new gravity data with preexisting measurements to produce an isostatic residual gravity map, which we then separated into two components reflecting (1) the density distribution in the pre-Cenozoic basement complex and (2) the distribution of low-density Cenozoic volcanic and sedimentary deposits that lie on top of the basement complex. The second component was inverted to estimate the three-dimensional distribution of Cenozoic deposits by using constraints from geology, drillholes, and time-domain electromagnetic soundings. In most of the base, the Cenozoic deposits are no more than 300 m thick, except in the basins with more than 500 m of fill beneath Coyote Lake, Red Pass Lake, west of Nelson Lake, west of Superior Lake, Bicycle Lake, and in the vicinity of Nelson Lake.

  20. Evolution of coiled tubing drilling technology accelerates

    SciTech Connect

    Simmons, J.; Adam, B.

    1993-09-01

    This paper reviews the status of coiled tubing technology in oil and gas drilling operations. The paper starts with a description of current coiled tubing technology and provides a cost comparison between conventional and coiled tubing drilling. The results show that offshore operations are already competitive while onshore operations will still lag behind conventional drilling methods. A list of known coiled tubing drilling operations is provided which gives the current borehole diameters and depths associated with this technology. The paper then goes on to provide the advantages and disadvantages of the technology. The advantages include improved well control, a continuous drillstring, reduced mobilization costs, simplified logging and measurement-while drilling measurements, and less tripping required. The disadvantages include high friction with the borehole wall, downhole motors required, limited drillhole size, and fatigued or damaged sections of the tubing cannot be removed. Finally, a review of the reliability of this technology is provided.

  1. Comparison of computer-based and manual coal resource estimation methods for the Cache coal bed, Recluse Geologic Model Area, Wyoming

    USGS Publications Warehouse

    Schneider, Gary B.; Crowley, Sharon S.; Carey, Mary Alice

    1984-01-01

    Coal resources have been estimated, using both manual and computer methods, for the Cache coal bed in the Recluse Geologic Model Area, which covers the White Tail Butte, Pitch Draw, Recluse, and Homestead Draw SW 7?-minute quadrangles in Campbell County, Wyoming. Approximately 300 coal thickness measurements from drill-hole logs are distributed throughout the area The Cache coal bed and associated strata are in the Paleocene Tongue River Member of the Fort Union Formation. The depth to the Cache coal bed ranges from 269 to 1,257 feet. The coal bed is as much as 31 feet thick but is absent in places. Comparisons between hand-drawn and computer-generated isopach maps show minimal differences. Total coal resources estimated by hand show the bed to contain 2,228 million short tons or about 2.6 percent more than the computer-calculated figure of 2,169 million short tons.

  2. Map showing depth to pre-Cenozoic basement in the Death Valley ground-water model area, Nevada and California

    SciTech Connect

    Blakely, R.J.; Ponce, D.A.

    2002-03-12

    This map shows the depth to pre-Cenozoic basement in the Death Valley ground-water model area. It was prepared utilizing gravity (Ponce and others, 2001), geologic (Jennings and others, 1977; Stewart and Carlson, 1978), and drill-hole information. Geophysical investigations of the Death Valley ground-water model area are part of an interagency effort by the U.S. Geological Survey (USGS) and the U.S. Department of Energy (Interagency Agreement DE-AI08-96NV11967) to help characterize the geology and hydrology of southwestern Nevada and parts of California. The Death Valley ground-water model is located between lat 35 degrees 00' and 38 degrees 15' N., and long 115 degrees and 118 degrees W.

  3. CRANBERRY WILDERNESS STUDY AREA, WEST VIRGINIA.

    USGS Publications Warehouse

    Meissner, Charles R.; Mory, P.C.

    1984-01-01

    The Cranberry Wilderness Study Area, West Virginia contains a large demonstrated resource of bituminous coal of coking quality. Demonstrated coal resources in beds more than 14 in. thick are about 110 million short tons of which 56. 5 million tons are in beds more than 28 in. thick in areas of substantiated coal resource potential. Other mineral resources in the study area include peat, shale and clay suitable for building brick and lightweight aggregate, sandstone suitable for low-quality glass sand, and sandstone suitable for construction material. These commodities are found in abundance in other areas throughout the State. Study of the drill-hole data did not reveal indications of a potential for oil and gas resources in the study area. Evidence of metallic mineral potential was not found during this investigation.

  4. Geology of the Rotorua geothermal system

    SciTech Connect

    Wood, C.P. )

    1992-04-01

    This paper discusses the Rotorua geothermal system located in the south part of Rotorua Caldera, which collapsed during and after the eruption of Mamaku Ignimbrite some 140 ka ago. Drillholes provide geological and hydrological information to 300 m depth. The Mamaku Ignimbrite aquifer has been drilled in the east and south of the field where it contains fluid at or near boiling point. The Ignimbrite drops from south to north across exposed and buried caldera collapse scarps. Rotorua City domes comprise a buried N-S ridge rising at either end to form north and south domes; both contain mostly sub-boiling water up to 190{degrees} C which flows laterally through the outer 40 m of permeably rhyolite as indicated by temperature data. The Fenton Park aquifer comprises sands and gravels in the shallow sedimentary sequence which contain hot water derived possibly from Whakarewarewa, the south dome or the Rotoatamaheke Fault.

  5. First data on the radiocarbon age of the Atelian deposits in the North Caspian Region

    NASA Astrophysics Data System (ADS)

    Bezrodnykh, Yu. P.; Romanyuk, B. F.; Sorokin, V. M.; Yanina, T. A.

    2017-03-01

    This paper reports data on the Atelian horizon identified in the Caspian Sea bottom. Seismoacoustic profiling has made it possible to determine its area, position, and setting in the Upper Quaternary sequence and the relation to the host deposits. According to the drillhole core data, the Atelian horizon is composed of continental clay loam and sandy loam containing peatlike organic remains. They are depleted in biogenic residues containing rare freshwater mollusk species. The Atelian deposits were accumulated in lake reservoirs filling the depressions developed in the strata of the Upper Khazarian horizon. The radiocarbon age determined for the first time by humic acids has been used to estimate the Atelian deposition time in the range of 40 000-45 000 calibrated years BP.

  6. Thickness of Cenozoic Deposits of Yucca Flat Inferred from Gravity Data, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Phelps, G.A.; Langenheim, V.E.; Jachens, R.C.

    1999-01-01

    The basin-basement contact for Yucca Flat was modeled using isostatic gravity data, a linear density-depth function for the basin deposits, and drill-hole constraints to produce a digital database of both the depth to basement and the gravitational anomaly associated with the basement rocks. The model predicts a depth of roughly 2,500 m in the deepest, southern part of the basin. The model shows offsets in the basement rocks along both the Carpetbag and Yucca faults. The basement rocks of Yucca Flat have a higher gravity anomaly west of the N-S trending Carpetbag fault, suggesting higher density rocks on the west side of the valley.

  7. Piceance Creek Basin, Colorado, Oil Shale Geodatabase

    USGS Publications Warehouse

    ,

    2006-01-01

    This geodatabase is a digital reproduction of three legacy USGS oil shale publications--MF-958 (Pitman and Johnson, 1978), MF-1069 (Pitman, 1979), and OC-132 (Pitman and others, 1990). The database consists of 106 feature classes in three feature datasets organized by publication. Each dataset contains isopach contours, isoresource contours, isoresource polygons, and corehole and drillhole locations with resource values for 12 kerogen-rich (R) and kerogen-lean (L) oil shale zones in the Piceance Creek Basin, Colorado. The uppermost zones, Mahogany and R-6, also contain detailed structure files. The zones in descending order are: Mahogany, R-6, L-5, R-5, L-4, R-4, L-3, R-3, L-2, R-2, L-1, and R-1.

  8. Bedrock geologic map of the Spring Valley, West Plains, and parts of the Piedmont and Poplar Bluff 30'x60' quadrangles, Missouri, including the upper Current River and Eleven Point River drainage basins

    USGS Publications Warehouse

    Weary, David J.; Harrison, Richard W.; Orndorff, Randall C.; Weems, Robert E.; Schindler, J. Stephen; Repetski, John E.; Pierce, Herbert A.

    2015-01-01

    Potentially economic mineral resources are present in the subsurface in the map area. Exploration drill-hole data indicate that anomalously high concentrations of base-metal sulfides locally occur within the Cambrian Bonneterre Formation. The geologic setting of these anomalous concentrations is similar to that found in the Viburnum Trend, part of the largest lead-mining district in the world. The southernmost part of the Viburnum Trend extends into the northern part of the map area and is exploited by the Sweetwater Mine. Undeveloped and potentially economic occurrences of base metals are known also beneath Blair Creek, a tributary to the Current River in the north-central part of the map area.

  9. Results of investigation at the Ahuachapan Geothermal Field, El Salvador

    SciTech Connect

    Fink, J.B. )

    1990-04-01

    The Ahuachapan Geothermal Field (AGF) is a 95 megawatt geothemal-sourced power-plant operated by the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) of El Salvador. During the past decade, as part of an effort to increase in situ thermal reserves in order to realize the full generation capacity of the AGF, extensive surface geophysical coverage has been obtained over the AGF and the prospective Chipilapa area to the east. The geophysical surveys were performed to determine physical property characteristics of the known reservoir and then to search for similar characteristics in the Chipilapa area. A secondary objective was to evaluate the surface recharge area in the highlands to the south of the AGF. The principal surface electrical geophysical methods used during this period were DC resistivity and magnetotellurics. Three available data sets have been reinterpreted using drillhole control to help form geophysical models of the area. The geophysical models are compared with the geologic interpretations.

  10. Designing gravel pack for uranium ISL wells

    NASA Astrophysics Data System (ADS)

    Ber, A. A.; Minaev, K. M.; Ber, L. M.; Isaev, Ye D.; Ulyanova, O. S.

    2016-09-01

    The paper describes the improvement of gravel packing technique applied for the production wells. The authors have suggested new design of gravel pack for gravel packing of productive formations. The issue is currently topical because gravel packing at drillhole ISL is less time- and money-consuming. The subject of the research is gravel pack design and content. The purpose defined by the authors is to design the gravel pack and to suggest the composition of gravel cement agent. As a result of the research, the authors have described different designs of the gravel pack, its optimal shape, as well as a choice and justification of cement agents, a hold cover of the gravel pack, and suggested the methods of experimental research.

  11. The permeability of gabbro in oceanic core complexes

    NASA Astrophysics Data System (ADS)

    Titarenko, S.; McCaig, A. M.

    2013-12-01

    In IODP Expedition 340T, a thermal gradient of about 100 °C km-1 was measured in IODP Hole U1309D (Blackman et al. 2013), located in 1.2 My old gabbroic crust in the footwall of an oceanic detachment fault in the Atlantis Massif, just west of the mid-Atlantic Ridge at 30° N. The gradient is linear below 748 mbsf, indicating an essentially conductive regime, and slightly concave above that depth, suggesting slow, long-term downward flow of seawater in surrounding rocks. The lack of any vigorous hydrothermal circulation at this site is remarkable considering that the serpentinite-hosted Lost City Hydrothermal Field (LCHF) is located only 5 km to the south, and has been venting highly alkaline fluids at 40-90 °C for at least the last 140,000 years. We have created a 2-D topographic model of the Atlantis Massif using a N-S profile through the LCHF and the drillhole location, and modelled hydrothermal circulation using Comsol Multiphysics. A maximum permeability of 10-17 m2 below 750 mbsf, and a basal heatflow of 0.22 Wm-1 are required at the drillhole location to suppress hydrothermal circulation and preserve the observed conductive thermal gradient at depth. The concave gradient above this depth can be closely fitted over long time periods with a layer 750 m thick of higher permeability, ~3x 10-14 m2. Fluid vents at the site of the LCHF and in a small knoll north of the drill hole, and enters the seafloor everywhere else, including the drillhole location. Model vent temperatures are only about 20 °C however, much less that at the LCHF. A model with a deeper permeable zone beneath the LCHF, with a permeability of 10-15 m2 or more, is required to match simultaneously both observed vent temperatures and the drillhole gradient. This deep permeable zone is hosted in serpentinite but is most likely related to active faulting related to the Atlantis Transform Fault, not lithological control on permeability. Data from the flanks of both fast and intermediate spreading

  12. Cerro Prieto geothermal field: exploration during exploitation

    SciTech Connect

    Not Available

    1982-07-01

    Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. The description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field are presented. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development.

  13. Geological and Sediment Thickness Data Sources From the U.S. Continental Margins

    NASA Astrophysics Data System (ADS)

    Hutchinson, D. R.; Childs, J. R.; Edgar, N. T.; Barth, G.; Hammar-Klose, E.; Dadisman, S. V.; Rowland, R.

    2005-12-01

    Although the United States has not yet ratified the United Nations Convention on the Law of the Sea (UNCLOS), work has begun to assess the geophysical and geological data sources that might be applied to an extended continental shelf submission under Article 76 of the UNCLOS. The U.S. Geological Survey, as a follow-up to the Congressional Report published by the University of New Hampshire on data relevant to a potential U.S. submission (Mayer and others, 2002), has identified existing seismic reflection, seismic refraction, and drill-hole data on the U.S. margins for the areas where an extended continental shelf submission could be considered. This work complements ongoing NOAA efforts to map the foot-of-the-slope. The USGS compilation includes more than 80,000 km of multichannel seismic data, 70,000 km of single-channel seismic reflection data, 25 refraction experiments, and 12 drill holes that penetrate to basement. Data quality varies according to year collected and acquisition system used. Data coverage is generally excellent within the 200-nm EEZ boundary, but new data will be required to adequately assess sediment thickness in the area beyond 200-nm in some of the poorly surveyed regions (e.g., the Arctic). Velocity and drill-hole control for deeper sedimentary units is generally poor; this deficiency will also need to be addressed in new data gathering efforts. Subsea mineral resources that might exist in the region of an extended continental shelf vary by region and include conventional hydrocarbons, gas hydrate, ferro-manganese crusts and nodules, and possibly phosphorite deposits. On-going efforts are directed at interpreting these data with reference to UNCLOS criteria and guidelines, as well as evaluating how recent submissions to the United Nations by other States might affect a possible U.S. submission.

  14. Sediment Volume Record of Paleogene-Neogene Transantarctic Mountains Erosion and Landscape Modification, McMurdo Sound Region, Antarctica

    NASA Astrophysics Data System (ADS)

    Hall, T.; Wilson, T. J.; Henrys, S.; Speece, M. A.

    2016-12-01

    The interplay of tectonics and climate is recorded in the sedimentary strata within Victoria Land Basin, McMurdo Sound, Antarctica. Patterns of Cenozoic sedimentation are documented from interpretation of seismic reflection profiles calibrated by drillhole data in McMurdo Sound, and these patterns provide enhanced constraints on the evolution of the coupled Transantarctic Mountains-West Antarctic Rift System and on ice sheet advance/retreat through multiple climate cycles. The research focuses on shifts from warm based to cold based ice sheets through the variable climate and ice sheet conditions that characterized the early to middle Miocene. The study seeks to test the view that cold based ice sheets in arid, polar deserts minimally erode the landscape by calculating sediment volumes for critical climatic intervals. Revised seismic mapping through McMurdo Sound has been completed, utilizing the seismic stratigraphic framework first established by Fielding et al. (2006) and new reflectors marking unconformities identified from the AND-2A core (Levy et al., 2016). Reflector age constraints are derived by tying surfaces to the Cape Roberts Project, CIROS-1, and AND-2A drillholes. Seismic facies coupled with AND-2A core provenance information provides insight into depositional mechanisms and ice sheet behavior. Seismic facies transitions occur across the major unconformity surfaces in the AND-2A core. Sediment volume calculations for subareas within McMurdo Sound where reflectors are most continuous indicate substantial decreases in preserved sediment volume between the Oligocene and Early Miocene sequences, and between the early and mid-Miocene sequences. Sediment volumes, used in combination with an ice sheet model in a backstacking procedure, provide constraints on landscape modification and further understanding of how landscapes erode under warm and cold based ice sheet regimes.

  15. ER-12-1 completion report

    SciTech Connect

    Russell, C.E.; Gillespie, D.; Cole, J.C.; Drellack, S.L.

    1996-12-01

    The objective of drillhole ER-12-1 was to determine the hydrogeology of paleozoic carbonate rocks and of the Eleana Formation, a regional aquitard, in an area potentially downgradient from underground nuclear testing conducted in nearby Rainier Mesa. This objective was addressed through the drilling of well ER-12-1 at N886,640.26 E640,538.85 Nevada Central Coordinates. Drilling of the 1094 m (3588 ft) well began on July 19, 1991 and was completed on October 17, 1991. Drilling problems included hole deviation and hole instability that prevented the timely completion of this borehole. Drilling methods used include rotary tri-cone and rotary hammer drilling with conventional and reverse circulation using air/water, air/foam (Davis mix), and bentonite mud. Geologic cuttings and geophysical logs were obtained from the well. The rocks penetrated by the ER-12-1 drillhole are a complex assemblage of Silurian, Devonian, and Mississippian sedimentary rocks that are bounded by numerous faults that show substantial stratigraphic offset. The final 7.3 m (24 ft) of this hole penetrated an unusual intrusive rock of Cretaceous age. The geology of this borehole was substantially different from that expected, with the Tongue Wash Fault encountered at a much shallower depth, paleozoic rocks shuffled out of stratigraphic sequence, and the presence of an altered biotite-rich microporphyritic igneous rock at the bottom of the borehole. Conodont CAI analyses and rock pyrolysis analyses indicate that the carbonate rocks in ER-12-1, as well as the intervening sheets of Eleana siltstone, have been thermally overprinted following movement on the faults that separate them. The probable source of heat for this thermal disturbance is the microporphyritic intrusion encountered at the bottom of the hole, and its age establishes that the major fault activity must have occurred prior to 102.3+0.5 Ma (middle Cretaceous).

  16. Subsurface mapping in the Iberian Pyrite Belt using seismic reflection profiling and potential-field data

    NASA Astrophysics Data System (ADS)

    Carvalho, João; Inverno, Carlos; Matos, João Xavier; Rosa, Carlos; Granado, Isabel; Branch, Tim; Represas, Patrícia; Carabaneanu, Livia; Matias, Luís; Sousa, Pedro

    2016-06-01

    The Iberian Pyrite Belt (IPB) hosts world-class massive sulphide deposits, such as Neves-Corvo in Portugal and Rio Tinto in Spain. In Portugal, the Palaeozoic Volcanic-Sedimentary Complex (VSC) hosts these ore deposits, extending from the Grândola-Alcácer region to the Spanish border with a NW-SE to WNW-ESE trend. In the study area, between the Neves-Corvo mine region and Alcoutim (close to the Spanish border), the VSC outcrops only in a small horst near Alcoutim. Sparse exploration drill-hole data indicate that the depth to the top of the VSC varies from several 100 m to about 1 km beneath the Mértola Formation Flysch cover. Mapping of the VSC to the SE of Neves-Corvo mine is an important exploration goal and motivated the acquisition of six 2D seismic reflection profiles with a total length of approximately 82 km in order to map the hidden extension of the VSC. The data, providing information deeper than 10 km at some locations, were integrated in a 3D software environment along with potential-field, geological and drill-hole data to form a 3D structural framework model. Seismic data show strong reflections that represent several long Variscan thrust planes that smoothly dip to the NNE. Outcropping and previously unknown Late Variscan near-vertical faults were also mapped. Our data strongly suggest that the structural framework of Neves-Corvo extends south-eastwards to Alcoutim. Furthermore, the VSC top is located at depths that show the existence within the IPB of new areas with good potential to develop exploration projects envisaging the discovery of massive sulphide deposits of the Neves-Corvo type.

  17. Three-dimensional model of the hydrostratigraphy and structure of the area in and around the U.S. Army-Camp Stanley Storage Activity Area, northern Bexar County, Texas

    USGS Publications Warehouse

    Pantea, Michael P.; Blome, Charles D.; Clark, Allan K.

    2014-01-01

    A three-dimensional model of the Camp Stanley Storage Activity area defines and illustrates the surface and subsurface hydrostratigraphic architecture of the military base and adjacent areas to the south and west using EarthVision software. The Camp Stanley model contains 11 hydrostratigraphic units in descending order: 1 model layer representing the Edwards aquifer; 1 model layer representing the upper Trinity aquifer; 6 model layers representing the informal hydrostratigraphic units that make up the upper part of the middle Trinity aquifer; and 3 model layers representing each, the Bexar, Cow Creek, and the top of the Hammett of the lower part of the middle Trinity aquifer. The Camp Stanley three-dimensional model includes 14 fault structures that generally trend northeast/southwest. The top of Hammett hydrostratigraphic unit was used to propagate and validate all fault structures and to confirm most of the drill-hole data. Differences between modeled and previously mapped surface geology reflect interpretation of fault relations at depth, fault relations to hydrostratigraphic contacts, and surface digital elevation model simplification to fit the scale of the model. In addition, changes based on recently obtained drill-hole data and field reconnaissance done during the construction of the model. The three-dimensional modeling process revealed previously undetected horst and graben structures in the northeastern and southern parts of the study area. This is atypical, as most faults in the area are en echelon that step down southeasterly to the Gulf Coast. The graben structures may increase the potential for controlling or altering local groundwater flow.

  18. Evaluation of hydrocarbon potential, Task 8

    SciTech Connect

    Cashman, P.H.; Trexler, J.H. Jr.

    1993-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vicinity. Our main focus is source rock stratigraphy in the Nevada Test Site (NTS) area in southern Nevada. In order to reconstruct the Paleozoic stratigraphy, we are also studying the geometry and kinematics of deformation at NTS. A thorough understanding of the structure will also be essential to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We are now provisionally limiting the name {open_quotes}Eleana Formation{close_quotes} to the rocks that make up the Eleana Range - i.e., the rocks that we have been calling {open_quotes}western Eleana{close_quotes}. The mudstone section (which we have until now called {open_quotes}eastern Eleana{close_quotes}) we are provisionally calling the {open_quotes}Chainman Shale{close_quotes}, in keeping with regional lithostratigraphic nomenclature. We continue to work out the internal stratigraphies and basin histories of both units; XRD (r-ray diffraction) determinations of clay mineralogy are an addition to our understanding of the Chainman. The basin histories place important constraints on regional paleogeographic and tectonic reconstructions. This year we have hired a consulting petroleum geologist for two jobs: (1) to review drillhole data from southern Nevada on file at NBMG and make recommendations about more detailed study of any interesting drillholes; and (2) to log the UE17e core (in the Chainman) and evaluate source rock potential. The results of these studies have been incorporated into this report, and the consultant`s reports.

  19. Subsurface mapping in the Iberian Pyrite Belt using seismic reflection profiling and potential-field data

    NASA Astrophysics Data System (ADS)

    Carvalho, João; Inverno, Carlos; Matos, João Xavier; Rosa, Carlos; Granado, Isabel; Branch, Tim; Represas, Patrícia; Carabaneanu, Livia; Matias, Luís; Sousa, Pedro

    2017-04-01

    The Iberian Pyrite Belt (IPB) hosts world-class massive sulphide deposits, such as Neves-Corvo in Portugal and Rio Tinto in Spain. In Portugal, the Palaeozoic Volcanic-Sedimentary Complex (VSC) hosts these ore deposits, extending from the Grândola-Alcácer region to the Spanish border with a NW-SE to WNW-ESE trend. In the study area, between the Neves-Corvo mine region and Alcoutim (close to the Spanish border), the VSC outcrops only in a small horst near Alcoutim. Sparse exploration drill-hole data indicate that the depth to the top of the VSC varies from several 100 m to about 1 km beneath the Mértola Formation Flysch cover. Mapping of the VSC to the SE of Neves-Corvo mine is an important exploration goal and motivated the acquisition of six 2D seismic reflection profiles with a total length of approximately 82 km in order to map the hidden extension of the VSC. The data, providing information deeper than 10 km at some locations, were integrated in a 3D software environment along with potential-field, geological and drill-hole data to form a 3D structural framework model. Seismic data show strong reflections that represent several long Variscan thrust planes that smoothly dip to the NNE. Outcropping and previously unknown Late Variscan near-vertical faults were also mapped. Our data strongly suggest that the structural framework of Neves-Corvo extends south-eastwards to Alcoutim. Furthermore, the VSC top is located at depths that show the existence within the IPB of new areas with good potential to develop exploration projects envisaging the discovery of massive sulphide deposits of the Neves-Corvo type.

  20. Dried and free flowing granules of Spinacia oleracea accelerate bone regeneration and alleviate postmenopausal osteoporosis.

    PubMed

    Adhikary, Sulekha; Choudhary, Dharmendra; Ahmad, Naseer; Kumar, Sudhir; Dev, Kapil; Mittapelly, Naresh; Pandey, Gitu; Mishra, Prabhat Ranjan; Maurya, Rakesh; Trivedi, Ritu

    2017-06-01

    The aim of this study was to demonstrate the efficacy of extract derived from Spinacia oleracea extract (SOE) in reversing bone loss induced by ovariectomy and bone healing properties in a drill-hole fracture model in rats. SOE was administered orally for 12 weeks in adult ovariectomized Sprague Dawley rats after inducing osteopenic condition. Bone micro-architecture, expressions of osteogenic and resorptive gene markers, biomechanical strength, new bone formation, and bone turnover markers were studied. Uterine histomorphometry was used to assess estrogenicity. Bone regeneration potential of SOE was assessed in a drill-hole fracture model. Fracture healing was assessed by calcein intensity and micro-CT analysis of callus at fracture region. SOE prevented ovariectomy-induced bone loss as evident from 122% increase in bone volume/tissue volume (BV/TV) and 29% decline in Tb.Sp in femoral trabecular micro-architecture. This was corroborated by the more than twofold stimulation in the expression of osteogenic genes runt-related transcription factor 2, osterix, osteocalcin, bone morphogenetic protein 2, collagen-1. Furthermore in the fracture healing model, we observed a 25% increase in BV/TV and enhancement in calcein intensity at the fractured site. The extract when converted into dried deliverable Spinaceae oleracea granule (SOG) form accelerated bone regeneration at fracture site, which was more efficient as evident by a 39% increase in BV/TV. Transforming SOE into dried granules facilitated prolonged systemic availability, thus providing enhanced activity for a period of 14 days. SOE treatment effectively prevents ovariectomy-induced bone loss and stimulated fracture healing in adult rats. The dried granular form of the extract of Spinaceae oleracea was effective in fracture healing at the same dose.

  1. Blood-gas and circulatory changes during total knee replacement. Role of the intramedullary alignment rod.

    PubMed

    Fahmy, N R; Chandler, H P; Danylchuk, K; Matta, E B; Sunder, N; Siliski, J M

    1990-01-01

    The use of an intramedullary alignment rod in the distal part of the femur is an important step in performing total knee-replacement arthroplasty. On the basis of our observation of a sudden decrease in oxygen saturation in some patients after insertion of the rod, a prospective study was done of the circulatory and blood-gas changes that were associated with insertion in thirty-five patients. We examined the effects of the use of an eight-millimeter solid alignment rod, with and without venting; an eight-millimeter fluted alignment rod, with venting; and an eight-millimeter fluted or solid alignment rod, inserted through a 12.7-millimeter drill-hole, but without other venting. A statistically significant reduction in oxygen saturation, arterial oxygen tension (PaO2), and end-tidal carbon-dioxide tension (PETCO2) occurred after insertion of both solid and fluted eight-millimeter alignment rods through an eight-millimeter hold in both vented and unvented femoral canals, in association with a significant increase (p less than 0.01) in intramedullary pressure. Bone-marrow contents and fat were retrieved from samples of blood from the right atrium, indicating that embolization of marrow contents had occurred during insertion of the alignment rod. A small decrease in systemic blood pressure and heart rate also occurred. These changes were completely eliminated by the use of a 12.7-millimeter drill-hole as the entry site of the eight-millimeter fluted rod. We concluded that insertion of an intramedullary alignment rod in the femur causes embolization of marrow contents, which decreases arterial oxygen tension, oxygen saturation, end-tidal carbon-dioxide tension, arterial blood pressure, and heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Massive sulfide exploration models of the Iberian Pyrite Belt Neves Corvo mine region, based in a 3D geological, geophysical and geochemical ProMine study

    NASA Astrophysics Data System (ADS)

    Inverno, Carlos; Matos, João Xavier; Rosa, Carlos; Mário Castelo-Branco, José; Granado, Isabel; Carvalho, João; João Baptista, Maria; Represas, Patrícia; Pereira, Zélia; Oliveira, Tomás; Araujo, Vitor

    2013-04-01

    The Iberian Pyrite Belt (IPB) hosts one of the largest concentrations of massive sulfides in the Earth's crust. This highly productive VMS belt contains more than 85 massive sulfide deposits, totalling an estimate of 1600 Mt of massive ore and about 250 Mt of stockwork ore (Leistel et al., 1998; Oliveira et al., 2005; Tornos, 2006). Included in the South Portuguese Zone the IPB is represented by the Phyllite-Quartzite Group (PQG) composed of shales and quartzites of late Devonian age followed by the Volcanic-Sedimentary Complex (VSC) a submarine succession of sediments and felsic and basic volcanic rocks (late Famennian-late Viséan age). Above the IPB a turbidite sedimentary unit occurs being represented by the Baixo Alentejo Flysch Group (BAFG). The ore deposits are hosted by felsic volcanic rocks and sediments that are dominant in the lower part of the VSC succession. The Neves Corvo (ProMine, EU FP7) project area is focused on the Neves Corvo deposit, an active copper mine. The project area is located between the Messejana Fault and the Portuguese/Spanish border which has been selected for the 3D geological and geophysical modelling study, based on high exploration potential of the Neves Corvo area (Oliveira et al. 2006, Relvas et al. 2006, Pereira et al. 2008, Rosa et al. 2008, Matos et al. 2011, Oliveira et al. 2013). In this study existing LNEG and AGC geological, geophysical and geochemistry databases were considered. New surveys were done: i) - A physical volcanology and palynostratigraphic age data study and log of the Cotovio drill-hole core (1,888 m, drilled by AGC). ii) - Interpretation of 280 km of Squid TEM performed by AGC. Based on the TEM data, significant conductors have been identified related with: shallow conductive cover, graphitic shale, black shale and sulphide mineralizations. The most important TEM conductors are related with the Neves Corvo massive sulphides lenses (1-10 Ωm). iii) - Ground and residual gravimetry studies including

  3. The Iceland Deep Drilling Project (IDDP): (7) Arsenic distribution within a Basalt-Hosted, High-Temperature Geothermal System, Reykjanes, Iceland

    NASA Astrophysics Data System (ADS)

    Olsen, N. J.; Bird, D. K.; Arnórsson, S.; Fridriksson, T.; Fridleifsson, G. O.; Elders, W. A.

    2009-12-01

    The Reykjanes geothermal system is an active, high-temperature, seawater-dominated system located on the southwestern coast of Iceland and is a target site for deep drilling by the Iceland Deep Drilling Project (IDDP). Geothermal fluids produced from drillholes in the Reykjanes geothermal system contain As concentrations up to 240 ppb; however, the distribution of arsenic within the geothermal system is poorly known. The Reykjanes geothermal system is located along the landward continuation of the Mid-Atlantic Ridge (MAR) and has been studied extensively through the efforts of the IDDP and others, and so provides an opportunity to evaluate the hydrothermal geochemistry of arsenic in a basalt-hosted geothermal system. We measured the bulk rock concentration of As, Fe, S, Ti and thirteen other trace metals and metalloids by ICP-MS and ICP-OES in fifty drillhole cutting samples from 350 to 3050 m depth in Reykjanes geothermal well RN-17. The host rock consists of layers of hyaloclastite and fractured crystalline basalts that are frequently intruded by shallow mafic intrusives. Previous studies indicate that the As content of Icelandic basalts is related to their degree of differentiation, with olivine-tholeiites containing 0.02-0.18 ppm As, tholeiites 0.36-0.38 ppm As, and Icelandites 0.76-1.59 ppm As. In RN-17, As content varied between 0.4 and 0.8 ppm for ~70% of the 2700 m profile, suggesting a background concentration of ~0.6 ppm As for the system. The As minima was 0.3 ppm at 2000 m. There were two distinct As maxima in the drillhole cuttings: As was elevated to 0.8-2.3 ppm and 1.7-2.9 ppm at 400-650 m and 1750-1900 m, respectively. From 2300 to ~2700 m, arsenic was slightly elevated (>0.6 - 1.1 ppm). Of the elements analyzed, As correlated most closely with S, and it did so more closely than any of the other elements, including the common chalcophiles Ni, Cu, Zn and Pb. This suggests that hydrothermal sulfides efficiently sequester arsenic and that arsenic is

  4. Contact metamorphism, partial melting and fluid flow in the granitic footwall of the South Kawishiwi Intrusion, Duluth Complex, USA

    NASA Astrophysics Data System (ADS)

    Benko, Z.; Mogessie, A.; Molnar, F.; Severson, M.; Hauck, S.; Lechler, P.; Arehart, G.

    2012-04-01

    The footwall of the South Kawishiwi Intrusion (SKI) a part of the Mesoproterozoic (1.1 Ga) Duluth Complex consists of Archean granite-gneiss, diorite, granodiorite (Giant Range Batholith), thin condensed sequences of Paleoproterozoic shale (Virginia Fm.), as well as banded iron formation (Biwabik Iron Fm). Detailed (re)logging and petrographic analysis of granitic footwall rocks in the NM-57 drillhole from the Dunka Pit area has been performed to understand metamorphic processes, partial melting, deformation and geochemical characteristics of de-volatilization or influx of fluids. In the studied drillhole the footwall consists of foliated metagranite that is intersected by mafic (dioritic) dykes of older age than the SKI. In the proximal contact zones, in the mafic dykes, the orthopyroxene+clinopyroxene+plagioclase+quartz+Fe-Ti-oxide+hornblende±biotite porphyroblasts embedded in a plagioclase+K-feldspar+orthopyroxene+apatite matrix indicate pyroxene-hornfels facies conditions. Migmatitization is revealed by the euhedral crystal faces of plagioclase and pyroxene against anhedral quartz crystals in the in-situ leucosome and by the presence of abundant in-source plagioclase±biotite leucosome veinlets. Amphibole in the melanosome of mafic dykes was formed with breakdown of biotite and implies addition of H2O to the system during partial melting. Towards the deeper zones, the partially melted metatexite-granite can be characterized by K-feldspar+plagioclase+quartz+ortho/clinopyroxene+biotite+Fe-Ti-oxide+apatite mineral assemblage. The felsic veins with either pegmatitic or aplititic textures display sharp contact both to the granite and the mafic veins. They are characterized by K-feldspar+quartz±plagioclase±muscovite mineral assemblage. Sporadic occurrence of muscovite suggest local fluid saturated conditions. Emplacement of gabbroic rocks of the SKI generated intense shear in some zones of the granitic footwall resulting in formation of biotite-rich mylonites with

  5. Cleat development in coals of the Upper Cretaceous Mesaverde Formation, Pilot Butte area, Wind River Reservation, Wyoming

    USGS Publications Warehouse

    Johnson, R.C.; Clark, A.C.; Szmajter, R.J.

    1993-01-01

    The cleat system developed in low-rank (mean viltrinite reflectance of 0.43 to 0.5 percent) coal beds in the Upper Cretaceous Mesaverde Formation was studied in outcrop and in coreholes drilled for coalbed methane evaluation near Pilot Butte in the central part of the Wind River Reservation. Cleats are the principal permeability pathway for fluids in coal beds. As a result, coalbed gas cannot be economically produced without significant cleat development. Two drillholes about 800 ft (244 m) apart encountered Mesaverde coal beds at depths ranging from 307 to 818 ft (93.6 to 249.3 m). One of the coal beds penetrated while drilling, the lowest coal in the Mesaverde coaly interval, is well exposed about a mile south of the two drillholes and the cleat development in this coal bed on outcrop was compared with that of the same coal in the drillholes.The 3 in (7.62 cm) diameter core is less than ideal for this study because cleat spacing in low-rank coals such as these typically averages greater than 7.62 cm. Nonetheless, face cleats at spacing of from 0.25 to 2.5 cm was observed in many of the coal beds. Cleats were less well-developed in other coal beds and no cleats were observed in a few beds. As expected, butt cleats were somewhat less well-developed than the face cleats. Attempts to relate cleat spacing to gas content, bed thickness, and ash content were not successful. A 3.0 m by 1.8 m area of the upper surface of the coal bed exposed a mile south of the drillsites was cleaned off and studied in detail. Cleat development in this limited study area varied from well-developed face and butt cleats in some places to few or no cleats in others. Face cleats trended roughly perpendicular to the fold axis of the nearby Pilot Butte anticline. Cleats did not penetrate a 2.5 cm thick carbonaceous shale bed about 20 cm above the base of the coal bed indicating that thin carbonaceous shale beds will act a permeability barriers. Two types of face cleats were observed on outcrop

  6. U-Pb dating of zircon in subsurface, hydrothermally altered pyroclastic deposits and implications for subsidence in a magmatically active rift: Taupo Volcanic Zone, New Zealand

    NASA Astrophysics Data System (ADS)

    Wilson, C. J. N.; Charlier, B. L. A.; Rowland, J. V.; Browne, P. R. L.

    2010-03-01

    Recognising and correlating hydrothermally altered rock units within buried volcanic sequences in the Taupo Volcanic Zone (TVZ) in New Zealand is difficult. This is because of broad similarities in the lithologies of many major ignimbrite units, and the destruction by hydrothermal alteration of distinctive chemical and mineralogical characteristics. However, magmatic zircons are commonly present, are highly resistant to hydrothermal alteration and yield crystallisation ages in intensely altered rocks. Crystallisation-age spectra have been obtained by SIMS techniques (SHRIMP-RG) on zircons extracted from cores from altered ignimbrites penetrated by drillholes at the Waiotapu, Te Kopia and Orakei Korako geothermal fields in the central TVZ. At Waiotapu, the thick (up to 350 m) densely welded Waiotapu Ignimbrite returned a zircon age spectrum with a probability density function (pdf) peak of 0.79 Ma, consistent with an eruption age (from 40Ar/ 39Ar techniques) of 0.71 ± 0.06 (1 s.d.) Ma. Three older ignimbrite sheets yielded age spectra that were consistent stratigraphically. The shallowest of the three yielded sparse zircons that gave a pdf peak of 1.24 Ma and it may correlate with the 1.18 ± 0.02 Ma Ahuroa ignimbrite. The middle sheet, although 220 m thick, yielded an age spectrum identical to that obtained from pumice in the widespread 1.21 ± 0.04 Ma Ongatiti ignimbrite, extending earlier estimates of the likely volume of this large deposit. The deepest sheet has a spectrum consistent with an eruption age of 1.45 ± 0.05 Ma; it has no surficial correlative, but its likely coeruptive ash forms part of a concentrated group of primary or secondary tephra in sediments on the ocean floor east of New Zealand and in sedimentary basins across the North Island. These three ignimbrites were previously correlated with either major ignimbrites exposed on the Paeroa Fault scarp, 10 km to the west, or the Akatarewa Ignimbrite that occurs in drillholes at Te Kopia and Orakei

  7. Using airborne magnetic data to map folding and faulting in sedimentary layers: implications for seismic hazard (Invited)

    NASA Astrophysics Data System (ADS)

    Langenheim, V. E.; Jachens, R. C.; Phelps, G. A.; Simpson, R. W.

    2010-12-01

    Aeromagnetic surveys are increasingly used to map structure within sedimentary rocks important for seismic assessment as better magnetometers, positioning, and techniques are developed. We present three examples in which aeromagnetic data are used to map folding and faulting within Cenozoic sedimentary rocks and deposits. In the Salton Trough, detailed aeromagnetic data collected in 1990 suffered from leveling problems that obscured low-amplitude (less than 2-3 nT) magnetic anomalies arising from Tertiary sedimentary rocks. Decorrugation and subtraction of a regional field (upward continuation of 100 m) isolated and enhanced these low-amplitude anomalies, some of which extend the length of the Clark fault, a major strand of the San Jacinto fault zone in southern California, another 20-25 km southwest of its termination point. Other anomalies point to distributed deformation confirmed by detailed surficial mapping by geologists. Detailed aeromagnetic data in the San Ramon Valley, California area show curvilinear anomalies that arise from folding and faulting of the Neroly sandstone, a Miocene unit whose magnetization is due to andesitic detritus. Detailed geologic maps and drillholes locally constrain the geometry of the Neroly Formation at the surface and subsurface, but constrained inversion of aeromagnetic data identified folds not earlier seen. In northern California (e.g. Ukiah), similar long (up to 50 km), curvilinear magnetic anomalies also occur, but in an area where drillholes are absent and geologic mapping is limited by dense vegetation, steep slopes, abundant landsliding, and thick soils. Magnetic susceptibility measurements from sparse outcrops show that the anomalies arise from lithic, volcanic-rich graywacke and metabasalt within the Franciscan Complex. The similarity in anomaly characteristics between the San Ramon and Ukiah areas suggests that the graywackes are folded, coherent bodies within an assemblage that at the surface is termed

  8. Coalbed methane: from hazard to resource

    USGS Publications Warehouse

    Flores, R.M.

    1998-01-01

    Coalbed gas, which mainly consists of methane, has remained a major hazard affecting safety and productivity in underground coal mines for more than 100 yr. Coalbed gas emissions have resulted in outbursts and explosions where ignited by open lights, smoking or improper use of black blasting powder, and machinery operations. Investigations of coal gas outbursts and explosions during the past century were aimed at predicting and preventing this mine hazard. During this time, gas emissions were diluted with ventilation by airways (eg, tunnels, vertical and horizontal drillholes, shsfts) and by drainage boreholes. The 1970s 'energy crisis' led to studies of the feasibility of producing the gas for commercial use. Subsequent research on the origin, accumulation, distribution, availability, and recoverability has been pursued vigorously during the past two decades. Since the 1970s research investigations on the causes and effects of coal mine outbursts and gas emissions have led to major advances towards the recovery and development of coalbed methane for commercial use. Thus, coalbed methane as a mining hazard was harnessed as a conventional gas resource.Coalbed gas, which mainly consists of methane, has remained a major hazard affecting safety and productivity in underground coal mines for more than 100 years. Coalbed gas emissions have resulted in outbursts and explosions where ignited by open lights, smoking or improper use of black blasting powder, and machinery operations. Investigations of coal gas outbursts and explosions during the past century were aimed at predicting and preventing this mine hazard. During this time, gas emissions were diluted with ventilation by airways (e.g., tunnels, vertical and horizontal drillholes, shafts) and by drainage boreholes. The 1970's `energy crisis' led to studies of the feasibility of producing the gas for commercial use. Subsequent research on the origin, accumulation, distribution, availability, and recoverability has been

  9. Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - I. A simple damage structure inferred from borehole core permeability

    USGS Publications Warehouse

    Lockner, David A.; Tanaka, Hidemi; Ito, Hisao; Ikeda, Ryuji; Omura, Kentaro; Naka, Hisanobu

    2009-01-01

    The 1995 Kobe (Hyogo-ken Nanbu) earthquake, M = 7.2, ruptured the Nojima fault in southwest Japan. We have studied core samples taken from two scientific drillholes that crossed the fault zone SW of the epicentral region on Awaji Island. The shallower hole, drilled by the Geological Survey of Japan (GSJ), was started 75 m to the SE of the surface trace of the Nojima fault and crossed the fault at a depth of 624 m. A deeper hole, drilled by the National Research Institute for Earth Science and Disaster Prevention (NIED) was started 302 m to the SE of the fault and crossed fault strands below a depth of 1140 m. We have measured strength and matrix permeability of core samples taken from these two drillholes. We find a strong correlation between permeability and proximity to the fault zone shear axes. The half-width of the high permeability zone (approximately 15 to 25 m) is in good agreement with the fault zone width inferred from trapped seismic wave analysis and other evidence. The fault zone core or shear axis contains clays with permeabilities of approximately 0.1 to 1 microdarcy at 50 MPa effective confining pressure (10 to 30 microdarcy at in situ pressures). Within a few meters of the fault zone core, the rock is highly fractured but has sustained little net shear. Matrix permeability of this zone is approximately 30 to 60 microdarcy at 50 MPa effective confining pressure (300 to 1000 microdarcy at in situ pressures). Outside this damage zone, matrix permeability drops below 0.01 microdarcy. The clay-rich core material has the lowest strength with a coefficient of friction of approximately 0.55. Shear strength increases with distance from the shear axis. These permeability and strength observations reveal a simple fault zone structure with a relatively weak fine-grained core surrounded by a damage zone of fractured rock. In this case, the damage zone will act as a high-permeability conduit for vertical and horizontal flow in the plane of the

  10. A multiple-point geostatistical approach to quantifying uncertainty for flow and transport simulation in geologically complex environments

    NASA Astrophysics Data System (ADS)

    Cronkite-Ratcliff, C.; Phelps, G. A.; Boucher, A.

    2011-12-01

    In many geologic settings, the pathways of groundwater flow are controlled by geologic heterogeneities which have complex geometries. Models of these geologic heterogeneities, and consequently, their effects on the simulated pathways of groundwater flow, are characterized by uncertainty. Multiple-point geostatistics, which uses a training image to represent complex geometric descriptions of geologic heterogeneity, provides a stochastic approach to the analysis of geologic uncertainty. Incorporating multiple-point geostatistics into numerical models provides a way to extend this analysis to the effects of geologic uncertainty on the results of flow simulations. We present two case studies to demonstrate the application of multiple-point geostatistics to numerical flow simulation in complex geologic settings with both static and dynamic conditioning data. Both cases involve the development of a training image from a complex geometric description of the geologic environment. Geologic heterogeneity is modeled stochastically by generating multiple equally-probable realizations, all consistent with the training image. Numerical flow simulation for each stochastic realization provides the basis for analyzing the effects of geologic uncertainty on simulated hydraulic response. The first case study is a hypothetical geologic scenario developed using data from the alluvial deposits in Yucca Flat, Nevada. The SNESIM algorithm is used to stochastically model geologic heterogeneity conditioned to the mapped surface geology as well as vertical drill-hole data. Numerical simulation of groundwater flow and contaminant transport through geologic models produces a distribution of hydraulic responses and contaminant concentration results. From this distribution of results, the probability of exceeding a given contaminant concentration threshold can be used as an indicator of uncertainty about the location of the contaminant plume boundary. The second case study considers a

  11. The deep structure of the Western Pyrenees: constraints from tomographic imaging, field and marine geological observations

    NASA Astrophysics Data System (ADS)

    Tugend, Julie; Manatschal, Gianreto; Chevrot, Sébastien; Mohn, Geoffroy

    2015-04-01

    Knowledge of magma-poor rifted margin architecture has significantly evolved over the past decades. Refraction seismic data combined with drill-hole observations unravelled the velocity structure and lithological assemblages of the most distal part of continental rifted margins. Present-day models of continental rifted margins include the occurrence of hyperextended domains consisting in extremely thinned continental crust and/or exhumed subcontinental mantle as described at many rifted margins. Studies in mountain belts revealed that remnants of hyperextended domains could also be identified in internal parts of collisional orogens. Integrating recent developments in the understanding of rifted margins in the study of mountain building processes, in particular the importance of the reactivation of inherited rift structures is therefore essential and may result in alternative interpretations of the lithospheric scale structure of collisional orogens. In this contribution, we focus on the western part of the Pyrenean orogen that resulted from the inversion of a complex Late Jurassic to Mid Cretaceous rift system. The transition from preserved oceanic and rift domains to the west (in the offshore Bay of Biscay) to their complete inversion in the east provides simultaneous access to seismically imaged and exposed parts of a hyperextended rift system. Based on a multi-scale dataset that combines sub-surface data (field and drill-hole observations) with tomographic imaging (PYROPE experiment) and integrating new concepts derived from the study of present-day rifted margins, we investigate the lithospheric-scale architecture of the Western Pyrenees. Our results suggest that the imaged north-dipping crustal root may correspond to the former exhumed mantle and hyperthinned domains that have been subducted/underthrust at the onset of convergence. This interpretation contrasts with the classical assumption that the crustal root is made of lower crustal rocks. This

  12. Structural evolution of the Currawong Pb-Zn-Cu deposit (Victoria, Australia) - new insights from 3D implicit modelling linked to structural observations

    NASA Astrophysics Data System (ADS)

    Vollgger, Stefan; Cruden, Alexander

    2015-04-01

    Structurally controlled mineralisation commonly shows distinctive geometries, orientations and spatial distributions that derive from associated structures. These structures have the ability to effectively transport, trap and focus fluids. Moreover, structures such as faults and shear zones can offset, truncate and spatially redistribute earlier mineralisation. We present a workflow that combines structural fieldwork with state-of-the-art 3D modelling to assess the structural framework of an ore deposit. Traditional 3D models of ore deposits rely on manual digitisation of cross sections and their subsequent linkage to form 3D objects. Consequently, the geological interpretation associated with each section will be reflected in the resulting 3D models. Such models are therefore biased and should be viewed and interpreted with caution. Conversely, 3D implicit modelling minimises the modelling bias by using an implicit function that is fitted to spatial data such as drillhole data. This function defines a scalar field, from which 3D isosurfaces can be extracted. Assay data can be visualised as 3D grade shells at various threshold grade values and used to analyse and measure the shape, distribution and orientation of mineralisation. Additionally, lithology codes from drillholes can be used to extract lithological boundaries in 3D without the need for manual digitisation. In our case study at the Palaeozoic Currawong Pb-Zn-Cu deposit (Victoria, Australia), orientations extracted from ore bodies within a 3D implicit model have been compared to structural field data collected around the deposit. The data and model suggest that Currawong's massive sulfide lenses have been structurally modified. Mineralisation trends are parallel to a dominant NW dipping foliation mapped in the field. This foliation overprints earlier bedding in the host metasediments that has been deformed into upright folds. Several sets of steep faults further increase the structural complexity of the

  13. Regional liquefaction hazard evaluation following the 2010-2011 Christchurch (New Zealand) earthquake sequence

    NASA Astrophysics Data System (ADS)

    Begg, John; Brackley, Hannah; Irwin, Marion; Grant, Helen; Berryman, Kelvin; Dellow, Grant; Scott, David; Jones, Katie; Barrell, David; Lee, Julie; Townsend, Dougal; Jacka, Mike; Harwood, Nick; McCahon, Ian; Christensen, Steve

    2013-04-01

    Following the damaging 4 Sept 2010 Mw7.1 Darfield Earthquake, the 22 Feb 2011 Christchurch Earthquake and subsequent damaging aftershocks, we completed a liquefaction hazard evaluation for c. 2700 km2 of the coastal Canterbury region. Its purpose was to distinguish at a regional scale areas of land that, in the event of strong ground shaking, may be susceptible to damaging liquefaction from areas where damaging liquefaction is unlikely. This information will be used by local government for defining liquefaction-related geotechnical investigation requirements for consent applications. Following a review of historic records of liquefaction and existing liquefaction assessment maps, we undertook comprehensive new work that included: a geologic context from existing geologic maps; geomorphic mapping using LiDAR and integrating existing soil map data; compilation of lithological data for the surficial 10 m from an extensive drillhole database; modelling of depth to unconfined groundwater from existing subsurface and surface water data. Integrating and honouring all these sources of information, we mapped areas underlain by materials susceptible to liquefaction (liquefaction-prone lithologies present, or likely, in the near-surface, with shallow unconfined groundwater) from areas unlikely to suffer widespread liquefaction damage. Comparison of this work with more detailed liquefaction susceptibility assessment based on closely spaced geotechnical probes in Christchurch City provides a level of confidence in these results. We tested our susceptibility map by assigning a matrix of liquefaction susceptibility rankings to lithologies recorded in drillhole logs and local groundwater depths, then applying peak ground accelerations for four earthquake scenarios from the regional probabilistic seismic hazard model (25 year return = 0.13g; 100 year return = 0.22g; 500 year return = 0.38g and 2500 year return = 0.6g). Our mapped boundary between liquefaction-prone areas and areas

  14. Using mineralogical and geochemical data as a tool for determining potential environmental changes

    NASA Astrophysics Data System (ADS)

    Perunović, Tamara; Jovančićević, Branimir; Brčeski, Ilija; Šajnović, Aleksandra; Stojanović, Ksenija; Simić, Vlada; Kašanin-Grubin, Milica

    2014-05-01

    Neogene lacustrine basins are often bearing coal, oil-shale and non-metallic minerals such as magnesite, borates and marls. Exploration of these deposits could put a lot of pressure on the landscape. Aim of this research is to show that geochemical and mineralogical data could be used as a tool in determining landscape sensitivity to an imposed change. To test this hypothesis Lower Miocen lacustrine Kremna basin, Serbia, was investigated. Kremna basin covers an area of approximately 15 km2 and is located in SW Serbia. For the purpose of this study, geomorphologic and microclimatic characteristics of the area were assessed and geochemical and mineralogical composition of 43 sediment samples from one borehole was determined. The purpose of the drilling was to determine the possible evaporite deposit and boron occurrence. The borehole was 343 m deep and ended in weathered serpentinite. Landscape of Kremna basin is hilly-mountainous with pastures, meadows and agriculture as dominant vegetation type. The area is sparsely populated with mountain villages dispersed and mostly isolated. Main water supplies for villages are springs. Climate data (1961-2012) indicate that the average precipitation is 988 mm, and temperature 7,5oC. However, variations in climatic conditions are evident since 1990 showing more profound change between colder and wetter, and warmer and drier years alternating every two to three years. The base and the edge of the Kremna basin consist predominantly of ultrabasic rocks, serpentinite and ophiolitic mélange, which are all prone to weathering. Drill-hole date showed that uppermost clay and Mg rich sediments were overlain by a thin soil layer (~ 15cm). Leaching tests performed on these uppermost sediments indicated that they are dispersive and prone to erosion. Higher average concentration of boron and certain heavy metals, as well as presents of Cr, Hg, As, Pb, Ni, Th, U was determined. Effect of these elements on the environment can be highly

  15. High Melt Porosity in the Lower Oceanic Crust Inferred from Phosphorus Zoning in Olivine

    NASA Astrophysics Data System (ADS)

    Hellebrand, E.; Welsch, B. T.; Hammer, J. E.

    2013-12-01

    The canonical view that the lower oceanic crust is composed of cumulates of fractional crystallization has been intensely debated in recent years. Migrating melts, reacting with previously crystallized minerals in the crystal mush, can modify the mineralogy and phase proportions inside the lower crust, as well as the composition of erupted MORB [1]. An extreme product of reactive melt migration was discovered during IODP Legs 304/305 at Atlantis Massif (MAR 30N). In this 1.5 km deep drillhole, there are several sequences of olivine-rich troctolite with ';textbook cumulate texture', which may be associated with the contact of a gabbroic pluton into peridotite [2,3]. While there is little ambiguity about the geological relationships, the exact mechanism for the in-situ reactive transformation of mantle peridotites into lower crustal gabbroic lithologies is still poorly understood. One widespread textural feature in support of the dominant role of reactive melt migration is the occurrence of interstitial and vermicular high-Mg# cpx, which form post-compaction at very low melt porosities. The rare screens of opx-bearing mantle peridotites in this drillhole also preserve evidence for low-porosity replacement of mantle opx by gabbroic cpx [4], with minimal volume change. However, we will show that a significant and possibly the main mass of the olivine crystals in the olivine-rich troctolites do not form at low melt porosities, but instead in a melt-rich local environment. Initially, olivines crystallize as rapidly grown dendrites, which is marked by distinct enrichments of the slowly diffusing element phosphorus. Subsequent slow growth produces the main mass of the otherwise P-free olivine crystal. Our observations on natural basalt-hosted and experimentally grown olivines indicate that strong undercooling in a crystal-poor environment is required for dendrite formation. By extrapolation, this would require a crystal-poor melt lens at the top of an evolving gabbroic

  16. The copper-nickel concentration log: A tool for stratigraphic interpretation within the ultramafic and basal zones of the stillwater complex, Montana

    USGS Publications Warehouse

    Drew, L.J.; Bawiec, W.J.; Page, N.J.; Schuenemeyer, J.H.

    1985-01-01

    An analogue to the electric well log was devised for copper-nickel concentration drill-hole data from the Basal and lower part of the Ultramafic zones of the Stillwater Complex using automated data processing. The copper-nickel concentration logs graphically represent intensity (concentration) values that reflect the distribution of the elements in sulfide and silicate minerals. Four major patterns are recognized by their characteristic variations in copper and nickel intensity: (1) relatively flat, low-level copper-intensity signatures associated with arcuate nickel-intensity patterns that correlate with rocks in the Peridotite member of the Ultramafic zone; (2) arcuate or bulb-like patterns of copper and nickel intensity that correlate closely with the Basal bronzite cumulate member of the Basal zone; (3) complex patterns consisting of intervals of low-intensity copper and moderate-intensity nickel, spikes of high nickel and copper intensity, and high copper intensity associated with low nickel intensity that correlate respectively with cordierite-pyroxene hornfels, massive sulfide, norites and mineralized diabase dikes in the Basal norite member; and (4) large intervals of extremely low copper and nickel intensity that correlate with quartz-orthopyroxene hornfels. The recognition and interpretation of these patterns allow two- and three-dimensional stratigraphic and lithologic reconstructions to be done by means of concentration-log correlations instead of variable quality lithologic logging. ?? 1985.

  17. Downhole measurements in the AND-1B borehole, ANDRILL McMurdo Ice Shelf Project, Antarctica

    USGS Publications Warehouse

    Morin, R.; Williams, T.; Henrys, S.; Crosby, T.; Hansaraj, D.

    2007-01-01

    A comprehensive set of downhole measurements was collected in the AND-1B drillhole as part of the on-ice scientific programme defined for the McMurdo Ice Shelf (MIS) Project. Geophysical logs were recorded over two operation phases and consisted of calliper, temperature, fluid conductivity, induction resistivity, magnetic susceptibility, natural gamma activity, acoustic televiewer, borehole deviation, and dipmeter. In addition, two standard vertical seismic profiles (VSP) and one walk-away VSP were obtained. Radioactive logs (porosity and density) were not run because of unstable borehole conditions. Although the total depth of the hole is 1285 metres below seafloor (mbsf), the depth range for in situ measurements was limited by the length of the wireline (1018 mbsf) and by the nullification of some geophysical logs due to the presence of steel casing. A depth correction was derived to account for systematic discrepancies in depth between downhole measurements and cores; consequently, log responses can be directly compared to core properties. The resulting data are amenable to studies of cyclicity and climate, heat flux and fluid flow, and stricture and stress. When integrated with physical properties and fractures measured on the core, this information should play a significant role in addressing many of the scientific objectives of the ANDRILL programme.

  18. Implicit Three-Dimensional Geo-Modelling Based on HRBF Surface

    NASA Astrophysics Data System (ADS)

    Gou, J.; Zhou, W.; Wu, L.

    2016-10-01

    Three-dimensional (3D) geological models are important representations of the results of regional geological surveys. However, the process of constructing 3D geological models from two-dimensional (2D) geological elements remains difficult and time-consuming. This paper proposes a method of migrating from 2D elements to 3D models. First, the geological interfaces were constructed using the Hermite Radial Basis Function (HRBF) to interpolate the boundaries and attitude data. Then, the subsurface geological bodies were extracted from the spatial map area using the Boolean method between the HRBF surface and the fundamental body. Finally, the top surfaces of the geological bodies were constructed by coupling the geological boundaries to digital elevation models. Based on this workflow, a prototype system was developed, and typical geological structures (e.g., folds, faults, and strata) were simulated. Geological modes were constructed through this workflow based on realistic regional geological survey data. For extended applications in 3D modelling of other kinds of geo-objects, mining ore body models and urban geotechnical engineering stratum models were constructed by this method from drill-hole data. The model construction process was rapid, and the resulting models accorded with the constraints of the original data.

  19. Offset of Tertiary arcs on the Alaska Peninsula: A section in Geological Survey research, fiscal year 1981

    USGS Publications Warehouse

    ,

    1984-01-01

    Geologic mapping and potassium-argon dating by R. L. Detterman, F. H. Wilson, J. E. Case, and Nora Shew in the Ugashik and western part of the Karluk quadrangles have shown that the Eocene and Oligocene volcanic arc continues into these quadrangles from the south in the Chignik and Sutwik Island quadrangles. Surface exposures of the arc extend northward to approximately 57°30'N., or midway through the Ugashik quadrangle, but none are observed north of that point. Subsurface drill-hole data (Brockway and others, 1975) indicate continuation of the arc, possibly offset to the northwest of the northernmost known surface exposures.In the extreme northern part of the Ugashik and Karluk quadrangles, volcanic rocks again become important. These volcanic rocks are as yet undated; however, they may be related to the Katmai late Tertiary volcanic centers.Like the early Tertiary volcanic arc, the present-day Aleutian arc is also offset to the northwest in the northern part of the Ugashik and Karluk quadrangles. No major offset of the Mesozoic rocks is indicated through the offset zone; this fact suggests a change in the Tertiary tectonic regime in the area of the offset.

  20. Erschließung eines Marmorkarstvorkommens als mitteltiefer Erdwärmesondenspeicher im Tuxertal, Tirol

    NASA Astrophysics Data System (ADS)

    Sass, Ingo; Heldmann, Claus-Dieter; Lehr, Clemens

    2016-06-01

    Borehole heat exchangers can be economically beneficial for meeting heating and cooling demands of houses or buildings. In karst aquifers development of thermal storage and exchange systems may be problematic in terms of groundwater protection and storage design, due to possibly high groundwater velocities. The new development of the Hochstegen marble unit in the Tux Valley (Zillertal, Austria) was designed in two stages for the requested cooling and heating demands. An enhanced geothermal response test was completed using optical frequency domain reflectometry in an exploration drillhole. Additional studies focussing on local geology and hydrology were also conducted. Geothermal parameters obtained at precise depths allowed differentiating between conductive and convective heat flow and were correlated with the lithostratigraphically-conditioned karst characteristics. The borehole heat exchanger field was developed with nine 400 m deep dual U-shaped tube probes in 2013 for 1 GWh/a extraction and 400 MWh/a induction. Along with borehole geophysics and geothermal response tests, the study has provided relevant geothermal data for improving storage design and exploration.

  1. A Hydrostratigraphic Model of the Pahute Mesa - Oasis Valley Area, Nye County, Nevada

    SciTech Connect

    S. L. Drellack, Jr.; L. B. Prothro; J. L. Gonzales

    2001-12-01

    A 3-D hydrostratigraphic framework model has been built for the use of hydrologic modelers who are tasked with developing a model to determine how contaminants are transported by groundwater flow in an area of complex geology. The area of interest includes Pahute Mesa, a former nuclear testing area at the Nevada Test Site (NTS), and Oasis Valley, a groundwater discharge area down-gradient from contaminant source areas on Pahute Mesa. To build the framework model, the NTS hydrogeologic framework was integrated with an extensive collection of drill-hole data (stratigraphic, lithologic, and alteration data); a structural model; and several recent geophysical, geological, and hydrological studies to formulate a hydrostratigraphic system. The authors organized the Tertiary volcanic units in the study area into 40 hydrostratigraphic units that include 16 aquifers, 13 confining units, and 11 composite units. The underlying pre-Tertiary rocks were divided into six hydrostratigraphic units, including two aquifers and four confining units. The model depicts the thickness, extent, and geometric relationships of these hydrostratigraphic units (''layers'' in the model) along with all the major structural features that control them, including calderas and faults. The complexity of the model area and the non-uniqueness of some of the interpretations incorporated into the base model made it necessary to address alternative interpretations for some of the major features in the model. Six of these alternatives were developed so they could be modeled in the same fashion as the base model.

  2. Geology of Vanport limestone (Pennsylvanian) in Elk County, Pennsylvania

    SciTech Connect

    Kuntz, T.J.

    1987-09-01

    The northernmost exposures of the Vanport limestone appear in Elk and southern McKean Counties, Pennsylvania. The Vanport limestone is structurally preserved in N45/sup 0/-50/sup 0/E trending synclinal folds. Surface exposures are almost all incomplete due to erosion. Drill-hole data assisted in defining areas of nondeposition within Elk County, variations in thickness, and erosional loss by channeling. The Vanport limestone thins to the southeast within Elk County and probably changes from limestone to a shaly limestone (transition zone) and then to shale. Analysis of 70 limestone samples indicated an average insoluble-residue content of 11.4%. The insoluble residue, mainly clay, increases toward the southeast, the direction of paleoshoreline and source of terrigenous sediments. A lack of quartz grains suggests a lack of detrital input from the source area. A study of the vertical variation of the total insoluble-residue content displayed an increase at the bottoms and tops of the stratigraphic section, mirroring the transgressive-regressive phases of the Vanport sea. The majority of allochems were skeletal material in a micritic matrix. Most abundant were mollusks, followed by forams, brachiopods, echinoderms, ostracods, and bryozoans. Composita brachiopods and pseudopunctate and/or punctate brachiopods inhabited offshore stillstand and nearshore transgressive-regressive environments, respectively. Other fossil assemblages displayed spatial and temporal variation. A darker matrix color occurred in stratigraphic sections closer to the paleoshoreline, due to higher clay and organic content. More offshore stratigraphic sections of the limestone were noticeably lighter in color.

  3. Watertightness of chiew larn reservoir, suratthani, Southern Thailand

    NASA Astrophysics Data System (ADS)

    Chittrakarn, P.

    Chiew Larn reservoir is formed by damming the Khlong Saeng valley which is located in Suratthani, Southern Thailand. The maximum water level and the limestone perviousness are the main problems of this project. At the southern reservoir rim, there is a limestone area that runs from Khlong Saeng to the Khlong Sok valley giving rise to concern about reservoir leakage. To cope with this problem, the hydrogeology of this basin was studied in order to confirm that the underground water table is higher than the reservoir level. Hydrogeological observations, such as the water inventory of the surface creeks and ponds, flourescence test of the underground water including underground water measurement in rotary drill-holes, demonstrated that the underground water table in this area is high enough to prevent the leakage of reservoir water. This conclusion is supported by the high water level recorded in DH-1, at the ground elevation of 176 mMSL, depth 80 m showing that the elevation of the ground water table is at 173 mMSL in April 1973, at the end of the dry season.

  4. Ship-borne electromagnetic induction sounding of sea-ice thickness in the southern Sea of Okhotsk

    NASA Astrophysics Data System (ADS)

    Uto, Shotaro; Toyota, Takenobu; Shimoda, Haruhito; Tateyama, Kazutaka; Shirasawa, Kunio

    Recent observations have revealed that dynamical thickening is dominant in the growth process of sea ice in the southern Sea of Okhotsk. That indicates the importance of understanding the nature of thick deformed ice in this area. The objective of the present paper is to establish a ship-based method for observing the thickness of deformed ice with reasonable accuracy. Since February 2003, one of the authors has engaged in the core sampling using a small basket from the icebreaker Soya. Based on these results, we developed a new model which expressed the internal structure of pack ice in the southern Sea of Okhotsk, as a one-dimensional multilayered structure. Since 2004, the electromagnetic (EM) inductive sounding of sea-ice thickness has been conducted on board Soya. By combining the model and theoretical calculations, a new algorithm was developed for transforming the output of the EM inductive instrument to ice + snow thickness (total thickness). Comparison with total thickness by drillhole observations showed fair agreement. The probability density functions of total thickness in 2004 and 2005 showed some difference, which reflected the difference of fractions of thick deformed ice.

  5. Flexible Mechanical Conveyors for Regolith Extraction and Transport

    NASA Technical Reports Server (NTRS)

    Walton, Otis R.; Vollmer, Hubert J.

    2013-01-01

    A report describes flexible mechanical conveying systems for transporting fine cohesive regolith under microgravity and vacuum conditions. They are totally enclosed, virtually dust-free, and can include enough flexibility in the conveying path to enable an expanded range of extraction and transport scenarios, including nonlinear drill-holes and excavation of enlarged subsurface openings without large entry holes. The design of the conveyors is a modification of conventional screw conveyors such that the central screw-shaft and the outer housing or conveyingtube have a degree of bending flexibility, allowing the conveyors to become nonlinear conveying systems that can convey around gentle bends. The central flexible shaft is similar to those used in common tools like a weed whacker, consisting of multiple layers of tightly wound wires around a central wire core. Utilization of compliant components (screw blade or outer wall) increases the robustness of the conveying, allowing an occasional oversized particle to pass hough the conveyor without causing a jam or stoppage

  6. Evaluation of the geothermal resource in the area of Albuquerque, New Mexico

    SciTech Connect

    Jiracek, G.R.; Swanberg, C.A.; Morgan, P.; Parker, M.D.

    1983-07-01

    Factors indicating a potential geothermal resource near Albuquerque are: (1) nearby volcanoes active as recently as 120,000 years ago, (2) gravity interpretation indicating a potential reservoir averaging 1.5 km thickness, (3) high heat flow near the city, (4) warm waters (>30/sup 0/C) in municipal wells, (5) recent seismicity indicating active faulting, thereby, allowing the possibility of deep hydrothermal circulation, (6) high shallow (<30 m) temperature gradients (>100/sup 0/C/km) discovered in our drillholes, (7) deeper (<500 m) gradients from water wells exceeding 80/sup 0/C/km, and (8) chemical analyses of 88 groundwater samples yielding estimated base reservoir temperatures as high as 190/sup 0/C. An area of elevated shallow temperature gradients (less than or equal to 140/sup 0/C/km) was discovered a few kilometers west of Albuquerque by our 69 hole drilling program. Resistivity, magnetic, and gravity measurements combined with computer modeling suggests that heated ground water is forced closer to the surface here by flow over a buried ridge. A well drilled nearby yielded the highest recorded temperature in the Albuquerque area at its maximum depth (32.8/sup 0/C at 364 m). The deep gradient is 35/sup 0/C/km. An oil test well close by reported large volumes of water at 1 km; therefore, the possibility of a low temperature (>50/sup 0/C) geothermal resource exists west of Albuquerque at less than 1 km depth.

  7. Geophysical-geological studies of possible extensions of the New Madrid Fault Zone. Annual report, 1982. Vol. 1

    SciTech Connect

    Hinze, W.J.; Braile, L.W.; Keller, G.R.; Lidiak, E.G.

    1983-05-01

    An integrated geophysical/geologic program is being conducted to evaluate the rift complex hypothesis as an explanation for the earthquake activity in the New Madrid Seismic Zone and its extensions, to refine our knowledge of the rift complex, and to investigate the possible northern extensions of the New Madrid Fault Zone, especially its possible connection to the Anna, Ohio seismogenic region. Drillhole basement lithologies are being investigated to aid in tectonic analysis and geophysical interpretation, particularly in the Anna, Ohio area. Gravity and magnetic modeling combined with limited seismic reflection studies in southwest Indiana are interpreted as confirming speculation that an arm of the New Madrid Rift Complex extends northeasterly into Indiana. The geologic and geophysical evidence confirm that the basement lithology in the Anna, Ohio area is highly variable reflecting a complex geologic history. The data indicate that as many as three major Late Precambrian tectonic features intersect within the basement of the Anna area suggesting that the seismicity may be related to basement zones of weakness.

  8. Seismic evidence for an extensive gas-bearing layer at shallow depth, offshore from Prudhoe Bay, Alaska

    USGS Publications Warehouse

    Boucher, G.; Reimnitz, E.; Kempema, E.

    1981-01-01

    High-resolution seismic reflection data, recorded offshore from Prudhoe Bay, Alaska, were processed digitally to determine the reflectivity structure of the uppermost layers of the seafloor. A prominent reflector, found at 27 m below the mud line (water depths 7-9 m), has a negative reflection coefficient greater than 0.5. The large acoustic impedance contrast, coupled with a report of gas encountered at a corresponding depth in a nearby drillhole, shows that the reflector is the upper boundary of a zone containing gas. The gas exists in sandy gravel capped by stiff, silty clay. Analysis of unprocessed conventional high-resolution records from the region indicates that the gas-bearing layer may extend over an area of at least 50 km2 at a depth of 20-35 m below the mud line. Similar-appearing reflectors (Reimnitz, 1972), previously unexplained, occur in patches over wide regions of the shelf where offshore oil development is beginning at a rapid pace. This suggests the exercise of caution with respect to possible hazards from shallow gas pockets.

  9. An integrated geochemical approach to investigate the concealed mineralization at the Redmoor Sn/W sheeted vein deposit, east Cornwall, England

    NASA Astrophysics Data System (ADS)

    Newall, P. S.

    Initial geochemical studies over the high grade zone of mineralization at Redmoor have indicated that it is characterized by elevated Cu, Pb, Zn, Sn, W, Li, As, Rb and F, and depleted Mn, Mg, Na and Sr. From this, the lower grade extension zone of the sheeted vein mineralization was geochemically investigated utilizing both percussion drill and float sample data. Single and multielement statistical techniques were used for interpretation, and these clearly delineated the sub-outcrop of the sheeted vein, lodes, granite intrusion and volcanic rocks. As a comparison, the -80# soil fraction was investigated using the same statistical techniques, and surprisingly, it was found that the float samples better geochemically defined the positions of the major geological features of the area. Also, a deep diamond drillhole which penetrated the high grade mineralization was investigated. The results showed that although the magnitude of the data was somewhat different to the float samples, the elements and their geochemical trends associated with the mineralization and volcanics were broadly similar. However, wallrock alteration appeared to be limited. In conclusion, evidence suggests that the wallrock alteration effects about the sheeted vein mineralization are generally minimal. However, by using a carefully selected choice of elements, correct sample media and powerful interpretive techniques, a broad anomalous zone about the mineralization, coupled with the location of other discrete geological features, can be identified.

  10. Hydrogeochemistry and microbiology of mine drainage: An update

    USGS Publications Warehouse

    Nordstrom, D. Kirk; Blowes, D.W; Ptacek, C.J.

    2015-01-01

    The extraction of mineral resources requires access through underground workings, or open pit operations, or through drillholes for solution mining. Additionally, mineral processing can generate large quantities of waste, including mill tailings, waste rock and refinery wastes, heap leach pads, and slag. Thus, through mining and mineral processing activities, large surface areas of sulfide minerals can be exposed to oxygen, water, and microbes, resulting in accelerated oxidation of sulfide and other minerals and the potential for the generation of low-quality drainage. The oxidation of sulfide minerals in mine wastes is accelerated by microbial catalysis of the oxidation of aqueous ferrous iron and sulfide. These reactions, particularly when combined with evaporation, can lead to extremely acidic drainage and very high concentrations of dissolved constituents. Although acid mine drainage is the most prevalent and damaging environmental concern associated with mining activities, generation of saline, basic and neutral drainage containing elevated concentrations of dissolved metals, non-metals, and metalloids has recently been recognized as a potential environmental concern. Acid neutralization reactions through the dissolution of carbonate, hydroxide, and silicate minerals and formation of secondary aluminum and ferric hydroxide phases can moderate the effects of acid generation and enhance the formation of secondary hydrated iron and aluminum minerals which may lessen the concentration of dissolved metals. Numerical models provide powerful tools for assessing impacts of these reactions on water quality.

  11. Fault geometry and cumulative offsets in the central Coast Ranges, California: Evidence for northward increasing slip along the San Gregorio-San Simeon-Hosgri fault

    USGS Publications Warehouse

    Langenheim, V.E.; Jachens, R.C.; Graymer, R.W.; Colgan, J.P.; Wentworth, C.M.; Stanley, R.G.

    2012-01-01

    Estimates of the dip, depth extent, and amount of cumulative displacement along the major faults in the central California Coast Ranges are controversial. We use detailed aeromagnetic data to estimate these parameters for the San Gregorio–San Simeon–Hosgri and other faults. The recently acquired aeromagnetic data provide an areally consistent data set that crosses the onshore-offshore transition without disruption, which is particularly important for the mostly offshore San Gregorio–San Simeon–Hosgri fault. Our modeling, constrained by exposed geology and in some cases, drill-hole and seismic-reflection data, indicates that the San Gregorio–San Simeon–Hosgri and Reliz-Rinconada faults dip steeply throughout the seismogenic crust. Deviations from steep dips may result from local fault interactions, transfer of slip between faults, or overprinting by transpression since the late Miocene. Given that such faults are consistent with predominantly strike-slip displacement, we correlate geophysical anomalies offset by these faults to estimate cumulative displacements. We find a northward increase in right-lateral displacement along the San Gregorio–San Simeon–Hosgri fault that is mimicked by Quaternary slip rates. Although overall slip rates have decreased over the lifetime of the fault, the pattern of slip has not changed. Northward increase in right-lateral displacement is balanced in part by slip added by faults, such as the Reliz-Rinconada, Oceanic–West Huasna, and (speculatively) Santa Ynez River faults to the east.

  12. Economics of Developing Hot Stratigraphic Reservoirs

    SciTech Connect

    Greg Mines; Hillary Hanson; Rick Allis; Joseph Moore

    2014-09-01

    Stratigraphic geothermal reservoirs at 3 – 4 km depth in high heat-flow basins are capable of sustaining 100 MW-scale power plants at about 10 c/kWh. This paper examines the impacts on the levelized cost of electricity (LCOE) of reservoir depth and temperature, reservoir productivity, and drillhole/casing options. For a reservoir at 3 km depth with a moderate productivity index by hydrothermal reservoir standards (about 50 L/s/MPa, 5.6 gpm/psi), an LCOE of 10c/kWh requires the reservoir to be at about 200°C. This is the upper temperature limit for pumps. The calculations assume standard hydrothermal drilling costs, with the production interval completed with a 7 inch liner in an 8.5 inch hole. If a reservoir at 4 km depth has excellent permeability characteristics with a productivity index of 100 L/s/MPa (11.3 gpm/psi), then the LCOE is about 11 c/kWh assuming the temperature decline rate with development is not excessive (< 1%/y, with first thermal breakthrough delayed by about 10 years). Completing wells with modest horizontal legs (e.g. several hundred meters) may be important for improving well productivity because of the naturally high, sub-horizontal permeability in this type of reservoir. Reducing the injector/producer well ratio may also be cost-effective if the injectors are drilled as larger holes.

  13. Impact of Micro-to Meso-scale Fractures on Sealing Behavior of Argillaceous Cap Rocks For CO2 Sequestration

    SciTech Connect

    Evans, James

    2016-08-01

    This multi-disciplinary project evaluated seal lithologies for the safety and security of long-term geosequestration of CO2. We used integrated studies to provide qualitative risk for potential seal failure; we integrated data sets from outcrop, core, geochemical analysis, rock failure properties from mechanical testing, geophysical wireline log analysis, and geomechanical modeling to understand the effects of lithologic heterogeneity and changing mechanical properties have on the mechanical properties of the seal. The objectives of this study were to characterize cap rock seals using natural field analogs, available drillhole logging data and whole-rock core, geochemical and isotopic analyses. Rock deformation experiments were carried out on collected samples to develop better models of risk estimation for potential cap rock seal failure. We also sampled variably faulted and fractured cap rocks to examine the impacts of mineralization and/or alteration on the mechanical properties. We compared CO2 reacted systems to non-CO2 reacted seal rock types to determine response of each to increased pore fluid pressures and potential for the creation of unintentional hydrofractures at depth.

  14. 3-D Projected L1 inversion of gravity data using truncated unbiased predictive risk estimator for regularization parameter estimation

    NASA Astrophysics Data System (ADS)

    Vatankhah, Saeed; Renaut, Rosemary A.; Ardestani, Vahid E.

    2017-09-01

    Sparse inversion of gravity data based on L1-norm regularization is discussed. An iteratively reweighted least squares algorithm is used to solve the problem. At each iteration the solution of a linear system of equations and the determination of a suitable regularization parameter are considered. The LSQR iteration is used to project the system of equations onto a smaller subspace that inherits the ill-conditioning of the full space problem. We show that the gravity kernel is only mildly to moderately ill-conditioned. Thus, while the dominant spectrum of the projected problem accurately approximates the dominant spectrum of the full space problem, the entire spectrum of the projected problem inherits the ill-conditioning of the full problem. Consequently, determining the regularization parameter based on the entire spectrum of the projected problem necessarily over compensates for the non-dominant portion of the spectrum and leads to inaccurate approximations for the full-space solution. In contrast, finding the regularization parameter using a truncated singular space of the projected operator is efficient and effective. Simulations for synthetic examples with noise demonstrate the approach using the method of unbiased predictive risk estimation for the truncated projected spectrum. The method is used on gravity data from the Mobrun ore body, northeast of Noranda, Quebec, Canada. The 3-D reconstructed model is in agreement with known drill-hole information.

  15. Uncertainty Analysis for Assessing Leakage Through Water Tunnels: A Case from Nepal Himalaya

    NASA Astrophysics Data System (ADS)

    Panthi, Krishna Kanta; Nilsen, Bjørn

    2010-09-01

    Water leakage problems in unlined or shotcrete lined water tunnels are not new issues. In many occasions severe water leakage problems have been faced that not only have reduced the stability of the rock mass, but also have caused valuable water to be lost from it, causing safety risk as well as huge economic loss to the projects. Hence, making tunnels water tight plays an important role in improving stability and safety of underground excavations. The real challenge is however accurate prediction and quantification of possible water leakage, so that cost consequences can be incorporated during planning of a water conveying tunnel project. The main purposes of this paper are to analyze extensive data on leakage test carried out through exploratory drillhole used to define the need for pre-injection grouting of Khimti headrace tunnel and to carry out probabilistic approach of uncertainty analysis based on relationship established between leakage, hydrostatic head and selected Q-value parameters. The authors believe that the new approach regarding uncertainty analysis of leakage presented in this paper will improve the understanding of leakage characteristics of the rock mass, and hope this will lead to a better understanding concerning quantification of possible water leakage from unlined and shotcrete lined water tunnels.

  16. The Erratic Behavior of Lesions in Burnt Bone.

    PubMed

    Collini, Federica; Amadasi, Alberto; Mazzucchi, Alessandra; Porta, Davide; Regazzola, Valeria Luisa; Garofalo, Paola; Di Blasio, Annalisa; Cattaneo, Cristina

    2015-09-01

    This study analyses depressed fractures (by blunt force trauma) and circular full-thickness injuries (drill injuries and gunshot wounds) in charred bones. Fifty bovine ribs (total 104 lesions) were divided into three groups. The first group consisted in 20 depressed hammer-produced fractures; in the second one, 60 round drill-holes were produced (30 circular, 30 semicircular); in the third group, 12 fleshed and 12 skeletonized ribs were hit by 9-mm bullets. Each specimen was carbonized in an electric oven up to 800°C. Morphological and metric analyses were performed before and after: morphological features were preserved, but depressed fractures showed an increase in their dimensions (p-value<0.05); the drilled holes shrunk (p-value<0.01); the charring cycle increased the number of fractures in samples with gunshot wounds differently in fleshed and defleshed ribs. This study showed the complex behavior of charred bone, for what concerns the interpretation of trauma and how caution should be applied.

  17. Tectonic events recorded in the sediments and crust of the Caribbean sea floor

    SciTech Connect

    Holcombe, T.L.

    1985-01-01

    A reconnaissance review of reflection-seismic sections from the Caribbean, together with limited information derived from dredged rocks, sediment cores, and drillholes, yields or contributes to first-order conclusions regarding the tectonic history of the water-covered Caribbean. Broadly speaking, tectonic episodes for which there is some evidence are: (1) late Cenozoic convergence and accretion along deformed continental or island margins off Panama, Colombia/Venezuela, and Hispaniola/Puerto Rico; (2) late Cenozoic generation of oceanic crust within the Cayman Trough; (3) late Cenozoic secondary deformation along the Caribbean-North American plate boundary zone, in the form of small pull-apart basins, transcurrent faults, tensional rift basins, and compressional features; (4) late Cenozoic slow disintegration of the western part of the Caribbean plate; (5) Cenozoic rift-basin formation on the upper Nicaraguan rise; (6) early Cenozoic or late Cretaceous opening of the Yucatan Basin; (7) late Cretaceous through early Cenozoic island arc formation; and (8) late Cretaceous and earlier emplacement of flow basalts in the northwestern Venezuelan Basin and possibly beneath large areas of the Caribbean. There is no evidence that except along their active margins, the Venezuelan Basin, Beata Ridge, Colombian Basin, and Nicaraguan rise areas have been sites for large-scale relative movements which created or destroyed plate material since late Cretaceous time - or earlier.

  18. An approach for 3D geoscientific data integration in underground planning

    NASA Astrophysics Data System (ADS)

    Zhong, Zheng; Tor, Yam Khoon; Tan, Guoxian

    2008-12-01

    Due to finite space, there is an increasing need to plan and develop strategic underground facilities and infrastructures for various military and non-military applications in Singapore in recent years. The awareness of the underground option among planners, developers, and financiers should be increased so that subsurface planning issues can be better addressed. The lack of adequate and accurate 3D spatial data often makes the design and construction of such underground works difficult. It is necessary to integrate all of the spatial objects for underground planning. Over the past two decades, a number of commercial software systems have been developed for 3D geographic and geological modeling. For example, VGEGIS software allows users to create 3D surface geological maps. 3D GeoModeller, a 3D geological modeling and geophysical inversion package, allows project geologists to build realistic 3D geology models. This paper presents an approach to integrate the geographic and geological models for underground planning. A prototype of 3D Geographic Information System (3DGIS) called "3DRock" has been developed by authors to implement the data integration with 3D GeoModeler. The results so far showed that 3DRock is able to integrate the above-surface, surface, and subsurface information available from maps, sections, terrain models, topographic data, drillholes, etc. for the Banyan Basin in Jurong Island, Singapore, in a case study.

  19. 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.

  20. Discovery of the Eureka volcanogenic massive sulphide lens using downhole electromagnetics

    NASA Astrophysics Data System (ADS)

    Paggi, Jacob; Macklin, Daniel

    2016-05-01

    The Eureka volcanogenic massive sulphide (VMS) lens forms part of the Stockman Project in north-east Victoria. Eureka was discovered in early 2013, heralding the first new VMS mineralised zone to be discovered at the project since 1979. Key drivers to the detection of Eureka included the combination of downhole electromagnetics (EM) and a robust geological model. The lens is located 350 m to the north-east of the Currawong deposit, at a vertical depth of 360 m. Surface EM methods played a significant role in the discovery of the nearby Currawong and Wilga deposits during the late 1970s. Despite this, modern day airborne and fixed-loop transient EM (FLTEM) surveys failed to detect Eureka, most likely due to its depth, moderate conductance and loop-edge effects masking anomalies. The key component in discovering the lens was the interpretation of two subtle downhole transient electromagnetics (DHTEM) responses from 2012 exploration drillholes. These responses were further strengthened by structural and short wave infrared modelling, presenting a compelling multi-component drill target. The lens was discovered soon thereafter, with a discovery intercept of 22.65 m at 1.2% Cu, 0.7% Pb, 3.9% Zn, 43 g/t Ag and 1.3 g/t Au.

  1. The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering

    PubMed Central

    Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A.; Janeczek, Agnieszka A.; Kontouli, Nasia; Kanczler, Janos M.; Evans, Nicholas D.; Oreffo, Richard OC

    2016-01-01

    Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p < 0.01). This human-avian system offers a simple refinement model for animal research and a step towards a humanized in vivo model for tissue engineering. PMID:27577960

  2. The Eocene-Oligocene Boundary in the Ross Sea (Antarctica), Based on Downhole Measurements

    NASA Astrophysics Data System (ADS)

    Buecker, C.; Jarrard, R.; Ehrmann, W.; Niessen, F.; Wonik, T.

    2001-12-01

    Drillholes CRP-1 to 3 of the Cape Roberts Project in the Northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land Basin to investigate Neogene to Paleogene climatic and tectonic history. Drilling on fast sea ice resulted in coring a stratigraphic succession with a composite thickness of 1500 m and an age range of 17 - 34 Ma. Well logging of CRP-3 has provided a complete and comprehensive dataset of in situ geophysical measurements down to 939 meters below sea floor (mbsf). By cluster analysis of the downhole logging data, it was possible to divide the borehole into three main sections. The upper section down to 230 mbsf is dominated by mudstones with clearly different physical properties from the mudstones occurring below this depth. Beneath 230 mbsf sandstones are dominating the lithology. Two types of sandstones could be characterized, with the lower sandstone being dominant below 630 mbsf down to a brecciated shear zone at 790 mbsf. These two types of sandstones, which are differentiated mainly by their magnetic properties, can be correlated to the detrital mode provenance analysis. The boundary marks the Eocene/Oligocene boundary. Comparison of these results with the seismic stratigraphy shows that the major change in sediment source from Victoria to Taylor Group is not seen by seismic sequence analysis. This finding will have consequences for the entire Ross Sea seismic stratigraphy.

  3. Downhole measurements and their use for stratigraphic correlations in the Ross Sea (Antarctica)

    NASA Astrophysics Data System (ADS)

    Bücker, C.; Jarrard, R.; Ehrmann, W.; Niessen, F.; Wonik, T.

    2003-04-01

    Drillholes CRP-1 to 3 of the Cape Roberts Project in the Northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land Basin to investigate Neogene to Paleogene climatic and tectonic history. Drilling on fast sea ice resulted in coring a stratigraphic succession with a composite thickness of 1500 m and an age range of 17 - 34 Ma. Well logging of CRP-3 has provided a complete and comprehensive dataset of in situ geophysical measurements down to 939 meters below sea floor (mbsf). By cluster analysis of the downhole logging data, it was possible to divide the borehole into three main sections. The upper section down to 230 mbsf is dominated by mudstones with clearly different physical properties from the mudstones occurring below this depth. Beneath 230 mbsf sandstones are dominating the lithology. Two types of sandstones could be characterized, with the lower sandstone being dominant below 630 mbsf down to a brecciated shear zone at 790 mbsf. These two types of sandstones, which are differentiated mainly by their magnetic properties, can be correlated to the detrital mode provenance analysis. The boundary marks the Eocene/Oligocene boundary. Comparison of these results with the seismic stratigraphy shows that the major change in sediment source from Victoria to Taylor Group is not seen by seismic sequence analysis. This finding will have consequences for the entire Ross Sea seismic stratigraphy.

  4. Cretaceous - Tertiary Hoploparia species: Occurrence, paleobiogeography and predation context

    NASA Astrophysics Data System (ADS)

    El-Shazly, Soheir

    2015-12-01

    The study of Hoploparia species in 25 localities in Northern and Southern Hemispheres from Early Cretaceous to Early Miocene reveals the appearance of 51 species in Early Cretaceous, mostly in Northern Hemisphere, 46 species from Late Cretaceous (42 and 4 carryover from the Early Cretaceous), 7 species from Danian (4 plus 3 carryover from the Late Cretaceous), 7 species from Eocene (6 plus one from the Early Cretaceous), 2 species from Lower Oligocene and the last recorded species Hoploparia persisted in the Early Miocene of Antarctica. The oldest Hoploparia was recorded from Europe and distributed through the Northern and Southern Hemispheres with the facilitation of the Indo-Madagascar sea-way and Hispanic corridor. The tolerance for temperature and water depth as well as the morphological changes in genus Hoploparia in the Late Cretaceous and Tertiary periods, helped some species to survive the K/T event. Drill-hole predation in Hoploparia longimana (Sowerby, 1826) was recorded for the first time from the Lower Cretaceous (Albian) of Egypt.

  5. Scientific drilling to study the roots of active hydrothermal systems related to young magmatic intrusions. [Abstract only

    SciTech Connect

    Muffler, L.J.P.

    1983-03-01

    At present, hydrothermal-magma processes can be studied only inferentially, using observations on hot springs and volcanic rocks, data from shallow- and intermediate-depth drill holes, analogies with exhumed fossil systems, and extrapolation of laboratory investigations. The Thermal Regimes Panel of the Continental Scientific Drilling Committee in a draft report concludes that an understanding of active hydrothermal-magma systems requires drill-hole investigations of deeper and hotter levels than have been drilled and studied to date. The Panel groups hydrothermal-magma systems in the United States into five classes: (1) dominantly andesitic centers, (2) spreading ridges, (3) basaltic fields, (4) evolved basaltic centers, and (5) silicic caldera complexes. Application of eight scientific criteria and three social criteria leads to the conclusion that silicic caldera complexes should be the first target of a focused drilling program to investigate the hydrothermal-magma interface at depths of 5 to 7 km. Primary targets are the three young, silicic caldera systems in the western conterminous United States: Yellowstone (Wyoming), Valles (New Mexico), and Long Valley (California). Scientific drilling of these active hydrothermal-magma systems complements scientific drilling proposed for fossil systems such as Creede (Colorado). In addition, the roots of the Salton Sea geothermal system (California) present an opportunity for add-on deep drilling and scientific experiments to supplement geothermal drilling by industry in this active spreading-ridge environment.

  6. Advances in downhole sampling of high temperature solutions

    SciTech Connect

    Bayhurst, G.K.; Janecky, D.R.

    1991-01-01

    A fluid sampler capable of sampling hot and/or deep wells has been developed at Los Alamos National Laboratory. In collaboration with Leutert Instruments, an off-the-shelf sampler design was modified to meet gas-tight and minimal chemical reactivity/contamination specifications for use in geothermal wells and deep ocean drillholes. This downhole sampler has been routinely used at temperatures up to 300{degrees}C and hole depths of greater than 5 km. We have tested this sampler in various continental wells, including Valles Caldera VC-2a and VC-2b, German KTB, Cajon Pass, and Yellowstone Y-10. Both the standard commercial and enhanced samplers have also been used to obtain samples from a range of depths in the Ocean Drilling Project's hole 504B and during recent mid-ocean ridge drilling efforts. The sampler has made it possible to collect samples at temperatures and conditions beyond the limits of other tools with the added advantage of chemical corrosion resistance.

  7. Tensor controlled-source audiomagnetotelluric survey over the Sulphur Springs thermal area, Valles Caldera

    SciTech Connect

    Wannamaker, P.E.

    1991-10-01

    The extensive tensor CSAMT survey of the Sulphur Springs geothermal area, Valles Caldera, New Mexico, consists of 45 high-quality soundings acquired in continuous-profiling mode and has been funded in support of CSDP drillholes VC-2A and VC-2B. Two independent transmitter bipoles were energized for tensor measurements using a 30 KW generator placed approximately 13 km south of the VC-2B wellhead. These current bipoles gave source fields over the receiver sites which were substantially independent in polarization and provided well-resolved tensor elements. The surroundings in the Sulphur Springs area were arranged in four profiles to cross major structural features. At each receiver, two orthogonal electric and three orthogonal magnetic field components were acquired in accordance with tensor principles. Derivation of model resistivity cross sections from our data and their correlation with structure and geochemistry are principal components of the OBES award. However, Sulphur Springs also can serve as a natural testbed of traditional assumptions and methods of CSAMT with quantification through rigorous model analysis. Issues here include stability and accuracy of scalar versus tensor estimates, theoretical versus observed field patterns over the survey area, and controls on near-field effects using CSAMT and natural field data both inside and outside the caldera.

  8. The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering

    NASA Astrophysics Data System (ADS)

    Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A.; Janeczek, Agnieszka A.; Kontouli, Nasia; Kanczler, Janos M.; Evans, Nicholas D.; Oreffo, Richard Oc

    2016-08-01

    Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p < 0.01). This human-avian system offers a simple refinement model for animal research and a step towards a humanized in vivo model for tissue engineering.

  9. Hydrogeology and physical characteristics of water samples at the Red River aluminum site, Stamps, Arkansas, April 2001

    USGS Publications Warehouse

    Czarnecki, John B.; Stanton, Gregory P.; Freiwald, David A.

    2001-01-01

    The Red River Aluminum site near Stamps, Arkansas, contains waste piles of salt cake and metal byproducts from the smelting of aluminum. The waste piles are subjected to about 50 inches of rainfall a year, resulting in the dissolution of the salts and metal. To assess the potential threat to underlying ground-water resources at the site, its hydrogeology was characterized by measuring water levels and field parameters of water quality in 23 wells and at 2 surface-water sites. Seventeen of these monitor wells were constructed at various depths for this study to allow for the separate characterization of the shallow and deep ground-water systems, the calculation of vertical gradients, and the collection of water samples at different depths within the flow system. Lithologic descriptions from drill-hole cuttings and geophysical logs indicate the presence of interbedded sands, gravels, silts, and clays to depths of 65 feet. The regionally important Sparta aquifer underlies the site. Water levels in shallow wells indicate radial flow away from the salt-cake pile located near the center of the site. Flow in the deep system is to the west and southwest toward Bodcau Creek. Water-level data from eight piezometer nests indicate a downward hydraulic gradient from the shallow to deep systems across the site. Values of specific conductance (an indicator of dissolved salts) ranged from 215 to 196,200 microsiemens per centimeter and indicate that saline waters are being transported horizontally and vertically downward away from the site

  10. Heat flow and subsurface temperature as evidence for basin-scale ground-water flow, North Slope of Alaska

    USGS Publications Warehouse

    Deming, D.; Sass, J.H.; Lachenbruch, A.H.; De Rito, R. F.

    1992-01-01

    Several high-resolution temperature logs were made in each of 21 drillholes and a total of 601 thermal conductivity measurements were made on drill cuttings and cores. Near-surface heat flow (??20%) is inversely correlated with elevation and ranges from a low of 27 mW/m2 in the foothills of the Brooks Range in the south, to a high of 90 mW/m2 near the north coast. Subsurface temperatures and thermal gradients estimated from corrected BHTs are similarly much higher on the coastal plain than in the foothills province to the south. Significant east-west variation in heat flow and subsurface temperature is also observed; higher heat flow and temperature coincide with higher basement topography. The observed thermal pattern is consistent with forced convection by a topographically driven ground-water flow system. Average ground-water (Darcy) velocity in the postulated flow system is estimated to be of the order of 0.1 m/yr; the effective basin-scale permeability is estimated to be of the order of 10-14 m2. -from Authors

  11. The national coal-resources data system of the U.S. geological survey

    USGS Publications Warehouse

    Carter, M.D.

    1976-01-01

    The National Coal Resources Data System (NCRDS) was designed by the U.S. Geological Survey (USGS) to meet the increasing demands for rapid retrieval of information on coal location, quantity, quality, and accessibility. An interactive conversational query system devised by the USGS retrieves information from the data bank through a standard computer terminal. The system is being developed in two phases. Phase I, which currently is available on a limited basis, contains published areal resource and chemical data. The primary objective of this phase is to retrieve, calculate, and tabulate coal-resource data by area on a local, regional, or national scale. Factors available for retrieval include: state, county, quadrangle, township, coal field, coal bed, formation, geologic age, source and reliability of data, and coal-bed rank, thickness, overburden, and tonnage, or any combinations of variables. In addition, the chemical data items include individual values for proximate and ultimate analyses, BTU value, and several other physical and chemical tests. Information will be validated and deleted or updated as needed. Phase II is being developed to store, retrieve, and manipulate basic point source coal data (e.g., field observations, drill-hole logs), including geodetic location; bed thickness; depth of burial; moisture; ash; sulfur; major-, minor-, and trace-element content; heat value; and characteristics of overburden, roof rocks, and floor rocks. The computer system may be used to generate interactively structure-contour or isoline maps of the physical and chemical characteristics of a coal bed or to calculate coal resources. ?? 1976.

  12. Imaging resin infiltration into non-cavitated carious lesions by optical coherence tomography.

    PubMed

    Schneider, Hartmut; Park, Kyung-Jin; Rueger, Claudia; Ziebolz, Dirk; Krause, Felix; Haak, Rainer

    2017-05-01

    Visualisation of the etching process and resin penetration at white spot carious lesions by spectral domain optical coherence tomography (SD-OCT). The non-cavitated carious lesions (ICDAS code 2) of four visually preselected extracted human molars and premolars were verified as enamel lesions by micro computed tomography (μCT). One region of interest (ROI) per tooth was marked by two drill-holes in occlusal-cervical direction. The lesions were imaged by SD-OCT. Lesions were infiltrated (Icon, DMG) according to the manufacturer's instructions. During each treatment step and after light curing of the infiltrant, the ROIs were imaged again by SD-OCT. Teeth were sectioned through the ROIs and section layers were imaged by scanning electron microscopy in order to compare with the OCT images. The image sequences for etching and infiltration were viewed in time lapse. During the etching process, numerous bubbles formed on the lesion surface. Using OCT, the process of resin penetration into the carious lesion body became visible. The early enamel carious lesion was completely infiltrated by the resin whereas infiltration of the advanced enamel carious lesion was incomplete and inhomogeneous. Resin infiltration can be increased by optimizing the etching process. Optical coherence tomography provides information about the process and degree of resin infiltration. Active acid application before resin infiltration is recommendable. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Primary sedimentary structures and the internal architecture of a Martian sand body in search of evidence for sand transport and deposition

    NASA Technical Reports Server (NTRS)

    Basu, Abhijit

    1988-01-01

    Lunar experiences show that unmanned sample return missions, despite limitations on sample size, can produce invaluable data to infer crustal processes, regolith processes, regolith-atmosphere/ionosphere interaction processes, etc. Drill cores provide a record of regolith evolution as well as a more complete sample of the regolith than small scoops and/or rakes. It is proposed that: (1) a hole be drilled in a sand body to obtain continuous oriented cores; a depth of about 10 m would be compatible with what we know of bed form hierarchy of terrestrial stream deposits; (2) two trenches, at right angles to each other and close to the drill-hole, be dug and the walls scraped lightly such that primary/internal sedimentary structures of the sand body become visible; (3) the walls of the trenches be made gravitationally stable by impregnation techniques; (4) acetate or other peels of a strip on each wall be taken; and (5) appropriately scaled photographs of the walls be taken at different sun-angles to ensure maximum ease of interpretation of sedimentary structures; and, to correlate these structural features with those in the core at different depth levels of the core.

  14. Introduction to the hydrogeochemical investigations within the International Stripa Project

    USGS Publications Warehouse

    Nordstrom, D.K.; Olsson, T.; Carlsson, L.; Fritz, P.

    1989-01-01

    The International Stripa Project (1980-1990) has sponsored hydrogeochemical investigations at several subsurface drillholes in the granitic portion of an abandoned iron ore mine, central Sweden. The purpose has been to advance our understanding of geochemical processes in crystalline bedrock that may affect the safety assessment of high-level radioactive waste repositories. More than a dozen investigators have collected close to a thousand water and gas samples for chemical and isotopic analyses to develop concepts for the behavior of solutes in a granitic repository environment. The Stripa granite is highly radioactive and has provided an exceptional opportunity to study the behavior of natural radionuclides, especially subsurface production. Extensive microfracturing, low permeability with isolated fracture zones of high permeability, unusual water chemistry, and a typical granitic mineral assemblage with thin veins and fracture coatings of calcite, chlorite, seriate, epidote and quartz characterize the site. Preliminary groundwater flow modeling indicates that the mine has perturbed the flow environment to a depth of about 3 km and may have induced deep groundwaters to flow into the mine. ?? 1989.

  15. Magnetotelluric data, Taos Plateau Volcanic Field, New Mexico

    USGS Publications Warehouse

    Ailes, Chad E.; Rodriguez, Brian D.

    2010-01-01

    The population of the San Luis Basin region of northern New Mexico is growing. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's groundwater resources. An important issue in managing the groundwater resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal groundwater aquifers. The shallow unconfined aquifer and the deeper confined Santa Fe Group aquifer in the San Luis Basin are the main sources of municipal water for the region. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey called magnetotellurics (MT), and hydrologic and lithologic data are being used to better understand the aquifers. This report describes a regional east-west MT sounding profile acquired in late July 2009 across the Taos Plateau Volcanic Field where drillhole data are sparse. Resistivity modeling of the MT data can be used to help map changes in electrical resistivity with depths that are related to differences in rock types. These various rock types help control the properties of aquifers. The purpose of this report is to release the MT sounding data collected along the east-west profile. No interpretation of the data is included.

  16. Comparative mineral chemistry and textures of SAFOD fault gouge and damage-zone rocks

    USGS Publications Warehouse

    Moore, Diane E.

    2014-01-01

    Creep in the San Andreas Fault Observatory at Depth (SAFOD) drillhole is localized to two foliated gouges, the central deforming zone (CDZ) and southwest deforming zone (SDZ). The gouges consist of porphyroclasts of serpentinite and sedimentary rock dispersed in a foliated matrix of Mg-smectite clays that formed as a result of shearing-enhanced reactions between the serpentinite and quartzofeldspathic rocks. The CDZ takes up most of the creep and exhibits differences in mineralogy and texture from the SDZ that are attributable to its higher shearing rate. In addition, a ∼0.2-m-wide sector of the CDZ at its northeastern margin (NE-CDZ) is identical to the SDZ and may represent a gradient in creep rate across the CDZ. The SDZ and NE-CDZ have lower clay contents and larger porphyroclasts than most of the CDZ, and they contain veinlets and strain fringes of calcite in the gouge matrix not seen elsewhere in the CDZ. Matrix clays in the SDZ and NE-CDZ are saponite and corrensite, whereas the rest of the CDZ lacks corrensite. Saponite is younger than corrensite, reflecting clay crystallization under declining temperatures, and clays in the more actively deforming portions of the CDZ have better equilibrated to the lower-temperature conditions.

  17. Preferred orientation and elastic anisotropy in shales.

    SciTech Connect

    Lonardelli, I.; Wenk, H.-R.; Ren, Y.; Univ. of California at Berkeley

    2007-03-01

    Anisotropy in shales is becoming an important issue in exploration and reservoir geophysics. In this study, the crystallographic preferred orientation of clay platelets that contributes to elastic anisotropy was determined quantitatively by hard monochromatic X-ray synchrotron diffraction in two different shales from drillholes off the coast of Nigeria. To analyze complicated diffraction images with five different phases (illite/smectite, kaolinite, quartz, siderite, feldspar) and many overlapping peaks, we applied a methodology based on the crystallographic Rietveld method. The goal was to describe the intrinsic physical properties of the sample (phase composition, crystallographic preferred orientation, crystal structure, and microstructure) and compute macroscopic elastic properties by averaging single crystal properties over the orientation distribution for each phase. Our results show that elastic anisotropy resulting from crystallographic preferred orientation of the clay particles can be determined quantitatively. This provides a possible way to compare measured seismic anisotropy and texture-derived anisotropy and to estimate the contribution of the low-aspect ratio pores aligned with bedding.

  18. Intracrustal complexity in the United States midcontinent: Preliminary results from COCORP surveys in northeastern Kansas

    NASA Astrophysics Data System (ADS)

    Brown, L.; Serpa, L.; Setzer, T.; Oliver, J.; Kaufman, S.; Lillie, R.; Steiner, D.; Steeples, Don W.

    1983-01-01

    Unusually clear indications of complex structure in the mid-to-lower crust is revealed by seismic reflection surveys in northeastern Kansas. This complexity contrasts markedly with the layer-cake simplicity of both the overlying sedimentary cover and most previous crustal models for the central United States. Seismic sections collected by COCORP (Consortium for Continental Reflection Profiling) as part of a major east-west traverse across the Neniaha Ridge and Midcontinent Geophysical Anomaly indicate that below a thin, relatively flat layered Paleozoic sedimentary section, the deep crust is characterized by numerous dipping and arcuate reflections and diffractions. In many places layered and crosscutting, these reflections suggest convoluted three-dimensional folded, faulted, and intruded structures. Specific identification of these deep features may be possible if future surveys can trace them to accessible depths. The basement above these reflection complexes contains significantly fewer reflections—consistent with, but not necessarily diagnostic of, the granitic terrane that dominates basement drill-hole samples in the region. Among the events at these shallower basement depths are several east-dipping reflections, some of which may be major faults. Travel times corresponding to expected Moho depths (about 36 km) are characterized less by specific reflections than by an apparent decrease in the density and number of reflections. While evidence of crustal heterogeneity is common among deep reflection studies, the Kansas seismic results outlined in this brief report stand out as being unusually clear representations of such. *Present address: Phillips Petroleum Company, Bartlesville, Oklahoma 74004

  19. Bulk densities and porosities of Cenozoic and Cretaceous basin-filling strata and Cretaceous and older basement rocks, Los Angeles Basin, California, determined from measurements of core samples

    USGS Publications Warehouse

    Beyer, L.A.; McCulloh, T.H.

    1998-01-01

    This report describes and provides a digital data file of selected bulk properties of subsurface rocks sampled in and around Los Angeles basin, California. Selected properties include measured dry bulk density (range 0.78 to 3.01 g/cm3), measured or estimated grain (matrix) density, calculated water saturated bulk density (range 1.47 to 3.01 g/cm3), calculated total porosity (range 0 to 69 porosity percent), geologic age, and lithology. Most of the rocks are conventional core samples taken from wells drilled by the petroleum industry. A small percentage of the core samples are from shallow borings. Rocks studied range in age from pre-Cambrian (?) to Recent and include sedimentary (98.8%), and volcanic, metamorphic and intrusive (1.2%) samples. Core samples studied were taken from measured drillhole depths that range from 35 to 20,234 ft (11 to 6,167 m). Version 1.0 of the data base (dated June 1998) contains information for 7378 samples from 234 wells, including two redrilled wells. This report/data base can be accessed on U. S. Geological Survey servers at http://geopubs.wr.usgs.gov/open-file/of98-788. Periodic additions to the on-line data base will be provided as new data is gathered.

  20. Preliminary report on the geology and geophysics of drill hole UE25a-1, Yucca Mountain, Nevada Test Site

    USGS Publications Warehouse

    Spengler, Richard W.; Muller, D.C.; Livermore, R.B.

    1979-01-01

    A subsurface geologic study in connection with the Nevada Nuclear Waste Storage Investigations has furnished detailed stratigraphic and structural information about tuffs underlying northeastern Yucca Mountain on the Nevada Test Site. Drill hole UE25a-1 penetrated thick sequences of nonwelded to densely welded ash-flow and bedded tuffs of Tertiary age. Stratigraphic units that were identified from the drill-hole data include the Tiva Canyon and Topopah Spring Members of the Paintbrush Tuff, tuffaceous beds of Calico Hills, and the Prow Pass and Bullfrog Members of the Crater Flat Tuff. Structural analysis of the core indicated densely welded zones to be highly fractured. Many fractures show near-vertical inclinations and are commonly coated with secondary silica, manganese and iron oxides, and calcite. Five fault zones were recognized, most of which occurred in the Topopah Spring Member. Shear fractures commonly show oblique-slip movement and some suggest a sizable component of lateral compression. Graphic logs are included that show the correlation of lithology, structural properties, and geophysical logs. Many rock units have characteristic log responses but highly fractured zones, occurring principally in the Tiva Canyon and Topopah Spring Members, restricted log coverage to the lower half of the drill hole.

  1. Use of geophysical logs in recognizing depositional environments in the Tongue River Member of the Fort Union Formation, Powder River area, Wyoming and Montana

    USGS Publications Warehouse

    Flores, R.M.; Toth, J.C.; Moore, T.A.

    1982-01-01

    The environmental conditions under which rocks in the Paleocene Tongue River Member of the Fort Union Formation were deposited in the Powder River area, Wyoming and Montana, can be determined using geophysical logs with some limitations. It is widely recognized that gamma ray and density logs are useful in identifying thickness and stratigraphic position of coal beds. In addition, gamma ray and electrical resistivity logs can be used to infer conditions of transportation and deposition of sandstones, siltstones, and other rock types. In particular, intensity responses of the gamma ray and resistance logs provide a clue to variations of grain size such as fining-upward and coarsening-upward characteristics of fluvial channel and crevasse splay deposits, respectively. These signatures in the geophysical logs are readily observed for some beds; for other beds however, the depositional conditions are difficult to determine because the beds do not produce clear-cut log-response patterns. Thus,. analysis of the environments of deposition of detrital rocks in drill holes can be made more accurate by a study of stratigraphically equivalent intervals in outcrops near drill-hole sites.

  2. The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering.

    PubMed

    Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A; Janeczek, Agnieszka A; Kontouli, Nasia; Kanczler, Janos M; Evans, Nicholas D; Oreffo, Richard Oc

    2016-08-31

    Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p < 0.01). This human-avian system offers a simple refinement model for animal research and a step towards a humanized in vivo model for tissue engineering.

  3. Texture development in naturally compacted and experimentally deformed silty clay sediments from the Nankai Trench and Forearc, Japan

    NASA Astrophysics Data System (ADS)

    Schumann, Kai; Stipp, Michael; Leiss, Bernd; Behrmann, Jan H.

    2014-12-01

    The petrophysical properties of fine-grained marine sediments to a large extent depend on the microstructure and crystallographic preferred orientations (CPOs). In this contribution we show that Rietveld-based synchrotron texture analysis is a new and valuable tool to quantify textures of water-saturated fine-grained phyllosilicate-rich sediments, and assess the effects of compaction and tectonic deformation. We studied the CPO of compositionally almost homogeneous silty clay drillcore samples from the Nankai Accretionary Prism slope and the incoming Philippine Sea plate, offshore SW Japan. Basal planes of phyllosilicates show bedding-parallel alignment increasing with drillhole depth, thus reflecting progressive burial and compaction. In some samples calcite and albite display a CPO due to crystallographically controlled non-isometric grain shapes, or nannofossil tests. Consolidated-undrained experimental deformation of a suite of thirteen samples from the prism slope shows that the CPOs of phyllosilicate and calcite basal planes develop normal to the experimental shortening axis. There is at least a qualitative relation between CPO intensity and strain magnitude. Scanning electron micrographs show concurrent evolution of preferred orientations of micropores and detrital illite flakes normal to axial shortening. This indicates that the microfabrics are sensitive strain gauges, and contribute to anisotropic physical properties along with the CPO.

  4. S-wave refraction survey of alluvial aggregate

    USGS Publications Warehouse

    Ellefsen, Karl J.; Tuttle, Gary J.; Williams, Jackie M.; Lucius, Jeffrey E.

    2005-01-01

    An S-wave refraction survey was conducted in the Yampa River valley near Steamboat Springs, Colo., to determine how well this method could map alluvium, a major source of construction aggregate. At the field site, about 1 m of soil overlaid 8 m of alluvium that, in turn, overlaid sedimentary bedrock. The traveltimes of the direct and refracted S-waves were used to construct velocity cross sections whose various regions were directly related to the soil, alluvium, and bed-rock. The cross sections were constrained to match geologic logs that were developed from drill-hole data. This constraint minimized the ambiguity in estimates of the thickness and the velocity of the alluvium, an ambiguity that is inherent to the S-wave refraction method. In the cross sections, the estimated S-wave velocity of the alluvium changed in the horizontal direction, and these changes were attributed to changes in composition of the alluvium. The estimated S-wave velocity of the alluvium was practically constant in the vertical direc-tion, indicating that the fine layering observed in the geologic logs could not be detected. The S-wave refraction survey, in conjunction with independent information such as geologic logs, was found to be suitable for mapping the thickness of the alluvium.

  5. Experiments on robot-assisted navigated drilling and milling of bones for pedicle screw placement.

    PubMed

    Ortmaier, T; Weiss, H; Döbele, S; Schreiber, U

    2006-12-01

    This article presents experimental results for robot-assisted navigated drilling and milling for pedicle screw placement. The preliminary study was carried out in order to gain first insights into positioning accuracies and machining forces during hands-on robotic spine surgery. Additionally, the results formed the basis for the development of a new robot for surgery. A simplified anatomical model is used to derive the accuracy requirements. The experimental set-up consists of a navigation system and an impedance-controlled light-weight robot holding the surgical instrument. The navigation system is used to position the surgical instrument and to compensate for pose errors during machining. Holes are drilled in artificial bone and bovine spine. A quantitative comparison of the drill-hole diameters was achieved using a computer. The interaction forces and pose errors are discussed with respect to the chosen machining technology and control parameters. Within the technological boundaries of the experimental set-up, it is shown that the accuracy requirements can be met and that milling is superior to drilling. It is expected that robot assisted navigated surgery helps to improve the reliability of surgical procedures. Further experiments are necessary to take the whole workflow into account. Copyright 2006 John Wiley & Sons, Ltd.

  6. New oil source rocks cut in Greek Ionian basin

    SciTech Connect

    Karakitsios, V.; Rigakis, N.

    1996-02-12

    The Ionian zone of Northwest Greece (Epirus region) constitutes part of the most external zones of the Hellenides (Paxos zone, Ionian zone, Gavrovo Tripolitza zone). The rocks of the Ionian zone range from Triassic evaporites and associated breccias through a varied series of Jurassic through Upper Eocene carbonates and lesser cherts and shales followed by Oligocene flysch. The surface occurrences of petroleum in the Ionian zone are mainly attributed to Toarcian Lower Posidonia beds source rocks and lesser to late Callovian-Tithonian Upper Posidonia beds and to the Albian-Cenomanian Upper Siliceous zone or Vigla shales of the Vigla limestones. Oil that could not be attributed to the above source rocks is believed to have an origin from Triassic formations that contain potential source rocks in Albania and Italy. However, several samples of the shales of Triassic breccias from outcrops and drillholes were analyzed in the past, but the analytical results were not so promising since their hydrocarbon potential was low. In this article, the authors will present their analytical results of the Ioannina-1 well, where for the first time they identified some very rich source beds in the Triassic breccias formation of Northwest Greece.

  7. We are in need of sampling the sedimentary cover and bedrock in the Amerasia Basin. (Suggested site locations in the Makarov Basin, the Mendeleev and Lomonosov ridges and adjacent areas.)

    NASA Astrophysics Data System (ADS)

    Lebedeva-Ivanova, N. N.

    2010-12-01

    The Amerasia Basin has a complex origin; alone, the geophysical data can support very different hypotheses. For understanding the tectonic evolution of the Basin and origin of the ridges and troughs it is important to collect geological samples. Based on analyzed seismic data (NP-28 and 26, HOTRAX, Arctic-2000 and TransArctic) over the Makarov Basin, the Mendeleev and Lomonosov ridges and adjacent areas, numbers of key drill sites are proposed. All proposed sites in combinations with other geophysical research of the area are fit well with most of the Site Survey Data Requirements (IODP) for a drilling site. Bedrock samples from key locations are especially needed, with full video or photo documentation of the sampling for avoiding later debates about whether bedrock or ice-drift was collected. Due to close locations to a sea bottom, bedrock can be sampled by gravity piston-cores or shallow drilling. Full stratigraphic sections though the Cenozoic and older sedimentary successions are needed at other proposed key locations for understanding the tectonic evolution of the Amerasia Basin. The depositional environment of the key reflections related to Cenozoic shallow water environments, as recorded in the ACEX drillholes, needs to be investigated in other locations. We will then be able to define better the nature of particular morphological features and construct more reliable tectonic models of the Amerasia Basin, in general.

  8. Nb sbnd Th sbnd Zr mineralization in microgranite—microsyenite at Jabal Tawlah, Midyan region, Kingdom of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Drysdall, Alan R.; Douch, Colin J.

    A composite sill of mineralized and highly radioactive microgranite—microsyenite caps Jabal Tawlah, a low ridge in the extreme NW of the Arabian Shield. The leucocratic composition, distribution of quartz and low K 2O:Na 2O ratios indicate that deuteric processes, including separation of a silica-rich phase and albitization, played a major role. Mineralization is in the form of a disseminated enrichment in Nb, Ta, Sn, Th, Y, heavy REE and Zr. Four Y- and heavy REE-bearing minerals, gagarinite [NaCaY(F,Cl) 6], fergusonite [(Y,Er,Ce,Fe)(Nb,Ta,Ti)O 4], xenotime and yttrian fluorite, as well as zircon, columbite, thorite, sphalerite, galena, pyrite, ilmenite, hematite, limonite, magnetite, goethite, siderite, possible chrysocolla and an MnO-bearing mineral have been identified. The geochemical signature of the mineralization is similar to that which distinguishes alkali granites from other granitic rocks. Jabal az Zuhd, a major plutonic complex consisting largely of alkali granite, crops out only 5 km NW of Jabal Tawlah. However, there is no other evidence of possible derivation from a parental alkali granite magma. Reserves indicated by outcrop dimensions and three drill-hole intersections are 6.4 million tonnes to an average depth of 65 m below wadi level, grading 0.34% Nb, 0.52% Y, 0.47% Zn and approximately 4% zircon (plus 175 ppm Ta, 380 ppm Sn, 700 ppm Th and heavy REE).

  9. Chlorine isotopic compositions of deep saline fluids in Ibusuki coastal geothermal region, Japan: using B-Cl isotopes to interpret fluid sources.

    PubMed

    Musashi, Masaaki; Oi, Takao; Kreulen, Rob

    2015-01-01

    We report chlorine stable isotopic compositions (δ(37)Cl, expressed in ‰ relative to the standard mean ocean chloride) as well as δ(2)H and δ(18)O values of deep saline fluids taken at eight drill-holes reaching from 73 to 780 m below sea level in the Ibusuki coastal geothermal region, Japan. Analytical results show that the δ(37)Cl values narrowly range between -0.26 and +0.21 ‰ with an analytical precision of ±0.06 ‰. Except for one sample, the samples examined are negative in δ(37)Cl value with varying Cl/B molar ratios from 117 to 1265. A correlation study between the Cl/B molar ratio and the δ(37)Cl/δ(11)B ratio indicates a hyperbola-type mixing of at least two Cl sources in the Ibusuki region. One of them depletes in (37)Cl with a higher value of Cl/B molar ratio; and the other one enriches in (37)Cl with a lower Cl/B molar ratio. The former is chemically identical to that of the deep brine, which is altered seawater through the seawater-hot rock interaction. The latter is chemically similar to gas condensate derived from the high-temperature (890 °C) vent of an island-arc volcano near the Ibusuki region.

  10. Heat flow and geothermal assessment of the Escalante Desert, southwestern Utah, with emphasis on the Newcastle KGRA

    SciTech Connect

    Clement, M.D.; Chapman, D.S.

    1981-02-01

    Twenty-five new regional heat flow measurements are presented for the Escalante Desert region within the Great Basin of the western US. Heat flow excluding geothermal areas ranges from 42 to 350 mW m/sup -2/ but much of the variability may be caused by deeply circulating groundwater redistributing the regional flux. A subset of 10 sites drilled specifically to characterize the heat flow of the region yielded a mean of 100 mW m/sup -2/ with a standard deviation of 22 mW m/sup -2/. An analysis of thermal conductivities of solid cylindrical discs and rock chips of rhyolite to andesite tuffs emphasized the importance of porosity corrections to thermal conductivity measurements. A blind geothermal system southwest of Newcastle, Utah, situated within the Escalante Desert has also been studied. Heat flow results from 11 local drillholes yield values between 163 and 3065 mW m/sup -2/. The 500 mW m/sup -2/ contour encloses an area of 9.4 km/sup 2/. By integrating the anomalous flux above background over the thermal anomaly, a thermal power loss of 12.8 mW and corresponding subsurface mass discharge of 32 kg s/sup -1/ are calculated for this geothermal system.

  11. Comparison of nanoparticular hydroxyapatite pastes of different particle content and size in a novel scapula defect model

    PubMed Central

    Hruschka, Veronika; Tangl, Stefan; Ryabenkova, Yulia; Heimel, Patrick; Barnewitz, Dirk; Möbus, Günter; Keibl, Claudia; Ferguson, James; Quadros, Paulo; Miller, Cheryl; Goodchild, Rebecca; Austin, Wayne; Redl, Heinz; Nau, Thomas

    2017-01-01

    Nanocrystalline hydroxyapatite (HA) has good biocompatibility and the potential to support bone formation. It represents a promising alternative to autologous bone grafting, which is considered the current gold standard for the treatment of low weight bearing bone defects. The purpose of this study was to compare three bone substitute pastes of different HA content and particle size with autologous bone and empty defects, at two time points (6 and 12 months) in an ovine scapula drillhole model using micro-CT, histology and histomorphometry evaluation. The nHA-LC (38% HA content) paste supported bone formation with a high defect bridging-rate. Compared to nHA-LC, Ostim® (35% HA content) showed less and smaller particle agglomerates but also a reduced defect bridging-rate due to its fast degradation The highly concentrated nHA-HC paste (48% HA content) formed oversized particle agglomerates which supported the defect bridging but left little space for bone formation in the defect site. Interestingly, the gold standard treatment of the defect site with autologous bone tissue did not improve bone formation or defect bridging compared to the empty control. We concluded that the material resorption and bone formation was highly impacted by the particle-specific agglomeration behaviour in this study. PMID:28233833

  12. Geophysical constraints on the location and geometry of the Las Vegas Shear Zone, Nevada

    USGS Publications Warehouse

    Langenheim, V.E.; Grow, J.A.; Jachens, R.C.; Dixon, G.L.; Miller, J.J.

    2001-01-01

    We model the basin configuration beneath Las Vegas Valley, Nevada, on the basis of gravity, drillhole, and seismic reflection data. We locate and characterize the various strands of the Las Vegas Valley Shear Zone (LVVSZ) by variations in basin thickness beneath the valley. The pre-Tertiary bedrock surface is complex, with subbasins buried beneath the flat alluvial surface of the valley. We suggest that these basins are formed from transtensional strain. Subbasins elongated N70??W and N50??W are interpreted as strike-slip basins. The deepest subbasin is 5 km west of Frenchman Mountain and strikes N40??E. This basin probably formed by combined movement on nonparallel strands of the LVVZ and an earlier episode of normal faulting. The basin thickness map constrains the minimum depth of the inferred detachment fault beneath Las Vegas Valley to at least 4 km. Seismic reflection data do not image a detachment fault in the upper 10 km beneath Las Vegas Valley. Our results also illustrate the utility of gravity in determining basinal structures and providing a three-dimensional perspective in areas with limited seismic reflection control.

  13. Geospatial data for coal beds in the Powder River Basin, Wyoming and Montana

    USGS Publications Warehouse

    Kinney, Scott A.; Scott, David C.; Osmonson, Lee M.; Luppens, James A.

    2015-01-01

    The purpose of this report is to provide geospatial data for various layers and themes in a Geographic Information System (GIS) format for the Powder River Basin, Wyoming and Montana. In 2015, as part of the U.S. Coal Resources and Reserves Assessment Project, the U.S. Geological Survey (USGS) completed an assessment of coal resources and reserves within the Powder River Basin, Wyoming and Montana. This report is supplemental to USGS Professional Paper 1809 and contains GIS data that can be used to view digital layers or themes, including the Tertiary limit of the Powder River Basin boundary, locations of drill holes, clinker, mined coal, land use and technical restrictions, geology, mineral estate ownership, coal thickness, depth to the top of the coal bed (overburden), and coal reliability categories. Larger scale maps may be viewed using the GIS data provided in this report supplemental to the page-size maps provided in USGS Professional Paper 1809. Additionally, these GIS data can be exported to other digital applications as needed by the user. The database used for this report contains a total of 29,928 drill holes, of which 21,393 are in the public domain. The public domain database is linked to the geodatabase in this report so that the user can access the drill-hole data through GIS applications. Results of this report are available at the USGS Energy Resources Program Web site,http://energy.usgs.gov/RegionalStudies/PowderRiverBasin.aspx.

  14. Geology of the Ferron Sandstone coalbed gas {open_quotes}fairway,{close_quotes} central Utah

    SciTech Connect

    Tabet, D.E.; Hucka, B.P.; Sommer, S.N.

    1996-12-31

    A major new coalbed gas play with as many as 1,000 wells already proposed is being developed in the Upper Cretaceous Ferron Sandstone of central Utah. The Ferron consists of a vertically stacked sequence of as many as seven fluvial-deltaic sandstones and laterally equivalent interdistributary coal swamp units. A new total-net-coal isopach map for the Ferron, compiled from the review of hundreds of well records, shows the greatest accumulation of coal generally occurs in a 6-to 10-mile-wide band, or fairway, directly to the west (landward) of the fluvial-deltaic sandstones. This fairway can be traced a distance of at least 80 miles, heading southwest from the vicinity of Price to the southeast corner of Sevier County. The fairway is interrupted roughly every 8-to-12 miles along its length by deltaic, distributary-channel systems. Well samples of Ferron coal were examined microscopically to determine vitrinite reflectance and maturity level. Near-surface coals, on the east side of the fairway, have vitrinite reflectance measurements as low as 0.5 percent. Reflectance values increase to the west, reaching a maximum of 0.71 percent. The maturity of coals with vitrinite reflectance readings between 0.5 and 0.71 percent is the early stage in which thermogenic methane generation begins. Examination of drill-hole data also shows that the coal fairway exists at shallow to moderate depths, ranging from surface exposures to 8,000 feet deep.

  15. Geology of the Ferron Sandstone coalbed gas [open quotes]fairway,[close quotes] central Utah

    SciTech Connect

    Tabet, D.E.; Hucka, B.P.; Sommer, S.N. )

    1996-01-01

    A major new coalbed gas play with as many as 1,000 wells already proposed is being developed in the Upper Cretaceous Ferron Sandstone of central Utah. The Ferron consists of a vertically stacked sequence of as many as seven fluvial-deltaic sandstones and laterally equivalent interdistributary coal swamp units. A new total-net-coal isopach map for the Ferron, compiled from the review of hundreds of well records, shows the greatest accumulation of coal generally occurs in a 6-to 10-mile-wide band, or fairway, directly to the west (landward) of the fluvial-deltaic sandstones. This fairway can be traced a distance of at least 80 miles, heading southwest from the vicinity of Price to the southeast corner of Sevier County. The fairway is interrupted roughly every 8-to-12 miles along its length by deltaic, distributary-channel systems. Well samples of Ferron coal were examined microscopically to determine vitrinite reflectance and maturity level. Near-surface coals, on the east side of the fairway, have vitrinite reflectance measurements as low as 0.5 percent. Reflectance values increase to the west, reaching a maximum of 0.71 percent. The maturity of coals with vitrinite reflectance readings between 0.5 and 0.71 percent is the early stage in which thermogenic methane generation begins. Examination of drill-hole data also shows that the coal fairway exists at shallow to moderate depths, ranging from surface exposures to 8,000 feet deep.

  16. Data regarding hydraulic fracturing distributions and treatment fluids, additives, proppants, and water volumes applied to wells drilled in the United States from 1947 through 2010

    USGS Publications Warehouse

    Gallegos, Tanya J.; Varela, Brian A.

    2015-01-01

    Comprehensive, published, and publicly available data regarding the extent, location, and character of hydraulic fracturing in the United States are scarce. The objective of this data series is to publish data related to hydraulic fracturing in the public domain. The spreadsheets released with this data series contain derivative datasets aggregated temporally and spatially from the commercial and proprietary IHS database of U.S. oil and gas production and well data (IHS Energy, 2011). These datasets, served in 21 spreadsheets in Microsoft Excel (.xlsx) format, outline the geographical distributions of hydraulic fracturing treatments and associated wells (including well drill-hole directions) as well as water volumes, proppants, treatment fluids, and additives used in hydraulic fracturing treatments in the United States from 1947 through 2010. This report also describes the data—extraction/aggregation processing steps, field names and descriptions, field types and sources. An associated scientific investigation report (Gallegos and Varela, 2014) provides a detailed analysis of the data presented in this data series and comparisons of the data and trends to the literature.

  17. Task 3: Evaluation of mineral resource potential, caldera geology, and volcano-tectonic framework at and near Yucca Mountain

    SciTech Connect

    Weiss, S.I.; Noble, D.C.; Larson, L.T.

    1994-12-31

    This report summarizes the work of Task 3 that was initially discussed in our monthly reports for the period October 1, 1993 through September 30, 1994, and is contained in our various papers and abstracts, both published and in press or currently in review. Our efforts during this period have involved the continuation of studies begun prior to October, 1993, focussed mainly on aspects of the caldera geology, magmatic activity, hydrothermal mineralization and extensional tectonics of the western and central parts of the southwestern Nevada volcanic field (SWNVF), studies of the subsurface rocks of Yucca Mountain utilizing drill-hole sampled obtained in 1991 and 1992, and studies of veins and siliceous ledges cropping out in northwestern Yucca Mountain. These veins and ledges provide evidence for near-surface hydrothermal activity in northwestern Yucca Mountain during the Crater Flat Tuff period of volcanism. During the period of this report we have concentrated our efforts on the production and publication of documents summarizing many of the data, interpretations and conclusions of Task 3 studies pertaining to hydrothermal activity and mineralization in the Yucca Mountain region and their relations to volcanism and tectonic activity. The resulting two manuscripts for journal publication and a compilation of radiometric age and trace-element geochemical data are appended to this report.

  18. Nature of basement rocks under the Los Angeles Basin, southern California, as inferred from aeromagnetic data

    SciTech Connect

    Langenheim, V.E.; Jachens, R.C. . Branch of Geophysics)

    1993-04-01

    The Los Angeles (L.A.) Basin, one of the world's richest oil-producing basins, is underlain by at least two basement assemblages. Because the thickness of the basin sediments reaches up to a minimum of 10 km, magnetic data allow a more regional view of the juxtaposition and nature of basement rocks than do available drill-hole data. Aeromagnetic data indicate that a zone of magnetic rocks extends along the coast east of the Newport-Inglewood fault zone from the San Joaquin Hills northwest to the Santa Monica Mountains. The magnetic highs produced by these rocks appear to be a continuation of intense magnetic highs that are present over exposed rocks of the Peninsular Ranges batholith to the southwest. Modeling of a 180 nT magnetic high over the San Joaquin Hills indicates that the tops of two concealed magnetic sources are at about 1.5 km and 4.5 km depth, which places these bodies at or beneath the basement surface. Modeling of magnetic highs over the exposed batholithic rocks to the south reveals a source with similar geometry and magnetic properties. The associated gravity highs of the San Joaquin Hills suggest that the probable lithology of these concealed magnetic bodies is a dense crystalline rock such as gabbro.

  19. Three-Dimensional Geologic Model of Complex Fault Structures in the Upper Seco Creek Area, Medina and Uvalde Counties, South-Central Texas

    USGS Publications Warehouse

    Pantea, Michael P.; Cole, James C.; Smith, Bruce D.; Faith, Jason R.; Blome, Charles D.; Smith, David V.

    2008-01-01

    This multimedia report shows and describes digital three-dimensional faulted geologic surfaces and volumes of the lithologic units of the Edwards aquifer in the upper Seco Creek area of Medina and Uvalde Counties in south-central Texas. This geologic framework model was produced using (1) geologic maps and interpretations of depositional environments and paleogeography; (2) lithologic descriptions, interpretations, and geophysical logs from 31 drill holes; (3) rock core and detailed lithologic descriptions from one drill hole; (4) helicopter electromagnetic geophysical data; and (5) known major and minor faults in the study area. These faults were used because of their individual and collective effects on the continuity of the aquifer-forming units in the Edwards Group. Data and information were compared and validated with each other and reflect the complex relationships of structures in the Seco Creek area of the Balcones fault zone. This geologic framework model can be used as a tool to visually explore and study geologic structures within the Seco Creek area of the Balcones fault zone and to show the connectivity of hydrologic units of high and low permeability between and across faults. The software can be used to display other data and information, such as drill-hole data, on this geologic framework model in three-dimensional space.

  20. Role of fluid in the mechanism of formation of volcaniclastic and coherent kimberlite facies: a diamond perspective

    NASA Astrophysics Data System (ADS)

    Fedortchouk, Yana; Chinn, Ingrid

    2016-04-01

    Dissolution features on diamonds recovered from kimberlites vary depending on the dissolution conditions and can be used as a reliable proxy for volatiles and their role in kimberlite emplacement. Volatiles determine the mechanism of magma emplacement; variation in volatile content and CO2/CO2+H2O ratio may affect the geology of kimberlite bodies and formation of coherent vs. volcaniclastic kimberlite facies. Here we examine the evolution of a kimberlite system during ascent using the resorption morphology of its diamond population. We use 655 macro-diamonds from a complex kimberlite pipe in the Orapa kimberlite field (Botswana) to examine the role of volatiles in the formation of the three facies comprising this pipe: two coherent kimberlite facies (CKA and CKB) and one massive volcaniclastic facies (MVK). The diamonds come from three drillholes through each of the studied kimberlite facies. Separate diamond samples derived from 2 - 13 m intervals were combined into 40 m depth intervals for statistical purposes. Four independent morphological methods allowed us to reliably discriminate products of resorption in kimberlite magma from resorption in the mantle, and use the former in our study. We found that the proportion of diamonds with kimberlitic resorption is the lowest in CKA - 22%, medium in MVK - 50%, and highest in CKB - 73%, and it increases with depth in each of the drillholes. Each kimberlite facies shows its own style of kimberlite-induced resorption on rounded tetrahexahedron (THH) diamonds: glossy surfaces in MVK, rough corroded surfaces in CKB, and combination of glossy surfaces with chains of circular pits in CKA, where these pits represent the initial stages of development of corrosive features observed on CKB diamonds. Based on the results of our previous experimental studies we propose that resorption of MVK diamonds is a product of interaction with COH fluid, resorption of CKB diamonds is a product of interaction with a volatile

  1. Application of fracture-flow hydrogeology to acid-mine drainage at the Bunker Hill Mine, Kellogg, Idaho

    NASA Astrophysics Data System (ADS)

    Lachmar, Thomas E.

    1994-03-01

    The mechanics of groundwater flow through fractured rock has become an object of major research interest during recent years. This project has investigated the flow of groundwater through fractured Precambrian metaquartzite rocks in a portion of the Bunker Hill Mine near Kellogg, Idaho. Groundwater flow through these types of rocks is largely dependent upon the properties of fractures such as faults, joints and relict bedding planes. Groundwater that flows into the mine via the fractures is acidic and is contaminated by heavy metals, which results in a severe acid mine drainage problem. A more complete understanding of how the fractures influence the groundwater flow system is a prerequisite of the evaluation of reclamation alternatives to reduce acid drainage from the mine. Fracture mapping techniques were used to obtain detailed information on the fracture properties observed in the New East Reed drift of the Bunker Hill Mine. The information obtained includes fracture type, orientation, trace length, the number of visible terminations, roughness, waviness, infilling material, and a qualitative measure of the amount of water flowing through each fracture. The hydrogeologic field data collected include routine measurements of the discharge from four individual structural features and four areas where large quantities of water are discharging from vertical rock bolts, the depths to water in three piezometer nests at the ground surface, the pressure variations in four diamond drillholes, and constant discharge flow tests conducted on three of the diamond drillholes. The field data indicate that relict bedding planes are the primary conduits for groundwater flow, and suggest that the two major joint sets that are present connect water flowing through the discontinuous bedding planes. The three minor joint sets that are present do not seem to have a significant impact on groundwater flow, but along with the two major joint sets may store relatively large quantities of

  2. Geologic mapping of Kentucky; a history and evaluation of the Kentucky Geological Survey--U.S. Geological Survey Mapping Program, 1960-1978

    USGS Publications Warehouse

    Cressman, Earle Rupert; Noger, Martin C.

    1981-01-01

    In 1960, the U.S. Geological Survey and the Kentucky Geological Survey began a program to map the State geologically at a scale of 1:24,000 and to publish the maps as 707 U.S. Geological Survey Geologic Quadrangle Maps. Fieldwork was completed by the spring of 1977, and all maps were published by December 1978. Geologic mapping of the State was proposed by the Kentucky Society of Professional Engineers in 1959. Wallace W. Hagan, Director and State Geologist of the Kentucky Geological Survey, and Preston McGrain, Assistant State Geologist, promoted support for the proposal among organizations such as Chambers of Commerce, industrial associations, professional societies, and among members of the State government. It was also arranged for the U.S. Geological Survey to supply mapping personnel and to publish the maps; the cost would be shared equally by the two organizations. Members of the U.S. Geological Survey assigned to the program were organized as the Branch of Kentucky Geology. Branch headquarters, including an editorial staff, was at Lexington, Ky., but actual mapping was conducted from 18 field offices distributed throughout the State. The Publications Division of the U.S. Geological Survey established a cartographic office at Lexington to prepare the maps for publication. About 260 people, including more than 200 professionals, were assigned to the Branch of Kentucky Geology by the U.S. Geological Survey at one time or another. The most geologists assigned any one year was 61. To complete the mapping and ancillary studies, 661 professional man-years were required, compared with an original estimate of 600 man-years. A wide variety of field methods were used, but most geologists relied on the surveying altimeter to obtain elevations. Surface data were supplemented by drill-hole records, and several dozen shallow diamond-drill holes were drilled to aid the mapping. Geologists generally scribed their own maps, with a consequent saving of publication costs

  3. Tensor controlled-source audiomagnetotelluric survey over the Sulphur Springs Thermal area, Valles Caldera, New Mexico, U.S.A.; Implication for structure of the western Caldera and for CSAMT methodology

    SciTech Connect

    Wannamaker, P.E.

    1994-06-01

    We have carried Out an extensive tensor CSAMT survey of the Sulphur Springs geothermal area, Valles Caldera, New Mexico. This survey, consisting of 45 high-quality sites, has been acquired by in support of Continental Scientific Drilling Program (CSDP) drillholes VC-2A and VC-2B. Two independent transmitter dipoles were energized for tensor measurements using a 30 kW generator placed approximately 13 km south of the VC-2B wellhead. The soundings in the Sulphur Springs area were arranged in four profiles to cross major structural features. The electric bipoles parallel to each profile were deployed contiguously to ensure against spatial aliasing of the impedance response corresponding to current flow across structural trends. The frequency range of acquisition was 4096 Hz down to 1 Hz for the central line, but only down to 4 Hz for most sites of the other lines. Data quality is high overall and is established by repeatability of measurements. Agreement between the CSAMT and available natural field MT data is very good over almost all the period range of overlap indicating that we are free of calibration problems and that far-field results are generally being obtained. Non plane-wave effects in the CSAMT around Sulphur Springs are apparent at 1 to 2 Hz, and perhaps slightly even at 4 Hz, however, which is near the bottom of our frequency range. CSAMT and MT data taken outside the Valles Caldera to the west were modeled in an attempt to compare resistivity structure exterior to the caldera to that within. With the availability of tensor CSAMT and MT data both inside and outside Valles Caldera, assumptions and methods of CSAMT are tested. In the Sulphur Springs area, near-coincident CSAMT and MT data near well VC -2B indicate that non-lane-wave effects in the apparent resistivity and impedance phase occure at a frequency near to that predicted from the resistivity structure local to the wester caldera.

  4. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multi-frequency EM

    NASA Astrophysics Data System (ADS)

    Hendricks, S.; Hoppmann, M.; Hunkeler, P. A.; Kalscheuer, T.; Gerdes, R.

    2015-12-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise and accumulate beneath nearby sea ice to form a several meter thick sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator for ice - ocean interactions. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and sub-ice platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions from platelet-layer conductivities using Archie's Law. The thickness results agreed well with drill-hole validation datasets within the uncertainty range, and the ice-volume fraction also yielded plausible results. Our findings imply that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties. However, we emphasize that the successful application of this technique requires a break with traditional EM sensor calibration strategies due to the need of absolute calibration with respect to a physical forward model.

  5. The variogram and the simple kriging estimator: Useful tools to complement lithologic correlation in a complex fluvial depositional environment

    SciTech Connect

    Murphy, J.

    1995-12-31

    Three dimensional grid estimation has been combined with an interpretive model of fluvial deposition for correlating low permeability zones in the shallow subsurface. Improvement in correlation reliability was realized by combining hand drawn interpretive cross-sections (spotting local trends in grain size, CPT log signature, etc.) with cross-section maps of the geostatistical grid model. The site is a military installation where soil contamination is being mapped and quantified using three dimensional modeling techniques. The subsurface is a complex fluvial depositional environment with intermittent bedrock highs and more frequent calcite and Calcium/Iron related cementation. Hence, the problem of lithologic correlation occurred where the drillhole spacing became wider than the channel belt width or cemented materials prevented detailed sampling. The goals of the sampling and analysis plan called for sampling within the first continuous silt or clay unit in order to quantify the zone of greatest contaminant retention on its downward migratory path. This paper will describe a three dimensional correlation technique which employs geostatistical analysis of CPT hole data specifically coded by permeability indicator thresholds. The process yielded variogram ranges applied to a simple kriging estimator on a 3-dimensional grid block. Estimates of clay probability are then provided as output and overlaid with the geologists cross section interpretation. The marriage of these two tools was invaluable in that geostatistical estimates sometimes behaved contrary to the channel depositional process, while on the other hand, the geologists interpretation often failed to recognize data in the third dimension (i.e. off section CPT data).

  6. Delineation of near-surface paleochannel using shallow seismic reflection techniques

    SciTech Connect

    Miller, R.D.; Xia, Jianghai; Cardinell, A.

    1995-12-31

    Shallow seismic reflection techniques were successful in delineating stratigraphic units and bedding geometries significant to the hydrologic modeling of unconsolidated sediments less than 60 in deep at Cherry Point Marine Air Base near Havelock, North Carolina. Discontinuous confining units beneath an industrialized portion of this major aircraft overhaul facility were thought to be due the erosion by a river that had cut through this area. Land shallow seismic reflection techniques provided images of alternating sand and clay sequences with average thicknesses on the order of 6 to 9 in. The land data have a dominant frequency of about 200 Hz, providing a minimum vertical bed resolution of about 2 in. Continuous seismic reflection data collected in the Neuse River directly north of the base have a dominant frequency around 600 Hz, providing a resolution potential of less than 1 in. Well defined cut and fill features that appear to have removed portions of the confining units are evident on the processed marine data. Correlation of the land CDP stacked seismic section with the drillhole-defined lithology was enhanced by incorporating electric logs and VSPs acquired in three strategically placed monitor wells. Some processed VSPs have interpretable reflections from within the upper 70 in that are consistent with the geologic section as inferred from drilling and electric logs. Subtle stratigraphic contacts, such as shell layers within sand or changes in the grain size of sand, were not easily interpretable on the CDP stacked sections. The land seismic reflection data provided the very high horizontal and vertical resolution necessary for determining continuity of confining units and stratigraphic variations between 10 and 60 in at this site.

  7. Using Reactive Transport Modeling to Understand Formation of the Stimson Sedimentary Unit and Altered Fracture Zones at Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    Hausrath, E. M.; Ming, D. W.; Peretyazhko, T.; Rampe, E. B.

    2017-01-01

    Water flowing through sediments at Gale Crater, Mars created environments that were likely habitable, and sampled basin-wide hydrological systems. However, many questions remain about these environments and the fluids that generated them. Measurements taken by the Mars Science Laboratory Curiosity of multiple fracture zones can help constrain the environments that formed them because they can be compared to nearby associated parent material (Figure 1). For example, measurements of altered fracture zones from the target Greenhorn in the Stimson sandstone can be compared to parent material measured in the nearby Big Sky target, allowing constraints to be placed on the alteration conditions that formed the Greenhorn target from the Big Sky target. Similarly, CheMin measurements of the powdered < 150 micron fraction from the drillhole at Big Sky and sample from the Rocknest eolian deposit indicate that the mineralogies are strikingly similar. The main differences are the presence of olivine in the Rocknest eolian deposit, which is absent in the Big Sky target, and the presence of far more abundant Fe oxides in the Big Sky target. Quantifying the changes between the Big Sky target and the Rocknest eolian deposit can therefore help us understand the diagenetic changes that occurred forming the Stimson sedimentary unit. In order to interpret these aqueous changes, we performed reactive transport modeling of 1) the formation of the Big Sky target from a Rocknest eolian deposit-like parent material, and 2) the formation of the Greenhorn target from the Big Sky target. This work allows us to test the relationships between the targets and the characteristics of the aqueous conditions that formed the Greenhorn target from the Big Sky target, and the Big Sky target from a Rocknest eolian deposit-like parent material.

  8. U-Pb ages, geochemistry, C-O-Nd-Sr-Hf isotopes and petrogenesis of the Catalão II carbonatitic complex (Alto Paranaíba Igneous Province, Brazil): implications for regional-scale heterogeneities in the Brazilian carbonatite associations

    NASA Astrophysics Data System (ADS)

    Guarino, Vincenza; Wu, Fu-Yuan; Melluso, Leone; de Barros Gomes, Celso; Tassinari, Colombo Celso Gaeta; Ruberti, Excelso; Brilli, Mauro

    2016-09-01

    The Catalão II carbonatitic complex is part of the Alto Paranaíba Igneous Province (APIP), central Brazil, close to the Catalão I complex. Drill-hole sampling and detailed mineralogical and geochemical study point out the existence of ultramafic lamprophyres (phlogopite-picrites), calciocarbonatites, ferrocarbonatites, magnetitites, apatitites, phlogopitites and fenites, most of them of cumulitic origin. U-Pb data have constrained the age of Catalão I carbonatitic complex between 78 ± 1 and 81 ± 4 Ma. The initial strontium, neodymium and hafnium isotopic data of Catalão II (87Sr/86Sri = 0.70503-0.70599; ɛNdi = -6.8 to -4.7; 176Hf/177Hf = 0.28248-0.28249; ɛHfi = -10.33 to -10.8) are similar to the isotopic composition of the Catalão I complex and fall within the field of APIP kimberlites, kamafugites and phlogopite-picrites, indicating the provenance from an old lithospheric mantle source. Carbon isotopic data for Catalão II carbonatites (δ13C = -6.35 to -5.68 ‰) confirm the mantle origin of the carbon for these rocks. The origin of Catalão II cumulitic rocks is thought to be caused by differential settling of the heavy phases (magnetite, apatite, pyrochlore and sulphides) in a magma chamber repeatedly filled by carbonatitic/ferrocarbonatitic liquids (s.l.). The Sr-Nd isotopic composition of the Catalão II rocks matches those of APIP rocks and is markedly different from the isotopic features of alkaline-carbonatitic complexes in the southernmost Brazil. The differences are also observed in the lithologies and the magmatic affinity of the igneous rocks found in the two areas, thus demonstrating the existence of regional-scale heterogeneity in the mantle sources underneath the Brazilian platform.

  9. A multiple-point geostatistical method for characterizing uncertainty of subsurface alluvial units and its effects on flow and transport

    USGS Publications Warehouse

    Cronkite-Ratcliff, C.; Phelps, G.A.; Boucher, A.

    2012-01-01

    This report provides a proof-of-concept to demonstrate the potential application of multiple-point geostatistics for characterizing geologic heterogeneity and its effect on flow and transport simulation. The study presented in this report is the result of collaboration between the U.S. Geological Survey (USGS) and Stanford University. This collaboration focused on improving the characterization of alluvial deposits by incorporating prior knowledge of geologic structure and estimating the uncertainty of the modeled geologic units. In this study, geologic heterogeneity of alluvial units is characterized as a set of stochastic realizations, and uncertainty is indicated by variability in the results of flow and transport simulations for this set of realizations. This approach is tested on a hypothetical geologic scenario developed using data from the alluvial deposits in Yucca Flat, Nevada. Yucca Flat was chosen as a data source for this test case because it includes both complex geologic and hydrologic characteristics and also contains a substantial amount of both surface and subsurface geologic data. Multiple-point geostatistics is used to model geologic heterogeneity in the subsurface. A three-dimensional (3D) model of spatial variability is developed by integrating alluvial units mapped at the surface with vertical drill-hole data. The SNESIM (Single Normal Equation Simulation) algorithm is used to represent geologic heterogeneity stochastically by generating 20 realizations, each of which represents an equally probable geologic scenario. A 3D numerical model is used to simulate groundwater flow and contaminant transport for each realization, producing a distribution of flow and transport responses to the geologic heterogeneity. From this distribution of flow and transport responses, the frequency of exceeding a given contaminant concentration threshold can be used as an indicator of uncertainty about the location of the contaminant plume boundary.

  10. Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Gibson, J.D.; Swan, F.H.; Wesling, J.R.; Bullard, T.F.; Perman, R.C.; Angell, M.M.; DiSilvestro, L.A.

    1992-01-01

    Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques.

  11. Multifractal magnetic susceptibility distribution models of hydrothermally altered rocks in the Needle Creek Igneous Center of the Absaroka Mountains, Wyoming

    USGS Publications Warehouse

    Gettings, M.E.

    2005-01-01

    measured data. Comparisons of the model and data from drillholes show good but not perfect agreement. ?? 2005 Author(s). This work is licensed under a Creative Commons License.

  12. Fluid-rock interactions in the Rhine Graben: A thermodynamic model of the hydrothermal alteration observed in deep drilling

    NASA Astrophysics Data System (ADS)

    Komninou, A.; Yardley, B. W. D.

    1997-02-01

    Deep drilling at Soultz-sous-Forêts, France, on the western flanks of the Rhine Graben, has penetrated Hercynian granite underlying Mesozoic sediments. Veins are present throughout the drilled granite, and there are flows of warm water localized in fractures within the granite. Detailed mineralogical study of core material from the research drillhole EPS 1 has been carried out in order to assess the alteration history of the Soultz granite, part of the crystalline basement of the Rhine Graben. The results of the study have been used, in conjunction with analyses of present-day fluids from deep drilling in the Rhine Graben reported in the literature, to model thermodynamically the alteration process, and in particular to evaluate if it is likely to be continuing today. Reaction-path calculations show that if deep basinal brines, such as are known from sediments of the central Rhine Graben, react with Hercynian granite, they will form different alteration assemblages depending on both the path that the fluid follows (e.g., descending through sediments or through granite) and the extent of preexisting alteration of the granite. The calculations suggest that fluid now sampled from granite in EPS-1 achieved its peak temperature, c. 200°C, while within Permo-Triassic sandstone. The modeling also indicates that present-day fluids from the Rhine Graben system are capable of producing the vein quartz and possibly also the baryte veins, seen in the EPS 1 core. Much of the alteration present in the granite in the vicinity of veins and fractures may have been produced by a flow regime similar to that prevailing today.

  13. Structure of the Rambler Rhyolite, Baie Verte Peninsula, Newfoundland: Inversions using UBC-GIF Grav3D and Mag3D

    NASA Astrophysics Data System (ADS)

    Spicer, B.; Morris, B.; Ugalde, H.

    2011-09-01

    Hosted within the Pacquet Harbour Group (PHG) on the Baie Verte Peninsula of north-central Newfoundland, the Rambler rhyolite is a 487 Ma unit of felsic tuffs, flows and subvolcanic intrusive rocks. The PHG has been affected by multiple phases of deformation with the youngest D4 deformation event producing broad northeast plunging upright cross folds in the Rambler rhyolite. Fold culminations on the upper bounding surface of the rhyolite host Cu +/- Au volcanogenic massive sulfide deposits (e.g. Rambler and Ming mines). Geophysical inversions of recently acquired high resolution gravity and magnetic data have been implemented to determine the extent of the fold axis (dome) at depth. To direct the outcome of the inversion process towards a more geologically reasonable solution this study outlines a procedure which permits the inclusion of known geological and geophysical constraints into the input (reference) model for inversion using the MAG3D and GRAV3D algorithms provided by the University of British Columbia Geophysical Inversion Facility. Reference model constraints included surficial geological contacts as defined by aeromagnetic data, and subsurface distribution of physical property variations from a series of drill-hole logs. The output (computed) model images the surface of the rhyolite dome as dipping roughly 40° to the northeast as a series of voxels with density values ranging from 2.71 to 2.75 g/cm3. While previously published ore deposit models parallel this structure in the near surface, results from these inversions suggest deeper exploration may be favorable. Magnetic inversion modeling has not provided any insight into dome morphology however it outlines the distribution of gabbroic dykes surrounding the dome.

  14. A molecular and isotopic study of palaeoenvironmental conditions through the middle Cambrian in the Georgina Basin, central Australia

    NASA Astrophysics Data System (ADS)

    Pagès, Anais; Schmid, Susanne; Edwards, Dianne; Barnes, Stephen; He, Nannan; Grice, Kliti

    2016-08-01

    The Cambrian period marks an important point in Earth's history with profound changes in the ocean's biogeochemistry and the occurrence of the most significant evolutionary event in the history of life, the Cambrian explosion. The Cambrian explosion is described as a succession of complex cycles of extinctions and radiations. This study integrates biomarkers and their compound-specific stable carbon isotopes to investigate the palaeoenvironmental depositional conditions in middle Cambrian (Series 3) sedimentary rocks (Thorntonia Limestone, Inca Formation and Currant Bush Limestone) from two drillholes in the Undilla Sub-basin in the eastern Georgina Basin, central Australia. The occurrence of photic zone euxinia (PZE) was detected throughout these three formations by the identification of green sulfur bacteria Chlorobiaceae-derived biomarkers, including a series of 2,3,6-aryl isoprenoids and the intact biomarker isorenieratane. Pulses of enhanced PZE conditions were detected in two core intervals (90-110 mKB, Currant Bush Limestone and 170-200 mKB, Inca Formation) by an increase in the 2,3,6-aryl isoprenoids and C19 biphenyl concentrations. These enhanced PZE conditions were followed by blooms of phytoplankton, as demonstrated by the increase in algal-derived biomarker (i.e. pristane, phytane and the C19n-alkane) concentrations and compound-specific isotopes. These observations confirm that palaeoenvironmental conditions were similar to those reported for the Permian/Triassic and Triassic/Jurassic mass extinction events. The sterane distributions varied across the three formations reflecting possible changes in the phytoplanktonic communities through time. Although a rise in atmospheric oxygen during the Cambrian has been previously associated with the rapid evolution of metazoans, the ecological challenges related to widespread anoxia must have had a major influence on the evolution of life in Cambrian oceans.

  15. Potential field analysis images Paleoproterozoic terrane boundaries in the unexposed Northern Gawler Craton, Australia

    NASA Astrophysics Data System (ADS)

    Baines, G.; Giles, D.; Betts, P.; Backé, G.

    2008-12-01

    In areas of limited or zero basement exposure, potential field analysis provides an invaluable tool for determining the architecture continental cratons. We present an example from the Northern Gawler Craton, Australia. Here, the basement rocks are almost completely covered by Neoproterozoic and younger sedimentary rocks (with <<1% basement outcrop), so are amongst the least studied on the Australian continent. However, these rocks should preserve the best record of the Gawler Craton's interactions with neighbouring cratons during the amalgamation of Proterozoic Australia. We focus on the basement architecture in the Marla region of the northernmost Gawler Craton. We use geophysical techniques and apply a top-down approach to penetrate the significant thickness of cover and determine the structure of the unexposed northern Gawler Craton. The architecture, density and magnetic susceptibility of the overlying cover sequences are constrained from the surficial geology, borehole data and seismic reflection profiles. The effect of these cover sequences is then removed from gravity and magnetic data highlighting the basement structure. We then determine the architecture of the basement with depth from the potential field data by combining depth-to-source analyses, with forward and inverse modelling techniques constrained by petrophysical data from drill-holes. Results of this analysis include the observation of a major crustal boundary at the NE-SW trending Middle Bore Fault. To the NW of this boundary, crustal scale sources produce large gravity and magnetic anomalies. Whereas to the SE anomalies are sourced in the upper crust and overlie uniform middle to lower crust. We suggest that the Middle Bore Fault represents a boundary between allochthonous terranes that may have accreted to the Gawler craton during the Kimban Orogeny (~1.7 Ga) and the Archaean Gawler Craton that is overlain by Paleoproterozoic metasediments. The basement structure revealed by this approach

  16. Gulf coastal Pleistocene units and time stratigraphy; reevaluation and problems of Atlantic correlation

    SciTech Connect

    Otvos, E.G. . Geology Section)

    1993-03-01

    Outdated glacial subdivisions and misinterpretations of alluvial interfluve ridges as marine terraces hampered advances in coastal stratigraphy. One problem involves C.W. Cooke's extension of his Atlantic shorelines along the NE Gulf into the Mississippi Embayment. The mirage of an inter-Wisconsinan interglacial gave way to beliefs in high glacial Wisconsinan sea levels that were assumed to have resulted in barriers and intensive alluvial aggradation on the TX-LA coastal plain. Without vertical definitions, Fisk assigned formation status to alluvial and brackish-marine sediments that directly underlie four coastwise Pleistocene terraces in SW Louisiana. The youngest (Prairie) and associated formations were recently (re)defined and correlated with other coastal areas. Brackish and marine deposits in the subsurface have been correlated with Fisk's second youngest coastwise surface. Detailed facies analyses of cores from hundreds of drillholes indicated that, in sharp contrast with Plio-Pleistocene barriers on the Atlantic coast, only a single, Sangamonian (Sg) barrier shore complex remains on the NE Gulf coastal plain after intensive uplift/erosion. Few isolated remnants of pre-Sg Pleistocene alluvial units occur, including flora elements in peat lenses at one location. An early, low Sg sea level stand near Apalachicola is marked by transgressive deposits at c. [minus]37.5m. Thin NE Gulf Sg sequence includes the fine-grained, open marine-to-estuarine Biloxi, the regressive, shallow subtidal-to-supratidal, mainland Gulfport barrier and the alluvial Prairie Formations. These are correlatable Gulfwide. Contrary to widespread assumption, the Gulfport-Ingleside barriers were not islands but mainland strandplains. The Sg complex correlates with oxygen isotope Stage 5 units of the Mid/South Atlantic coastal plain and shelf. Thick LA-TX shelf/slope intervals display about ten fourth-order cycles within 4 primary ones.

  17. Rock-mass classification of candidate repository units at Yucca Mountain, Nye County, Nevada

    SciTech Connect

    Langkopf, B.S.; Gnirk, P.R.

    1986-02-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) Project managed by the Nevada Operations Office of the Department of energy, is examining the feasibility of siting a repository for high-level radioactive waste at Yucca Mountain, a tuff site on and adjacent to the Nevada Test Site, Nye County, Nevada. Between 1981 and 1983, four tuff units were considered as potential units for emplacement of radioactive waste. Two of the four units are above the water table: the welded, devitrified portion of the Topopah Spring Member of the paintbrush Tuff and the zeolitized, nonwelded portion of the Tuffaceous Beds of Calico Hills. The other two units are below the water table: the welded, devitrified portion of the Bullfrog Member of the Crater Flat Tuff and the welded, devitrified portion of the Tram Member of the Crater Flat Tuff. In this study, available site-specific information from drillholes, supplemented by the needed information from tuff units at other locations, was used in conjunction with two rock-mass-classification systems to evaluate the relative excavation stability of these units. The two rock-mass-classification systems are the South African Council for Scientific and Industrial Research Classification System developed by Bieniawski and the Norwegian Geotechnical Institute Classification System developed by Barton. Two other tuff units located at Rainier Mesa on the Nevada Test Site, the welded portion of the Grouse Canyon Member of the Belted Range Tuff and the nonwelded Tunnel Bed 5, were also evaluated using these rock-mass-classification systems. These last two units were never considered as possible locations for waste emplacement but were evaluated as a basis for comparison with Yucca Mountain units because there are existing stable tunnels in the Rainier Mesa units.

  18. Prunetin signals via G-protein-coupled receptor, GPR30(GPER1): Stimulation of adenylyl cyclase and cAMP-mediated activation of MAPK signaling induces Runx2 expression in osteoblasts to promote bone regeneration.

    PubMed

    Khan, Kainat; Pal, Subhashis; Yadav, Manisha; Maurya, Rakesh; Trivedi, Arun Kumar; Sanyal, Sabyasachi; Chattopadhyay, Naibedya

    2015-12-01

    Prunetin is found in red clover and fruit of Prunus avium (red cherry). The effect of prunetin on osteoblast function, its mode of action and bone regeneration in vivo were investigated. Cultures of primary osteoblasts, osteoblastic cell line and HEK293T cells were used for various in vitro studies. Adult female rats received drill-hole injury at the femur diaphysis to assess the bone regenerative effect of prunetin. Prunetin at 10nM significantly (a) increased proliferation and differentiation of primary cultures of osteoblasts harvested from rats and (b) promoted formation of mineralized nodules by bone marrow stromal/osteoprogenitor cells. At this concentration, prunetin did not activate any of the two nuclear estrogen receptors (α and β). However, prunetin triggered signaling via a G-protein-coupled receptor, GPR30/GPER1, and enhanced cAMP levels in osteoblasts. G15, a selective GPR30 antagonist, abolished prunetin-induced increases in osteoblast proliferation, differentiation and intracellular cAMP. In osteoblasts, prunetin up-regulated runt-related transcription factor 2 (Runx2) protein through cAMP-dependent Erk/MAP kinase activation that ultimately resulted in the up-regulation of GPR30. Administration of prunetin at 0.25mg/kg given to rats stimulated bone regeneration at the site of drill hole and up-regulated Runx2 expression in the fractured callus and the effect was comparable to human parathyroid hormone, the only clinically used osteogenic therapy. We conclude that prunetin promotes osteoinduction in vivo and the mechanism is defined by signaling through GPR30 resulting in the up-regulation of the key osteogenic gene Runx2 that in turn up-regulates GPR30.

  19. High-resolution chemical composition of geothermal scalings from Hungary: Preliminary results

    NASA Astrophysics Data System (ADS)

    Boch, Ronny; Dietzel, Martin; Deák, József; Leis, Albrecht; Mindszenty, Andrea; Demeny, Attila

    2015-04-01

    Geothermal fluids originating from several hundreds to thousands meters depth mostly hold a high potential for secondary mineral precipitation (scaling) due to high total dissolved solid contents at elevated temperature and pressure conditions. The precipitation of e.g. carbonates, sulfates, sulfides, and silica has shown to cause severe problems in geothermal heat and electric power production, when clogging of drill-holes, downhole pumps, pipes and heat exchangers occurs (e.g. deep geothermal doublet systems). Ongoing scaling reduces the efficiency in energy extraction and might even question the abandonment of installations in worst cases. In an attempt to study scaling processes both temporally and spatially we collected mineral precipitates from selected sites in Hungary (Bükfürdo, Szechenyi, Szentes, Igal, Hajduszoboszlo). The samples of up to 8 cm thickness were recovered from different positions of the geothermal systems and precipitated from waters of various temperatures (40-120 °C) and variable overall chemical composition. Most of these scalings show fine lamination patterns representing mineral deposition from weeks up to 45 years at our study sites. Solid-fluid interaction over time captured in the samples are investigated applying high-resolution analytical techniques such as laser-ablation mass-spectrometry and electron microprobe, micromill-sampling for stable isotope analysis, and micro-XRD combined with hydrogeochemical modeling. A detailed investigation of the processes determining the formation and growth of precipitates can help to elucidate the short-term versus long-term geothermal performance with regard to anthropogenic and natural reservoir and production dynamics. Changes in fluid chemistry, temperature, pressure, pH, degassing rate (CO2) and flow rate are reflected by the mineralogical, chemical and isotopic composition of the precipitates. Consequently, this high-resolution approach is intended as a contribution to decipher the

  20. Three-dimensional geologic model of the southeastern Espanola Basin, Santa Fe County, New Mexico

    USGS Publications Warehouse

    Pantea, Michael P.; Hudson, Mark R.; Grauch, V.J.S.; Minor, Scott A.

    2011-01-01

    This multimedia model and report show and describe digital three-dimensional faulted surfaces and volumes of lithologic units that confine and constrain the basin-fill aquifers within the Espanola Basin of north-central New Mexico. These aquifers are the primary groundwater resource for the cities of Santa Fe and Espanola, six Pueblo nations, and the surrounding areas. The model presented in this report is a synthesis of geologic information that includes (1) aeromagnetic and gravity data and seismic cross sections; (2) lithologic descriptions, interpretations, and geophysical logs from selected drill holes; (3) geologic maps, geologic cross sections, and interpretations; and (4) mapped faults and interpreted faults from geophysical data. Modeled faults individually or collectively affect the continuity of the rocks that contain the basin aquifers; they also help define the form of this rift basin. Structure, trend, and dip data not previously published were added; these structures are derived from interpretations of geophysical information and recent field observations. Where possible, data were compared and validated and reflect the complex relations of structures in this part of the Rio Grande rift. This interactive geologic framework model can be used as a tool to visually explore and study geologic structures within the Espanola Basin, to show the connectivity of geologic units of high and low permeability between and across faults, and to show approximate dips of the lithologic units. The viewing software can be used to display other data and information, such as drill-hole data, within this geologic framework model in three-dimensional space.

  1. U-Pb ages, geochemistry, C-O-Nd-Sr-Hf isotopes and petrogenesis of the Catalão II carbonatitic complex (Alto Paranaíba Igneous Province, Brazil): implications for regional-scale heterogeneities in the Brazilian carbonatite associations

    NASA Astrophysics Data System (ADS)

    Guarino, Vincenza; Wu, Fu-Yuan; Melluso, Leone; de Barros Gomes, Celso; Tassinari, Colombo Celso Gaeta; Ruberti, Excelso; Brilli, Mauro

    2017-09-01

    The Catalão II carbonatitic complex is part of the Alto Paranaíba Igneous Province (APIP), central Brazil, close to the Catalão I complex. Drill-hole sampling and detailed mineralogical and geochemical study point out the existence of ultramafic lamprophyres (phlogopite-picrites), calciocarbonatites, ferrocarbonatites, magnetitites, apatitites, phlogopitites and fenites, most of them of cumulitic origin. U-Pb data have constrained the age of Catalão I carbonatitic complex between 78 ± 1 and 81 ± 4 Ma. The initial strontium, neodymium and hafnium isotopic data of Catalão II (87Sr/86Sri = 0.70503-0.70599; ɛNdi = -6.8 to -4.7; 176Hf/177Hf = 0.28248-0.28249; ɛHfi = -10.33 to -10.8) are similar to the isotopic composition of the Catalão I complex and fall within the field of APIP kimberlites, kamafugites and phlogopite-picrites, indicating the provenance from an old lithospheric mantle source. Carbon isotopic data for Catalão II carbonatites (δ13C = -6.35 to -5.68 ‰) confirm the mantle origin of the carbon for these rocks. The origin of Catalão II cumulitic rocks is thought to be caused by differential settling of the heavy phases (magnetite, apatite, pyrochlore and sulphides) in a magma chamber repeatedly filled by carbonatitic/ferrocarbonatitic liquids ( s.l.). The Sr-Nd isotopic composition of the Catalão II rocks matches those of APIP rocks and is markedly different from the isotopic features of alkaline-carbonatitic complexes in the southernmost Brazil. The differences are also observed in the lithologies and the magmatic affinity of the igneous rocks found in the two areas, thus demonstrating the existence of regional-scale heterogeneity in the mantle sources underneath the Brazilian platform.

  2. Low resistivity and permeability in actively deforming shear zones on the San Andreas Fault at SAFOD

    USGS Publications Warehouse

    Morrow, Carolyn A.; Lockner, David A.; Hickman, Stephen H.

    2015-01-01

    The San Andreas Fault Observatory at Depth (SAFOD) scientific drillhole near Parkfield, California crosses the San Andreas Fault at a depth of 2.7 km. Downhole measurements and analysis of core retrieved from Phase 3 drilling reveal two narrow, actively deforming zones of smectite-clay gouge within a roughly 200 m-wide fault damage zone of sandstones, siltstones and mudstones. Here we report electrical resistivity and permeability measurements on core samples from all of these structural units at effective confining pressures up to 120 MPa. Electrical resistivity (~10 ohm-m) and permeability (10-21 to 10-22 m2) in the actively deforming zones were one to two orders of magnitude lower than the surrounding damage zone material, consistent with broader-scale observations from the downhole resistivity and seismic velocity logs. The higher porosity of the clay gouge, 2 to 8 times greater than that in the damage zone rocks, along with surface conduction were the principal factors contributing to the observed low resistivities. The high percentage of fine-grained clay in the deforming zones also greatly reduced permeability to values low enough to create a barrier to fluid flow across the fault. Together, resistivity and permeability data can be used to assess the hydrogeologic characteristics of the fault, key to understanding fault structure and strength. The low resistivities and strength measurements of the SAFOD core are consistent with observations of low resistivity clays that are often found in the principal slip zones of other active faults making resistivity logs a valuable tool for identifying these zones.

  3. 3D Magnetization Vector Inversion of Magnetic Data: Improving and Comparing Methods

    NASA Astrophysics Data System (ADS)

    Liu, Shuang; Hu, Xiangyun; Zhang, Henglei; Geng, Meixia; Zuo, Boxin

    2017-09-01

    Magnetization vector inversion is an useful approach to invert for magnetic anomaly in the presence of significant remanent magnetization and self-demagnetization. However, magnetizations are usually obtained in many different directions under the influences of geophysical non-uniqueness. We propose an iteration algorithm of magnetization vector inversion (M-IDI) that one couple of magnetization direction is iteratively computed after the magnetization intensity is recovered from the magnitude magnetic anomaly. And we compare it with previous methods of (1) three orthogonal components inversion of total magnetization vector at Cartesian framework (MMM), (2) intensity, inclination and declination inversion at spherical framework (MID), (3) directly recovering the magnetization inclination and declination (M-IDCG) and (4) estimating the magnetization direction using correlation method (M-IDC) at the sequential inversion frameworks. The synthetic examples indicate that MMM returns multiply magnetization directions and MID results are strongly dependent on initial model and parameter weights. M-IDI computes faster than M-IDC and achieves a constant magnetization direction compared with M-IDCG. Additional priori information constraints can improve the results of MMM, MID and M-IDCG. Obtaining one magnetization direction, M-IDC and M-IDI are suitable for single and isolated anomaly. Finally, M-IDI and M-IDC are used to invert and interpret the magnetic anomaly of the Galinge iron-ore deposit (NW China) and the results are verified by information from drillholes and physical properties measurements of ore and rock samples. Magnetization vector inversion provides a comprehensive way to evaluate and investigate the remanent magnetization and self-demagnetization.

  4. The Momotombo Geothermal Field, Nicaragua: Exploration and development case history study

    SciTech Connect

    1982-07-01

    This case history discusses the exploration methods used at the Momotombo Geothermal Field in western Nicaragua, and evaluates their contributions to the development of the geothermal field models. Subsequent reservoir engineering has not been synthesized or evaluated. A geothermal exploration program was started in Nicaragua in 1966 to discover and delineate potential geothermal reservoirs in western Nicaragua. Exploration began at the Momotombo field in 1970 using geological, geochemical, and geophysical methods. A regional study of thermal manifestations was undertaken and the area on the southern flank of Volcan Momotombo was chosen for more detailed investigation. Subsequent exploration by various consultants produced a number of geotechnical reports on the geology, geophysics, and geochemistry of the field as well as describing production well drilling. Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. This report presents the description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development. Our principal finding is that data developed at each stage were not sufficiently integrated to guide further work at the field, causing inefficient use of

  5. Geophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications

    SciTech Connect

    Grauch, V.J.S.; Sawyer, D.A.; Fridrich, C.J.; Hudson, M.R.

    2000-06-08

    Gravity and magnetic data, when integrated with other geophysical, geological, and rock-property data, provide a regional framework to view the subsurface geology in the southwestern Nevada volcanic field. The authors have loosely divided the region into six domains based on structural style and overall geophysical character. For each domain, they review the subsurface tectonic and magmatic features that have been inferred or interpreted from previous geophysical work. Where possible, they note abrupt changes in geophysical fields as evidence for potential structural or lithologic control on ground-water flow. They use inferred lithology to suggest associated hydrogeologic units in the subsurface. The resulting framework provides a basis for investigators to develop hypotheses for regional ground-water pathways where no drill-hole information exists. The authors discuss subsurface features in the northwestern part of the Nevada Test Site and west of the Nevada Test Site in more detail to address potential controls on regional ground-water flow away from areas of underground nuclear-weapons testing at Pahute Mesa. Subsurface features of hydrogeologic importance in these areas are (1) the resurgent intrusion below Timber Mountain, (2) a NNE-trending fault system coinciding with western margins of the Silent Canyon and Timber Mountain caldera complexes, (3) a north-striking, buried fault east of Oasis Mountain extending for 15 km, which they call the Hogback fault, and (4) an east-striking transverse fault or accommodation zone that, in part, bounds Oasis Valley basin on the south, which they call the Hot Springs fault. In addition, there is no geophysical nor geologic evidence for a substantial change in subsurface physical properties within a corridor extending from the northwestern corner of the Rainier Mesa caldera to Oasis Valley basin (east of Oasis Valley discharge area). This observation supports the hypothesis of other investigators that regional ground water

  6. Modified Sauve-Kapandji procedure for disorders of the distal radioulnar joint in patients with rheumatoid arthritis. Surgical technique.

    PubMed

    Fujita, Satoru; Masada, Kazuhiro; Takeuchi, Eiji; Yasuda, Masataka; Komatsubara, Yoshio; Hashimoto, Hideo

    2006-03-01

    The Sauvé-Kapandji procedure has become popular for the treatment of disorders of the distal radioulnar joint in patients with rheumatoid arthritis, but this procedure is impossible to perform in patients with poor bone quality in the distal part of the ulna. We have modified the procedure for patients with poor bone quality in the distal part of the ulna. The modified procedure involves resecting the distal part of the ulna, making a drill-hole in the ulnar cortex of the distal part of the radius, rotating the resected portion of the ulna 90 degrees, inserting it into the distal part of the radius, and fixing it at that site with use of an AO cancellous-bone screw. In the present report, we describe the new operative technique and report the results after a minimum duration of follow-up of three years. This operation was performed in fifty-six patients (sixty-six wrists) with rheumatoid arthritis. The mean age at the time of the operation was 59.3 years. The mean duration of follow-up was forty-eight months. Patients were evaluated in terms of wrist pain, grip strength, and range of motion. Radiographic evaluation included calculation of the carpal translation index to assess the extent of ulnar translation of the carpus. Osseous union was achieved in all cases. Wrist pain resolved or decreased in all patients. The mean total range of forearm rotation increased from 144 degrees preoperatively to 167 degrees at the time of the most recent follow-up (p < 0.01). The mean carpal translation index did not change after the operation. The modified Sauvé-Kapandji procedure results in rigid fixation of the grafted bone. The technique provides sufficient osseous support of the carpus even in patients with rheumatoid arthritis and poor bone quality in the distal part of the ulna.

  7. Modified Sauvé-Kapandji procedure for disorders of the distal radioulnar joint in patients with rheumatoid arthritis.

    PubMed

    Fujita, Satoru; Masada, Kazuhiro; Takeuchi, Eiji; Yasuda, Masataka; Komatsubara, Yoshio; Hashimoto, Hideo

    2005-01-01

    The Sauvé-Kapandji procedure has become popular for the treatment of disorders of the distal radioulnar joint in patients with rheumatoid arthritis, but this procedure is impossible to perform in patients with poor bone quality in the distal part of the ulna. We have modified the procedure for patients with poor bone quality in the distal part of the ulna. The modified procedure involves resecting the distal part of the ulna, making a drill-hole in the ulnar cortex of the distal part of the radius, rotating the resected portion of the ulna 90 degrees , inserting it into the distal part of the radius, and fixing it at that site with use of an AO cancellous-bone screw. In the present report, we describe the new operative technique and report the results after a minimum duration of follow-up of three years. This operation was performed in fifty-six patients (sixty-six wrists) with rheumatoid arthritis. The mean age at the time of the operation was 59.3 years. The mean duration of follow-up was forty-eight months. Patients were evaluated in terms of wrist pain, grip strength, and range of motion. Radiographic evaluation included calculation of the carpal translation index to assess the extent of ulnar translation of the carpus. Osseous union was achieved in all cases. Wrist pain resolved or decreased in all patients. The mean total range of forearm rotation increased from 144 degrees preoperatively to 167 degrees at the time of the most recent follow-up (p < 0.01). The mean carpal translation index did not change after the operation. The modified Sauvé-Kapandji procedure results in rigid fixation of the grafted bone. The technique provides sufficient osseous support of the carpus even in patients with rheumatoid arthritis and poor bone quality in the distal part of the ulna.

  8. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Quarterly progress report, July 1--September 30, 1995

    SciTech Connect

    Allison, M.L.

    1995-10-30

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. Technical progress this quarter is divided into regional stratigraphy, case studies, stochastic modeling and fluid-flow simulation, and technology transfer activities. The regional stratigraphy of the Ferron Sandstone outcrop belt is being described and interpreted. Detailed geological and petrophysical characterization of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir, is continuing at selected case-study areas. Interpretations of lithofacies, bounding surfaces, and other geologic information are being combined with permeability measurements from closely spaced traverses and from drill-hole cores (existing and two drilled during the quarter). Petrophysical and statistical analyses are being incorporated with the geological characterization to develop a three-dimensional model of the reservoirs through fluid-flow simulation.

  9. Reconstruction of the anterior cruciate ligament in the skeletally immature athlete: a review of current concepts: AAOS exhibit selection.

    PubMed

    Fabricant, Peter D; Jones, Kristofer J; Delos, Demetris; Cordasco, Frank A; Marx, Robert G; Pearle, Andrew D; Warren, Russell F; Green, Daniel W

    2013-03-06

    Intrasubstance tears of the anterior cruciate ligament (ACL) were once considered a rare injury in skeletally immature athletes but are now observed with increasing frequency. Treatment strategies have evolved as recent studies have identified unique considerations specific to the skeletally immature patient. The current literature now supports the trend toward early operative treatment to restore knee stability and prevent progressive meniscal and/or articular cartilage damage, but the optimal approach to ACL reconstruction in this age group remains controversial. Despite the reported clinical success of transphyseal reconstruction, iatrogenic growth disturbance secondary to physeal damage remains a genuine concern. The reluctance to place drill-holes across open physes has led to the development of numerous "physeal-sparing" reconstruction techniques using anatomic femoral and tibial footprints that have adequately restored anteroposterior and rotational knee stability in biomechanical studies but have demonstrated mixed results in the clinical setting. The intent of this review is to (1) highlight the unique anatomic considerations pertaining to ACL reconstruction in the skeletally immature athlete, (2) discuss preoperative clinical and radiographic assessment of the pediatric patient with a suspected ACL injury, (3) review transphyseal and physeal-sparing reconstruction techniques and highlight surgical technical considerations, (4) present clinical outcomes according to patient and technique-specific factors, and (5) review age-specific injury prevention treatment strategies and a novel treatment algorithm based on skeletal maturity. ACL reconstruction in the skeletally immature athlete typically results in a successful clinical outcome, yet the optimal surgical technique is still controversial. This review will help guide the management of ACL injuries in the pediatric athlete.

  10. Geochronology of Mount Morning, Antarctica: two-phase evolution of a long-lived trachyte-basanite-phonolite eruptive center

    NASA Astrophysics Data System (ADS)

    Martin, Adam P.; Cooper, Alan F.; Dunlap, W. James

    2010-04-01

    Mount Morning is a Cenozoic, alkaline eruptive center in the south-west Ross Sea, Antarctica. New ages on 17 Mount Morning volcanic rocks (combined with 34 existing ages) allows division of Mount Morning volcanism into two phases, erupted between at least 18.7 Ma and 11.4 Ma, and 6.13 and 0.02 Ma. The position of Mount Morning on the active West Antarctic Rift System within the stationary Antarctic plate is a key factor in the eruptive center’s longevity. The earliest, mildly alkaline, Phase I volcanism comprises predominantly trachytic rocks produced by combined assimilation and fractional crystallization processes over 7.3 m.y. Strongly alkaline Phase II volcanism is dominated by a basanite - phonolite lineage, with the youngest (post last glacial maximum) activity dominated by small volume primitive basanite eruptions. The evolution from mildly to strongly alkaline chemistry between phases reflects magma residence time in the crust, the degree of mantle melting, or the degree of magma—country-rock interaction. Phase I magmatism occurred over a comparable area to the present-day, Phase II shield. The 5.2 m.y. volcanic hiatus separating Phase I and II coincides with a cycle of eruption and glacial erosion at the nearby Minna Bluff eruptive center. Mount Morning is the likely source of volcanic detritus in Cape Roberts drill-core (about 24.1 to 18.4 Ma) and in ANDRILL drill-hole 1B (about 13.6 Ma), located 170 km north and 105 km north-east respectively, of Mount Morning. Based upon the timing of eruptions and high heat-flow, Mount Morning should be considered a dormant volcano.

  11. The crater-facies kimberlite system of Tokapal, Bastar District, Chhattisgarh, India

    NASA Astrophysics Data System (ADS)

    Mainkar, Datta; Lehmann, Bernd; Haggerty, Stephen E.

    2004-09-01

    Discovery of diamondiferous kimberlites in the Mainpur Kimberlite Field, Raipur District, Chhattisgarh in central India, encouraged investigation of similar bodies in other parts of the Bastar craton. The earlier known Tokapal ultramafic intrusive body, located beyond the 19-km milestone in Tokapal village along the Jagdalpur-Geedam road, was reinterpreted as crater-facies kimberlite. Its stratigraphic position in the Meso-Neoproterozoic intracratonic sedimentary Indravati basin makes it one of the oldest preserved crater-facies kimberlite systems. Ground and limited subsurface data (dug-, tube-wells and exploratory boreholes) have outlined an extensive surface area (>550 ha) of the kimberlite. The morphological and surface color features of this body on enhanced satellite images suggest that there is a central feeder surrounded by a collar and wide pyroclastic apron. Exploration drilling indicates that the central zone probably corresponds to a vent overlain by resedimented volcaniclastic (epiclastic) rocks that are surrounded by a 2-km-wide spread of pyroclastic rocks (lapilli tuff, tuff/ash beds and volcaniclastic breccia). Drill-holes also reveal that kimberlitic lapilli tuffs and tuffs are sandwiched between the Kanger and Jagdalpur Formations and also form sills within the sedimentary sequence of the Indravati basin. The lapilli tuffs are commonly well stratified and display slumping. Base surges and lava flows occur in the southern part of the Tokapal system. The geochemistry and petrology of the rock correspond to average Group I kimberlite with a moderate degree of contamination. However, the exposed rock is intensely weathered and altered with strong leaching of mobile elements (Ba, Rb, Sr). Layers of vesicular fine-grained glassy material represent kimberlitic lava flows. Tuffs containing juvenile lapilli with pseudomorphed olivine macrocrysts are set in a talc-serpentine-carbonate matrix with locally abundant spinel and sphene. Garnet has not been

  12. The sub-ice platelet layer and its influence on freeboard to thickness conversion of Antarctic sea ice

    NASA Astrophysics Data System (ADS)

    Price, D.; Rack, W.; Langhorne, P. J.; Haas, C.; Leonard, G.; Barnsdale, K.

    2014-02-01

    This is an investigation to quantify the influence of the sub-ice platelet layer on satellite measurements of total freeboard and their conversion to thickness of Antarctic sea ice. The sub-ice platelet layer forms as a result of the seaward advection of supercooled ice shelf water from beneath ice shelves. This ice shelf water provides an oceanic heat sink promoting the formation of platelet crystals which accumulate at the sea ice-ocean interface. The build-up of this porous layer increases sea ice freeboard, and if not accounted for, leads to overestimates of sea ice thickness from surface elevation measurements. In order to quantify this buoyant effect, the solid fraction of the sub-ice platelet layer must be estimated. An extensive in situ data set measured in 2011 in McMurdo Sound in the south-western Ross Sea is used to achieve this. We use drill-hole measurements and the hydrostatic equilibrium assumption to estimate a mean value for the solid fraction of this sub-ice platelet layer of 0.16. This is highly dependent upon the uncertainty in sea ice density. We test this value with independent Global Navigation Satellite System (GNSS) surface elevation data to estimate sea ice thickness. We find that sea ice thickness can be overestimated by up to 19%, with a mean deviation of 12% as a result of the influence of the sub-ice platelet layer. It is concluded that in close proximity to ice shelves this influence should be considered universally when undertaking sea ice thickness investigations using remote sensing surface elevation measurements.

  13. The sub-ice platelet layer and its influence on freeboard to thickness conversion of Antarctic sea ice

    NASA Astrophysics Data System (ADS)

    Price, D.; Rack, W.; Langhorne, P. J.; Haas, C.; Leonard, G.; Barnsdale, K.

    2014-06-01

    This is an investigation to quantify the influence of the sub-ice platelet layer on satellite measurements of total freeboard and their conversion to thickness of Antarctic sea ice. The sub-ice platelet layer forms as a result of the seaward advection of supercooled ice shelf water from beneath ice shelves. This ice shelf water provides an oceanic heat sink promoting the formation of platelet crystals which accumulate at the sea ice-ocean interface. The build-up of this porous layer increases sea ice freeboard, and if not accounted for, leads to overestimates of sea ice thickness from surface elevation measurements. In order to quantify this buoyant effect, the solid fraction of the sub-ice platelet layer must be estimated. An extensive in situ data set measured in 2011 in McMurdo Sound in the southwestern Ross Sea is used to achieve this. We use drill-hole measurements and the hydrostatic equilibrium assumption to estimate a mean value for the solid fraction of this sub-ice platelet layer of 0.16. This is highly dependent upon the uncertainty in sea ice density. We test this value with independent Global Navigation Satellite System (GNSS) surface elevation data to estimate sea ice thickness. We find that sea ice thickness can be overestimated by up to 19%, with a mean deviation of 12% as a result of the influence of the sub-ice platelet layer. It is concluded that within 100 km of an ice shelf this influence might need to be considered when undertaking sea ice thickness investigations using remote sensing surface elevation measurements.

  14. Reservoir uncertainty, Precambrian topography, and carbon sequestration in the Mt. Simon Sandstone, Illinois Basin

    USGS Publications Warehouse

    Leetaru, H.E.; McBride, J.H.

    2009-01-01

    Sequestration sites are evaluated by studying the local geological structure and confirming the presence of both a reservoir facies and an impermeable seal not breached by significant faulting. The Cambrian Mt. Simon Sandstone is a blanket sandstone that underlies large parts of Midwest United States and is this region's most significant carbon sequestration reservoir. An assessment of the geological structure of any Mt. Simon sequestration site must also include knowledge of the paleotopography prior to deposition. Understanding Precambrian paleotopography is critical in estimating reservoir thickness and quality. Regional outcrop and borehole mapping of the Mt. Simon in conjunction with mapping seismic reflection data can facilitate the prediction of basement highs. Any potential site must, at the minimum, have seismic reflection data, calibrated with drill-hole information, to evaluate the presence of Precambrian topography and alleviate some of the uncertainty surrounding the thickness or possible absence of the Mt. Simon at a particular sequestration site. The Mt. Simon is thought to commonly overlie Precambrian basement granitic or rhyolitic rocks. In places, at least about 549 m (1800 ft) of topographic relief on the top of the basement surface prior to Mt. Simon deposition was observed. The Mt. Simon reservoir sandstone is thin or not present where basement is topographically high, whereas the low areas can have thick Mt. Simon. The paleotopography on the basement and its correlation to Mt. Simon thickness have been observed at both outcrops and in the subsurface from the states of Illinois, Ohio, Wisconsin, and Missouri. ?? 2009. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  15. Reactivation of Deep Subsurface Microbial Community in Response to Methane or Methanol Amendment

    PubMed Central

    Rajala, Pauliina; Bomberg, Malin

    2017-01-01

    Microbial communities in deep subsurface environments comprise a large portion of Earth’s biomass, but the microbial activity in these habitats is largely unknown. Here, we studied how microorganisms from two isolated groundwater fractures at 180 and 500 m depths of the Outokumpu Deep Drillhole (Finland) responded to methane or methanol amendment, in the presence or absence of sulfate as an additional electron acceptor. Methane is a plausible intermediate in the deep subsurface carbon cycle, and electron acceptors such as sulfate are critical components for oxidation processes. In fact, the majority of the available carbon in the Outokumpu deep biosphere is present as methane. Methanol is an intermediate of methane oxidation, but may also be produced through degradation of organic matter. The fracture fluid samples were incubated in vitro with methane or methanol in the presence or absence of sulfate as electron acceptor. The metabolic response of microbial communities was measured by staining the microbial cells with fluorescent redox sensitive dye combined with flow cytometry, and DNA or cDNA-derived amplicon sequencing. The microbial community of the fracture zone at the 180 m depth was originally considerably more respiratory active and 10-fold more numerous (105 cells ml-1 at 180 m depth and 104 cells ml-1 at 500 m depth) than the community of the fracture zone at the 500 m. However, the dormant microbial community at the 500 m depth rapidly reactivated their transcription and respiration systems in the presence of methane or methanol, whereas in the shallower fracture zone only a small sub-population was able to utilize the newly available carbon source. In addition, the composition of substrate activated microbial communities differed at both depths from original microbial communities. The results demonstrate that OTUs representing minor groups of the total microbial communities play an important role when microbial communities face changes in

  16. Three-dimensional velocity structure and hypocenter distribution in the Campi Flegrei caldera, Italy

    NASA Astrophysics Data System (ADS)

    Aster, R. C.; Meyer, R. P.

    1988-06-01

    The Campi Flegrei (Phlegraean Fields) are dominated by a Quaternary explosive calders, about 10 km in diameter. Within the caldera are numerous later eruptive vents, the last of which formed in 1538 A.D. Well documented local elevation changes of ≈ 10 m have occurred in the caldera since Roman times. Recent inflation of the central caldera began in 1968, after over 400 years of subsidence. During this time more than 2 m of localized uplift occurred, predominantly from 1980 through 1985. Microearthquakes associated with this uplift were recorded by a portable three-component digital network deployed by the University of Wisconsin and the Vesuvius Observatory from August 1983 through May 1984. Those data have been used to obtain detailed information about the velocity structure of the caldera. A best-fit homogeneous half-space model was obtained by a systematic search for optimal residual statistics. A residual-based tomographic technique was applied to isolate a low-seismicity, anomalously-high {v p}/{v s} region in the central caldera, roughly coincident with the region of greatest uplift. Finally, P and S arrival times were used to simultaneously relocate 228 earthquakes and obtain a three-dimensional vp and vs model for the caldera. The results of this velocity study, considered along with drillhole findings, composite fault-plane solutions, and the space-time distribution of earthquakes, suggest that the {v p}/{v s} anomaly may represent an incompetent, highly fractured volume, saturated with liquid water. Hypocenter locations indicate a zone of concentrated seismicity north of the point of highest measured uplift. An inward-dipping elliptical hypocenter pattern suggests a ring fault.

  17. Heat flow in the Kenya rift zone

    NASA Astrophysics Data System (ADS)

    Wheildon, J.; Morgan, Paul; Williamson, K. H.; Evans, T. R.; Swanberg, C. A.

    1994-09-01

    An understanding of the processes of continental rifting is fundamental to understanding the evolution of the continents. Considerable evidence exists to suggest that continental rift zones are associated with high heat flow and elevated lithospheric geotherms, but direct heat-flow measurements from young rifts do not clearly define surface heat-flow anomalies associated with deep-seated thermal processes in these rifts. The first detailed compilation of heat-flow data from the Neogene Kenya rift is presented here. Heat-flow data are presented from traditional heat-flow determinations in water drill-holes, from bottom-hole-temperature measurements in oil wells, and from heat-flow estimates from groundwater silica data. These data define generally low heat flow on the flanks of the Kenya rift, with high, but variable heat flow on the rift floor. There is a spatial association among high heat-flow values, Quaternary volcanism and faulting, and hydrothermal manifestations on the rift floor. We interpret these results to suggest that any deep-seated thermal anomaly associated with the Kenya rift has not yet been conducted to the surface. The high heat-flow values are interpreted to result from heat advected into the axial rift zone with local redistribution of this heat by hydrothermal convection. Normal to moderately high heat flow was measured in eastern Kenya between the rift zone and the coast. The regional heat flow in eastern Kenya is interpreted to be normal, with local shallow modification by groundwater flow eastward from the Kenya dome. These interpretations support a model of relatively young evolution of the asthenospheric anomaly beneath the Kenya rift zone, with the age of heating of the mantle at the Mono no older than about 10 Ma.

  18. Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - II. Microstructures and their implications for permeability and strength

    USGS Publications Warehouse

    Moore, Diane E.; Lockner, D.A.; Ito, H.; Ikeda, R.; Tanaka, H.; Omura, K.

    2009-01-01

    Samples of damage-zone granodiorite and fault core from two drillholes into the active, strike-slip Nojima fault zone display microstructures and alteration features that explain their measured present-day strengths and permeabilities and provide insight on the evolution of these properties in the fault zone. The least deformed damage-zone rocks contain two sets of nearly perpendicular (60-90?? angles), roughly vertical fractures that are concentrated in quartz-rich areas, with one set typically dominating over the other. With increasing intensity of deformation, which corresponds generally to increasing proximity to the core, zones of heavily fragmented rock, termed microbreccia zones, develop between prominent fractures of both sets. Granodiorite adjoining intersecting microbreccia zones in the active fault strands has been repeatedly fractured and locally brecciated, accompanied by the generation of millimeter-scale voids that are partly filled with secondary minerals. Minor shear bands overprint some of the heavily deformed areas, and small-scale shear zones form from the pairing of closely spaced shear bands. Strength and permeability measurements were made on core collected from the fault within a year after a major (Kobe) earthquake. Measured strengths of the samples decrease regularly with increasing fracturing and fragmentation, such that the gouge of the fault core and completely brecciated samples from the damage zone are the weakest. Permeability increases with increasing disruption, generally reaching a peak in heavily fractured but still more or less cohesive rock at the scale of the laboratory samples. Complete loss of cohesion, as in the gouge or the interiors of large microbreccia zones, is accompanied by a reduction of permeability by 1-2 orders of magnitude below the peak values. The core samples show abundant evidence of hydrothermal alteration and mineral precipitation. Permeability is thus expected to decrease and strength to increase somewhat

  19. Seasonal Changes of Arctic Sea Ice Physical Properties Observed During N-ICE2015: An Overview

    NASA Astrophysics Data System (ADS)

    Gerland, S.; Spreen, G.; Granskog, M. A.; Divine, D.; Ehn, J. K.; Eltoft, T.; Gallet, J. C.; Haapala, J. J.; Hudson, S. R.; Hughes, N. E.; Itkin, P.; King, J.; Krumpen, T.; Kustov, V. Y.; Liston, G. E.; Mundy, C. J.; Nicolaus, M.; Pavlov, A.; Polashenski, C.; Provost, C.; Richter-Menge, J.; Rösel, A.; Sennechael, N.; Shestov, A.; Taskjelle, T.; Wilkinson, J.; Steen, H.

    2015-12-01

    Arctic sea ice is changing, and for improving the understanding of the cryosphere, data is needed to describe the status and processes controlling current seasonal sea ice growth, change and decay. We present preliminary results from in-situ observations on sea ice in the Arctic Basin north of Svalbard from January to June 2015. Over that time, the Norwegian research vessel «Lance» was moored to in total four ice floes, drifting with the sea ice and allowing an international group of scientists to conduct detailed research. Each drift lasted until the ship reached the marginal ice zone and ice started to break up, before moving further north and starting the next drift. The ship stayed within the area approximately 80°-83° N and 5°-25° E. While the expedition covered measurements in the atmosphere, the snow and sea ice system, and in the ocean, as well as biological studies, in this presentation we focus on physics of snow and sea ice. Different ice types could be investigated: young ice in refrozen leads, first year ice, and old ice. Snow surveys included regular snow pits with standardized measurements of physical properties and sampling. Snow and ice thickness were measured at stake fields, along transects with electromagnetics, and in drillholes. For quantifying ice physical properties and texture, ice cores were obtained regularly and analyzed. Optical properties of snow and ice were measured both with fixed installed radiometers, and from mobile systems, a sledge and an ROV. For six weeks, the surface topography was scanned with a ground LIDAR system. Spatial scales of surveys ranged from spot measurements to regional surveys from helicopter (ice thickness, photography) during two months of the expedition, and by means of an array of autonomous buoys in the region. Other regional information was obtained from SAR satellite imagery and from satellite based radar altimetry. The analysis of the data collected has started, and first results will be

  20. Boron contents and isotopic compositions of the hydrothermally altered oceanic crust from the Troodos ophiolite, Cyprus

    NASA Astrophysics Data System (ADS)

    Matsukura, S.; Yamaoka, K.; Ishikawa, T.; Kawahata, H.

    2010-12-01

    The boron contents and isotopic compositions were determined for the hydrothermally altered oceanic crust through the Troodos ophiolite. The samples were represented by the International Crustal Research Drilling Group (ICRDG) drill-Holes CY1 (479m), CY2A (689m), CY4 (2263m), and selected outcrops along the Akaki river. Hole CY1 was composed upper and lower pillow lava, CY4 constituted sheeted dike complex and gabbro section, and the samples along Akaki river formed from pillow lava to sheeted dike complex. Hole CY2A was composed pillow lava and sheeted dike, drilled near Agrokipia ‘B’ deposit a stockwork type which completely enclosed within the lower pillow lava. The goal of this study is to understand the Boron geochemistry during hydrothermal alteration of the oceanic crust including hydrothermal ore deposit as Agrokipia ‘B’. The average boron contents of each sequence from Troodos ophiolite were pillow lava (63.2ppm), sheeted dike complex (4.5ppm), gabbro section (1.6ppm). But then, those of Oman ophiolite were 7.9ppm, 5.3ppm, 1.7ppm (Yamaoka et al., 2010 submitted). Thus, both of these ophiolites, the vertical profile of boron content decreased with depth, also the boron contents were much richer than fresh-MORB (0.5ppm) (Spivack and Edmond, 1987; Chaussidon and Jambon, 1994). This indicates boron rich of the altered oceanic crust were derived from seawater. And sheeted dike complex and gabbro section were similar value relatively, but pillow lava differed widely. These results may represent the difference of length being submarine, because these ophiolites were generated in deep water of the Tethys sea about 90Ma (Late Cretaceous) (Tilton et al., 1981; Mukasa and Ludden, 1987), and Oman ophiolite was obducted about 70Ma (Lanphere, 1981) but Troodos ophiolite uplifted about 10Ma (Middle Miocene) (Robertson and Woodcock, 1979).

  1. Ovariectomized Rats with Established Osteopenia have Diminished Mesenchymal Stem Cells in the Bone Marrow and Impaired Homing, Osteoinduction and Bone Regeneration at the Fracture Site.

    PubMed

    Tewari, Deepshikha; Khan, Mohd Parvez; Sagar, Nitin; China, Shyamsundar P; Singh, Atul K; Kheruka, Subhash C; Barai, Sukanta; Tewari, Mahesh C; Nagar, Geet K; Vishwakarma, Achchhe L; Ogechukwu, Omeje E; Bellare, Jayesh R; Gambhir, Sanjay; Chattopadhyay, Naibedya

    2015-04-01

    We investigated deleterious changes that take place in mesenchymal stem cells (MSC) and its fracture healing competence in ovariectomy (Ovx)-induced osteopenia. MSC from bone marrow (BM) of ovary intact (control) and Ovx rats was isolated. (99m)Tc-HMPAO (Technitium hexamethylpropylene amine oxime) labeled MSC was systemically transplanted to rats and fracture tropism assessed by SPECT/CT. PKH26 labeled MSC (PKH26-MSC) was bound in scaffold and applied to fracture site (drill-hole in femur metaphysis). Osteoinduction was quantified by calcein binding and microcomputed tomography. Estrogen receptor (ER) antagonist, fulvestrant was used to determine ER dependence of osteo-induction by MSC. BM-MSC number was strikingly reduced and doubling time increased in Ovx rats compared to control. SPECT/CT showed reduced localization of (99m)Tc-HMPAO labeled MSC to the fracture site, 3 h post-transplantation in Ovx rats as compared with controls. Post-transplantation, Ovx MSC labeled with PKH26 (Ovx PKH26-MSC) localized less to fracture site than control PKH26-MSC. Transplantation of either control or Ovx MSC enhanced calcein binding and bone volume at the callus of control rats over placebo group however Ovx MSC had lower efficacy than control MSC. Fulvestrant blocked osteoinduction by control MSC. When scaffold bound MSC was applied to fracture, osteoinduction by Ovx PKH26-MSC was less than control PKH26-MSC. In Ovx rats, control MSC/E2 treatment but not Ovx MSC showed osteoinduction. Regenerated bone was irregularly deposited in Ovx MSC group. In conclusion, Ovx is associated with diminished BM-MSC number and its growth, and Ovx MSC displays impaired engraftment to fracture and osteoinduction besides disordered bone regeneration.

  2. DATA QUALIFICATION REPORT: WATER-LEVEL DATA FROM THE NYE COUNTY EARLY WARNING DRILLING PROGRAM

    SciTech Connect

    F. H. Dove, P. Sanchez, and L. Saraka

    2000-04-21

    The objective of this work is to evaluate unqualified, water-level data gathered under the Nye County Early Warning Drilling Program (EWDP) and to determine whether the status of the data should be changed to ''qualified'' data in accordance with AP-SIII.2Q (Qualification of Unqualified Data and the Documentation of Rationale for Accepted Data). The corroboration method (as defined in Attachment 2 of AP-SIII.2Q) was implemented to qualify water-level data from Nye County measurements obtained directly from the Nye County Nuclear Waste Repository Program Office (NWRPO). Comparison of United States Geological Survey (USGS) measurements contained in DTN GS990608312312.003 with the Nye County water-level data has shown that the differences in water-level altitudes for the same wells are significantly less than 1 meter. This is an acceptable finding. Evaluation and recommendation criteria have been strictly applied to qualify Nye County measurements of water levels in selected wells measured by the USGS. However, the process of qualifying measured results by corroboration also builds confidence that the Nye County method for measurement of water levels is adequate for the intended use of the data (which is regional modeling). Therefore, it is reasonable to extend the term of ''qualified'' to water-level measurements in the remaining Nye County Phase I wells on the basis that the method has been shown to produce adequate results for the intended purpose of supporting large-scale modeling activities for the Yucca Mountain Project (YMP). The Data Qualification Team recommends the Nye County, water-level data contained in Appendix D of this report be designated as ''qualified''. These data document manual measurements of water-levels in eight (8) EWDP Phase I drillholes that were obtained prior to the field installation of continuous monitoring equipment.

  3. Exploration of geothermal energy in the western Pannonian basin

    NASA Astrophysics Data System (ADS)

    Tóth, T.; Wórum, G.; Nádor, A.; Uhrin, A.; Bíró, I.; Musitz, B.; Kóbor, M.; Dövényi, G.; Horváth, F.; Pap, N.

    2012-04-01

    The Pannonian basin has been a favourable site for hot water utilisation in spas since the medieval ages. Deliberate drilling activity started already more than a century ago and Hungary has become soon a center of balneological teraphy in Central Europe. The increasing interest for wellness resorts and mainly geothermal energy prospects has initiated recently the first systematic survey in the western Pannonian basin. The regional scale of the survey and access to a wealth of drillhole and seismic data led to the elaboration of novel research strategy. The Pannonian basin formed by rifting, major extension and subsidence of an Alpine orogenic terrain during the Middle Miocene. In the Late Miocene to Pliocene postrift period it was a big lake, which has been filled up by clastic materials transported by big rivers. Four regional aquifers can be defined in the basin from top to bottom: (1) delta front sand packages and their lateral equivalents (Újfalu Formation), (2) deep water delta front turbidite and sheet sand packages (Szolnok Formation), (3) Middle Miocene biogenic limestones and (4) fractured and karstified Mesozoic carbonates in the basement of Tertiary strata. In order to fully evaluate the geothermal potential of these aquifers seismic mapping was completed by borehole geology, well logs and flow tests. In addition a large and most complete geothermal data base available for the region has been prepared to facilitate integrated interpretation. A series of maps will be presented to illustrate the main results of the project and deliver the most important message: there are favourable conditions at large areas in the western Pannonian basin for multipurpose utilisation of geothermal energy.

  4. Dry Storage Casks Monitoring by Means of Ultrasonic Tomography

    NASA Astrophysics Data System (ADS)

    Salchak, Y.; Bulavinov, A.; Pinchuk, R.; Lider, A.; Bolotina, I.; Sednev, D.

    Spent nuclear fuel (SNF) is one of the most hazardous types of nuclear power plant waste. This fact emphasizes the importance of careful handling and storage of SNF. There are two current state-of-the art technologies of SNF storage facility: wet and dry. It is important to mention that IAEA does not determine which kind of handling strategy should be chosen, however it is noted that dry storage of SNF could be used for one hundred years. Mining and Chemical Enterprise (MCE) is one of the leading Russian companies that deals exclusively with the dry storage of SNF. This company has implemented a long-term storage scheme. At the same time MCE faced the challenge of nondestructive monitoring of the degradation process of structural material of cask and its sealing with weld seam. Currently, X-ray testing is used for this purpose but in order to provide an effective nonradioactive method of monitoring MCE has initiated a collaborative R&D project with TPU supported by the Russian Government. Ultrasonic industrial tomography technique was proposed as the solution. The method is based on application of phased and sparse arrays transducer with real-time visualization algorithm. Received acoustic data is processed and realized by means of Sampling Phased Array technology which is a collaborative development of TPU and I-Deal Technology, GmbH. The multichannel ultrasonic set-up of immersion control was assembled for performing testing of seven experimental specimens with representative defects (side drill-holes, notches, natural welding flaws). X-ray tomography of high-resolution was chosen as the reference method. All indications were successfully reconstructed in B and C-scans and 3D image. The next step is to automate the monitoring procedure completely and to introduce an evaluation tool for current flaw state and prediction of its further behavior.

  5. Geophysically inferred structural and lithologic map of the precambrian basement in the Joplin 1 degree by 2 degrees Quadrangle, Kansas and Missouri

    USGS Publications Warehouse

    McCafferty, Anne E.; Cordell, Lindrith E.

    1992-01-01

    This report is an analysis of regional gravity and aeromagnetic data that was carried out as part of a Conterminuous United States Mineral Assessment Program (CUSMAP) study of the Joplin 1° X 2° quadrangle, Kansas and Missouri. It is one in a series of reports representing a cooperative effort between the U.S. Geological Survey, Kansas Geological Survey, and Missouri Department of Natural Resources, Division of Geology and Land Survey. The work presented here is part of a larger project whose goal is to assess the mineral resource potential of the Paleozoic sedimentary section and crystalline basement within the quadrangle. Reports discussing geochemical, geological, and various other aspects of the study area are included in this Miscellaneous Field Studies Map series as MF-2125-A through MF-2125-E. Geophysical interpretation of Precambrian crystalline basement lithology and structure is the focus of this report. The study of the crystalline basement is complicated by the lack of exposures due to the presence of a thick sequence of Phanerozoic sedimentary cover. In areas where there are no outcrops, the geologist must turn to other indirect methods to assist in an understanding of the basement. Previous investigations of the buried basement in this region used available drill hole data, isotope age information, and regional geophysical data (Sims, 1990; Denison and others, 1984; Bickford and others, 1986). These studies were regional in scope and were presented at state and multistate scales. The work documented here used recently collected detailed gravity and aeromagnetic data to enhance the regional geologic knowledge of the area. Terrace-density and terrace-magnetization maps were calculated from the gravity and aeromagnetic data, leading directly to inferred physical-property (density and magnetization) maps. Once these maps were produced, the known geology and drill-hole data were reconciled with the physical-property maps to form a refined structural and

  6. Characterization of Unfractured Wall Rocks of TCDP Hole-B by Combination of Thermal-Property and TDR Measurements in Laboratory

    NASA Astrophysics Data System (ADS)

    Matsubayashi, O.; Lin, W.; Hirono, T.; Song, S.; Hung, J.

    2005-12-01

    As part of comprehensive studies of non-destructive physical properties of the cores from Hole-B drilled for the Taiwan Chelungpu-fault Drilling Project (TCDP), we have closely examined the data of combined thermal-property and TDR (water content) measurements which were carefully performed in laboratory. The purpose is to establish the bulk characteristics of thermal-properties in response to water content for the non-fractured part of the formations in TCDP Hole-B, so that we can properly assess the baseline thermal regime undisturbed by the thermal effect of fault activity. The sections studied in this work are unfractured parts of the cores (i) from 1142 to 1170m, and (ii) from 1200 to 1235m of Hole-B, which compose the wall rocks immediately below the fault zones of 1137m and 1194m depths, respectively. The instruments used were a transient type thermal-property analyzer with a half space probe for thermal conductivity, and a parallel-rod sensor probe for TDR water content, both are commercially available. Measured value of thermal conductivity ranges from 2.2 to 3.7 W/mK, while TDR water content value covers the approximate range of 15 to 26 percent. It is found by a correlation plot of thermal conductivity (Lamda) vs. water content (w) that within each section there is a very good negative correlation between the two for most of the good quality measurements, indicating thermal conductivity being primarily controlled by the volume ratio of solid grain to interstitial water. Such a relationship is reasonable and would be very useful in evaluation of thermal-properties of the whole section along the drillhole, and also for estimating the thermal-properties of fault zones in particular, which is always difficult to measure directly due to practical constrains.

  7. Buried Mesozoic rift basins of the U. S. middle Atlantic continental margin

    SciTech Connect

    Benson, R.N. )

    1991-08-01

    The Atlantic continental margin is one of the frontier areas for oil and gas exploration in the US. Most the activity has been offshore where Upper Jurassic-Lower Cretaceous siliciclastic and carbonate rocks have been the drilling objectives, with only one significant but noncommercial gas discover. Onshore, recent exploration activities have focused on early Mesozoic rift basins buried beneath the postrift sediments of the middle Atlantic coastal plain. Many of the basins are of interest because they contain fine-grained lacustrine rocks that have sufficient organic richness, if not lost through hydrocarbon generation, to be classified as source beds for oil or gas. Locations of inferred rift basins beneath the middle Atlantic coastal plain were determined by analysis of drill-hole data in combination with gravity anomaly and aeromagnetic maps. Two basins in Delaware and the Queen Anne basin of Maryland are imaged on a regional Vibroseis profile. Areas enclosing inferred rift basins in the offshore region were mapped from interpretation of seismic reflection profiles. Assuming that petroleum source beds are present in the basin (synrift) rocks, hydrocarbon-generation models (Lopatin method) indicate that for a basin just offshore Delaware that is buried by 7 km of postrift sediments, only dry gas would be present in reservoir rocks; for the Norfolk basin of the Virginia coast buried by only 3 km of postrift rocks, the upper few hundred meters of synrift rocks are still within the oil-generation window. The less deeply buried basins beneath the coastal plain likely are still within the oil window.

  8. Seismic analyses of the Triassic in Northern Germany for hydrogeothermal exploitation

    NASA Astrophysics Data System (ADS)

    Beilecke, Thies; Buness, Hermann; Musmann, Patrick; Schulz, Rüdiger

    2010-05-01

    Hydrothermal resources provide a large potential for the energy supply in Germany. However, the risk in reservoir detection is a major obstacle for its commercial utilization. Deep drillholes for a geothermal plant demand financial investments of several ten million Euros, without a comprehensive guarantee that the delivery and temperature of the required energy supply are met. A risk reduction is offered through the application of seismic techniques that have been developed in the oil and gas industry. Yet, in the geothermic business the topic of exploration cost reduction often has a higher priority. This is the reason why the necessity of 3D seismic is being repeatedly questioned. However, a seismic dataset from northern Germany currently being studied reveals a complicated fault zone network that has been partly generated by salt tectonics. It would be unrepresentable without the aid of 3D seismic. For fault detection in particular, time slices of the signal variance with a short time window and few traces have proven their suitability. In northern Germany some strata of the middle and lower Triassic are being regarded as hydrogeothermal reservoirs because of their temperature and permeability. Typically, areal amplitude distributions are being analyzed for anomalies. In the referred dataset, such areal analyses are however degraded by the intercalated complicated fault zone structures. In particular, in large sections of the lower Triassic the fault zone detection with signal variance calculation is also poor because of small seismic reflection amplitudes. It can be concluded that in some cases, 3D seismic offers the only way to recognize the subsurface structures. On the other hand, there are cases where even 3D seismic data needs carefully guided analysis instead of automatic algorithms.

  9. Clustering of induced earthquakes in Oklahoma and the relation to subsurface geologic features

    NASA Astrophysics Data System (ADS)

    Shah, A. K.; Keller, G. R., Jr.

    2015-12-01

    Recent research shows that a significant amount of seismic activity in Oklahoma since 2009 is likely related to fluid injection. Seismicity has been observed to generally increase in areas where injection volume and rates are highest but there is a significant amount of variation, with nearby areas experiencing notably different amounts of seismicity. Likely contributors to these differences are the presence of optimally oriented faults and differences in rock permeability structure since rocks with higher permeability are more likely to experience pore fluid pressure changes that can bring faults closer to failure. Most earthquakes occur at depths of ~4-8 km, within crystalline rock of the mid-Proterozoic western granite-rhyolite terrane. Within this terrane, drill-hole data show instances of mafic intrusive rocks that may in part be related to the mid-continent rift. To better understand relations between subsurface geology and seismicity, we reprocessed 1970's NURE airborne magnetic data. The 5-8-km line spacing of the surveys is coarse, but the processed data show subtle, ~20-35-km long lineaments trending mostly NNW but also NW and NE. Some of these correspond to mapped faults; others are interpreted to represent faults or folds. In some areas the lineaments correspond to earthquake locations, but the magnetic data are often too coarse to establish a clear correspondence. The magnetic maps also show rounded highs that are located near sites where drilling has encountered mafic rock, strongly suggesting that the highs represent mafic intrusions. We find that many earthquakes cluster around or near the edges of the magnetic highs but much less frequently over them, even when they are located close to high-volume injection wells. We hypothesize that the rounded magnetic highs represent mafic intrusions with decreased permeability. In contrast, contacts at the edges of these intrusions may have higher permeability and are thus more likely to experience seismicity.

  10. Geophysical Framework Investigations Influencing Ground-Water Resources in East-Central Nevada and West-Central Utah

    USGS Publications Warehouse

    Watt, Janet T.; Ponce, David A.

    2007-01-01

    A geophysical investigation was undertaken as part of an effort to characterize the geologic framework influencing ground-water resources in east-central Nevada and west-central Utah. New gravity data were combined with existing aeromagnetic, drill-hole, and geologic data to help determine basin geometry, infer structural features, estimate depth to pre-Cenozoic basement rocks, and further constrain the horizontal extents of exposed and buried plutons. In addition, a three-dimensional (3D) geologic model was constructed to help illustrate the often complex geometries of individual basins and aid in assessing the connectivity of adjacent basins. In general, the thirteen major valleys within the study area have axes oriented north-south and frequently contain one or more sub-basins. These basins are often asymmetric and typically reach depths of 2 km. Analysis of gravity data helped delineate geophysical lineaments and accommodation zones. Structural complexities may further compartmentalize ground-water flow within basins and the influence of tectonics on basin sedimentation further complicates their hydrologic properties. The horizontal extent of exposed and, in particular, buried plutons was estimated over the entire study area. The location and subsurface extents of these plutons will be very important for regional water resource assessments, as these features may act as either barriers or pathways for groundwater flow. A previously identified basement gravity low strikes NW within the study area and occurs within a highly extended terrane between the Butte and Confusion synclinoria. Evidence from geophysical, geologic, and seismic reflection data suggests relatively lower density plutonic rocks may extend to moderate crustal depths and rocks of similar composition may be the source of the entire basement gravity anomaly.

  11. Status of volcanic hazard studies for the Nevada Nuclear Waste Storage Investigations. Volume II

    SciTech Connect

    Crowe, B.M.; Wohletz, K.H.; Vaniman, D.T.; Gladney, E.; Bower, N.

    1986-01-01

    Volcanic hazard investigations during FY 1984 focused on five topics: the emplacement mechanism of shallow basalt intrusions, geochemical trends through time for volcanic fields of the Death Valley-Pancake Range volcanic zone, the possibility of bimodal basalt-rhyolite volcanism, the age and process of enrichment for incompatible elements in young basalts of the Nevada Test Site (NTS) region, and the possibility of hydrovolcanic activity. The stress regime of Yucca Mountain may favor formation of shallow basalt intrusions. However, combined field and drill-hole studies suggest shallow basalt intrusions are rare in the geologic record of the southern Great Basin. The geochemical patterns of basaltic volcanism through time in the NTS region provide no evidence for evolution toward a large-volume volcanic field or increases in future rates of volcanism. Existing data are consistent with a declining volcanic system comparable to the late stages of the southern Death Valley volcanic field. The hazards of bimodal volcanism in this area are judged to be low. The source of a 6-Myr pumice discovered in alluvial deposits of Crater Flat has not been found. Geochemical studies show that the enrichment of trace elements in the younger rift basalts must be related to an enrichment of their mantle source rocks. This geochemical enrichment event, which may have been metasomatic alteration, predates the basalts of the silicic episode and is, therefore, not a young event. Studies of crater dimensions of hydrovolcanic landforms indicate that the worst case scenario (exhumation of a repository at Yucca Mountain by hydrovolcanic explosions) is unlikely. Theoretical models of melt-water vapor explosions, particularly the thermal detonation model, suggest hydrovolcanic explosion are possible at Yucca Mountain. 80 refs., 21 figs., 5 tabs.

  12. Integrated geophysical imaging of a concealed mineral deposit: a case study of the world-class Pebble porphyry deposit in southwestern Alaska

    USGS Publications Warehouse

    Shah, Anjana K.; Bedrosian, Paul A.; Anderson, Eric D.; Kelley, Karen D.; Lang, James

    2013-01-01

    We combined aeromagnetic, induced polarization, magnetotelluric, and gravity surveys as well as drillhole geologic, alteration, magnetic susceptibility, and density data for exploration and characterization of the Cu-Au-Mo Pebble porphyry deposit. This undeveloped deposit is almost completely concealed by postmineralization sedimentary and volcanic rocks, presenting an exploration challenge. Individual geophysical methods primarily assist regional characterization. Positive chargeability and conductivity anomalies are observed over a broad region surrounding the deposit, likely representing sulfide minerals that accumulated during multiple stages of hydrothermal alteration. The mineralized area occupies only a small part of the chargeability anomaly because sulfide precipitation was not unique to the deposit, and mafic rocks also exhibit strong chargeability. Conductivity anomalies similarly reflect widespread sulfides as well as water-saturated glacial sediments. Mineralogical and magnetic susceptibility data indicate magnetite destruction primarily within the Cu-Au-Mo mineralized area. The magnetic field does not show a corresponding anomaly low but the analytic signal does in areas where the deposit is not covered by postmineralization igneous rocks. The analytic signal shows similar lows over sedimentary rocks outside of the mineralized area, however, and cannot uniquely distinguish the deposit. We find that the intersection of positive chargeability anomalies with analytic signal lows, indicating elevated sulfide concentrations but low magnetite at shallow depths, roughly delineates the deposit where it is covered only by glacial sediments. Neither chargeability highs nor analytic signal lows are present where the deposit is covered by several hundred meters of sedimentary and volcanic rocks, but a 3D resistivity model derived from magnetotelluric data shows a corresponding zone of higher conductivity. Gravity data highlight geologic features within the

  13. On-going post-glacial reverse faulting in Scandinavia, field evidence from Finnmark, northern Norway

    NASA Astrophysics Data System (ADS)

    Pascal, C.; Gabrielsen, R. H.; Cloetingh, S.

    2003-04-01

    Deglaciation in Scandinavia was followed by a dramatic seismic burst as evidenced by the numerous post-glacial fault scarps documented in Lapland. The post-glacial faults usually show reverse slip and trend NE-SW. This climax of earthquake activity is believed to have been triggered by the sudden removal of the glacial load and Scandinavia is considered tectonically quiet present-day. Roberts (1991, 2000) observed in Finnmark, northern Norway, various boreholes offset by reverse faults with few cm of displacement. It was unclear if these reverse faults represented active faulting or stress-relief features. Following Roberts, a field work campaign was conducted in July 2002. The purpose was to examine boreholes along road-sections and in quarries of Finnmark. About 20 drill-hole reverse offsets ranging from a few mm up to 14 cm were measured in western and central Finnmark. The azimuth of the associated slip vectors was found to be consistent towards the E-SE. In the Ifjord area, central Finnmark, some of the fault planes offsetting boreholes show continuous mud-smears of ~10 cm long. In the same area, additional observations include two reverse faults with 2 cm of offset each. The first one disrupts a wall road worked out in 1986. The second reverse fault disrupts a natural scarp presumably of glacial origin. In direct connection with these observations numerous rock blocks are seen to disrupt the ground surface. The most impressive ones are more than 1 m high. The blocks are bounded by pre-existing fractures and cleavage and appear to be displaced to the SE as well. These "standing-stones" are interpreted as small-scale tectonic push-ups. Field observations argue for active reverse faulting in Finnmark. The documented fault motions agree with a regional NW-SE compression induced by the North Atlantic ridge-push.

  14. Assessment of the potential for karst in the Rustler Formation at the WIPP site.

    SciTech Connect

    Lorenz, John Clay

    2006-01-01

    This report is an independent assessment of the potential for karst dissolution in evaporitic strata of the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site. Review of the available data suggests that the Rustler strata thicken and thin across the area in depositional patterns related to lateral variations in sedimentary accommodation space and normal facies changes. Most of the evidence that has been offered for the presence of karst in the subsurface has been used out of context, and the different pieces are not mutually supporting. Outside of Nash Draw, definitive evidence for the development of karst in the Rustler Formation near the WIPP site is limited to the horizon of the Magenta Member in drillhole WIPP-33. Most of the other evidence cited by the proponents of karst is more easily interpreted as primary sedimentary structures and the localized dissolution of evaporitic strata adjacent to the Magenta and Culebra water-bearing units. Some of the cited evidence is invalid, an inherited baggage from studies made prior to the widespread knowledge of modern evaporite depositional environments and prior to the existence of definitive exposures of the Rustler Formation in the WIPP shafts. Some of the evidence is spurious, has been taken out of context, or is misquoted. Lateral lithologic variations from halite to mudstone within the Rustler Formation under the WIPP site have been taken as evidence for the dissolution of halite such as that seen in Nash Draw, but are more rationally explained as sedimentary facies changes. Extrapolation of the known karst features in Nash Draw eastward to the WIPP site, where conditions are and have been significantly different for half a million years, is unwarranted. The volumes of insoluble material that would remain after dissolution of halite would be significantly less than the observed bed thicknesses, thus dissolution is an unlikely explanation for the lateral variations from halite to mudstone and siltstone

  15. Instruments and MethodsAutonomous underwater vehicles (AUVs) and investigations of the ice-ocean interface in Antarctic and Arctic waters

    NASA Astrophysics Data System (ADS)

    Dowdeswell, J. A.; Evans, J.; Mugford, R.; Griffiths, G.; McPhail, S.; Millard, N.; Stevenson, P.; Brandon, M. A.; Banks, C.; Heywood, K. J.; Price, M. R.; Dodd, P. A.; Jenkins, A.; Nicholls, K. W.; Hayes, D.; Abrahamsen, E. P.; Tyler, P.; Bett, B.; Jones, D.; Wadhams, P.; Wilkinson, J. P.; Stansfield, K.; Ackley, S.

    Limitations of access have long restricted exploration and investigation of the cavities beneath ice shelves to a small number of drillholes. Studies of sea-ice underwater morphology are limited largely to scientific utilization of submarines. Remotely operated vehicles, tethered to a mother ship by umbilical cable, have been deployed to investigate tidewater-glacier and ice-shelf margins, but their range is often restricted. The development of free-flying autonomous underwater vehicles (AUVs) with ranges of tens to hundreds of kilometres enables extensive missions to take place beneath sea ice and floating ice shelves. Autosub2 is a 3600 kg, 6.7 m long AUV, with a 1600 m operating depth and range of 400 km, based on the earlier Autosub1 which had a 500m depth limit. A single direct-drive d.c. motor and five-bladed propeller produce speeds of 1-2 ms-1. Rear-mounted rudder and stern-plane control yaw, pitch and depth. The vehicle has three sections. The front and rear sections are free-flooding, built around aluminium extrusion space-frames covered with glass-fibre reinforced plastic panels. The central section has a set of carbon-fibre reinforced plastic pressure vessels. Four tubes contain batteries powering the vehicle. The other three house vehicle-control systems and sensors. The rear section houses subsystems for navigation, control actuation and propulsion and scientific sensors (e.g. digital camera, upward-looking 300 kHz acoustic Doppler current profiler, 200 kHz multibeam receiver). The front section contains forward-looking collision sensor, emergency abort, the homing systems, Argos satellite data and location transmitters and flashing lights for relocation as well as science sensors (e.g. twin conductivity-temperature-depth instruments, multibeam transmitter, sub-bottom profiler, AquaLab water sampler). Payload restrictions mean that a subset of scientific instruments is actually in place on any given dive. The scientific instruments carried on Autosub

  16. Integrated 3D geophysical and geological modelling of the Hercynian Suture Zone in the Champtoceaux area (south Brittany, France)

    NASA Astrophysics Data System (ADS)

    Martelet, G.; Calcagno, P.; Gumiaux, C.; Truffert, C.; Bitri, A.; Gapais, D.; Brun, J. P.

    2004-04-01

    This paper combines geological knowledge and geophysical imagery at the crustal scale to model the 3D geometry of a segment of the Hercynian suture zone of western Europe in the Champtoceaux area (Brittany, France). The Champtoceaux complex consists of a stack of metamorphic nappes of gneisses and micaschists, with eclogite-bearing units. The exhumation of the complex, during early Carboniferous times, was accompanied by deformation during regional dextral strike-slip associated with a major Hercynian shear zone (the South Armorican Shear Zone, SASZ). Dextral shearing produced a km-scale antiformal structure with a steeply dipping axial plane and a steeply eastward plunging axis. Armor 2 deep seismic profile shows that the regional structure was cut by a set of faults with northward thrusting components. Based on the seismic constraint, direct 2D crustal-scale modelling was performed throughout the Champtoceaux fold on seven radial gravity profiles, also using geological data, and density measurements from field and drill-hole samples. The 3D integration of the cross-sections, the digitised geological map, and the structural information (foliation dips) insure the geometrical and topological consistency of all sources of data. The 2D information is interpolated to the whole 3D space using a geostatistical analysis. Finally, the 3D gravity contribution of the resulting model is computed taking into account densities for each modelled geological body and compared to the Bouguer anomaly. The final 3D model is thus compatible with the seismic and gravity data, as well as with geological data. Main geological results derived from the modelling are (i) the overall 3D geometry of the south dipping thrust system interpreted on the seismic profile emphasises northward thrusting and folding of the Champtoceaux complex which was coeval with strike-slip along the South Armorican Shear Zone; (ii) the gravity modelling suggests the presence of a relatively dense body below the

  17. Structurally controlled volcanism and contrasting types of mineralization, Tuscarora mining district and vicinity, Nevada

    SciTech Connect

    Wright, B.A. ); Boden, D.R.; Struhsacker, E.M.

    1993-04-01

    The Tuscarora district lies within an Eocene volcanic field that covers [approximately]800 km[sup 2] in the northern Tuscarora Mountains in northwest Elko County. Geologic mapping of [approximately]100 km[sup 2] at Tuscarora and vicinity and new K-Ar age determinations reveal a complex, rapidly evolving volcanic history. Volcanism began with construction of a poorly preserved andesitic stratovolcano(s) at 42+ Ma. Subsequently, the 7- by 10-km Mt. Blitzen graben developed between 41--42 Ma. The graben filled with the tuff of Mt. Blitzen. Graben subsidence occurred along NE to ENE and NNW to NW faults, and a variety of dikes and plugs, including the 39.8-Ma Mt. Neva granodiorite, locally intruded the bounding faults. Rocks of the graben strike NE, dip moderately to steeply, and are cut by penecontemporaneous NE-striking dikes, indicating that the graben formed in response to NW-SE-directed extension. Collapse of the rhyolitic Big Cottonwood Canyon caldera truncated the northern part of the Mt. Blitzen graben between 40.6 and 41.0 Ma. Rocks of the Mt. Blitzen graben range from silicic andesite to rhyodacite, whereas rocks of the Big Cottonwood Canyon caldera are rhyolite and high-silica rhyolite. Mineralization at Tuscarora occurs near the southeast margin of the Mt. Blitzen graben and mainly as quartz-adularia veins filling ENE, N, and NW faults. New K-Ar analyses on adularia from the Dexter and Grand Prize veins yield ages of 38.9 and 39.9 Ma, respectively. Although closely developed in space and time, the Ag-rich, base-metal-bearing mineralization, characterized by the Grand Prize vein, and the Au-rich, base-metal-poor Dexter vein zone likely represent separate, unrelated hydrothermal events. In general, alteration in the district, as observed in outcrops and drill-hole cuttings, changes from fault or fracture controlled in the north to more pervasive in the Dexter pit area and eastward under pediment.

  18. Sediments overlying exhumed continental mantle: a proxy for the morphotectonic evolution of the Ocean Continent Transition in magma-poor rifted margins

    NASA Astrophysics Data System (ADS)

    Karpoff, A. M.; Manatschal, G.; Bernoulli, D.; Lagabrielle, Y.

    2003-04-01

    Observations from ancient and present-day magma-poor rifted margins in the Alps and Iberia provide compelling evidence that within the ocean-continent transition (OCT) crustal and sub-continental mantle rocks were exhumed along downward-concave faults which were active during final rifting and accommodated high amounts of extension. The faults are overlain by stranded allochthons of continental origin, pillow basalts, and pelagic sediments, i.e. radiolarites and/or pelagic limestones, and hemipelagic shales. Associated with the faults are tectono-sedimentary breccias and various types of clastic sediments, ranging from debris flow deposits to laminated sandstone, and quartz-rich silt- and claystones. Mineralogical studies of the shales, red jaspers, and red cherts overlying mantle rocks in the Alps of eastern Switzerland are typically quartz-rich and contain variable amounts of phyllosilicates (chlorite and/or mica), feldspars, ± calcite, oxides, pyrite, and epidote. Their main geochemical characteristic is the high silica and low iron and manganese content, which contrasts with that of "metalliferous" Fe-Mn-Si-rich sediments overlying oceanic basalts. High Fe, Ba, REE, U/Th values measured in black shales overlying mantle rocks in the proximal OCT point to a strong hydrothermal activity associated with mantle exhumation. The clastic sediments in the OCT show a wide range of compositions related to mantle, continental crust, and/or pelagic contributions. In particular, the fact that these sediments contain abundant material derived from continental basement rocks seems at odds with their occurrence on top of tectonized mantle rocks. However, drilling in the Iberia margin, where tectonized mantle rocks are overlain by sedimentary breccias (e.g. ODP Sites 1068, 1070), shed new light on the observations in the Alps. Based on drill-hole and seismic data, the tectono-sedimentary breccias drilled in the OCT off Iberia may be interpreted to result from a conveyor

  19. Geologic map and structure sections of the Clear Lake Volcanics, Northern California

    USGS Publications Warehouse

    Hearn, B.C.; Donnelly-Nolan, J. M.; Goff, F.E.

    1995-01-01

    . Thickness for most units is estimated from topographic relief except where drill-hole data were available.

  20. Cataclasis and processes of particle size reduction

    NASA Astrophysics Data System (ADS)

    Blenkinsop, Tom G.

    1991-05-01

    The particle size distribution (P.S.D.) of fragmented geological materials is affected by the fragmentation process, initial size distribution, number of fracturing events, energy input, strain, and confining pressure. A summary of literature shows that the fractal dimension ( D) of the P.S.D. is increased by the number of fracturing events, energy input, strain, and confining pressure. Cenozoic cataclasis of granite, granodiorites, gneisses and arkose seen in cores from the Cajon Pass drillhole, southern California, produced P.S.D.s with values of D that varied from 1.88 to 3.08. Each rock type has a characteristic and more limited range of D. Areas of dilatant texture and mode I fracture-fillings have low average values (2.32 and 2.37) compared to an average value of 2.67 in shear fracture-fillings D has a good inverse correlation with average particle size. Data from fault rocks in the San Gabriel fault zone, southern California ( Anderson et al., 1983) have been reanalyzed to show that values of D are higher (2.10 5.52) and average particle size is lower than the Cajon Pass samples, but the ranges of values overlap, and the inverse correlation between D and average particle size is extended. Microstructural observations combined with these results suggest that three processes contributed to particle size reduction during cataclasis. The first process of feldspar alteration, which leads to low values of D, has not been previously recognized. The second process is probably constrained comminution ( Sammis et al., 1987), since the average D in shear fracture-fillings is close to the value of 2.58 predicted by this theory. A further stage of particle size reduction is demonstrated by an increase of D with cataclasis. This third process is selective fracture of larger particles, which may also operate during localization and the cataclastic flow-to-faulting transition as observed in experiments. A transition from constrained comminution to selective fracture of

  1. A multidisciplinary study for mining landscape reclamation: A study case on two tailing ponds in the Region of Murcia (SE Spain)

    NASA Astrophysics Data System (ADS)

    Martínez-Pagán, P.; Faz, A.; Acosta, J. A.; Carmona, D. M.; Martínez-Martínez, S.

    The aim of this work was to evaluate the mobility of Pb, Cu, Zn and Cd in two tailing ponds (Brunita and San Cristobal) from mine activity in the Southeast of Spain before applying reclamation measures for reducing the risk for human and environment. To achieve this objective, five profiles of electrical resistivity imaging (ERI) in Brunita, three profiles in San Cristobal, a drill-hole in each pond and undisturbed columns amended with marble waste for leaching experiments were taken. Results showed that all layers of the two ponds exceed the maximum Pb and Zn concentrations allowed by the selected European legislations. In both ponds, the mixture of tailings with natural soil is the main process involved in soil pollution under the ponds. However, due to high pH in the substrate the metals are precipitated and their solubility reduced, therefore there is not a risk of leaching to groundwater. At Brunita tailing pond electrical resistivity sections displayed some lower electrical resistivity region into the bedrock which has been described as some fault occurrence due to breaking events suffered by the tailing pond. At San Cristobal tailing pond geochemical results were consistent with data obtained by the electrical resistivity imaging (ERI) method where no evidence of faults or cracks into the bedrock and the ponds were observed. Therefore, no preferential pathways of acid mine drainages containing heavy metals were reported. Leaching experiments indicated that, after 11 weeks of leaching, amended and control columns showed comparable values of pH (∼2.3) and similar trends for Cu, Cd and Zn, with a very drastic decrease up to week 3 and thereafter the tendency was to reach near steady-state conditions. In contrast, the evolution of Pb showed that marble amended reduces significantly its concentration over time compared with the control. In accordance with the results, future reclamation action should be based on the reduction of heavy metal mobility by means of

  2. Tectonics and geology of spreading ridge subduction at the Chile Triple Junction: a synthesis of results from Leg 141 of the Ocean Drilling Program

    USGS Publications Warehouse

    Behrmann, J.H.; Lewis, S.D.; Cande, S.C.

    1994-01-01

    An active oceanic spreading ridge is being subducted beneath the South American continent at the Chile Triple Junction. This process has played a major part in the evolution of most of the continental margins that border the Pacific Ocean basin. A combination of high resolution swath bathymetric maps, seismic reflection profiles and drillhole and core data from five sites drilled during Ocean Drilling Program (ODP) Leg 141 provide important data that define the tectonic, structural and stratigraphic effects of this modern example of spreading ridge subduction. A change from subduction accretion to subduction erosion occurs along-strike of the South American forearc. This change is prominently expressed by normal faulting, forearc subsidence, oversteepening of topographic slopes and intensive sedimentary mass wasting, overprinted on older signatures of sediment accretion, overthrusting and uplift processes in the forearc. Data from drill sites north of the triple junction (Sites 859-861) show that after an important phase of forearc building in the early to late Pliocene, subduction accretion had ceased in the late Pliocene. Since that time sediment on the downgoing oceanic Nazca plate has been subducted. Site 863 was drilled into the forearc in the immediate vicinity of the triple junction above the subducted spreading ridge axis. Here, thick and intensely folded and faulted trench slope sediments of Pleistocene age are currently involved in the frontal deformation of the forearc. Early faults with thrust and reverse kinematics are overprinted by later normal faults. The Chile Triple Junction is also the site of apparent ophiolite emplacement into the South American forearc. Drilling at Site 862 on the Taitao Ridge revealed an offshore volcanic sequence of Plio-Pleistocene age associated with the Taitao Fracture Zone, adjacent to exposures of the Pliocene-aged Taitao ophiolite onshore. Despite the large-scale loss of material from the forearc at the triple junction

  3. Fluid-deposited graphitic inclusions in quartz: Comparison between KTB (German Continental Deep-Drilling) core samples and artificially reequilibrated natural inclusions

    USGS Publications Warehouse

    Pasteris, J.D.; Chou, I.-Ming

    1998-01-01

    We used Raman microsampling spectroscopy (RMS) to determine the degree of crystallinity of minute (2-15 ??m) graphite inclusions in quartz in two sets of samples: experimentally reequilibrated fluid inclusions in a natural quartz grain and biotite-bearing paragneisses from the KTB deep drillhole in SE Germany. Our sequential reequilibration experiments at 725??C on initially pure CO2 inclusions in a quartz wafer and the J. Krautheim (1993) experiments at 900-1100??C on organic compounds heated in gold or platinum capsules suggest that, at a given temperature, (1) fluid-deposited graphite will have a lower crystallinity than metamorphosed organic matter and (2) that the crystallinity of fluid-deposited graphite is affected by the composition of the fluid from which it was deposited. We determined that the precipitation of more-crystalline graphite is favored by lower fH2 (higher fO2), and that the crystallinity of graphite is established by the conditions (including gas fugacities) that pertain as the fluid first reaches graphite saturation. Graphite inclusions within quartz grains in the KTB rocks show a wide range in crystallinity index, reflecting three episodes of carbon entrapment under different metamorphic conditions. Isolated graphite inclusions have the spectral properties of totally ordered, completely crystalline graphite. Such crystallinity suggests that the graphite was incorporated from the surrounding metasedimentary rocks, which underwent metamorphism at upper amphibolite-facies conditions. Much of the fluid-deposited graphite in fluid inclusions, however, shows some spectral disorder. The properties of that graphite resemble those of experimental precipitates at temperatures in excess of 700??C and at elevated pressures, suggesting that the inclusions represent precipitates from C-O-H fluids trapped under conditions near those of peak metamorphism at the KTB site. In contrast, graphite that is intimately associated with chlorite and other

  4. A novel therapeutic approach with Caviunin-based isoflavonoid that en routes bone marrow cells to bone formation via BMP2/Wnt-β-catenin signaling.

    PubMed

    Kushwaha, P; Khedgikar, V; Gautam, J; Dixit, P; Chillara, R; Verma, A; Thakur, R; Mishra, D P; Singh, D; Maurya, R; Chattopadhyay, N; Mishra, P R; Trivedi, R

    2014-09-18

    Recently, we reported that extract of Dalbergia sissoo made from leaves and pods have antiresorptive and bone-forming effects. The positive skeletal effect attributed because of active molecules present in the extract of Dalbergia sissoo. Caviunin 7-O-[β-D-apiofuranosyl-(1-6)-β-D-glucopyranoside] (CAFG), a novel isoflavonoid show higher percentage present in the extract. Here, we show the osteogenic potential of CAFG as an alternative for anabolic therapy for the treatment of osteoporosis by stimulating bone morphogenetic protein 2 (BMP2) and Wnt/β-catenin mechanism. CAFG supplementation improved trabecular micro-architecture of the long bones, increased biomechanical strength parameters of the vertebra and femur and decreased bone turnover markers better than genistein. Oral administration of CAFG to osteopenic ovariectomized mice increased osteoprogenitor cells in the bone marrow and increased the expression of osteogenic genes in femur and show new bone formation without uterine hyperplasia. CAFG increased mRNA expression of osteoprotegerin in bone and inhibited osteoclast activation by inhibiting the expression of skeletal osteoclastogenic genes. CAFG is also an effective accelerant for chondrogenesis and has stimulatory effect on the repair of cortical bone after drill-hole injury at the tissue, cell and gene level in mouse femur. At cellular levels, CAFG stimulated osteoblast proliferation, survival and differentiation. Signal transduction inhibitors in osteoblast demonstrated involvement of p-38 mitogen-activated protein kinase pathway stimulated by BMP2 to initiate Wnt/β-catenin signaling to reduce phosphorylation of GSK3-β and subsequent nuclear accumulation of β-catenin. Osteogenic effects were abrogated by Dkk1, Wnt-receptor blocker and FH535, inhibitor of TCF-complex by reduction in β-catenin levels. CAFG modulated MSC responsiveness to BMP2, which promoted osteoblast differentiation via Wnt/β-catenin mechanism. CAFG at 1 mg/kg(/)day dose in

  5. Explaining the thick crust in Paraná basin, Brazil, with satellite GOCE gravity observations

    NASA Astrophysics Data System (ADS)

    Mariani, Patrizia; Braitenberg, Carla; Ussami, Naomi

    2013-08-01

    Seismologic observations in the last decades have shown that the crustal thickness in Paraná basin locally is over 40 km thick, which is a greater value than expected by the simple isostatic model considering the topographic load. The goal of this work is to explain this apparent discrepancy by modeling the internal crustal density anomalies through the gravity field. We use the latest Earth Gravity Model derived from the observations of the GOCE satellite mission, to retrieve the gravity anomaly and correct it for topographic effects, thus obtaining the Bouguer field. We then model the gravity effect of known stratigraphic units and of the seismological crustal thickness. The large Paraná basin comprises over 3500 m of Paleozoic sedimentary sequence with density between 2400 and 2600 kg/m3. During the Early Cretaceous the same basin was affected by a large amount of igneous activity with a volume of over 0.1 Mkm3. The flood basalt volcanism is known as the Serra Geral Formation, and has a maximum thickness of 1500 m. The stratigraphic units of the basin are topped by post-volcanic deposits of the Bauru Group, of about 300 m thickness, located in the northern part of the basin. The density and thickness of the sedimentary sequence are constrained by sonic logs of drill-holes and exploration seismic. We use the crustal thickness estimated from the newest seismological results for South America to calculate its gravity effect. Further we model the isostatic crustal thickness variation, allowing the comparison between a seismological Moho, an isostatic Moho, and a gravity-based Moho. We find that there is a clear positive Bouguer residual anomaly located in the northern and southern part of the Paraná basin, indicating the presence of a hidden mass, not considered up to now. We propose a model that explains this mass as magmatic rock, probably gabbro in lower crust, with density contrast of 200 kg/m3 and thickness of more than 10 km, thus demonstrating that the

  6. Subsidence of Surtsey volcano, 1967-1991

    USGS Publications Warehouse

    Moore, J.G.; Jakobsson, S.; Holmjarn, J.

    1992-01-01

    The Surtsey marine volcano was built on the southern insular shelf of Iceland, along the seaward extension of the east volcanic zone, during episodic explosive and effusive activity from 1963 to 1967. A 1600-m-long, east-west line of 42 bench marks was established across the island shortly after volcanic activity stopped. From 1967 to 1991 a series of leveling surveys measured the relative elevation of the original bench marks, as well as additional bench marks installed in 1979, 1982 and 1985. Concurrent measurements were made of water levels in a pit dug on the north coast, in a drill hole, and along the coastline exposed to the open ocean. These surveys indicate that the dominant vertical movement of Surtsey is a general subsidence of about 1.1??0.3 m during the 24-year period of observations. The rate of subsidence decreased from 15-20 cm/year for 1967-1968 to 1-2 cm/year in 1991. Greatest subsidence is centered about the eastern vent area. Through 1970, subsidence was locally greatest where the lava plain is thinnest, adjacent to the flanks of the eastern tephra cone. From 1982 onward, the region closest to the hydrothermal zone, which is best developed in the vicinity of the eastern vent, began showing less subsidence relative to the rest of the surveyed bench marks. The general subsidence of the island probably results from compaction of the volcanic material comprising Surtsey, compaction of the sea-floor sediments underlying the island, and possibly downwarping of the lithosphere due to the laod of Surtsey. The more localized early downwarping near the eastern tephra cone is apparently due to greater compaction of tephra relative to lava. The later diminished local subsidence near the hydrothermal zone is probably due to a minor volume increase caused by hydrous alteration of glassy tephra. However, this volume increase is concentrated at depth beneath the bottom of the 176-m-deep cased drillhole. ?? 1992 Springer-Verlag.

  7. Fracture distribution and porosity in a fault-bound hydrothermal system (Grimsel Pass, Swiss Alps)

    NASA Astrophysics Data System (ADS)

    Egli, Daniel; Küng, Sulamith; Baumann, Rahel; Berger, Alfons; Baron, Ludovic; Herwegh, Marco

    2017-04-01

    The spatial distribution, orientation and continuity of brittle and ductile structures strongly control fluid pathways in a rock mass by joining existing pores and creating new pore space (fractures, joints) but can also act as seals to fluid flow (e.g. ductile shear zones, clay-rich fault gouges). In long-lived hydrothermal systems, permeability and the related fluid flow paths are therefore dynamic in space and time. Understanding the evolution and behaviour of naturally porous and permeable rock masses is critical for the successful exploration and sustainable exploitation of hydrothermal systems and can advance methods for planning and implementation of enhanced geothermal systems. This study focuses on an active fault-bound hydrothermal system in the crystalline basement of the Aar Massif (hydrothermal field Grimsel Pass, Swiss Alps) that has been exhumed from few kilometres depth and which documents at least 3 Ma of hydrothermal activity. The explored rock unit of the Aar massif is part of the External Crystalline Massifs that hosts a multitude of thermal springs on its southern border in the Swiss Rhône valley and furthermore represents the exhumed equivalent of potentially exploitable geothermal reservoirs in the deep crystalline subsurface of the northern Alpine foreland basin. This study combines structural data collected from a 125 m long drillhole across the hydrothermal zone, the corresponding drill core and surface mapping. Different methods are applied to estimate the porosity and the structural evolution with regard to porosity, permeability and fracture distribution. Analyses are carried out from the micrometre to decametre scale with main focus on the flow path evolution with time. This includes a large variety of porosity-types including fracture-porosity with up to cm-sized aperture down to grain-scale porosity. Main rock types are granitoid host rocks, mylonites, paleo-breccia and recent breccias. The porosity of the host rock as well as the

  8. A Hydrostrat Model and Alternatives for Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainer Mesa-Shoshone Mountain, Nye County, Nevada

    SciTech Connect

    NSTec Geotechnical Sciences Group

    2007-03-01

    The three-dimensional hydrostratigraphic framework model for the Rainier Mesa-Shoshone Mountain Corrective Action Unit was completed in Fiscal Year 2006. The model extends from eastern Pahute Mesa in the north to Mid Valley in the south and centers on the former nuclear testing areas at Rainier Mesa, Aqueduct Mesa, and Shoshone Mountain. The model area also includes an overlap with the existing Underground Test Area Corrective Action Unit models for Yucca Flat and Pahute Mesa. The model area is geologically diverse and includes un-extended yet highly deformed Paleozoic terrain and high volcanic mesas between the Yucca Flat extensional basin on the east and caldera complexes of the Southwestern Nevada Volcanic Field on the west. The area also includes a hydrologic divide between two groundwater sub-basins of the Death Valley regional flow system. A diverse set of geological and geophysical data collected over the past 50 years was used to develop a structural model and hydrostratigraphic system for the model area. Three deep characterization wells, a magnetotelluric survey, and reprocessed gravity data were acquired specifically for this modeling initiative. These data and associated interpretive products were integrated using EarthVision{reg_sign} software to develop the three-dimensional hydrostratigraphic framework model. Crucial steps in the model building process included establishing a fault model, developing a hydrostratigraphic scheme, compiling a drill-hole database, and constructing detailed geologic and hydrostratigraphic cross sections and subsurface maps. The more than 100 stratigraphic units in the model area were grouped into 43 hydrostratigraphic units based on each unit's propensity toward aquifer or aquitard characteristics. The authors organized the volcanic units in the model area into 35 hydrostratigraphic units that include 16 aquifers, 12 confining units, 2 composite units (a mixture of aquifer and confining units), and 5 intrusive confining

  9. Withaferin A: a proteasomal inhibitor promotes healing after injury and exerts anabolic effect on osteoporotic bone

    PubMed Central

    Khedgikar, V; Kushwaha, P; Gautam, J; Verma, A; Changkija, B; Kumar, A; Sharma, S; Nagar, G K; Singh, D; Trivedi, P K; Sangwan, N S; Mishra, P R; Trivedi, R

    2013-01-01

    supplementation improved trabecular micro-architecture of the long bones, increased biomechanical strength parameters of the vertebra and femur, decreased bone turnover markers (osteocalcin and TNFα) and expression of skeletal osteoclastogenic genes. It also increased new bone formation and expression of osteogenic genes in the femur bone as compared with vehicle groups (Sham) and ovariectomy (OVx), Bortezomib (known PI), injectible parathyroid hormone and alendronate (FDA approved drugs). WFA promoted the process of cortical bone regeneration at drill-holes site in the femur mid-diaphysis region and cortical gap was bridged with woven bone within 11 days of both estrogen sufficient and deficient (ovariectomized, Ovx) mice. Together our data suggest that WFA stimulates bone formation by abrogating proteasomal machinery and provides knowledge base for its clinical evaluation as a bone anabolic agent. PMID:23969857

  10. A novel therapeutic approach with Caviunin-based isoflavonoid that en routes bone marrow cells to bone formation via BMP2/Wnt-β-catenin signaling

    PubMed Central

    Kushwaha, P; Khedgikar, V; Gautam, J; Dixit, P; Chillara, R; Verma, A; Thakur, R; Mishra, D P; Singh, D; Maurya, R; Chattopadhyay, N; Mishra, P R; Trivedi, R

    2014-01-01

    Recently, we reported that extract of Dalbergia sissoo made from leaves and pods have antiresorptive and bone-forming effects. The positive skeletal effect attributed because of active molecules present in the extract of Dalbergia sissoo. Caviunin 7-O-[β-D-apiofuranosyl-(1-6)-β-D-glucopyranoside] (CAFG), a novel isoflavonoid show higher percentage present in the extract. Here, we show the osteogenic potential of CAFG as an alternative for anabolic therapy for the treatment of osteoporosis by stimulating bone morphogenetic protein 2 (BMP2) and Wnt/β-catenin mechanism. CAFG supplementation improved trabecular micro-architecture of the long bones, increased biomechanical strength parameters of the vertebra and femur and decreased bone turnover markers better than genistein. Oral administration of CAFG to osteopenic ovariectomized mice increased osteoprogenitor cells in the bone marrow and increased the expression of osteogenic genes in femur and show new bone formation without uterine hyperplasia. CAFG increased mRNA expression of osteoprotegerin in bone and inhibited osteoclast activation by inhibiting the expression of skeletal osteoclastogenic genes. CAFG is also an effective accelerant for chondrogenesis and has stimulatory effect on the repair of cortical bone after drill-hole injury at the tissue, cell and gene level in mouse femur. At cellular levels, CAFG stimulated osteoblast proliferation, survival and differentiation. Signal transduction inhibitors in osteoblast demonstrated involvement of p-38 mitogen-activated protein kinase pathway stimulated by BMP2 to initiate Wnt/β-catenin signaling to reduce phosphorylation of GSK3-β and subsequent nuclear accumulation of β-catenin. Osteogenic effects were abrogated by Dkk1, Wnt-receptor blocker and FH535, inhibitor of TCF-complex by reduction in β-catenin levels. CAFG modulated MSC responsiveness to BMP2, which promoted osteoblast differentiation via Wnt/β-catenin mechanism. CAFG at 1 mg/kg/day dose in

  11. Withaferin A: a proteasomal inhibitor promotes healing after injury and exerts anabolic effect on osteoporotic bone.

    PubMed

    Khedgikar, V; Kushwaha, P; Gautam, J; Verma, A; Changkija, B; Kumar, A; Sharma, S; Nagar, G K; Singh, D; Trivedi, P K; Sangwan, N S; Mishra, P R; Trivedi, R

    2013-08-22

    supplementation improved trabecular micro-architecture of the long bones, increased biomechanical strength parameters of the vertebra and femur, decreased bone turnover markers (osteocalcin and TNFα) and expression of skeletal osteoclastogenic genes. It also increased new bone formation and expression of osteogenic genes in the femur bone as compared with vehicle groups (Sham) and ovariectomy (OVx), Bortezomib (known PI), injectible parathyroid hormone and alendronate (FDA approved drugs). WFA promoted the process of cortical bone regeneration at drill-holes site in the femur mid-diaphysis region and cortical gap was bridged with woven bone within 11 days of both estrogen sufficient and deficient (ovariectomized, Ovx) mice. Together our data suggest that WFA stimulates bone formation by abrogating proteasomal machinery and provides knowledge base for its clinical evaluation as a bone anabolic agent.

  12. Neurotrophin-3 Induces BMP-2 and VEGF Activities and Promotes the Bony Repair of Injured Growth Plate Cartilage and Bone in Rats.

    PubMed

    Su, Yu-Wen; Chung, Rosa; Ruan, Chun-Sheng; Chim, Shek Man; Kuek, Vincent; Dwivedi, Prem P; Hassanshahi, Mohammadhossein; Chen, Ke-Ming; Xie, Yangli; Chen, Lin; Foster, Bruce K; Rosen, Vicki; Zhou, Xin-Fu; Xu, Jiake; Xian, Cory J

    2016-06-01

    Injured growth plate is often repaired by bony tissue causing bone growth defects, for which the mechanisms remain unclear. Because neurotrophins have been implicated in bone fracture repair, here we investigated their potential roles in growth plate bony repair in rats. After a drill-hole injury was made in the tibial growth plate and bone, increased injury site mRNA expression was observed for neurotrophins NGF, BDNF, NT-3, and NT-4 and their Trk receptors. NT-3 and its receptor TrkC showed the highest induction. NT-3 was localized to repairing cells, whereas TrkC was observed in stromal cells, osteoblasts, and blood vessel cells at the injury site. Moreover, systemic NT-3 immunoneutralization reduced bone volume at injury sites and also reduced vascularization at the injured growth plate, whereas recombinant NT-3 treatment promoted bony repair with elevated levels of mRNA for osteogenic markers and bone morphogenetic protein (BMP-2) and increased vascularization and mRNA for vascular endothelial growth factor (VEGF) and endothelial cell marker CD31 at the injured growth plate. When examined in vitro, NT-3 promoted osteogenesis in rat bone marrow stromal cells, induced Erk1/2 and Akt phosphorylation, and enhanced expression of BMPs (particularly BMP-2) and VEGF in the mineralizing cells. It also induced CD31 and VEGF mRNA in rat primary endothelial cell culture. BMP activity appears critical for NT-3 osteogenic effect in vitro because it can be almost completely abrogated by co-addition of the BMP inhibitor noggin. Consistent with its angiogenic effect in vivo, NT-3 promoted angiogenesis in metatarsal bone explants, an effect abolished by co-treatment with anti-VEGF. This study suggests that NT-3 may be an osteogenic and angiogenic factor upstream of BMP-2 and VEGF in bony repair, and further studies are required to investigate whether NT-3 may be a potential target for preventing growth plate faulty bony repair or for promoting bone fracture healing. © 2016

  13. Modeling and Inversion of three-dimensional crustal structures beneath the Pyrenees and their foreland basins based upon geological, gravimetric and seismological data

    NASA Astrophysics Data System (ADS)

    Spangenberg, Hannah; Chevrot, Sébastien; Courrioux, Gabriel; Guillen, Antonio

    2017-04-01

    Our goal is to obtain a three-dimensional (3D) model of mass density and seismic velocities beneath the Pyrenees and their foreland basins (Aquitaine and Ebro basins), which accounts for all the geological and geophysical information available for that region. This model covers the whole mountain range going from the Atlantic Ocean to the Mediterranean Sea, and from the Iberian range to the Massif Central. The model is described by different units: the lower, middle, and upper crusts, the accretionary prism, and the consolidated and unconsolidated sediment layers. Furthermore, a sub-continental, serpentinized European mantle is introduced to describe the exhumed mantle bodies which are responsible for the positive Bouguer gravity anomalies in the western Pyrenees. We build a first 3D model using all the geological information: drill-hole surveys, seismic sections, and the geological map. We use the potential field method implemented in Geomodeler to interpolate these geological data. However, these data are too sparse to build a model that explains seismic travel times or gravimetric data, especially the Labourd and the St. Gaudens Bouguer gravity anomalies. In addition, inconsistencies between the different data sets exist. We thus add by trial and error additional data points, comparing modeled and observed Bouguer gravimetric anomalies. The result of this procedure is a 3D geological model that respects the geological data and explains the measured Bouguer gravimetric anomalies. In a second step, we use this model to determine the average density and seismic velocities inside each geological unit assuming uniform layers. To constrain the seismic velocities we use travel time picks extracted from the bulletin of the Pyrenean seismicity released by the Observatoire Midi Pyrenées. In a third step, we use this 3D a priori model in a Monte Carlo inversion to invert jointly gravimetric data and seismic travel times from the bulletin. This probabilistic approach

  14. Measuring and interpretation of three-component borehole magnetic data

    NASA Astrophysics Data System (ADS)

    Virgil, C.; Ehmann, S.; Hördt, A.; Leven, M.; Steveling, E.

    2012-04-01

    Three-component borehole magnetics provides important additional information compared with total field or horizontal and vertical measurements. The "Göttinger Bohrloch Magnetometer" (GBM) is capable of recording the vector of the magnetic field along with the orientation of the tool using three fluxgate magnetometers and fibre-optic gyros. The GBM was successfully applied in the Outokumpu Deep Drill Hole (OKU R2500), Finland in September 2008 and in the Louisville Seamount Trail (IODP Expedition 330) from December 2010 until February 2011, and in several shallower boreholes. With the declination of the magnetic field, the GBM provides additional information compared to conventional tools, which reduces the ambiguity for structural interpretation. The position of ferromagnetic objects in the vicinity of the borehole can be computed with higher accuracy. In the case of drilled-through structures, three-component borehole magnetics allow the computation of the vector of magnetization. Using supplementary susceptibility data, the natural remanent magnetization (NRM) vector can be derived, which yields information about the apparent polar wander curve and/or about the structural evolution of the rock units. The NRM vector can further be used to reorient core samples in regions of strong magnetization. The most important aspect in three-component borehole magnetics is the knowledge of the orientation of the probe along the drillhole. With the GBM we use three fibre-optic gyros (FOG), which are aligned orthogonal to each other. These instruments record the turning rate about the three main axes of the probe. The FOGs benefit from a high resolution (< 9 · 10-4 °) and a low drift (< 2 °/h). However, to reach optimal results, extensive data processing and calibration measurements are necessary. Properties to be taken into account are the misalignment, scaling factors and offsets of the fluxgate and FOG triplet, temperature dependent drift of the FOGs, misalignment of the

  15. Revised preliminary geologic map of the Rifle Quadrangle, Garfield County, Colorado

    USGS Publications Warehouse

    Shroba, R.R.; Scott, R.B.

    1997-01-01

    The Rifle quadrangle extends from the Grand Hogback monocline into the southeastern part of the Piceance basin. In the northeastern part of the map area, the Wasatch Formation is nearly vertical, and over a distance of about 1 km, the dip decreases sharply from about 70-85o to about 15-30o toward the southwest. No evidence of a fault in this zone of sharp change in dip is observed but exposures in the Shire Member of the Wasatch Formation are poor, and few marker horizons that might demonstrate offset are distinct. In the central part of the map area, the Shire Member is essentially flat lying. In the south and southwest part of the map area, the dominant dip is slightly to the north, forming an open syncline that plunges gently to the northwest. Evidence for this fold also exists in the subsurface from drill-hole data. According to Tweto (1975), folding of the early Eocene to Paleocene Wasatch Formation along the Grand Hogback reqired an early Eocene age for the last phase of Laramide compression. We find the attitude of the Wasatch Formation to be nearly horizontal, essentially parallel to the overlying Anvil Points Member of the Eocene Green River Formation; therefore, we have no information that either confirms or disputes that early Eocene was the time of the last Laramide event. Near Rifle Gap in the northeast part of the map area, the Mesaverde Group locally dips about 10o less steeply than the overlying Wasatch Formation, indicating that not only had the formation of the Hogback monocline not begun by the time the Wasatch was deposited at this locality, but the underlying Mesaverde Group was locally tilted slightly toward the present White River uplift. Also the basal part of the Atwell Gulch Member of the Wasatch Formation consists of fine-grained mudstones and siltstones containing sparse sandstone and rare conglomerates, indicating that the source of sediment was not from erosion of the adjacent Upper Cretaceous Mesaverde Group. The most likely source of

  16. Middle-Late Eocene structure of the southern Levant continental margin — Tectonic motion versus global sea-level change

    NASA Astrophysics Data System (ADS)

    Segev, Amit; Schattner, Uri; Lyakhovsky, Vladimir

    2011-03-01

    During the Paleogene greenhouse episode Earth experienced the warmest period of the Cenozoic while global sea level rose by more than 100 m. However, geological evidence from the Levant margin, northwestern Arabian plate, indicates that throughout this period seabed deepening exceeded 1000 m. Lithology from Israel, Syria, Lebanon and Jordan is mainly pelagic and neritic, interfered by occasional fossil sub-marine slumps. In order to understand this dissimilarity we quantify the vertical tectonic motion of the Levant continental margin through the Paleogene. The margin began to take shape during the Late Permian and it was reactivated during the Oligocene. Based on information from outcrops, drillholes, seismic reflection and refraction, gravity, and previous publications, a multi-layered model of the Levant lithosphere was established. Layers include the Moho, top of the crystalline basement and covering sediments up to the Late Eocene. The model was restored horizontally by 100 km along the younger Dead Sea transform. Assuming local isostatic compensation, vertical restoration yielded the paleo-bathymetry which prevailed across northwestern Arabia during the Middle-Late Eocene. Results show that following the margin subsidence the Cretaceous Levantine platform became ramp shaped during the Eocene. Most parts of the central Levant were submerged under ~ 200 to ~ 1800 m of water, while the paleo-bathymetric gradients ranged from ~ 2° at the shelf to ~ 6° at the slope. The apparent dissimilarity between sea level and our tectonic-based calculations is up to an order of magnitude. These differences may be resolved by accounting for vertical tectonic motions and sediment supply rates. Our results stress the importance of the presented crustal structure. As opposed to the backstripping procedure, the structural map of the top Eocene interface was constructed upwards from the well established top Turonian (Judea Group) interface since only scarce and sporadic outcrops

  17. Exploration case study using indicator minerals in till at the giant Pebble porphyry Cu-Au-Mo deposit, southwest Alaska, USA

    USGS Publications Warehouse

    Eppinger, Robert G.; Kelley, Karen D.; Fey, David L.; Giles, Stuart A.; Smith, Steven G.

    2011-01-01

    The Pebble deposit in southwest Alaska (Fig. 1) contains one of the largest resources of copper and gold in the world. It includes a measured and indicated resource of 5,942 million tonnes (Mt) at 0.42% Cu, 0.35 g/t Au, and 250 ppm Mo (0.30% copper equivalent, CuEQ, cut off) and contains significant concentrations of Ag, Pd, and Re (Northern Dynasty Minerals 2011). The deposit remains open at depth. The Pebble West zone was discovered in 1989 by Cominco American. In 2005, Northern Dynasty Minerals Ltd. (NDM) discovered Pebble East, and in July 2007, NDM partnered with Anglo American to form the Pebble Limited Partnership (PLP). The U.S. Geological Survey began collaborative investigations with PLP in 2007 to identify techniques that will improve mineral exploration in covered terranes. The Pebble deposit is an ideal location for such a study because the deposit is undisturbed (except for drilling), is almost entirely concealed by post-mineral volcanic rocks and glacial deposits, and because its distribution is well constrained in the subsurface by PLP’s drill-hole geology and geochemistry. An exploration method developed by Averill (2007) that utilizes porphyry copper indicator minerals (PCIMR) in glacial till samples was applied at Pebble; samples were collected up- and down-ice (of former glaciers) from the deposit. The distribution of several PCIMs identifies the deposit, which suggests that PCIMs may be useful in exploration for other concealed porphyry deposits in the region. In this study, we compare the efficacy of PCIMs relative to that of pond and stream sediments also collected in the deposit area. The Pebble deposit is located 380 km southwest of Anchorage, in the Bristol Bay region of southwest Alaska. There is no road network and access to the study area is by helicopter. The deposit is situated in a broad glacially sculpted topographic low at the head of three drainages, Talarik Creek, North Fork Koktuli River, and the South Fork Koktuli River (Fig

  18. Curiosity Self-Portrait at Murray Buttes.

    NASA Image and Video Library

    2016-10-03

    This self-portrait of NASA's Curiosity Mars rover shows the vehicle at the "Quela" drilling location in the "Murray Buttes" area on lower Mount Sharp. Key features on the skyline of this panorama are the dark mesa called "M12" to the left of the rover's mast and pale, upper Mount Sharp to the right of the mast. The top of M12 stands about 23 feet (7 meters) above the base of the sloping piles of rocks just behind Curiosity. The scene combines approximately 60 images taken by the Mars Hand Lens Imager (MAHLI) camera at the end of the rover's robotic arm. Most of the component images were taken on Sept. 17, 2016, during the 1,463rd Martian day, or sol, of Curiosity's work on Mars. Two component images of the drill-hole area in front of the rover were taken on Sol 1466 (Sept. 20) to show the hole created by collecting a drilled sample at Quela on Sol 1464 (Sept. 18). The skyline sweeps from west on the left to south-southwest on the right, with the rover's mast at northeast. The rover's location when it recorded this scene was where it ended a drive on Sol 1455, mapped at http://mars.nasa.gov/msl/multimedia/images/?ImageID=8029. The view does not include the rover's arm nor the MAHLI camera itself, except in the miniature scene reflected upside down in the parabolic mirror at the top of the mast. That mirror is part of Curiosity's Chemistry and Camera (ChemCam) instrument. MAHLI appears in the center of the mirror. Wrist motions and turret rotations on the arm allowed MAHLI to acquire the mosaic's component images. The arm was positioned out of the shot in the images, or portions of images, that were used in this mosaic. This process was used previously in acquiring and assembling Curiosity self-portraits taken at other sample-collection sites, including "Rocknest" (PIA16468), "Windjana" (PIA18390"), "Buckskin" (PIA19808) and "Gobabeb" (PIA20316). For scale, the rover's wheels are 20 inches (50 centimeters) in diameter and about 16 inches (40 centimeters) wide. http

  19. Geostatistical Analysis of Spatial Variability of Mineral Abundance and Kd in Frenchman Flat, NTS, Alluvium

    SciTech Connect

    Carle, S F; Zavarin, M; Pawloski, G A

    2002-11-01

    LLNL hydrologic source term modeling at the Cambric site (Pawloski et al., 2000) showed that retardation of radionuclide transport is sensitive to the distribution and amount of radionuclide sorbing minerals. While all mineralogic information available near the Cambric site was used in these early simulations (11 mineral abundance analyses from UE-5n and 9 from RNM-l), these older data sets were qualitative in nature, with detection limits too high to accurately measure many of the important radionuclide sorbing minerals (e.g. iron oxide). Also, the sparse nature of the mineral abundance data permitted only a hypothetical description of the spatial distribution of radionuclide sorbing minerals. Yet, the modeling results predicted that the spatial distribution of sorbing minerals would strongly affect radionuclide transport. Clearly, additional data are needed to improve understanding of mineral abundances and their spatial distributions if model predictions in Frenchman Flat are to be defensible. This report evaluates new high-resolution quantitative X-Ray Diffraction (XRD) data on mineral distributions and their abundances from core samples recently collected from drill hole ER-5-4. The total of 94 samples from ER-5-4 were collected at various spacings to enable evaluation of spatial variability at a variety of spatial scales as small as 0.3 meters and up to hundreds of meters. Additional XRD analyses obtained from drillholes UE-Sn, ER-5-3, and U-11g-1 are used to augment evaluation of vertical spatial variability and permit some evaluation of lateral spatial variability. A total of 163 samples are evaluated. The overall goal of this study is to understand and characterize the spatial variation of sorbing minerals in Frenchman Flat alluvium using geostatistical techniques, with consideration for the potential impact on reactive transport of radionuclides. To achieve this goal requires an effort to ensure that plausible geostatistical models are used to

  20. Breaking the paradigm at magma-poor and magma-rich rifted margins

    NASA Astrophysics Data System (ADS)

    Tugend, Julie; Manatschal, Gianreto; Gillard, Morgane; Nirrengarten, Michael; Epin, Marie-Eva; Sauter, Daniel; Autin, Julia; Harkin, Caroline; Kusznir, Nick

    2017-04-01

    Rifted margins used to be classified into volcanic or non-volcanic passive margins. Because magmatism is evidenced even in so-called 'non-volcanic' settings, this terminology was later adjusted to magma-poor and magma-rich rifted margins. This classification represents a simplification into end-member magmatic types depending on the magmatic budget related to rifting and/or breakup processes. New observations derived from higher quality geophysical data sets and drill-hole data revealed the great diversity of rifted margin architecture and highly variable distribution of rift-related and/or breakup related magmatism. Recent studies suggest that rifted margins have a more complex tectono-magmatic evolution than previously assumed and cannot be characterized based on the observed volume of magma alone. In this study, we present seismic observations from 2D high resolution long-offset deep reflection seismic profiles across the East-Indian and South-Atlantic rifted margins. We aim to compare structural similarities between rifted margins with different magmatic budgets. We apply a systematic seismic interpretation approach to describe and characterize the first-order architecture and magmatic budget of our case examples. The identification of magmatic additions based on seismic observations only is indeed not unequivocal, in spite of the high-resolution dataset. Interpretations are related to large uncertainties in particular at ocean-continent transitions (i.e. outer highs) where most of the magmatism seems to be located. For each line, we present three different interpretations based on offshore and/or onshore field analogues. These interpretations illustrate scenarios for the nature of the outer highs that we believe are geologically meaningful and reasonable, and imply different magmatic budgets at breakup. Based on these interpretations we discuss different mechanisms for lithospheric breakup involving either a gradual or more instantaneous process independently

  1. Patterns and processes of shell fragmentation in modern and ancient marine environments

    NASA Astrophysics Data System (ADS)

    Zuschin, Martin; Stachowitsch, Michael; Stanton, Robert J.

    2003-10-01

    contact with one another or with coarser grains; taphonomic features (e.g., drillholes) have only minor influence. A key step in interpreting fragments is to categorize breakage into repaired versus unrepaired, diagnostic versus non-diagnostic, and severe versus localized damage. Quantifying the above categories can then provide useful information on breakage patterns and underlying processes. Understanding the many characteristics of shells and their fragments is a significant interpretive tool in maximizing the information gain in palaeoecological and taphofacies analyses.

  2. Gravimetric response of water table fluctuations in the Sahelian Diffa site (East Niger): local effects including poro-elasticity

    NASA Astrophysics Data System (ADS)

    Hector, B.; Genthon, P.; Le Coz, M.; Hinderer, J.; Chalikakis, K.; Descloitres, M.

    2010-12-01

    observed gravimetic signal and the results of the global hydrological model GLDAS are offset with respect to the piezometric one. In order to assess the influence of local effects, the groundwater level is modeled with the USGS finite-difference ModFlow code using different properties sets of the aquifer deduced from statistical analysis of drill-holes data. Poroelasticity effects resulting from variable saturation of the clay layers observed near the water level on the Bagara site are assessed. The ability of gravity data for monitoring annual and long term water level changes in the uppermost aquifer is then discussed.

  3. Aeromagnetic map of northwest Utah and adjacent parts of Nevada and Idaho

    USGS Publications Warehouse

    Langenheim, Victoria

    2016-01-01

    Two aeromagnetic surveys were flown to promote further understanding of the geology and structure in northwest Utah and adjacent parts of Nevada and Idaho by serving as a basis for geophysical interpretations and by supporting geological mapping, water and mineral resource investigations, and other topical studies. Although this area is in general sparsely populated, (except for cities and towns along the Wasatch Front such as Ogden and Brigham City), it encompasses metamorphic core complexes in the Grouse Creek and Raft River Mountains (figure 1) of interest to earth scientists studying Cenozoic extension. The region was shaken in 1909 and 1934 by M6+ earthquakes east of the Hansel Mountains (Doser, 1989; Arabasz and others, 1994); damage from the 1934 earthquake occurred as far east as Logan, Utah (http:// www.seis.utah.edu/lqthreat/nehrp_htm/1934hans/n1934ha1. shtml#urbse). The presence of Quaternary shield volcanoes and bimodal Pleistocene volcanism in Curlew Valley (Miller and others, 1995; Felger and others, 2016) as well as relatively high temperature gradients encountered in the Indian Cove drillhole in the north arm of Great Salt Lake (Blackett and others, 2014) may indicate some potential for geothermal energy development in the area (Miller and others, 1995). The area also hosts four significant mining districts, in the northern Pilot Range, the Goose Creek Mountains in the northwest corner of the map, the southern end of the Promontory Mountains, and the southwest part of the Raft River Mountains, although production notably waned after World War II (Doelling, 1980). Other prospects of interest include those in the southern Grouse Creek Mountains, Silver Island, and the northern Newfoundland Mountains.Large areas of northwest Utah are covered by young, surficial deposits or by Great Salt Lake or are down-dropped into deep Cenozoic basins, making extrapolation of bedrock geology from widely spaced exposures difficult or tenuous (figure 1). Local spatial

  4. Geomechanical models of impact cratering: Puchezh-Katunki structure

    NASA Technical Reports Server (NTRS)

    Ivanov, B. A.

    1992-01-01

    Impact cratering is a complex natural phenomenon that involves various physical and mechanical processes. Simulating these processes may be improved using the data obtained during the deep drilling at the central mound of the Puchezh-Katunki impact structure. A research deep drillhole (named Vorotilovskaya) has been drilled in the Puchezh-Katunki impact structure (European Russia, 57 deg 06 min N, 43 deg 35 min E). The age of the structure is estimated at about 180 to 200 m.y. The initial rim crater diameter is estimated at about 40 km. The central uplift is composed of large blocks of crystalline basement rocks. Preliminary study of the core shows that crystalline rocks are shock metamorphosed by shock pressure from 45 GPa near the surface to 15-20 GPa at a depth of about 5 km. The drill core allows the possibility of investigating many previously poorly studied cratering processes in the central part of the impact structure. As a first step one can use the estimates of energy for the homogeneous rock target. The diameter of the crater rim may be estimated as 40 km. The models elaborated earlier show that such a crater may be formed after collapse of a transient cavity with a radius of 10 km. The most probable range of impact velocities from 11.2 to 30 km/s may be inferred for the asteroidal impactor. For the density of a projectile of 2 g/cu cm the energy of the impact is estimated as 1E28 to 3E28 erg. In the case of vertical impact, the diameter of an asteroidal projectile is from 1.5 to 3 km for the velocity range from 11 to 30 km/s. For the most probable impact angle of 45 deg, the estimated diameter of an asteroid is slightly larger: from 2 to 4 km. Numerical simulation of the transient crater collapse has been done using several models of rock rheology during collapse. Results show that the column at the final position beneath the central mound is about 5 km in length. This value is close to the shock-pressure decay observed along the drill core. Further

  5. Using Archean and Paleoproterozoic Shales and Tillites as a Window into Crustal Evolution and Surface Conditions

    NASA Astrophysics Data System (ADS)

    Bindeman, I. N.; Bekker, A.; Zakharov, D. O.

    2014-12-01

    Precambrian shales and tillites have been insufficiently studied so far. We present oxygen and hydrogen isotope data for 103 bulk shale and tillites that were collected from drillholes on all continents from 3.2 to 1.4Ga. These samples have also been analyzed for total organic and inorganic carbon, total sulfur, δ13Corg values and by XRF for major and trace elements to calculate chemical index of alteration (CIA). Having uncompromised fresh samples from drillcores is a must for this kind of investigation. We have a particularly good coverage for the ca. 2.7-2.2 Ga time interval when Earth experienced 3-4 Snowball Earth glaciations associated with the rapid rise in atmospheric O2 and fluctuations in CO2, thus affecting weathering cycle and attainment of isotopic fractionation. All units have similar to Phanerozoic ranges in δ13Corg values (-23 to -33‰ PDB) and Corg content (0.1 to 10 wt. %). Compared to Phanerozoic shales, Precambrian shales have comparable ranges in δ18O values (+7 to +20‰), with slightly decreasing means with increasing age, and identical δ17O-δ18O slope (0.528). Shales in some drill holes display wide δ18O ranges over short stratigraphic intervals suggesting significant variability in the provenance. We however observe a significant, several permil downward shift and decrease in the range of δ18O values (7-9‰) in 2.2-2.5 Ga shales from several continents that are associated with the Paleoproterozoic glaciations. Scattered negative correlation of CIA with δ18O, for some of these shales broadly associated with the Paleoproterozoic glaciations suggest contact with glacial meltwater having ultra-low-δ18O values during deposition or diagenesis of these shales. The δD values of shales range from -50 to -75‰, and are comparable to Phanerozoic values, with the exception of the ~2.5-2.2 Ga shales that reach to -100‰. We also compare O isotope values of ultra-low-δ18O, +8 to -27‰ SMOW subglacial hydrothermal rocks recently discovered

  6. Pore fluid ‘ages’ suggest fluid replacement events across the San Andreas Fault at Depth, Parkfield, CA (Invited)

    NASA Astrophysics Data System (ADS)

    Ali, S.; Stute, M.; Torgersen, T.; Hemming, S. R.; Fleisher, M. Q.; Winckler, G.

    2009-12-01

    The presence of aqueous reaction produced low strength mineral surfaces is linked to low friction slip along the San Andreas Fault Zone (SAFZ) as shown in core samples recovered from the San Andreas Fault Observatory at Depth (SAFOD) in Parkfield, CA. These mineral phases are a product of fluid-rock interaction in the fault zone. SAFOD drill cores show multiple zones of alteration and deformation due to fluid-rock interaction (Schleicher et. al, 2008), which requires transport of fluids into the fault zone. We present pore fluid ages, age gradients, as well as 3He and 4He isotope profiles of matrix fluids obtained from drill core samples during SAFOD phases 1, 2, and 3 to constrain fluid flow across the SAFZ. Helium and argon concentration profiles in the pore fluids suggest the fault represents a sink for 3He, 4He and 40Ar. The 3He/4He profile across the SAFZ confirms the mantle helium signature is introduced from the North American Plate side of the SAFOD drillhole and the lack of mantle-derived fluid component through the fault zone. Noble gas measurements on the solid phase indicate that more than 90% of in situ produced He has entered the fluid phase. The presence of mantle-derived He in both plates and the fault zone suggests that the fluids are accumulating both locally produced and externally produced He. Apparent maximum pore fluid ages range from ˜300,000-700,000 years (3050m-measured depth (MD)) in the Pacific Plate and ˜300,000 -500,000 years (3989m-MD) in the North American Plate, compared to relatively younger ages of <200,000 years in the actively creeping trace of the SAFZ at 3300m-MD. The pore fluid ages suggest fluid flow events on these or shorter timescales in the respective zones. Each fluid event results into further dissolution and precipitation in the SAFZ creating a new layer of minerals, which in turn can enhance further slip along the fault.

  7. Primary Igneous Anhydrite: Progress Since the 1982 El Chichón Eruption (Mexico)

    NASA Astrophysics Data System (ADS)

    Luhr, J. F.

    2006-05-01

    Anhydrite (CaSO4) was confirmed as a stable primary igneous mineral, capable of precipitating from a silicate melt, through petrographic observations of fresh trachyandesitic pumices erupted in the spring of 1982 from El Chichón, a little known, isolated tuff and lava-dome complex in eastern Mexico. The 1982 eruption was also notable for the associated release of an estimated 5-9 megatons of SO2 to the stratosphere and troposphere, as measured by the Total Ozone Mapping Spectrometer. Subsequent years saw confirmation of primary igneous anhydrite in laboratory phase-equilibrium experiments, and anhydrite was also observed in the products of several subsequent explosive eruptions, most importantly dacitic pumices from the massive 15 June 1991 eruption of Mount Pinatubo, in the Philippines. That eruption involved ~5X the mass of magma and ~3X the mass of SO2 release compared to El Chichón's eruption. For both the Pinatubo and El Chichón eruptions, it has been concluded that the sulfur released to the atmosphere was too great in mass to have been dissolved in the erupted melt volume just prior to eruption. In both cases workers advocated the existence of a separate gas phase prior to eruption, where much of the subsequently released sulfur was present. Thus, primary igneous anhydrite has been linked with another important phenomenon: excess sulfur release during volcanic eruptions. This presentation will review other developments concerning primary igneous anhydrite since 1982. These include: (1) other examples of primary anhydrite from volcanic samples (Nevado del Ruiz, Colombia; Lascar, Chile; Sutter Buttes, USA; Eagle Mountain, USA; Shiveluch, Russia; (2) examples of primary anhydrite from plutonic samples (Julcani, Peru; Santa Rita, USA; Cajon Pass Scientific Drillhole, USA); (3) laboratory experiments that have expanded our understanding of the T-P-fO2 conditions of anhydrite stability, melt/vapor partition coefficients for sulfur as a function of these

  8. Fractal scaling and fluid flow in fracture networks in rock

    SciTech Connect

    Barton, C.C.

    1996-12-31

    Recovery of oil and gas resources and injection of toxic waste materials requires quantitative models to describe and predict the movement of fluids in rock. Existing models based on pore-space flow are inappropriate for study of the more rapid process of fluid flow through fracture networks. This type of flow is not a simple function of the fracture characteristics at any particular scale, but rather the integration of fracture contributions at all scales. The mathematical constructs of fractal geometry are well suited to quantify and model relationships within complex systems that are statistically self-similar over a wide range of scales. Analyses show that fracture traces mapped on two-dimensional slices through three-dimensional nature fracture networks in rock follow a fractal scaling law over six orders of magnitude. Detailed measurements of 17 two-dimensional samples of fracture networks (at diverse scales in rocks of dissimilar age, lithology, and tectonic setting) show similar fractal dimensions in the range 1.3-1.7. The range in fractal dimension implies that a single physical process of rock fracturing operates over a wide range of scales, from microscopic cracks to large, regional fault systems. The knowledge that rock-fracture networks are fractal allows the use of data from a one-dimensional drill-hole sample to predict the two- and three-dimensional scaling of the fracture system. The spacing of fractures in drill holes is a fractal Cantor distribution, and the range of fractal dimension is 0.4-0.6, which is an integer dimension less than that of fracture-trace patterns exposed on two-dimensional, planar sections. A reconstruction of the fracture history at the point of initial connectivity across the network (percolation) has a fractal dimension of 1.35 as compared to a dimension of 1.9 for the percolation cluster in a two-dimensional model. Paleo flow was mapped based on the deposition of aqueous minerals on the fracture surface.

  9. Fractal scaling and fluid flow in fracture networks in rock

    SciTech Connect

    Barton, C.C. )

    1996-01-01

    Recovery of oil and gas resources and injection of toxic waste materials requires quantitative models to describe and predict the movement of fluids in rock. Existing models based on pore-space flow are inappropriate for study of the more rapid process of fluid flow through fracture networks. This type of flow is not a simple function of the fracture characteristics at any particular scale, but rather the integration of fracture contributions at all scales. The mathematical constructs of fractal geometry are well suited to quantify and model relationships within complex systems that are statistically self-similar over a wide range of scales. Analyses show that fracture traces mapped on two-dimensional slices through three-dimensional nature fracture networks in rock follow a fractal scaling law over six orders of magnitude. Detailed measurements of 17 two-dimensional samples of fracture networks (at diverse scales in rocks of dissimilar age, lithology, and tectonic setting) show similar fractal dimensions in the range 1.3-1.7. The range in fractal dimension implies that a single physical process of rock fracturing operates over a wide range of scales, from microscopic cracks to large, regional fault systems. The knowledge that rock-fracture networks are fractal allows the use of data from a one-dimensional drill-hole sample to predict the two- and three-dimensional scaling of the fracture system. The spacing of fractures in drill holes is a fractal Cantor distribution, and the range of fractal dimension is 0.4-0.6, which is an integer dimension less than that of fracture-trace patterns exposed on two-dimensional, planar sections. A reconstruction of the fracture history at the point of initial connectivity across the network (percolation) has a fractal dimension of 1.35 as compared to a dimension of 1.9 for the percolation cluster in a two-dimensional model. Paleo flow was mapped based on the deposition of aqueous minerals on the fracture surface.

  10. Mapping hyper-extended rift systems offshore and onshore: insights from the Bay of Biscay- Western Pyrenees

    NASA Astrophysics Data System (ADS)

    Tugend, Julie; Manatschal, Gianreto; Kusznir, Nicolas J.; Masini, Emmanuel; Thinon, Isabelle

    2013-04-01

    Research conducted at present-day passive continental margins shows more varied crustal architectures than previously assumed. New seismic data together with drill-holes have revealed the occurrence of extremely thinned continental crust in the distal part of the margin as well as exhumed serpentinised sub-continental mantle oceanwards. In addition the understanding of the formation of hyper-extended rift systems has also greatly benefited from the study of onshore analogs preserved in mountain belts. The Bay of Biscay and Western Pyrenees correspond to a Lower Cretaceous rift system leading to the development of hyper-extended domains and ultimately oceanic crust in the Bay of Biscay. This domain represents one of the best natural laboratories to study the formation processes and evolution of hyper-extended domains. During late Cretaceous compression, these rifted domains were inverted resulting in the present-day Pyrenean mountain belt. In this contribution, we present a new paleogeographic map of the Bay of Biscay-Pyrenean rift system. We integrate results from previous works and new work using different mapping methods to distinguish distinctive crustal domains related to hyper-extended systems both offshore and onshore. We combine seismic interpretations with gravity anomaly inversion and residual depth anomaly analysis to distinguish the different crustal domains across the offshore margin. Onshore, we use an innovative approach based on observations from present-day rifted margin architecture associated with classical field work to map the former hyper-extended domains. Another outcome of this work is the creation of a crustal thickness map using gravity inversion linking offshore and onshore domains from the Bay of Biscay to that of the Western-Pyrenees. This multidisciplinary approach enables us to investigate the spatial and temporal evolution of the Bay of Biscay rift system with the aim of better understanding the formation of hyper-extended domains

  11. Stress feature interpretation from ICDP drill holes to constrain the orientations of the three principal stresses: Snake River Plain (USA)

    NASA Astrophysics Data System (ADS)

    Pierdominici, Simona; Kück, Jochem; Harms, Ulrich; Schmitt, Douglas R.

    2016-04-01

    Downhole data from drilled holes provide a unique opportunity to identify wellbore failure and understand physical properties of the deep sediments and rocks. In the framework of the ICDP (International Continental Scientific Drilling Program) we have obtained and analysed a set of geophysical logging data of two deep boreholes (Kimama and Kimberly) in the Snake River Plain in southern Idaho for the ICDP Hot Spot project. The Snake River Plain represents the track of a deep-seated mantle hotspot that has thinned the lithosphere and fuelled the intrusion of up to 10 km of hot basaltic-rhyolitic magma into the lower and middle crust. This area represents the ideal place for geothermal exploration and exploitation. For that a study of the complete state of stress in this region becomes a key point to know and understand the distribution of fractures and failures and how they can influence the permeability of the Hot Spot geothermal reservoir. Processed acoustic borehole images acquired along two boreholes detect a variety of natural and drilling induced features on the borehole wall, including bedding, fractures and breakouts. Three primary types of stress-induced drillhole indicators, breakouts, petal centre-line fractures and tensile fractures, were analysed in detail in order to define the orientation of the present-day stress state. Borehole breakouts are stress-induced elongations of a borehole cross section and on borehole images they appear as dark features and in some cases, incipient breakouts have been identified by conjugate shear fractures, where no spalling of the borehole wall has occurred. The drilling induced tensile fractures appear as dark electrically conductive features, with a strike parallel to the direction of the far-field greatest horizontal stress. They can be differentiated from natural fractures because they do not cross the borehole, do not form complete sinusoids shape on BHTV images and show a discontinuous nature. On the contrary the

  12. Morphology of Lonar Crater, India: Comparisons and implications

    USGS Publications Warehouse

    Fudali, R.F.; Milton, D.J.; Fredriksson, K.; Dube, A.

    1980-01-01

    Lonar Crater is a young meteorite impact crater emplaced in Deccan basalt. Data from 5 drillholes, a gravity network, and field mapping are used to reconstruct its original dimensions, delineate the nature of the pre-impact target rocks, and interpret the emplacement mode of the ejecta. Our estimates of the pre-erosion dimensions are: average diameter of 1710 m; average rim height of 40 m (30-35 m of rim rock uplift, 5-10 m of ejected debris); depth of 230-245 m (from rim crest to crater floor). The crater's circularity index is 0.9 and is unlikely to have been lower in the past. There are minor irregularities in the original crater floor (present sediment-breccia boundary) possibly due to incipient rebound effects. A continuous ejecta blanket extends an average of 1410 m beyond the pre-erosion rim crest. In general, 'fresh' terrestrial craters, less than 10 km in diameter, have smaller depth/diameter and larger rim height/diameter ratios than their lunar counterparts. Both ratios are intermediate for Mercurian craters, suggesting that crater shape is gravity dependent, all else being equal. Lonar demonstrates that all else is not always equal. Its depth/diameter ratio is normal but, because of less rim rock uplift, its rim height/diameter ratio is much smaller than both 'fresh' terrestrial and lunar impact craters. The target rock column at Lonar consists of one or more layers of weathered, soft basalt capped by fresh, dense flows. Plastic deformation and/or compaction of this lower, incompetent material probably absorbed much of the energy normally available in the cratering process for rim rock uplift. A variety of features within the ejecta blanket and the immediately underlying substrate, plus the broad extent of the blanket boundaries, suggest that a fluidized debris surge was the dominant mechanism of ejecta transportation and deposition at Lonar. In these aspects, Lonar should be a good analog for the 'fluidized craters' of Mars. ?? 1980 D. Reidel

  13. Geothermal modelling of faulted metamorphic crystalline crust: a new model of the Continental Deep Drilling Site KTB (Germany)

    NASA Astrophysics Data System (ADS)

    Szalaiová, Eva; Rabbel, Wolfgang; Marquart, Gabriele; Vogt, Christian

    2015-11-01

    The area of the 9.1-km-deep Continental Deep Drillhole (KTB) in Germany is used as a case study for a geothermal reservoir situated in folded and faulted metamorphic crystalline crust. The presented approach is based on the analysis of 3-D seismic reflection data combined with borehole data and hydrothermal numerical modelling. The KTB location exemplarily contains all elements that make seismic prospecting in crystalline environment often more difficult than in sedimentary units, basically complicated tectonics and fracturing and low-coherent strata. In a first step major rock units including two known nearly parallel fault zones are identified down to a depth of 12 km. These units form the basis of a gridded 3-D numerical model for investigating temperature and fluid flow. Conductive and advective heat transport takes place mainly in a metamorphic block composed of gneisses and metabasites that show considerable differences in thermal conductivity and heat production. Therefore, in a second step, the structure of this unit is investigated by seismic waveform modelling. The third step of interpretation consists of applying wavenumber filtering and log-Gabor-filtering for locating fractures. Since fracture networks are the major fluid pathways in the crystalline, we associate the fracture density distribution with distributions of relative porosity and permeability that can be calibrated by logging data and forward modelling of the temperature field. The resulting permeability distribution shows values between 10-16 and 10-19 m2 and does not correlate with particular rock units. Once thermohydraulic rock properties are attributed to the numerical model, the differential equations for heat and fluid transport in porous media are solved numerically based on a finite difference approach. The hydraulic potential caused by topography and a heat flux of 54 mW m-2 were applied as boundary conditions at the top and bottom of the model. Fluid flow is generally slow and

  14. CARIBENORTE Project: Studying the deep structure of the NE Caribbean Plate

    NASA Astrophysics Data System (ADS)

    Carbo-Gorosabel, A.; Davila, J. M.; Cordoba Barba, D.; Granja, J. L.; Llanes Estrada, M.; Munoz Martin, A.; Druet, M.; Gomez, M.; Pazos, A.; Catalan, M.; ten Brink, U. S.; Payero, J.; Lopez, O.; Quijano, J.

    2009-12-01

    Despite the high number of studies carried out in the NE Caribbean there is still not a geodynamic model that is capable of integrating all of the local tectonic settings present in the area. The CaribeNorte Project aims to analyze the geodynamics of the area by studying the deep crustal structure of the North-eastern Caribbean Plate Boundary Zone across the Dominican Republic (DR) and by analyzing the morphostructure of the southern insular slope because most works have focused on the northern side of the arc. The main objectives of the project are: 1) to define the deep structure from north to south across the island arc and to test whether the Caribbean Plate’s interior is subducting beneath the DR, as has been hypothesized, 2) to analyse the deep and shallow structure of the northern Beata Ridge and to assess its origin and evolution, 3) to study the morphostructure of the zone of collision between the Muertos fold-and-thrust belt and the aseismic Beata Ridge, and 4) to evaluate the seismic and tsunami risk in the area. The new data was acquired during a research cruise held in the spring of 2009 aboard the Spanish R/V Hesperides. Swath bathymetry was obtained covering an area of 34.460 km2 in the south of the DR, overlapping by the east with data from our previous cruise Geoprico-Do. Along the track lines we have continuously collected gravity and magnetic data and high-resolution seismic profiles (TOPAS system). The active seismic experiment consisted on 3 deep seismic soundings profiles with a total of 16 OBS, deployed from the DR’s ship Orion, and 340 seismic land stations. For the deep seismic experiment the R/V Hesperides was shooting every 90 s with airguns having a total power of 3.850 ci. In addition, the Dominican Republic’s DGM collaborated with 3 drill-hole explosions on-shore. The five seismic profiles have a total of 980 km offshore and 650 km onshore, running across the Bahamas Carbonate platform, the DR island along two transects, the

  15. Friction of DFDP-2 Ccuttings at Hhydrothermal Conditions

    NASA Astrophysics Data System (ADS)

    Moore, D. E.; Lockner, D. A.; Toy, V.; Sutherland, R.; Townend, J.

    2016-12-01

    Cuttings samples from the depth interval 299-886 m of the Deep Fault Drilling Program DFDP-2 drillhole into the Alpine Fault Zone of New Zealand are being used in laboratory friction experiments at hydrothermal conditions. The samples, which consist largely of muscovite, biotite, quartz, and plagioclase, have very similar coefficients of friction of 0.56-0.60 and are velocity-strengthening in room-temperature triaxial tests at 100 MPa effective normal stress. Heating to 350°C raises the coefficient of friction by 0.10 and is accompanied by a change to velocity weakening, which is consistent with previous results for phyllosilicate-bearing quartzofeldspathic rocks including Alpine Fault-derived gouges. A slide-hold-slide experiment was conducted at 350°C, 150 MPa effective normal stress (100 MPa pore pressure), and an axial displacement rate of 1.0 µm/s for hold times between 4 and 350,000 s. Over the entire range of hold times, frictional healing (∆µ) is well fit by a log-linear relationship to hold time, with a healing rate of 0.008 per decade. The reduction in µ during a hold also varies with the log of hold time over the tested range, at a rate of -0.042 per decade. The resumption of displacement following hold times of 3200 s and greater resulted in an interval of oscillatory slip before slip stabilized, and the number of stress drops per interval increased with increasing hold time. The uniform healing rate measured here contrasts with several previous studies conducted on natural and analogue fault zone materials, in which the healing rate increased for hold times greater than 1000-3000 s. In those studies, the change in healing rate generally was attributed to a change in the dominant healing mechanism with increasing time. In contrast, the constant rate in our experiment suggests that the same healing process(es) may dominate throughout. Additional experiments and petrographic studies are planned to identify the mechanism(s) involved in healing at

  16. Structure of the Demerara Plateau : syn- and post-rift deformations at the intersection of transform and divergent margin segments

    NASA Astrophysics Data System (ADS)

    Basile, C.; Maillard, A.; Patriat, M.; Roest, W.; Loncke, L.; Gaullier, V.

    2009-04-01

    The continental margin of French Guyana presents a divergent segment (East of Demerara Plateau) between two transform segments (North of Demerara Plateau and the eastern margin). This area was surveyed in 2003 by GUYAPLAC cruise, that improved our knowledge of its structure and evolution, which is presented here relatively to the post-rift unconformity, regionally dated early Albian by drill-holes. Post-unconformity sediments were stacked by aggradation on the Plateau. After their deposition, they were systematically affected by two processes : tilting oceanwards (towards ENE) of the whole margin, and massive fluid escapes. Fluid escapes are evidenced in seismic lines by a polygonal faulting network, linked at seafloor with pockmark fields, and rooted below the post-rift unconformity. Unlike most of the transform margins that were uplifted along the continent-ocean boundary, the late oceanward tilting of the Demerara Plateau may be in relation with its peculiar position at the intersection of transform and divergent continental segments. The post-rift unconformity seals complex and highly deformed structures, involving tilted blocks, folds and reversed faults. The post-rift unconformity is itself sometimes shifted by the polygonal fault network, that seems to be influenced by the deeper structures : the density of post-unconformity faults increases above the structural highs (top of titlted blocks, fold hinges) cut by the unconformity. Detailled analysis demonstrated that the unconformity progressively eroded folded structures, allowing the datation of the reverse slip on previously normal faults bounding tilted blocks. However, the spacing of available seismic lines does not allow to identify probable strike-slip displacements or transpression. Relationships of these features with possible magmatic intrusions on northern and northeastern edges of the Plateau are also unclear. Such tectonic inversion has been previously reported for other transform margins within

  17. Drilling Addendum to Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California

    SciTech Connect

    Taylor, Gary C.; Bacon, C. Forrest; Chapman, Rodger H.; Chase, Gordon W.; Majmundar, Hasmukhrai H.

    1981-05-01

    This addendum report presents the results of the California Division of Mines and Geology (CDMG) drilling program at Calistoga, California, which was the final geothermal-resource assessment investigation performed under terms of the second year contract (1979-80) between the U.S. Department of Energy (DOE) and the CDMG under the State Coupled Program. This report is intended to supplement information presented in CDMG's technical report for the project year, ''Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California''. During the investigative phase of the CDMG's Geothermal Project, over 200 well-driller's reports were obtained from the Department of Water Resources (DWR). It was hoped that the interpretation and correlation of these logs would reveal the subsurface geology of the Upper Napa Valley and also provide a check for the various geophysical surveys that were performed in the course of the study. However, these DWR driller logs proved to be inadequate due to the brief, non-technical, and erroneous descriptions contained on the logs. As a result of the lack of useable drill-hole data, and because information was desired from,deeper horizons, it became evident that drilling some exploratory holes would be necessary in order to obtain physical evidence of the stratigraphy and aquifers in the immediate Calistoga area. Pursuant to this objective, a total of twelve sites were selected--four under jurisdiction of Napa County and eight under jurisdiction of the City of Calistoga. A moratorium is currently in existence within Napa County on most geothermal drilling, and environmental and time constraints precluded CDMG from obtaining the necessary site permits within the county. However, a variance was applied for and obtained from the City of Calistoga to allow CDMG to drill within the city limits. With this areal constraint and also funding limits in mind, six drilling sites were selected on the basis of (1

  18. Mesozoic intracontinental underthrust in the SE margin of the North China Block: Insights from the Xu-Huai thrust-and-fold belt

    NASA Astrophysics Data System (ADS)

    Shu, Liangshu; Yin, Hongwei; Faure, Michel; Chen, Yan

    2017-06-01

    The Xu-Huai thrust-and-fold belt, located in the southeastern margin of the North China Block, consists mainly of thrust and folded pre-Mesozoic strata. Its geodynamic evolution and tectonic setting are topics of long debate. This paper provides new evidence from geological mapping, structural analysis, and making balance cross-sections, with restoration of cross-sections. Results suggest that this belt was subjected to two-phase deformation, including an early-phase regional-scale NW-ward thrust and fold, and a late-phase extension followed by the emplacement of dioritic, monzodioritic porphyrites dated at 131-135 Ma and locally strike-slip shearing. According to the mapping, field observations and drill-hole data, three structural units were distinguished, namely, (1) the pre-Neoproterozoic crystalline basement in the eastern segment, (2) the nappe unit or the thrust-and-fold zone in the central segment, which is composed of Neoproterozoic to Ordovician carbonate rocks and Carboniferous-Permian coal-bearing rocks, about 2600 m thick, and (3) the western frontal zone. A major decollement fault has also been identified in the base of the nappe unit, on which dozen-meter to km-scale thrust-and-fold bodies were commonly developed. All pre-Mesozoic depositional sequences were involved into a widespread thrust and fold event. Six uncompetent-rock layers with biostratigraphic ages (Nanjing University, 1996) have been recognized, and each uncompetent-rock layer occurred mainly in the top of the footwall, playing an important role in the development of the Xu-Huai thrust-and-fold belt. Geometry of the major decollement fault suggests that the nappe unit of this belt was rooted in its eastern side, near the Tan-Lu Fault Zone. Two geological cross-sections were chosen for structural balancing and restoration. From the balanced cross-sections, ramp-flat and imbricated faults as well as fault-related folds were identified. A shortening of 20.6-29.6 km was obtained from

  19. Energy Dissipation in Calico Hills Tuff due to Pore Collapse

    NASA Astrophysics Data System (ADS)

    Lockner, D. A.; Morrow, C. A.

    2008-12-01

    Laboratory tests indicate that the weakest portions of the Calico Hills tuff formation are at or near yield stress under in situ conditions and that the energy expended during incremental loading can be more than 90 percent irrecoverable. The Calico Hills tuff underlies the Yucca Mountain waste repository site at a depth of 400 to 500 m within the unsaturated zone. The formation is highly variable in the degree of both vitrification and zeolitization. Since 1980, a number of boreholes penetrated this formation to provide site characterization for the YM repository. In the past, standard strength measurements were conducted on core samples from the drillholes. However, a significant sampling bias occurred in that tests were preferentially conducted on highly vitrified, higher-strength samples. In fact, the most recent holes were drilled with a dry coring technique that would pulverize the weakest layers, leaving none of this material for testing. We have re-examined Calico Hills samples preserved at the YM Core Facility and selected the least vitrified examples (some cores exceeded 50 percent porosity) for mechanical testing. Three basic tests were performed: (i) hydrostatic crushing tests (to 350 MPa), (ii) standard triaxial deformation tests at constant effective confining pressure (to 70 MPa), and (iii) plane strain tests with initial conditions similar to in situ stresses. In all cases, constant pore pressure of 10 MPa was maintained using argon gas as a pore fluid and pore volume loss was monitored during deformation. The strongest samples typically failed along discrete fractures in agreement with standard Mohr-Coulomb failure. The weaker, high porosity samples, however, would fail by pure pore collapse or by a combined shear-induced compaction mechanism similar to failure mechanisms described for porous sandstones and carbonates. In the plane-strain experiments, energy dissipation due to pore collapse was determined for eventual input into dynamic wave

  20. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multifrequency EM

    NASA Astrophysics Data System (ADS)

    Hoppmann, Mario; Hunkeler, Priska A.; Hendricks, Stefan; Kalscheuer, Thomas; Gerdes, Rüdiger

    2016-04-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise, accumulate beneath nearby sea ice, and subsequently form a several meter thick, porous sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator of the health of an ice shelf. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions within the platelet layer using Archie's Law. The thickness results agreed well with drillhole validation datasets within the uncertainty range, and the ice-volume fraction yielded results comparable to other studies. Both parameters together enable an estimation of the total ice volume within the platelet layer, which was found to be comparable to the volume of landfast sea ice in this region, and corresponded to more than a quarter of the annual basal melt volume of the nearby Ekström Ice Shelf. Our findings show that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties, with important implications for research into ocean/ice-shelf/sea-ice interactions. However, a successful application of this

  1. New Age of 3D Geological Modelling or Complexity is not an Issue Anymore

    NASA Astrophysics Data System (ADS)

    Mitrofanov, Aleksandr

    2017-04-01

    modelling allows to develop geological models that really correspond with complicated geological reality. Models can include fault blocking, complex structural trends and folding; can be based on excessive input dataset (like lots of drilling on the mining stage) or, on the other hand, on a quite few drillholes intersections with significant input from geological interpretation of the deposit. In any case implicit modelling, if is used correctly, allows to incorporate the whole batch of geological data and relatively quickly get the easily adjustable, flexible and robust geological wireframes that can be used as a reliable foundation on the following stages of geological investigations. In SRK practice nowadays almost all the wireframe models used for structural and resource geology are developed with implicit modelling tools which significantly increased the speed and quality of geological modelling.

  2. Sampling and analysis of chemical element concentration distribution in rock units and orebodies

    NASA Astrophysics Data System (ADS)

    Agterberg, F. P.

    2012-01-01

    other orebody datasets (Whalesback copper deposit, Witwatersrand goldfields and Black Cargo titanium deposit). Additionally, it is discussed that nugget effects exist in a binary series of alternating mostly gneiss and metabasite previously derived from KTB borehole velocity and lithology logs, and within a series of 2796 copper concentration values from this same drill-hole.

  3. Current Research at the Endeavour Ridge 2000 Integrated Studies Site

    NASA Astrophysics Data System (ADS)

    Butterfield, D. A.; Kelley, D. S.; Ridge 2000 Community, R.

    2004-12-01

    Integrated geophysical, geological, chemical, and biological studies are being conducted on the Endeavour segment with primary support from NSF, the W.M. Keck Foundation, and NSERC (Canada). The research includes a seismic network, physical and chemical sensors, high-precision mapping and time-series sampling. Several research expeditions have taken place at the Endeavour ISS in the past year. In June 2003, an NSF-sponsored cruise with R.V. al T.G.Thompson/ROV al Jason2 installed microbial incubators in drill-holes in the sides of active sulfide chimneys and sampled rocks, fluids, and microbes in the Mothra and Main Endeavour Field (MEF). In July 2003, with al Thompson/Jason2, an NSF-LEXEN project at Baby Bare on Endeavour east flank conducted sampling through seafloor-penetrating probes, plus time-series sampling of fluids, microbes, and rocks at the MEF. In September 2003, with al Thompson/ROV al ROPOS, the Keck Proto-Neptune project installed a seismic network consisting of 1 broadband and 7 short-period seismometers, installation of chemical/physical sensors and time-series samplers for chemistry and microbiology in the MEF and Clam Bed sites, collection of rocks, fluids, animals, and microbes. In May/June 2004, an NSF-sponsored al Atlantis/Alvin cruise recovered sulfide incubators installed in 2003, redeployed a sulfide incubator, mapped MEF and Mothra vent fields with high-resolution Imagenix sonar, sampled fluids from MEF, Mothra, and Clam Bed, recovered year-long time-series fluid and microbial samplers from MEF and Clam Bed, recovered and installed hot vent temperature-resistivity monitors, cleaned up the MEF and deployed new markers at major sulfide structures. In August 2004, there were two MBARI/Keck-sponsored cruises with R.V. al Western Flyer/ROV al Tiburon. The first cruise completed the seismic network with addition of two more broadband seismometers and serviced all 7 short-period seismometers. al Tiburon then performed microbial and chemical

  4. Prediction and discovery of new geothermal resources in the Great Basin: Multiple evidence of a large undiscovered resource base

    USGS Publications Warehouse

    Coolbaugh, M.F.; Raines, G.L.; Zehner, R.E.; Shevenell, L.; Williams, C.F.

    2006-01-01

    Geothermal potential maps by themselves cannot directly be used to estimate undiscovered resources. To address the undiscovered resource base in the Great Basin, a new and relatively quantitative methodology is presented. The methodology involves three steps, the first being the construction of a data-driven probabilistic model of the location of known geothermal systems using weights of evidence. The second step is the construction of a degree-of-exploration model. This degree-of-exploration model uses expert judgment in a fuzzy logic context to estimate how well each spot in the state has been explored, using as constraints digital maps of the depth to the water table, presence of the carbonate aquifer, and the location, depth, and type of drill-holes. Finally, the exploration model and the data-driven occurrence model are combined together quantitatively using area-weighted modifications to the weights-of-evidence equations. Using this methodology in the state of Nevada, the number of undiscovered geothermal systems with reservoir temperatures ???100??C is estimated at 157, which is 3.2 times greater than the 69 known systems. Currently, nine of the 69 known systems are producing electricity. If it is conservatively assumed that an additional nine for a total of 18 of the known systems will eventually produce electricity, then the model predicts 59 known and undiscovered geothermal systems are capable of producing electricity under current economic conditions in the state, a figure that is more than six times higher than the current number. Many additional geothermal systems could potentially become economic under improved economic conditions or with improved methods of reservoir stimulation (Enhanced Geothermal Systems).This large predicted geothermal resource base appears corroborated by recent grass-roots geothermal discoveries in the state of Nevada. At least two and possibly three newly recognized geothermal systems with estimated reservoir temperatures

  5. Sedimentary basins reconnaissance using the magnetic Tilt-Depth method

    USGS Publications Warehouse

    Salem, A.; Williams, S.; Samson, E.; Fairhead, D.; Ravat, D.; Blakely, R.J.

    2010-01-01

    basement). The method is especially valuable as a reconnaissance tool in regions where drillhole or seismic information are either scarce, lacking, or ambiguous.

  6. The potential of stalagmites from the Patagonian Andes as sub-annually-resolved paleoclimate records

    NASA Astrophysics Data System (ADS)

    Kilian, Rolf; Schimpf, Daniel; Mangini, Augusto; Kronz, Andreas; Wörner, Gerhard; Simon, Klaus; Spötl, Christoph; Arz, Helge

    2010-05-01

    Stalagmites of the superhumid southern Andes are occasionally formed in small non-carst caves in a metamorphic and/or granitoid basement. They originate from coastal erosion in fracture zones during periods of higher sea levels. These small and relatively open caves are equilibrated with outside temperatures. Their drip rates reflect regional precipitation related to westerly wind intensities. To evaluate the reproducibility of proxies of different stalagmites we have investigated three U/Th-dated stalagmites (each one with 14-16 ages) from a single cave which grew simultaneously during the last 5 Ka. The host rocks provide a large variety of fine-grained siliciclastic minerals which are deposited on the stalagmite. Thin sections, scanning electron microscope, electron microprobe, and cave monitoring show that up to 3 wt% of siliciclastic minerals was accumulated successively on top of the stalagmites, depending on the individual drip rates above a certain threshold level. The amount of detritus was determined by the contents of detrital elements like Y and HREE, which were measured by ICP-MS (LAM-ICP-MS) from drill-holes (1-1.5 mm diameter) and laser ablation (5-10 μm steps). The LAM-ICP-MS pattern of e.g. Y and Al show a monthly resolution with clear seasonal cycles for the last 5 Kyrs. The presumable annual cycles match well into the time span in-between single Th/U ages. The seasonality results from two times higher drip rates in southern hemisphere summer (stronger westerlies) compared to winter. The time series show annual as well as typical sun-spot-related cyclicities (~11, 90, 210 years). Since these proxies are only sensitive to precipitation (and westerly changes) we suggest that the westerly intensities are controlled indirectly by changes in the sun's activity. Typically acid soil water with pH values of 3-5 leach several elements (U, Sr, Fe, Mg etc.) from the surrounding rocks, leading to high Mg/Ca ratios in the stalagmite during less humid periods

  7. Early postcaldera rhyolite and structural resurgence at Long Valley Caldera, California

    NASA Astrophysics Data System (ADS)

    Hildreth, Wes; Fierstein, Judy; Calvert, Andrew

    2017-04-01

    After the 767-ka caldera-forming eruption of 650 km3 of rhyolite magma as the Bishop Tuff, 90-100 km3 of similar rhyolite erupted in the west-central part of Long Valley caldera in as many as 40 batches spread over the 110,000-year interval from 750 ka to 640 ka. Centrally, this Early Rhyolite (ER) is as thick as 622 m, but it spread radially to cover much of the caldera floor, where half its area is now concealed by post-ER sediments and lavas. At least 75% of the ER is aphyric rhyolite tuff. Drillholes encountered 22 (altered) ER lava flows intercalated in the pyroclastic pile, and another 11 units of (largely fresh) ER lava are exposed on the caldera's resurgent dome and at Lookout Mountain. Exposed units have been distinguished, mapped, studied petrographically and chemically, and radioisotopically dated; each is described in detail. Their phenocryst contents range from 0 to 2.5 wt%. All the phyric units have plagioclase, orthopyroxene, and ilmenite; most have biotite and rare tiny magnetite, and a few contain rare zircon. The compositional range of fresh obsidians is narrow-74.3-75.0% SiO2, 1.21-1.37% FeO*, and 5.12-5.26% K2O, but wider variations in Ti, Ba, Sr, and Zr permit distinction of individual units and eruptive groups. The limited chemical and petrographic variability shown by so many ER batches released episodically for 110,000 years suggests a thermally buffered and well-stirred reservoir. The ER central area, where ER eruptions had taken place, was uplifted 400 m to form a structural dome 10 km in diameter. Most of the inflation is attributable to 10 sills of ER that intrude the Bishop Tuff beneath the uplift, but other processes potentially contributing to resurgence are also considered. As shown by erratics of Mesozoic rocks ice-rafted from the Sierra Nevada and dropped on ER lavas, much of the ER had erupted early enough and at low enough elevation to be inundated by the intracaldera lake and was only later lifted by the resurgence that also

  8. Fischer Assays of Oil-Shale Drill Cores and Rotary Cuttings from the Greater Green River Basin, Southwestern Wyoming

    USGS Publications Warehouse

    ,

    2008-01-01

    ,000 Fischer assays from 186 core holes and 240 rotary drill holes. Most of the oil yield data are from analyses performed by the former U.S. Bureau of Mines oil shale laboratory in Laramie, Wyoming, with some analyses made by private laboratories. Location data for 971 Wyoming oil-shale drill holes are listed in a spreadsheet that is included in the CD-ROM. These Wyoming Fischer assays and histograms are part of a much larger collection of oil-shale information, including geophysical and lithologic logs, water data, chemical and X-ray diffraction analyses on the Green River oil-shale deposits in Colorado, Utah, and Wyoming held by the U.S. Geological Survey. Because of an increased interest in oil shale, this CD-ROM containing Fischer assay data and oil-yield histograms for the Green River oil-shale deposits in southwestern Wyoming is being released to the public. Microsoft Excel spreadsheets included with Chapter 2 contain the Fischer assay data from the 426 holes and data on the company name and drill-hole name, and location. Histograms of the oil yields obtained from the Fischer assays are presented in both Grapher and PDF format. Fischer assay text data files are also included in the CD-ROM.

  9. Erosion modelling and sedimentary balance in an early anthropised watershed during the Holocene

    NASA Astrophysics Data System (ADS)

    Vella, C.; Canut, V.; Parisot, J.-C.; Hermitte, D.; Fleury, J.; Dussouillez, P.; Pailles, C.; Duval, S.; Chausserie-Laprée, J.

    2009-04-01

    The ria of Renaïres, on the western part of a small calcareous range between Marseilles and the Rhône delta, is a natural, elongated and narrow calanque drained by only one stream, the Reraille. The reduced size of its catchment (12km2) enables the easy identification of the local influence of climate and sea level fluctuations on sedimentation rythms. The relative sea level rise was revealed by peat deposits located only 10 kilometers away from the ria (Vella et al., 2005). Human occupation is deduced by archaeological data on the catchment area (Martigues Local council Services) allowing comparison between diachronic maps of human occupation from the Neolitic to medieval period. As such, the watershed of Reraille is the perfect site to study influences of human impact on erosion and sedimentation during the Holocene. Sedimentation in the upper part of the basin has been completely excavated by recent archaelogical works prior to urban development. Sediment accumulation is totaly quantified and dated by archaelogical remains and radiocarbon datings. In the bottom of the basin, erosional products are measured from the sedimentation trapped in the highly protected ria. Quantification of the trapped sediment was determined from 10 geotechnical drillholes, 5 cored holes of 10m length, and an electrical resistivity survey comprising a longitudinal profile and 4 cross-sections. The data sets were integrated into a GIS program and allowed a 3D reconstruction of volumes trapped at the exit of the system. Although the outgoing volumes are considered as unimportant, an offshore seismic reflection survey is planned for september 2009 to establish baseline data. The results indicate that the sedimentation speed increased in the upper part of the catchment : sedimentation was low before VIth century BC, it increased for 1500 years and was highest during the modern period. This sedimentation dynamic could suggest an increased destabilization of hillsides particularly during

  10. QUANTITATIVE METHODS FOR RESERVOIR CHARACTERIZATION AND IMPROVED RECOVERY: APPLICATION TO HEAVY OIL SANDS

    SciTech Connect

    James W. Castle; Fred J. Molz; Ronald W. Falta; Cynthia L. Dinwiddie; Scott E. Brame; Robert A. Bridges

    2002-10-30

    Improved prediction of interwell reservoir heterogeneity has the potential to increase productivity and to reduce recovery cost for California's heavy oil sands, which contain approximately 2.3 billion barrels of remaining reserves in the Temblor Formation and in other formations of the San Joaquin Valley. This investigation involves application of advanced analytical property-distribution methods conditioned to continuous outcrop control for improved reservoir characterization and simulation, particularly in heavy oil sands. The investigation was performed in collaboration with Chevron Production Company U.S.A. as an industrial partner, and incorporates data from the Temblor Formation in Chevron's West Coalinga Field. Observations of lateral variability and vertical sequences observed in Temblor Formation outcrops has led to a better understanding of reservoir geology in West Coalinga Field. Based on the characteristics of stratigraphic bounding surfaces in the outcrops, these surfaces were identified in the subsurface using cores and logs. The bounding surfaces were mapped and then used as reference horizons in the reservoir modeling. Facies groups and facies tracts were recognized from outcrops and cores of the Temblor Formation and were applied to defining the stratigraphic framework and facies architecture for building 3D geological models. The following facies tracts were recognized: incised valley, estuarine, tide- to wave-dominated shoreline, diatomite, and subtidal. A new minipermeameter probe, which has important advantages over previous methods of measuring outcrop permeability, was developed during this project. The device, which measures permeability at the distal end of a small drillhole, avoids surface weathering effects and provides a superior seal compared with previous methods for measuring outcrop permeability. The new probe was used successfully for obtaining a high-quality permeability data set from an outcrop in southern Utah. Results obtained

  11. Black shale source rocks and oil generation in the Cambrian and Ordovician of the central Appalachian Basin, USA

    USGS Publications Warehouse

    Ryder, R.T.; Burruss, R.C.; Hatch, J.R.

    1998-01-01

    Nearly 600 million bbl of oil (MMBO) and 1 to 1.5 trillion ft3 (tcf) of gas have been produced from Cambrian and Ordovician reservoirs (carbonate and sandstone) in the Ohio part of the Appalachian basin and on adjoining arches in Ohio, Indiana, and Ontario, Canada. Most of the oil and gas is concentrated in the giant Lima-Indiana field on the Findlay and Kankakee arches and in small fields distributed along the Knox unconformity. Based on new geochemical analyses of oils, potential source rocks, bitumen extracts, and previously published geochemical data, we conclude that the oils in both groups of fields originated from Middle and Upper Ordovician blcak shale (Utica and Antes shales) in the Appalachian basin. Moroever, we suggest that approximately 300 MMBO and many trillions of cubic feet of gas in the Lower Silurian Clinton sands of eastern Ohio originated in the same source rocks. Oils from the Cambrian and Ordovician reservoirs have similar saturated hydrocarbon compositions, biomarker distributions, and carbon isotope signatures. Regional variations in the oils are attributed to differences in thermal maturation rather than to differences in source. Total organic carbon content, genetic potential, regional extent, and bitument extract geochemistry identify the balck shale of the Utica and Antes shales as the most plausible source of the oils. Other Cambrian and Ordovician shale and carbonate units, such as the Wells Creek formation, which rests on the Knox unconformity, and the Rome Formation and Conasauga Group in the Rome trough, are considered to be only local petroleum sources. Tmax, CAI, and pyrolysis yields from drill-hole cuttings and core indicate that the Utica Shale in eastern and central Ohio is mature with respect to oil generation. Burial, thermal, and hydrocarbon-generation history models suggest that much of the oil was generated from the Utica-Antes source in the late Paleozoic during the Alleghanian orogeny. A pervasive fracture network

  12. Structure and change of Piton de la Fournaise volcano inferred from gravity surveys (Reunion Island, Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Lénat, J.; Gailler, L.; Lambert, M.; Levieux, G.; Villeneuve, N.; Froger, J.

    2008-12-01

    A new gravity map of Piton de la Fournaise volcano has been established using new on land and offshore measurements. The data coverage allows for the differentiation of shallow and deeper structures. 3D and 2 3/4 D models have been calculated. Short wavelength positive anomalies depict the presence of piles of thick dense lava flows filling volcano-tectonic depressions. The lateral extension and the depth of paleo- depressions associated with the collapses of the Plaine des Sables-Fond de la Rivière de l'Est and of the Enclos Fouqué are thus estimated. The negative short wavelength of the Central Cone suggests it has been built by thin, highly vesisculated and fractured lava flows. Low density hydrothermally altered rock beneath the summit can also contribute to the gravity low as well as a column of fractured rocks between the surface collapse and a magma reservoir. Negative short to medium wavelength anomalies have been observed in the Rivière des Remparts-Rivière Langevin zone and above the offshore continuation of the NE and SE rift zones. We speculate that the former zone is underlain by breccias related to erosion or mass- wasting events. The offshore continuation of the rift zones is most likely built by hyaloclastites and pillow lavas. Two main deeper dense structures exist: the Grand Brûlé complex and a complex beneath the Plaine des Sables and part of the Enclos. From a deep drill-hole it has been established that the Grand Brûlé complex is a hypovolcanic complex of intrusions and cumulates. We show that this structure is disconnected from the present day Piton de la Fournaise volcano. Its interpretation as the hypovolcanic complex of the ancient concealed Les Alizés volcano remains valid. The similar nature of the other dense complex is inferred by analogy with comparable anomalies in this geological context and by the presence of frequent gabbro and peridotite xenoliths in eruptive products in this area. We suggest that this complex has

  13. Hafnium-neodymium isotope systematics of ocean island basalts

    NASA Astrophysics Data System (ADS)

    Salters, V. J.; Hart, S. R.; Blichert-Toft, J.

    2002-12-01

    We have measured Hf and Nd isotopes in basalts from Koolau, Hawaii, as well as from the Samoa hot spot chain. The Hawaiian samples, the Koolau drillhole, show limited variation in Hf or Nd isotope composition (epsilon Nd varies from 4.2 to 7.3 and epsilon Hf varies from 8 to 12.2). The correlated variation, based on 38 samples, has an R-squared of 0.86. The data results in a slope of 1.23 on a Hf-Nd isotope correlation diagram (epsilon notation). This slope is shallower than the mantle array defined by ocean island basalts which is 1.4. Contrary to previous work the Hf-Nd-isotope correlation for Samoa shows an even shallower slope than the Hawaiian samples. The Samoan samples are surface samples as well as recently dredged samples of the youngest extension of the Samoan hot spot [Hart et al., 2000]. The samples show a large range in Sr-Nd and Hf compositions with epsilon-Nd ranging from -2.2 to 3.5 and epsilon-Hf ranging from 2.2 to 7.5 and large range in Sr-isotopic composition with extreme values up to 0.7088. Hf-isotopic composition is well correlated with both Sr and Nd isotopic composition (R-squared is 0.93 and 0.95 respectively). Based on 10 samples the slope of the correlated isotope variation on an epsilon Hf-Nd isotope diagram is 0.97, which is shallower than any Hf-Nd-isotope correlation measured before. The shallow slope of the Hawaiian basalts on a Hf-Nd isotope correlation diagram has been interpreted as being distinctive of a contribution of recycled pelagic sediments [Blichert-Toft et al., 1999]. However, for Samoa the influence of pelagic sediments was thought to be limited as EMII basalts were thought to find its source in either a mixture of recycled oceanic crust with terrigenous sediments, or carbonatite metasomatism as an EMII-like component has been recognized in xenoliths affected by carbonatite metasomatism with Sr-isotopic compositions up to 0.7128 [Hauri et al., 1993]. Our new Hf-isotope data seem to rule out a recycled terrigenous

  14. Sub-crop geologic map of pre-Tertiary rocks in the Yucca Flat and northern Frenchman Flat areas, Nevada Test Site, southern Nevada

    SciTech Connect

    Cole, J.C.; Harris, A.G.; Wahl, R.R.

    1997-10-02

    This map displays interpreted structural and stratigraphic relations among the Paleozoic and older rocks of the Nevada Test Site region beneath the Miocene volcanic rocks and younger alluvium in the Yucca Flat and northern Frenchman Flat basins. These interpretations are based on a comprehensive examination and review of data for more than 77 drillholes that penetrated part of the pre-Tertiary basement beneath these post-middle Miocene structural basins. Biostratigraphic data from conodont fossils were newly obtained for 31 of these holes, and a thorough review of all prior microfossil paleontologic data is incorporated in the analysis. Subsurface relationships are interpreted in light of a revised regional geologic framework synthesized from detailed geologic mapping in the ranges surrounding Yucca Flat, from comprehensive stratigraphic studies in the region, and from additional detailed field studies on and around the Nevada Test Site. All available data indicate the subsurface geology of Yucca Flat is considerably more complicated than previous interpretations have suggested. The western part of the basin, in particular, is underlain by relics of the eastward-vergent Belted Range thrust system that are folded back toward the west and thrust by local, west-vergent contractional structures of the CP thrust system. Field evidence from the ranges surrounding the north end of Yucca Flat indicate that two significant strike-slip faults track southward beneath the post-middle Miocene basin fill, but their subsurface traces cannot be closely defined from the available evidence. In contrast, the eastern part of the Yucca Flat basin is interpreted to be underlain by a fairly simple north-trending, broad syncline in the pre-Tertiary units. Far fewer data are available for the northern Frenchman Flat basin, but regional analysis indicates the pre-Tertiary structure there should also be relatively simple and not affected by thrusting. This new interpretation has implications

  15. Individual and combined effects of noise-like whole-body vibration and parathyroid hormone treatment on bone defect repair in ovariectomized mice.

    PubMed

    Matsumoto, Takeshi; Sato, Daisuke; Hashimoto, Yoshihiro

    2016-01-01

    The effectiveness of intermittent administration of parathyroid hormone and exposure to whole-body vibration on osteoporotic fracture healing has been previously investigated, but data on their concurrent use are lacking. Thus, we evaluated the effects of intermittent administration of parathyroid hormone, whole-body vibration, and their combination on bone repair in osteoporotic mice. Noise-like whole-body vibration with a broad frequency range was used instead of conventional sine-wave whole-body vibration at a specific frequency. Mice were ovariectomized at 9 weeks of age and subjected to drill-hole surgery in the right tibial diaphysis at 11 weeks. The animals were divided into four groups (n = 12 each): a control group, and groups treated with intermittent administration of parathyroid hormone, noise-like whole-body vibration, and both. From postoperative day 2, the groups treated with intermittent administration of parathyroid hormone and groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration were subcutaneously administered parathyroid hormone at a dose of 30 µg/kg/day. The groups treated with noise-like whole-body vibration and groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration were exposed to noise-like whole-body vibration at a root mean squared acceleration of 0.3g and frequency components of 45-100 Hz for 20 min/day. Following 18 days of interventions, the right tibiae were harvested, and the regenerated bone was analyzed by micro-computed tomography and nanoindentation testing. Compared with the control group, callus volume fraction was 40% higher in groups treated with intermittent administration of parathyroid hormone and 73% higher in groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration, and callus thickness was 35% wider in groups treated with both

  16. Unravelling the deep fluid composition in the Taupo Volcanic Zone: insight into the magmatic-hydrothermal transition

    NASA Astrophysics Data System (ADS)

    Chambefort, I. S.; Lewis, B.; Boseley, C.; Begue, F.; Rae, A.

    2012-12-01

    The Ngatamariki Geothermal Field represents the only location in the Taupo Volcanic Zone where geothermal well drilling has intercepted intrusive rocks with a high temperature alteration halo. Thus it presents the perfect opportunity to study the magmatic-hydrothermal transition in the TVZ by characterising the nature of the deep magmatic fluids inferred to be linked to the geothermal heat source. In addition to the calc-alkaline Ngatamariki diorite (encountered in a 1985 drillhole; Wood, 1986), recent (2012) geothermal drilling encountered a quartz-phyric tonalite. After emplacement, these intrusions cooled, degassed, and produced a high temperature alteration halo, associated with intense quartz-illite/muscovite-pyrite alteration and pervasive quartz replacement of the overlying tuff-breccia. This alteration zone contains abundant high temperature quartz veins, similar to quartz veining stockwork characteristic of Porphyry Cu (±Au-Mo) systems. The recently encountered quartz-phyric tonalite contains common phenocrysts of quartz and pseudomorphs of plagioclase and minor ferromagnesian minerals (predominantly amphiboles) in a medium-grained, magnetite-bearing felsic groundmass. Quartz phenocrysts are generally rounded and embayed quartz eyes (≤1 cm diam.), or skeletal crystals. SEM-CL imaging was used to map the crystallisation history of the phenocrystic quartz in the tonalite and the quartz veins cross-cutting the diorite and overlying pyroclastic rocks. The quartz eyes show a complex growth history with zones of dissolution and recrystallisation. Skeletal quartz crystals also have complex zoning and are outlined by myrmekitic textures and/or dendritic overgrowths with the groundmass (granophyric textures). These features form in granites due to undercooling during shallow magmatic emplacement and are often associated with the exsolution of a volatile phase. Cathodoluminescence indicates that the edges of the quartz veins are lined by euhedral crystals

  17. Geophysical logs and water-quality data collected for boreholes Kimama-1A and -1B, and a Kimama water supply well near Kimama, southern Idaho

    USGS Publications Warehouse

    Twining, Brian V.; Bartholomay, Roy C.

    2011-01-01

    with visual inspection of core photographs. Temperature logs from the water table surface (about 260 feet BLS) to the bottom of borehole Kimama-1B (2,498 feet BLS) were nearly isothermal, ranging from about 62 to 64 degrees Fahrenheit. Gyroscopic data revealed that borehole Kimama-1B begins to separate from borehole Kimama-1A near a depth of 676 feet BLS. Drillhole azimuth and horizontal deviation at total logged depth for boreholes Kimama-1A and -1B were 172.6 and 188.3 degrees and 25.9 and 82.0 feet, respectively. Water samples were collected and analyzed for common ions; selected trace elements; nutrients; isotopes of hydrogen, oxygen, and carbon; and selected radionuclides. One set of water samples was collected from the KWS well and the two other sample sets were collected from borehole Kimama-1A near 460 and 830 feet BLS. With one exception, data for all three zones sampled near Kimama generally indicated that the water chemistry was similar. The exception was found in the deepest zone in borehole Kimama-1A (830 feet BLS) where concentrations probably were affected by the drilling mud. A comparison of the inorganic, organic, and stable chemistry data between the KWS well and the 460-foot zone in borehole Kimama-1A indicated similar chemistry of the aquifer water, except for some variability with nitrate plus nitrite, orthophosphate, iron, zinc, and carbon-14. Radionuclide concentrations were either less than reporting levels or at background levels for the eastern Snake River Plain aquifer.

  18. Oxygen isotope perspective on crustal evolution on early Earth: A record of Precambrian shales with emphasis on Paleoproterozoic glaciations and Great Oxygenation Event

    NASA Astrophysics Data System (ADS)

    Bindeman, I. N.; Bekker, A.; Zakharov, D. O.

    2016-03-01

    We present stable isotope and chemical data for 206 Precambrian bulk shale and tillite samples that were collected mostly from drillholes on all continents and span the age range from 0.5 to 3.5 Ga with a dense coverage for 2.5-2.2 Ga time interval when Earth experienced four Snowball Earth glaciations and the irreversible rise in atmospheric O2. We observe significant, downward shift of several ‰ and a smaller range of δ18 O values (7 to 9‰) in shales that are associated with the Paleoproterozoic and, potentially, Neoproterozoic glaciations. The Paleoproterozoic samples consist of more than 50% mica minerals and have equal or higher chemical index of alteration than overlying and underlying formations and thus underwent equal or greater degrees of chemical weathering. Their pervasively low δ18 O and δD (down to - 85 ‰) values provide strong evidence of alteration and diagenesis in contact with ultra-low δ18 O glacial meltwaters in lacustrine, deltaic or periglacial lake (sikussak-type) environments associated with the Paleoproterozoic glaciations. The δDsilicate values for the rest of Precambrian shales range from -75 to - 50 ‰ and are comparable to those for Phanerozoic and Archean shales. Likewise, these samples have similar ranges in δ13Corg values (-23 to - 33 ‰ PDB) and Corg content (0.0 to 10 wt%) to Phanerozoic shales. Precambrian shales have a large range of δ18 O values comparable to that of the Phanerozoic shales in each age group and formation, suggesting similar variability in the provenance and intensity of chemical weathering, except for the earliest 3.3-3.5 Ga Archean shales, which have consistently lower δ18 O values. Moreover, Paleoproterozoic shales that bracket in age the Great Oxidation Event (GOE) overlap in δ18 O values. Absence of a step-wise increase in δ18 O and δD values suggests that despite the first-order change in the composition of the atmosphere, weathering cycle was not dramatically affected by the GOE at ∼2

  19. Paleoproterozoic pyrobitumen: Re-Os goechemistry reveals the fate of giant carbon accumulations in Russian Karelia

    NASA Astrophysics Data System (ADS)

    Hannah, J. L.; Stein, H. J.; Yang, G.; Zimmerman, A.

    2010-12-01

    Carbon-rich pyrobitumen is exposed in abundance in the Onega Basin of Karelia, northwestern Russia - the fossil remains of a giant oil field [1]. The pyrobitumen, locally termed “shungite”, occurs as veins, lenses, and droplets within the Zaonezhskaya and Kondopozhskaya Formations, part of a Paleoproterozoic platform sequence developed on a rifted continental margin. In its purest form, this material approaches 100% C. Less pure pyrobitumen occurs in Corg-rich siltstones, which are intercalated with basaltic flows and sills, including peperites. Locally, the pyrobitumen forms a massive organo-siliceous diapir, cross-cutting the sedimentary section. A Re-Os isochron for six samples of Corg-rich siltstone taken from a mine adit in Shunga village yields a precise age of 2.05 Ga [2], fitting existing constraints for the depositional age. The initial 187Os/188Os ratio given by the isochron for the Shunga adit samples is within uncertainty of chondritic (0.113 at 2.05 Ga), as expected in a restricted rift basin dominated by hydrothermal Os. Re-Os data for samples from ICDP FAR-DEEP drillhole 13A near Shunga village, tell the rest of the story. Eleven ~500 mg samples, drilled from two 3-cm intervals 0.5 m apart in a single core, yield an isochron age of ~1.73 Ga with initial 187Os/188Os = 5. This age is consistent with the latest phase of the Svecofennian orogeny [3], known to have impacted the Onega Basin. Assuming isotopic homogenization (maturation) of the pyrobitumen took place during a relatively brief thermal maximum, the largest control on the present-day 187Os/188Os is the 187Re/188Os. The 187Re/188Os for the 17 siltstone samples analyzed to date range from 280 to 1250. An average 187Re/188Os of 900 will raise the 187Os/188Os from 0.113 to about 5 during the 320 m.y. between deposition (2.05 Ga) and maturation (1.73 Ga) - precisely the value determined by our isochron. Similarly, the lower 187Re/188Os of 280 for three samples of lustrous pyrobitumen from the

  20. Single-well tracer test sensitivity w. r. to hydrofrac and matrix parameters (case study for the Horstberg site in the N-German Sedimentary Basin)

    NASA Astrophysics Data System (ADS)

    Ghergut, I.; Behrens, H.; Holzbecher, E.; Jung, R.; Sauter, M.; Tischner, T.

    2012-04-01

    At the geothermal pilot site Horstberg in the N-German Sedimentary Basin, a complex field experiment program was conducted (2003-2007) by the Federal Institute for Geosciences and Natural Resources (BGR) together with the Leibniz Institute for Applied Geosciences (GGA), aimed at evaluating the performance of innovative technologies for heat extraction, for direct use, from a single geothermal well[1],[2]. The envisaged single-well operation schemes comprised inter-layer circulation through a large-area hydrofrac (whose successful creation could thus be demonstrated), and single-screen 'huff-puff' in suitable (stimulated) layers, seated in sandstone-claystone formations in 3-4 km depth, with temperatures exceeding 160 ° C. Relying on Horstberg tracer-test data, we analyze heat and solute tracer transport in three characteristic hydraulic settings: (A) single-screen, multi-layer push-pull, with spiking and sampling at lower well-screen in low-permeability sandstone layer ('Detfurth'), from which hydrofrac propagation (through several adjacent layers) was initiated; (B) single-screen, single-layer push-pull, with spiking and sampling at upper well-screen within a more permeable sandstone layer ('Solling'); (C) inter-layer vertical push through above-mentioned hydrofrac, with spiking at well-screen of A, and sampling at well-screen of B. Owing to drill-hole deviation, the hydraulically-induced frac will, in its vertical propagation, reach the upper sandstone layer in a certain horizontal distance X from the upper well-screen, whose value turns out to be the major controlling parameter for the system's thermal lifetime under operation scheme C (values of X below ~8 m leading to premature thermal breakthrough, with the minimum-target rate of fluid turnover; however, the injection pressure required for maintaining the target outflow rate will also increase with X, which renders scheme C uneconomical, or technically-infeasible, when X exceeds ~15 m). Tracer signals in C

  1. 2.8-Ma ash-flow caldera at Chegem River in the northern Caucasus Mountains (Russia), contemporaneous granites, and associated ore deposits

    USGS Publications Warehouse

    Lipman, P.W.; Bogatikov, O.A.; Tsvetkov, A.A.; Gazis, C.; Gurbanov, A.G.; Hon, K.; Koronovsky, N.V.; Kovalenko, V.I.; Marchev, P.

    1993-01-01

    Diverse latest Pliocene volcanic and plutonic rocks in the north-central Caucasus Mountains of southern Russia are newly interpreted as components of a large caldera system that erupted a compositionally zoned rhyolite-dacite ash-flow sheet at 2.83 ?? 0.02 Ma (sanidine and biotite 40Ar/39Ar). Despite its location within a cratonic collision zone, the Chegem system is structurally and petrologically similar to typical calderas of continental-margin volcanic arcs. Erosional remnants of the outflow Chegem Tuff sheet extend at least 50 km north from the source caldera in the upper Chegem River. These outflow remnants were previously interpreted by others as erupted from several local vents, but petrologic similarities indicate a common origin and correlation with thick intracaldera Chegem Tuff. The 11 ?? 15 km caldera and associated intrusions are superbly exposed over a vertical range of 2,300 m in deep canyons above treeline (elev. to 3,800 m). Densely welded intracaldera Chegem Tuff, previously described by others as a rhyolite lava plateau, forms a single cooling unit, is > 2 km thick, and contains large slide blocks from the caldera walls. Caldera subsidence was accommodated along several concentric ring fractures. No prevolcanic floor is exposed within the central core of the caldera. The caldera-filling tuff is overlain by andesitic lavas and cut by a 2.84 ?? 0.03-Ma porphyritic granodiorite intrusion that has a cooling age analytically indistinguishable from that of the tuffs. The Eldjurta Granite, a pluton exposed low in the next large canyon (Baksan River) 10 km to the northwest of the caldera, yields variable K-feldspar and biotite ages (2.8 to 1.0 Ma) through a 5-km vertical range in surface and drill-hole samples. These variable dates appear to record a prolonged complex cooling history within upper parts of another caldera-related pluton. Major W-Mo ore deposits at the Tirniauz mine are hosted in skarns and hornfels along the roof of the Eldjurta Granite

  2. Environmental Challenges Related to the Acquisition of the Trans Carpathian Wide Angle Reflection and Refraction Line

    NASA Astrophysics Data System (ADS)

    Dragut, Dorina-Alina; Schultz, Gehrig; Mocanu, Victor; Stephenson, Randell; Janik, Tomasz; Starostenko, Vitaly

    2015-04-01

    Complex structures like the Carpathian Orogen and its neighbouring platforms and related inter-orogenic basin system can be understood only by complex integration of complementary investigative tools. Most of regional geoscientific investigations in Romania have targeted the very intricate, high intermediate-depth seismicity, clustered Carpathian Bend Zone: Vrancea. Despite huge geological and geophysical efforts, the area remains a matter of robust debate, at least from the point of view of geodynamic driving mechanisms. However, other areas outside Vrancea remained somehow "orphaned". However, a large wide angle refraction and reflection (WARR) survey was carried out in the summer of 2014 by a large international partnership in order to study the transition from the East European Platform to the northern part of the Romanian Eastern Carpathians, Transylvanian Basin and the Apuseni Mountains. The main scientific objectives of the WARR project relate to three main investigation domains: crustal architecture; affinity of crystalline basement and sedimentary basins architecture. The profile is about 700 km in total, in Ukraine and Romania. Recorders were placed at 1.75 - 2.0 km intervals along an alignment forming the Romanian segment. Recorders used were stand-alone DSS Cubes from the Helmholz Center of GFZ Potsdam and from the Institute of Geophysics of the Polish Academy of Sciences. The seismic sources were explosives ("Riogel" and "Riodet" by Maxam), with shotpoints spaced at 20 - 65 km with a total of 800 - 1200 kg explosives/site in clusters of drill-holes loaded with 50 kg explosive/hole, average depth of 25 m. Very complicated and legally-challenging environmental permitting requirements represented a real issue for successful implementation of the project. The main concern of local and central authorities related to potential pollution of sensitive components. Here, we present the strategy, actions and results concluded in order to reach the scientific and

  3. Geophysical Characterization of Yucca Fault in Yucca Flat, Nevada Test Site, Nevada

    NASA Astrophysics Data System (ADS)

    Burton, B. L.; Haines, S. S.; Sweetkind, D. S.; Asch, T. H.

    2007-12-01

    Yucca Fault is a north-striking, east-dipping normal fault located in the eastern half of Yucca Flat, an elongate basin on the Nevada Test Site in the Basin and Range province. The fault offsets alluvial material in the shallow subsurface and has a prominent surface scarp; abundant drill-hole data record offsets of 200 to 400 m on underlying Miocene volcanic rocks and Paleozoic carbonate bedrock. Understanding the geometry and physical properties of the Yucca Fault and other fault zones in Yucca Flat is an important component in assessing the role of faults in the groundwater flow and transport at the Nevada Test Site. From 2005 to 2007, we conducted near- surface geophysical studies across the surface trace of the Yucca Fault to determine the feasibility of the chosen methods in helping to evaluate the extent of footwall damage and to investigate possible hanging wall splay faults. In particular, we selected an area of the fault that exhibited marked sinuosity and multiple splays that result from the interaction of en echelon linked segments. We acquired direct current (dc) resistivity, compressional (P) and shear wave seismic, ground magnetic, and audio magnetotelluric (AMT) data. The dc resistivity data, including both two-dimensional and three-dimensional data sets, show a 200 ohm-m higher resistivity on the hanging wall than on the footwall. These data sets provide the best high-resolution detail of the subsurface geometry of the fault zone for the top 30 to 35 m. These data correlate well with detailed surface fracture mapping, where subtle changes in the shallow resistivity structure are interpreted to be a result of structural disruption of caliche cementation within the alluvium. The P-wave seismic data show a lower velocity zone that corresponds with the surface expression of the fault. The shear wave data, however, appear to suffer from converted (P-wave) arrivals produced by the shallow caliche layer and therefore do not provide useful information. The

  4. Observations From the Alpine Tethys and the Iberia/Newfoundland Margins Pertinent to the Interpretation of Magma-Poor Rifted Margins

    NASA Astrophysics Data System (ADS)

    Manatschal, G.; Lavier, L. L.

    2005-05-01

    Although the Iberia/Newfoundland and Alpine Tethys margins are of different age and ultimately had a different fate, they share remarkable similarities. These similarities permit us to compare direct observation and unlimited sampling of the ancient Alpine margins with the drill-hole and geophysical data from the present-day Iberia/Newfoundland margins. This exercise results in new concepts for the near surface response of lithospheric rupturing at magma-poor rifted margins. Rifting at these two pairs of margins can be described by three modes of extension: a stretching mode, a thinning mode and an exhumation mode. Each mode is characterized by a particular isostatic response to extension, its basin architecture and fault geometry, and the bulk rheological evolution of the extending lithosphere. Initial rifting was controlled by the stretching mode. Deformation in the upper crust and upper mantle was decoupled along mylonitic shear zones in the middle crust, rift-shoulder uplift was moderate to weak, and basins were distributed across the whole subsiding margin. During an advanced stage of rifting, extension became localized in the future distal margin and was controlled by the thinning mode. Extension in the upper crust and upper mantle were coupled along major mylonitic shear zones, rift-shoulder uplift was very pronounced and resulted in sub-aerial exposure of parts of the future distal margin. During this stage, the crust in the future distal margin was thinned by more than 15 km although no evidence for upper crustal extension is found in the stratigraphic record. Final rifting was localized in the previously thinned crust and was controlled by the exhumation mode. During this stage, downwards-concave faults exhumed lower crustal and mantle rocks to the seafloor leading to a tens of kilometres wide Zone of Exhumed Continental Mantle (ZECM). Despite of the high extension, these faults did not produce a major fault bounded topography. This final stage of rifting

  5. Discovery of Talc in SAFOD Serpentinite Cuttings: Possible Implications for the Origin of Creep in the San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Moore, D. E.; Rymer, M. J.

    2006-12-01

    The San Andreas Fault Observatory at Depth (SAFOD) drillsite is located near the southern end of the creeping section, and a portion of the well casing is actively deforming in response to creep on a fault strand intersected by the drillhole. Moderate amounts of serpentinite are present in SAFOD cuttings collected at 3320-3350 m measured depth, at the eastern margin of the zone of active deformation. Serpentinite also is found locally in surface exposures of the San Andreas Fault (SAF) along the creeping section. Aeromagnetic surveys indicate the presence of a flat-lying slab of serpentinite at several kilometers' depth on the northeast side of the SAF; this body truncates against the fault along a 50 kilometer segment northwest of Parkfield. Serpentinite commonly is invoked as the cause of creep along the SAF, but the frictional strengths of the serpentine minerals are too high overall to explain the low strength of the creeping section, as indicated by modelling of heat flow data and earthquake focal mechanisms. In addition, the serpentine minerals have the potential for unstable slip under certain P-T-velocity conditions. However, another mineral sometimes associated with serpentinite -- talc -- potentially could provide the connection between serpentinite and creep. Talc is a magnesium-rich phyllosilicate with a higher Si/Mg ratio than serpentine and it commonly forms as a result of Si-metasomatism of serpentinite and other ultramafic rocks. Recent experimental studies show that talc has a coefficient of friction on the order of 0.10-0.15 in the temperature range 100-400 degrees C (upper crustal temperatures) and it is characterized by inherently stable, velocity-strengthening behavior. Localization of shear in a talc-rich gouge zone could therefore satisfy the conditions for creep without the need to invoke other weakening mechanisms such as fluid overpressures. Talc has been identified in serpentinite grains from the SAFOD cutttings, using scanning electron

  6. After a century-Revised Paleogene coal stratigraphy, correlation, and deposition, Powder River Basin, Wyoming and Montana

    USGS Publications Warehouse

    Flores, Romeo M.; Spear, Brianne D.; Kinney, Scott A.; Purchase, Peter A.; Gallagher, Craig M.

    2010-01-01

    The stratigraphy, correlation, mapping, and depositional history of coal-bearing strata in the Paleogene Fort Union and Wasatch Formations in the Powder River Basin were mainly based on measurement and description of outcrops during the early 20th century. Subsequently, the quality and quantity of data improved with (1) exploration and development of oil, gas, and coal during the middle 20th century and (2) the onset of coalbed methane (CBM) development during the late 20th and early 21st centuries that resulted in the drilling of more than 26,000 closely spaced wells with accompanying geophysical logs. The closeness of the data control points, which average 0.5 mi (805 m) apart, made for better accuracy in the subsurface delineation and correlation of coal beds that greatly facilitated the construction of regional stratigraphic cross sections and the assessment of resources. The drillhole data show that coal beds previously mapped as merged coal zones, such as the Wyodak coal zone in the Wyoming part of the Powder River Basin, gradually thinned into several discontinuous beds and sequentially split into as many as 7 hierarchical orders westward and northward. The thinning and splitting of coal beds in these directions were accompanied by as much as a ten-fold increase in the thicknesses of sandstone-dominated intervals within the Wyodak coal zone. This probably resulted from thrust loading by the eastern front of the Bighorn uplift accompanied by vertical displacement along lineaments that caused subsidence of the western axial part of the Powder River Basin during Laramide deformation in Late Cretaceous and early Tertiary time. Accommodation space was thereby created for synsedimentary alluvial infilling that controlled thickening, thinning, splitting, pinching out, and areal distribution of coal beds. Equally important was differential subsidence between this main accommodation space and adjoining areas, which influenced the overlapping, for example, of the

  7. Coalbed methane resource potential and current prospects in Pennsylvania

    USGS Publications Warehouse

    Markowski, A.K.

    1998-01-01

    methane potential. Phase I of this study involved the entire Pennsylvanian coal-bearing interval of southwestern Pennsylvania. Phase II focused on a stratigraphic delineation and evaluation of Allegheny Group coal beds and associated sandstones. Several prospective coal beds and associated facies relationships with channel-fill sandstones were determined. Possible non-coal scenarios for coalbed methane include erosional contacts between coal beds and overlying channel-fill sandstones and areas of stacked channel-fill sandstones. Repetitive sequences of coal accumulation are stacked, commonly with shale interburden, and are also potential coalbed methane targets. Additional Pennsylvania Geological Survey drilling/coalbed methane sampling occurred in Armstrong, Beaver, Cambria, Greene, Lawrence, Somerset, and Washington Counties. Raw coalbed methane desorption data tables/graphical displays of gas contents versus depth, thickness, and time, and average composition and heating values from coal beds of the Allegheny Group to the Dunkard Group are available at the Pennsylvania Geological Survey. Further information on cross-sections, isopleth maps, isopach maps, raw drillhole data, and ownership issues can also be obtained from the same source.A mapping of the regional geology of the bituminous coal-bearing intervals in southwestern Pennsylvania reveal several prospective coal beds and associated facies relationships with channel-fill sandstones. Possible non-coal scenarios for coalbed methane include erosional contacts between coalbeds and overlying channel-fill sandstones and areas of stacked channel-fill sandstones. Repetitive sequences of coal accumulation are stacked, commonly with shale interburden. and are also potential coalbed methane targets.

  8. Mineralization by nanobacteria

    NASA Astrophysics Data System (ADS)

    Kajander, E. Olavi; Bjorklund, Michael; Ciftcioglu, Neva

    1998-07-01

    Nanobacteria are the smallest cell-walled bacteria, only recently discovered in human and cow blood and in commercial cell culture serum. In this study, we identified with energy-dispersive x-ray microanalysis and chemical analysis that all growth phases of nanobacteria produce biogenic apatite on their cell envelope. Fourier transform IR spectroscopy revealed the mineral as carbonate apatite. Previous models for stone formation have lead to a hypothesis that an elevated pH due to urease and/or alkaline phosphatase activity are important lithogenic factors. Our results indicate that carbonate apatite can be formed without these factors at pH 7.4 at physiological phosphate and calcium concentrations. Due to their specific macromolecules, nanobacteria can produce apatite very efficiency in media mimicking tissue fluids and glomerular filtrate and rapidly mineralizing most of available calcium and phosphate. This can be also monitored by (superscript 85)Sr incorporation and provides a unique model for in vitro studies on calcification. Recently, bacteria have been implicated in the formation of carbonate (hydroxy)fluorapatite in marine sediments. Apatite grains are found so commonly in sedimentary rocks that apatite is omitted in naming the stone. To prove that apatite and other minerals are formed by bacteria would implicate that the bacteria could be observed and their actions followed in stones. We have started to approach this in two ways. Firstly, by the use of sensitive methods for detecting specific bacterial components, like antigens, muramic acid and nucleic acids, that allow for detecting the presence of bacteria and, secondly, by follow-up of volatile bacterial metabolites observed by continuous monitoring with ion mobility spectrometry, IMCELL, working like an artificial, educatable smelling nose. The latter method might allow for remote real time detection of bacterial metabolism, a signature of life, in rocks via fractures of drillholes with or without

  9. Research Drilling on the Mid-Atlantic Ridge: IDDP Wells of Opportunity at Reykjanes, Iceland

    NASA Astrophysics Data System (ADS)

    Fridleifsson, G. O.; Franzson, H.; Thorhallsson, S.; Elders, W. A.

    2005-12-01

    There are some 10 new geothermal wells at Reykjanes, in SW-Iceland, being considered by the Iceland Deep Drilling Project (IDDP) as potential candidate wells of opportunity to explore for deep (4-5 km) supercritical fluids. The drill field is located where the Mid-Atlantic Ridge emerges from the Atlantic ocean at the tip of the Reykjanes Peninsula. The site is an ideal locality for a combined study on the evolution of a rifted oceanic crust and an active black smoker-type geothermal system. However, the oceanic pillow basaltic crust at Reykjanes is some 2-3 times thicker than normal ocean floor crust, which undoubtedly relates to it being part of the Icelandic Large Igneous Province. The deepest of the geothermal wells at Reykjanes is Drillhole RN-17, that was completed to 3082 m depth in February 2005. It is currently the prime candidate for deepening by the IDDP. The plan is to deepen it to 4 km in 2006, and to 5 km depth in 2007, with funding coming from Icelandic energy companies (Hitaveita Sudurnesja, Landsvirkjun and Orkuveita Reykjavikur), the Government of Iceland, the International Scientific Continental Drilling Program (ICDP) and the US National Science Foundation (NSF). The well RN-17 was drilled as a conventional production well with a 12 ¼ inch drillbit to 3082 m depth, and left barefoot, with a 13 3/8 inch production casing cemented down to 900 m. It will be flow tested this autumn. If the RN-17 well is selected by the IDDP for deepening, a 9 5/8 inch in casing will be cemented to 3081 m and drilling will be continued with an 8 ½ inch tricone bit to 4 km in the autumn of 2006. The ICDP and NSF will fund spot coring for scientific studies in this depth interval and a second flow test would be performed in winter 2007. The following autumn, a 7 inch casing would be cemented to 4 km depth and then a 5 inch retrievable liner would be inserted to support a hybrid coring system to continuously core down to 5 km depth, retrieving HQ sized core. A third

  10. Rift inheritance in orogenes: a case study from the Western Pyrenees

    NASA Astrophysics Data System (ADS)

    Masini, E.; Manatschal, G.; Tugend, J.; Kusznir, N. J.; Flament, J.

    2012-12-01

    In plate tectonics, there is a general assumption that rifted margins represent most of the former material accreted into collisional orogenic prisms. In this regard, the former architecture, structures and composition of rifted margins, i.e. the pre-orogenic inheritances, play undoubtedly a major role during tectonic inversion. Studies have shown that rifted margins are more complex than a succession of tilted blocks. Indeed, the discovery of hyper-extended domains, where low-angle detachments replace high-angle normal faults and mantle material is exhumed to the seafloor implies a revision of the margin's template used in orogenic models. Because of overprint, the role of rift inheritance in orogenes remains often underestimated. The Pyrenees, located along the Iberian-European plate boundary, can be considered as one of the best places to study the reactivation of hyper-extended rifts. In this orogen, the Late Cretaceous and Tertiary convergence overprints a Latest Jurassic to Lower Cretaceous intracontinental rift linked with the opening of the North Atlantic. There, Albian hyper-extended rift basins developed where deep crustal and mantle rocks were exhumed along low-angle detachments to the seafloor. In this work we discuss the example of the Mauléon-Arzacq domain, which escaped from the most pervasive deformation because of its specific location between the western termination of the chain and the Bay of Biscay oceanic domain. Combining field study with subsurface geophysical and drillhole data, we show that the overall rift domain is asymmetric. The northern European upper plate is on the hangingwall of low-angle detachment systems affecting the southern Iberian Lower plate. The upper plate records depth-dependent crustal thinning and the development of a syn-rift sag basin. In contrast, the lower plate resulted from the hyper-extension of Iberian continental crust accommodated at the surface by two diachronous top-basement detachment systems. The first

  11. Bi-cycles petrographic association in middle part of East Pana PGE layers deposit

    NASA Astrophysics Data System (ADS)

    Asavin, Alex; Veksler, Ilya; Gorbunov, Artem

    2016-04-01

    The PGE mineralization in the East Pana layered gabbroic intrusion forms three discrete layers at different stratigraphic levels, which are traditionally labeled as zones A, B and C. In order to investigate possible relationships of mineralization with magmatic layering we sampled a 120 m long drill core section across zone B in the middle part of the intrusion and carried out detailed petrographic, mineralogical and geochemical studies of the samples. The ore zone is located in medial part of the of East's Pana deposite. The samples represent mainly from a layered sequence of gabbro and gabbro-norite. This zone is composed of interlayers of gabbroic sequences and gabbro-norite of various color, with different structures and different relationship of rock-forming minerals of Ol-Opx-Cpx-Pl. We studied one of key's drill-hole section of ore zone, in which is located two ore horizons. Fundamental feature layered intrusions are presence in cross-section cycles includes of stable petrographic association. In section of ore zone it is possible to select two most contrast petrographic types. Whole-rock analyses and petrographic observations reveal two units of modal layering comprising, from bottom to top, melanocratic gabbro grading upwards into mesocratic gabbro and gabbro-norite overlain by pegmatoidal, gabbroic rock with has sharp footwall and hanging wall contacts.There is also an olivine-bearing gabbro at the bottom of the lower unit. The ore horizons are located in same gabbro-norite type rock. The ore horizons are located in same gabbro-norite type part. The second upper ore zone located in more differential species types. There is the common trend of system evolution of well distinguished on triangle of Ol-Pl-Di, Ol-Pl-Q and other. However composition of the rocks in the two parts of our section show us similar, but independent trends. For example on diagram differentiation of rocks composition, with normative content of anorthite on the X axis, trends of

  12. Cenozoic Tectonic Activity of the "Passive" North America Margin: Evidence for Cenozoic Activity on Mesozoic or Paleozoic Faults

    NASA Astrophysics Data System (ADS)

    Nedorub, O. I.; Knapp, C. C.

    2012-12-01

    The tectonic history of the Eastern North American Margin (ENAM) incorporates two cycles of continental assembly, multiple pulses of orogeny, rifting, and post-rift geodynamic evolution. This is reflected in the heterogeneous lithosphere of the ENAM which contains fault structures originated in Paleozoic to Mesozoic eras. The South Georgia Rift basin is probably the largest Mesozoic graben within its boundaries that is associated with the breakup of Pangea. It is composed of smaller sub-basins which appear to be bounded by high-angle normal faults, some of which may have been inverted in late Cretaceous and Cenozoic eras. Paleozoic structures may have been reactivated in Cenozoic time as well. The ENAM is characterized by N-NE maximum horizontal compressive stress direction. This maximum compressional stress field is sub-parallel to the strike of the Atlantic Coast province fault systems. Camden, Augusta, Allendale, and Pen Branch faults are four of the many such reactivated faults along the southern part of ENAM. These faults are now buried under the 0-400 m of loosely consolidated Cretaceous and Cenozoic age sediments and thus are either only partially mapped or currently not recognized. Some of the objectives of this study are to map the subsurface expression and geometry of these faults and to investigate the post Cretaceous deformation and possible causes of fault reactivation on a passive margin. This study employs an integrated geophysical approach to investigate the upper 200 m of identified locations of the above mentioned faults. 2-D high-resolution shallow seismic reflection and refraction methods, gravity surveys, GPR, 2-D electrical resistivity and well data are used for analyses and interpretation. Preliminary results suggest that Camden fault shows signs of Cenozoic reactivation through an approximately 30 m offset NW side up mainly along a steeply dipping fault zone in the basal contact of Coastal Plain sediments with the Carolina Piedmont. Drill-hole

  13. Groundwater Visualisation System (GVS): A software framework for integrated display and interrogation of conceptual hydrogeological models, data and time-series animation

    NASA Astrophysics Data System (ADS)

    Cox, Malcolm E.; James, Allan; Hawke, Amy; Raiber, Matthias

    2013-05-01

    Valley, and the Surat Basin, a large sedimentary basin of confined artesian aquifers. This latter example required more detail in the hydrostratigraphy, correlation of formations with drillholes and visualisation of simulation piezometric surfaces. Both alluvial system GVS models were developed during drought conditions to support government strategies to implement groundwater management. The Surat Basin model was industry sponsored research, for coal seam gas groundwater management and community information and consultation. The "virtual" groundwater systems in these 3D GVS models can be interactively interrogated by standard functions, plus production of 2D cross-sections, data selection from the 3D scene, rear end database and plot displays. A unique feature is that GVS allows investigation of time-series data across different display modes, both 2D and 3D. GVS has been used successfully as a tool to enhance community/stakeholder understanding and knowledge of groundwater systems and is of value for training and educational purposes. Projects completed confirm that GVS provides a powerful support to management and decision making, and as a tool for interpretation of groundwater system hydrological processes. A highly effective visualisation output is the production of short videos (e.g. 2-5 min) based on sequences of camera 'fly-throughs' and screen images. Further work involves developing support for multi-screen displays and touch-screen technologies, distributed rendering, gestural interaction systems. To highlight the visualisation and animation capability of the GVS software, links to related multimedia hosted online sites are included in the references.

  14. Ground-water outflow from Chino Basin, Upper Santa Ana Valley, southern California

    USGS Publications Warehouse

    French, James J.

    1972-01-01

    Ground-water outflow from Chino basin was calculated ,by a direct method using the equation Q = PIA, in which Q is the quantity of ground-water outflow, P is the average coefficient of permeability of the sediments through which the flow occurs, I is the average hydraulic gradient, and A is the cross-sectional area of the sediments through which the flow occurs. The period selected for the calculation was 1930-66. Permeability of the water-bearing sediments was calculated from aquifer test data and from computations involving specific-capacity data from 200 wells in the outflow area. Permeability ranged from less than 100 to more than 5,000 gallons per day per square foot. The annual hydraulic gradient was derived from contour maps of average water levels in wells for each water year for the period 1930-66. The cross-sectional area used to calculate ground-water outflow from Chino basin extends southwestward from Pedley Hills to Puente Hills. The area of the outflow section is the saturated thickness of permeable materials measured along the line of section. Part of the lower boundary is the interface between the alluvium and the underlying basement complex, and part is a change in permeability within sedimentary rocks. Geological methods were combined with geophysical methods to determine the cross-sectional area of the water-bearing sediments. Gravity and seismic traverses, drill-hole logs, and data from a more than 600 drill holes, including eight test holes drilled as a part of this investigation, were used to delineate the size and the shape of the outflow area. For the period of calculation, 1930-66, the total area of the outflow section varied from about 16 to 22 million square feet. The fluctuation in total area is caused by changes in the altitude of the water table. Annual ground-water outflow from Chino basin calculated by the direct method for the period 1930-66 ranged from 38,000 acre-feet in the 1941 water year to 9,400 acre-feet in the 1966 water

  15. Sub-crop geologic map of pre-Tertiary rocks in the Yucca Flat and northern Frenchman Flat areas, Nevada Test Site, southern Nevada

    USGS Publications Warehouse

    Cole, James C.; Harris, Anita G.; Wahl, Ronald R.

    1997-01-01

    This map displays interpreted structural and stratigraphic relations among the Paleozoic and older rocks of the Nevada Test Site region beneath the Miocene volcanic rocks and younger alluvium in the Yucca Flat and northern Frenchman Flat basins. These interpretations are based on a comprehensive examination and review of data for more than 77 drillholes that penetrated part of the pre-Tertiary basement beneath these post-middle Miocene structural basins. Biostratigraphic data from conodont fossils were newly obtained for 31 of these holes, and a thorough review of all prior microfossil paleontologic data is incorporated in the analysis. Subsurface relationships are interpreted in light of a revised regional geologic framework synthesized from detailed geologic mapping in the ranges surrounding Yucca Flat, from comprehensive stratigraphic studies in the region, and from additional detailed field studies on and around the Nevada Test Site.All available data indicate the subsurface geology of Yucca Flat is considerably more complicated than previous interpretations have suggested. The western part of the basin, in particular, is underlain by relics of the eastward-vergent Belted Range thrust system that are folded back toward the west and thrust by local, west-vergent contractional structures of the CP thrust system. Field evidence from the ranges surrounding the north end of Yucca Flat indicate that two significant strike-slip faults track southward beneath the post-middle Miocene basin fill, but their subsurface traces cannot be closely defined from the available evidence. In contrast, the eastern part of the Yucca Flat basin is interpreted to be underlain by a fairly simple north-trending, broad syncline in the pre-Tertiary units. Far fewer data are available for the northern Frenchman Flat basin, but regional analysis indicates the pre- Tertiary structure there should also be relatively simple and not affected by thrusting.This new interpretation has implications

  16. Geologic and hydrologic considerations for various concepts of high-level radioactive waste disposal in conterminous United States

    USGS Publications Warehouse

    Ekren, E.B.; Dinwiddie, G.A.; Mytton, J.W.; Thordarson, William; Weir, J.E.; Hinrichs, E.N.; Schroder, L.J.

    1974-01-01

    rise is very low, (3) where a possible return of glacial or pluvial climate will not cause potentially hazardous changes in surface- or ground-water regimens, and (4) where danger of exhumation by erosion is nil. The geographic location for an optimum site is one that is far removed from major drainages, lakes, and oceans, where population density is low, and where the topographic relief is gentle in order to avoid steep surface-water drainage gradients that would allow rapid distribution of contaminants in case of accident. The most suitable medium for the unproven deep drill-hole, matrix-holes, and exploded-cavity methods appears to be crystalline rocks, either intrusive igneous or metamorphic because of their potentially low permeabilities and high mechanical strengths. Salt (either in thick beds or stable domes), tuff, and possibly shale appear to be suitable for mined chambers and cavities with separate manmade structures. Salt appears to be suitable because of its very low permeability, high thermal conductivity, and natural plasticity. Tuff and shale appear suitable because of their very low permeabilities and high ion-exchange capacities. Sedimentary rocks other than shale and volcanic rocks, exclusive of tuff, are considered to be generally unsuitable for waste emplacement because of their potentially high permeabilities. Areas that appear to satisfy most geohydrologic requirements for the deep drill hole and the matrix holes include principally (1) the stable continental interior where the sedimentary cover is thin or absent, (2) the shield area of the North-Central States, and (3) the metamorphic belt of Eastern United States--primarily the Piedmont. These areas are possibly suitable also for the exploded cavity and the mined chamber because the possibility of finding rock with very- permeability at depths from 1,000? feet (305? m) to 20,000 feet (6,100 m) appears to be high. The Basin and Range province of Western United States, particula

  17. Study of borehole probing methods to improve the ground characterization

    NASA Astrophysics Data System (ADS)

    Naeimipour, Ali

    partially condition of discontinuities. Two of the more promising tools have been tested during this project, which are QL40OBI Optical TV and Slim Borehole Scanner (SBS) manufacture by ALT-Mount Sopris and DMT, respectively. The field experiment with QL40OBI showed that the images generated for downward and sub-horizontal boreholes are of good quality and can be used to evaluate the joint conditions. However, this device is not suitable for use inside the upward drillholes. The Slim Borehole Scanner (SBS) manufactured by DMT in Germany has the required features for borescoping the roofbolt holes. This includes the ease of operation and suitable geometry along with an unwrapped 360-degree picture of the borehole wall. This instrument was concluded to be the best option yet for obtaining images from boreholes with any arbitrary orientation. In addition, a new tool, called Rock Strength Borehole Probe (RSBP), was developed for estimation of the rock strength through scratching the rock surface in the borehole. This device is designed to be a light, flexible, quick, non-disruptive, and cost effective alternative to estimate the rock strength inside the boreholes in underground mines and tunnels. An extensive number of laboratory tests under variable conditions were conducted to develop equations to estimate the Uniaxial Compressive Strength (UCS) and Brazilian Tensile Strength (BTS) of the rock from measured cutting forces. In these experiments, 27 different rock types were tested by full scale scratch tests, including the cutting tests by a miniature disc. The results show a good correlation between the normal force and the compressive strength of sedimentary/metamorphic rock if the depth of scratch is known. No significant correlation was observed for igneous rocks, due to the impacts of grain size. Current studies show promising results for using RSBP. The laboratory and field tests proved the functionality of this tool. This probe is capable of entering boreholes of 45 mm

  18. Detailed lithologic log of the Dow Chemical #1 B.L. Garrigan Drill Hole, Mississippi County, Arkansas

    USGS Publications Warehouse

    Collins, Donley S.; Skipp, Gary L.

    1995-01-01

    arch and is an important source of core from the Reelfoot basin (Collins and others, 1992). Therefore, this drill hole is important for understanding structure and Paleozoic stratigraphy in a basin where stratigraphic and structural data are sparse. Rocks in the Garrigan were originally logged and described by J.R. Howe (personal communication to D.S. Collins, 1990) and published as a composite stratigraphic section along with the rock description for the Dow Chemical #1 Wilson drill hole (Howe, 1984). F.A. McKeown later relogged the rocks in the Garrigan and presented a generalized log in McKeown and others (1990). Swolfs (1991) presented another version of the Garrigan drill-hole geologic section (fig. 2). Aided by new biostratigraphic information, Taylor and others (1991) corrected major errors in the characterization and correlation of rocks in the Garrigan (fig. 2). Collins (1991) described the insoluble residues from the cuttings of the Garrigan, but could not correlate them with the insoluble resides from rocks of the carbonate platform west of the basin. However Taylor and others (1991), Collins and others (1992), and Collins and Bohm (1993) did correlate fossils from the Garrigan to other drill holes in the Reelfoot basin and adjacent areas. Using these correlated data, Collins and Bohm (1993) provided information on the structural relief across a part of the Reelfoot basin. Collins and others (1992) also interpreted the depositional setting for the Paleozoic rocks of the Garrigan. This report presents a detailed lithologic log of the Paleozoic rocks penetrated by the Garrigan that differs from the lithologic logs of previous workers (Howe, 1984; McKeown and others, 1990; see also Dart, 1992, p. 18-19). The lithologic descriptions of the Garrigan are derived from observations of well cuttings and core. Cored intervals used were 11,426-11,402 ft, 10,229-10,200 ft, and 8,002-7,979 ft. These intervals were the only intervals cored during the Garrigan drill