Sample records for heterogeneous geological formations

  1. Simulation of Non-Fickian Transport in Geological Formations With Variable-Scale Heterogeneities

    NASA Astrophysics Data System (ADS)

    Cortis, A.; Dentz, M.; Margolin, G.; Scher, H.; Berkowitz, B.

    2003-12-01

    We study solute transport through heterogeneous media by use of continuous time random walk (CTRW) theory. Transport is governed by a joint probability density ? (s,t), which characterizes tracer particle displacements s with associated times t. Previous work has shown the CTRW theory to be a highly effective transport framework to account for non-Fickian transport in field, laboratory and numerical experiments. Here, we introduce a number of innovations that allow for general solution of the CTRW for arbitrary ? (s,t) and boundary conditions in 1-3 spatial dimensions. While in many cases, the transition times and distances are governed strictly by the flow field, they can in other cases be strongly influenced by mechanisms such as tracer diffusion into and out of ``stagnant'' zones of the medium and/or adsorption/desorption from the rock surfaces. All of these mechanisms, in addition to the flow field, can be specified, either implicitly or explicitly, in the determination of ? (s,t), which then can account for a wide range of transport behaviors. By treating unresolved, small-scale heterogeneities (residues) probabilistically with the CTRW formalism, and large-scale heterogeneity variations (trends) deterministically, we develop and solve a Fokker-Planck equation that contains a memory term and a generalized concentration flux term. The advection-dispersion equation is a special case of this equation. The parameters defining these terms are measurable quantities. Our calculations demonstrate long tailing arising (principally) from the memory term, and effects on arrival times that are controlled largely by the generalized concentration flux term. The impact of these extensions to CTRW theory is to provide a means to calculate transport of both passive and sorbing (reactive) tracers in non-stationary geological formations.

  2. Dynamic effective properties of heterogeneous geological formations with spherical inclusions under periodic time variations

    NASA Astrophysics Data System (ADS)

    Rabinovich, A.; Dagan, G.; Miloh, T.

    2013-04-01

    In unsteady groundwater flow (or similar processes of heat/electrical conduction), the heterogeneous medium structure is characterized by two random properties, the conductivity K and the specific storativity S. The average head field ?H ?and the associated effective properties Kef, Sef are determined for a layer with a periodic head drop between boundaries, such that H is periodic in time, and a medium made up of a matrix with a dilute concentration of spherical inclusions. In the common quasi-steady approximation, Kef is equal to the classical steady solution while Sef = SA, the arithmetic mean. We derive expressions for the frequency dependent Kef, Sef, which are generally complex, i.e., dynamic. The main result is the delineation of the ranges of the parameters: dimensionless frequency (?) and contrasts of conductivity (?) and storativity (s) between the matrix and the inclusions, for which dynamic effects are significant.

  3. Formation evaluation: Geological procedures

    SciTech Connect

    Whittaker, A.

    1985-01-01

    This volume goes beyond a discussion of petroleum geology and the techniques of hydrocarbon (oil and gas) logging as a reservoir evaluation tool. It provides the logging geologist with a review of geological techniques and classification systems that will ensure the maximum development of communicable geological information. Contents include: 1. Introduction--cuttings recovery, cutting sampling, core sampling, rock classification; 2. Detrital rocks--classification, description; 3. Carbonate rocks--classification, description; 4. Chemical rocks-introduction, siliceous rocks, ferruginous rocks, aluminous rocks, phosphatic rocks, aluminous rocks, carbonaceous rocks; 5. Igneous and metamorpbic rocks; Appendix; References and Index.

  4. Method of fracturing a geological formation

    DOEpatents

    Johnson, James O. (2679-B Walnut, Los Alamos, NM 87544)

    1990-01-01

    An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

  5. River-Aquifer Interactions, Geologic Heterogeneity, and River Management

    NASA Astrophysics Data System (ADS)

    Fleckenstein, J. H.; Niswonger, R. G.; Fogg, G. E.

    2005-12-01

    Managing rivers and their underlying aquifers for minimum flows, riparian habitat or aquifer recharge requires an understanding of the spatial patterns and temporal dynamics of river-aquifer exchange. Results are presented from investigations of the effects of geologic heterogeneity on river-aquifer exchange, minimum river flows and water availability in the riparian corridor for a typical alluvial fan system in the western USA. River-aquifer interactions were simulated on a regional-scale (~50km) and for a river reach (~2000m) using numerical codes for saturated and variably saturated flow. Geologic heterogeneity of the alluvial fan system was characterized with a geostatistical approach, based on transition probabilities and Markov Chains. Different hydrofacies models for a 50 km segment and a 2 km reach were created from sequential indicator simulations. Variably saturated flow between the river and the deep regional water table were explicitly simulated in both models. Groundwater levels, river flows, sediment saturation and temperature data were used to calibrate the models. The regional simulations showed that different spatial arrangements of hydrofacies have significant effects on minimum river flows with implications for salmon migration. Although total annual seepage volumes were relatively insensitive to geologic heterogeneity spatial and temporal variability of seepage was large between the different heterogeneous models. Local reconnections developed seasonally in some models and the period with sufficient flows for salmon fall-migration varied by up to 13 days between the models. The reach-scale simulations demonstrated that perched zones, which form between the river and the regional water table, can be important in supporting river base flows and riparian vegetation. Connected pathways between the river channel and the riparian corridor, which could be characterized with the temperature data, may sustain phreatophytes even when the regional water table is far below the river channel. These results elucidate some important effects of geologic heterogeneity on river-aquifer interactions, which could be crucial for the management of alluvial river systems.

  6. Accounting for aquifer heterogeneity from geological data to management tools.

    PubMed

    Blouin, Martin; Martel, Richard; Gloaguen, Erwan

    2013-01-01

    A nested workflow of multiple-point geostatistics (MPG) and sequential Gaussian simulation (SGS) was tested on a study area of 6 km(2) located about 20 km northwest of Quebec City, Canada. In order to assess its geological and hydrogeological parameter heterogeneity and to provide tools to evaluate uncertainties in aquifer management, direct and indirect field measurements are used as inputs in the geostatistical simulations to reproduce large and small-scale heterogeneities. To do so, the lithological information is first associated to equivalent hydrogeological facies (hydrofacies) according to hydraulic properties measured at several wells. Then, heterogeneous hydrofacies (HF) realizations are generated using a prior geological model as training image (TI) with the MPG algorithm. The hydraulic conductivity (K) heterogeneity modeling within each HF is finally computed using SGS algorithm. Different K models are integrated in a finite-element hydrogeological model to calculate multiple transport simulations. Different scenarios exhibit variations in mass transport path and dispersion associated with the large- and small-scale heterogeneity respectively. Three-dimensional maps showing the probability of overpassing different thresholds are presented as examples of management tools. PMID:22924605

  7. Secondary Organic Aerosol Formation by Heterogeneous

    E-print Network

    Goddard III, William A.

    Secondary Organic Aerosol Formation by Heterogeneous Reactions of Aldehydes and Ketones: A Quantum), for various short-chain aldehydes and ketones. We show that quantum mechanical gas- phase Gibbs free energies constants (reported as log K) of aerosol-phase chemical reactions, including hydration reactions and aldol

  8. Petroleum geology of formation waters

    SciTech Connect

    Billo, S.M. [King Saud Univ. (Saudi Arabia)

    1996-06-01

    Some researchers have argued that most petroleum traps are hydrostatic and the potentiometric surface is a level plane, whereas others have emphasized the importance of hydrodynamic traps and that the potentiometric surface slopes. The Salt Creek oil field, Wyoming is a prime example of the large, anticlinal traps that has produced over 500 million barrels of oil, and was located by a large oil seep over the trap. The structure has five producing zones, all sandstones in the Cretaceous and the Sundance sand (Jurassic). Each has a separate oil-water contact and a transition zone, indicating a lack of permeable interconnection. The multiple oil-water contacts dip northward in pact with the hydraulic gradient of the region. The slope of the potentiometric surface determines whether the water is in a state of static or dynamic equilibrium. A hydrodynamic condition is usually dependent on the topography of the surface and/or the geology of the region. Knowledge of subsurface waters can help in the discovery and seismic mapping of hydrocarbon reservoirs through valuation of possible changes imposed on the waters in the presence of hydrocarbons; by recognition of changes related to conducive development of traps; and eventually by defining condition of origin and migration of oil and gas.

  9. Simulation of Seismic Tunnel Detection Experiments in Heterogeneous Geological Media

    NASA Astrophysics Data System (ADS)

    Sherman, C. S.; Glaser, S. D.; Rector, J.

    2013-12-01

    Detecting covert tunnels and other underground openings is an important yet challenging problem for geophysicists, especially where geological heterogeneity is pronounced. A number of geophysical methods have been employed to solve this problem, each with varying degrees of success. We focus on the near-surface seismic techniques of surface wave backscattering, surface wave attenuation tomography, body wave diffraction imaging, and resonant imaging. We use the elastodynamic wave propagation code E3D to simulate tunnel detection experiments completed at this site for a range of synthetic fractal velocity models. The Black Diamond mine, located near Pittsburg California, is used for the field test of our analysis. Our results show that for the relatively low-frequency surface wave attenuation and backscattering methods, the maximum detectable tunnel depth in a homogenous medium is approximately equal to the wavelength of the probing Rayleigh wave. The higher-frequency body wave diffraction and resonant imaging techniques are able to locate tunnels at greater depths, but require more sophisticated analysis and are prone to greater attenuation losses. As is expected, for large values of heterogeneity amplitude, ?, the percent standard deviation from the mean velocity model, the average observed surface wave attenuation signal decreases and the maximum detectable tunnel depth decreases. However, for moderate values of heterogeneity amplitude (? < 3%), the average surface wave attenuation signal increases and the maximum detectable tunnel depth increases. For the body wave diffraction and resonant imaging experiments, as ? increases the complexity of the observed signal increases, resulting in more difficult processing and interpretation. The additional scattering attenuation tends to degrade the signals significantly due to their reliance on lower amplitude and higher frequency waves.

  10. Adaptable formations utilizing heterogeneous unmanned systems

    NASA Astrophysics Data System (ADS)

    Barnes, Laura E.; Garcia, Richard; Fields, MaryAnne; Valavanis, Kimon

    2009-05-01

    This paper addresses the problem of controlling and coordinating heterogeneous unmanned systems required to move as a group while maintaining formation. We propose a strategy to coordinate groups of unmanned ground vehicles (UGVs) with one or more unmanned aerial vehicles (UAVs). UAVs can be utilized in one of two ways: (1) as alpha robots to guide the UGVs; and (2) as beta robots to surround the UGVs and adapt accordingly. In the first approach, the UAV guides a swarm of UGVs controlling their overall formation. In the second approach, the UGVs guide the UAVs controlling their formation. The unmanned systems are brought into a formation utilizing artificial potential fields generated from normal and sigmoid functions. These functions control the overall swarm geometry. Nonlinear limiting functions are defined to provide tighter swarm control by modifying and adjusting a set of control variables forcing the swarm to behave according to set constraints. Formations derived are subsets of elliptical curves but can be generalized to any curvilinear shape. Both approaches are demonstrated in simulation and experimentally. To demonstrate the second approach in simulation, a swarm of forty UAVs is utilized in a convoy protection mission. As a convoy of UGVs travels, UAVs dynamically and intelligently adapt their formation in order to protect the convoy of vehicles as it moves. Experimental results are presented to demonstrate the approach using a fully autonomous group of three UGVs and a single UAV helicopter for coordination.

  11. Geologic Study of the Coso Formation

    SciTech Connect

    D. L. Kamola; J. D. Walker

    1999-12-01

    There have been great advances in the last 20 years in understanding the volcanic, structural, geophysical, and petrologic development of the Coso Range and Coso geothermal field. These studies have provided a wealth of knowledge concerning the geology of the area, including general structural characteristics and kinematic history. One element missing from this dataset was an understanding of the sedimentology and stratigraphy of well-exposed Cenozoic sedimentary strata - the Coso Formation. A detailed sedimentation and tectonics study of the Coso Formation was undertaken to provide a more complete picture of the development of the Basin and Range province in this area. Detailed mapping and depositional analysis distinguishes separate northern and southern depocenters, each with its own accommodation and depositional history. While strata in both depocenters is disrupted by faults, these faults show modest displacement, and the intensity and magnitude of faulting does no t record significant extension. For this reason, the extension between the Sierran and Coso blocks is interpreted as minor in comparison to range bounding faults in adjacent areas of the Basin and Range.

  12. Electromagnetic instruments for imaging structure in geologic formations

    Microsoft Academic Search

    Stolarczyk

    1987-01-01

    An apparatus is described for the detection and analysis of anomalies within geological formations comprising: a down hole transmitter set comprising a tuned-loop antenna for orienting vertically within a geological formation, the antenna electrically coupled to a transmitter and mechanically coupled to a drive means whereby the antenna may be rotated about a vertical axis; a down hole receiving set

  13. High-resolution truncated plurigaussian simulations for the characterization of heterogeneous formations

    E-print Network

    Mariethoz, Grégroire; Cornaton, Fabien; Jaquet, Olivier; 10.1111/j.1745-6584.2008.00489.x

    2011-01-01

    Integrating geological concepts, such as relative positions and proportions of the different lithofacies, is of highest importance in order to render realistic geological patterns. The truncated plurigaussian simulation method provides a way of using both local and conceptual geological information to infer the distributions of the facies and then those of hydraulic parameters. The method (Le Loc'h and Galli 1994) is based on the idea of truncating at least two underlying multi-Gaussian simulations in order to create maps of categorical variable. In this manuscript we show how this technique can be used to assess contaminant migration in highly heterogeneous media. We illustrate its application on the biggest contaminated site of Switzerland. It consists of a contaminant plume located in the lower fresh water Molasse on the western Swiss Plateau. The highly heterogeneous character of this formation calls for efficient stochastic methods in order to characterize transport processes.

  14. Constructing Hydraulic Barriers in Deep Geologic Formations

    SciTech Connect

    Carter, E.E.; Carter, P.E. [Technologies Co, Texas (United States); Cooper, D.C. [Ph.D. Idaho National Laboratory, Idaho Falls, ID (United States)

    2008-07-01

    Many construction methods have been developed to create hydraulic barriers to depths of 30 to 50 meters, but few have been proposed for depths on the order of 500 meters. For these deep hydraulic barriers, most methods are potentially feasible for soil but not for hard rock. In the course of researching methods of isolating large subterranean blocks of oil shale, the authors have developed a wax thermal permeation method for constructing hydraulic barriers in rock to depths of over 500 meters in competent or even fractured rock as well as soil. The technology is similar to freeze wall methods, but produces a permanent barrier; and is potentially applicable in both dry and water saturated formations. Like freeze wall barriers, the wax thermal permeation method utilizes a large number of vertical or horizontal boreholes around the perimeter to be contained. However, instead of cooling the boreholes, they are heated. After heating these boreholes, a specially formulated molten wax based grout is pumped into the boreholes where it seals fractures and also permeates radially outward to form a series of columns of wax-impregnated rock. Rows of overlapping columns can then form a durable hydraulic barrier. These barriers can also be angled above a geologic repository to help prevent influx of water due to atypical rainfall events. Applications of the technique to constructing containment structures around existing shallow waste burial sites and water shutoff for mining are also described. (authors)

  15. Are geological media homogeneous or heterogeneous for neutron investigations?

    PubMed

    Wo?nicka, U; Drozdowicz, K; Gaba?ska, B; Krynicka, E; Igielski, A

    2003-01-01

    The thermal neutron absorption cross section of a heterogeneous material is lower than that of the corresponding homogeneous one which contains the same components. When rock materials are investigated the sample usually contains grains which create heterogeneity. The heterogeneity effect depends on the mass contribution of highly and low-absorbing centers, on the ratio of their absorption cross sections, and on their sizes. An influence of the granulation of silicon and diabase samples on the absorption cross section measured with Czubek's method has been experimentally investigated. A 20% underestimation of the absorption cross section has been observed for diabase grains of sizes from 6.3 to 12.8 mm. PMID:12485675

  16. Method and apparatus for laser treatment of geological formations

    Microsoft Academic Search

    1978-01-01

    A method and apparatus are disclosed for drilling gas, oil or geothermal wells in geological formations and for ''fracing'' the pay zones of such wells to increase recovery, using a laser beam projected into the well bore along a beam guide so as to make available laser energy adequate to melt or vaporize the formation under down-hole conditions. Fluid circulation

  17. Geologic/stochastic mapping of heterogeneity in a carbonate reservoir

    SciTech Connect

    Lucia, F.J. (California Univ., Davis, CA (USA). Dept. of Land, Air, and Water Resources); Fogg, G.E. (Texas Univ., Austin, TX (USA). Bureau of Economic Geology)

    1990-10-01

    Two major problems in estimating interwell porosity and permeability patterns are estimating permeability profiles in uncored wells and interpolating wellbore information between wells. This paper reports on a technique combining core analysis, rock fabrics, and wireline logs used to estimate permeability values at 1-ft intervals in 32 wells in Section 15 of the Dune field. Stochastic geologic interpolation was generated with a geostatistical method known as conditional simulation. Simulation of water-flooding showed that the stochastic realizations with a low degree of continuity gave the most realistic results. Infill drilling to achieve an average well spacing of 2.5 acres increased recovery by 27 to 32%.

  18. FORMATION OF SCATTERNETS WITH HETEROGENEOUS BLUETOOTH DEVICES

    Microsoft Academic Search

    Paal Engelstad; Do Van Thanh; Tore E. Jonvik

    Bluetooth is an open specification for short-range wireless communication. It has gradually been extended to meet the demand for personal ad-hoc networking. A Bluetooth ad-hoc network consists of Bluetooth devices interconnected into piconets and piconets interconnected into scatternets. A number of scatternet formation algorithms have been proposed, but none has yet taken into account that Bluetooth devices may have very

  19. A Bluetooth Scatternet Formation Algorithm for Networks with Heterogeneous Device

    E-print Network

    Abouzeid, Alhussein A.

    A Bluetooth Scatternet Formation Algorithm for Networks with Heterogeneous Device Capabilities replacement. We argue that, in practice, Bluetooth devices will have different power capabilities, classi. Bluetooth devices connect into piconets, each consisting of a master and up to seven slaves, while master

  20. Geological pattern formation by growth and dissolution in aqueous systems

    SciTech Connect

    Paul Meakin

    2010-03-01

    Although many geological processes take place on time scales that are very long compared with the human experience, essentially all geological processes, fast or slow, are far from equilibrium processes. Surprisingly often, geological processes lead to the formation of quite simple and distinctive patterns, which hint at an underlying simplicity in many complex geological systems.. The ability to predict the seasons was critically important to early human society, and Halley’s prediction of the return of the comet that bears his name is still considered to be a scientific milestone. Spatial patterns have also attracted attention because of their aesthetic appeal, which depends in subtle ways on a combination of regularity and irregularity. In recent decades, rapid growth in the capabilities of digital computers has facilitated the simulation of pattern formation processes, and computer simulations have become an important tool for evaluating theoretical concepts and for scientific discovery. Computer technology in combination with other technologies such as high resolution digital cameras, scanning microprobes (atomic force microscopy AFM), confocal microscopy, and scanning tunneling microscopy (STM), for example) has facilitated the quantitative characterization of patterns over a wide range of scales and has enabled rapid advances in our ability to understand the links between large scale pattern formation and microscopic processes. The ability to quantitatively characterize patterns is important because it enables a more rigorous comparison between the predictions of computer models and real world patterns and their formation.In some cases, the idea that patterns with a high degree of regularity have simple origins appears to be justified, but in other cases, such as the formation of almost perfectly circular stone rings due to freeze-thaw cycles simple patterns appear to be the consequence of quite complex processes. In other cases, it has been shown that very simple non-linear processes can lead to extremely complicated patterns, and that some apparently complex disordered systems can be described quantitatively in terms of simple fractal models.

  1. Engineering geological mapping of gypsiferous formations, Sivas, Central Eastern Turkey

    Microsoft Academic Search

    T. Y. Irfan; I. Özkaya

    1981-01-01

    Preliminary engineering geological investigation has been carried out for a proposed railway route in Central Eastern Turkey.\\u000a The area is dominantly composed of Pliocene clastic deposits and Oligo-Miocene evaporitic formations overlying older rocks\\u000a of flysch and limestones. Problems caused by the engineering characteristics of gypsum, anhydrite and halite, which should\\u000a be taken into consideration in any kind of engineering work,

  2. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site

    SciTech Connect

    Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan

    2012-02-01

    The microbial diversity in subsurface sediments at the Hanford Site's 300 Area in southeastern Washington State was investigated by analyzing 21 samples recovered from depths that ranged from 9 to 52 m. Approximately 8000 non-chimeric Bacterial and Archaeal 16S rRNA gene sequences were analyzed across geological strata that contain a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units, defined at the 97% identity level). Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (based upon Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic transition zone, richness was about 325 and declined to less than 50 in the deeper reduced zones. The Bacterial community in the oxic Hanford and Ringold Formations contained members of 9 major well-recognized phyla as well 30 as unusually high proportions of 3 candidate divisions (GAL15, NC10, and SPAM). The deeper Ringold strata were characterized by low OTU richness and a very high preponderance (ca. 90%) of Proteobacteria. The study has greatly expanded the intralineage phylogenetic diversity within some major divisions. These subsurface sediments have been shown to contain a large number of phylogenetically novel microbes, with substantial heterogeneities between sediment samples from the same geological formation.

  3. Role of particulate metals in heterogenous secondary sulfate formation

    NASA Astrophysics Data System (ADS)

    Clements, Andrea L.; Buzcu-Guven, Birnur; Fraser, Matthew P.; Kulkarni, Pranav; Chellam, Shankararaman

    2013-08-01

    A series of field sampling and controlled laboratory experiments were undertaken to quantify the role of trace metals found in ambient fine particulate matter and metal-rich primary sources in the heterogenous catalytic conversion of SO2 gas into sulfate particulate matter (PM) in the atmosphere. Analysis produced source profiles of three primary source materials, fluidized-bed catalytic cracking catalyst, coal-fired combustion fly ash, and paved road dust, featuring 33 elements including rare earth metals, which are not commonly reported in the literature. Subsequently three sets of experiments were conducted exposing 1) source materials, 2) ambient PM, and 3) ambient PM augmented with approximately an equal amount of source material to SO2 gas and measuring sulfate formation. Source material experiments revealed that the greatest extent of reaction was on the surface of coal fly ash with sulfate formation of 19 ± 5 mg sulfate g-1 material. Ambient fine particulate matter (PM) experiments showed sulfate formation ranging from negligible amounts to 180 ± 10 mg sulfate g-1 PM. It was much more difficult to quantify the sulfate formation on ambient filters augmented with the source materials. In these experiments, sulfate formation ranged from negligible amounts to 40 ± 8 mg sulfate g-1 of particles (ambient + augmented material). These three sets of experiments shows that heterogenous sulfate formation is often negligible but, under some conditions can contribute 10% or more to the total sulfate concentrations when exposed to high SO2 concentrations such as those found in plumes. Factor analysis of the source material experiments grouped metals into two categories, crustal components and anthropogenically emitted metals representative of catalyst material, with the former showing the strongest correlation with sulfate formation. Subsequent analysis of data collected from the ambient PM experiments showed a much weaker correlation of sulfate formation with the crustal components, including iron and titanium, remaining clustered with sulfate formation. Independent research has been previously reported in the literature establishing mechanisms for the iron and titanium catalyzed conversion of S(IV) to S(VI) suggesting there may be other metals within these crustal type metal components that behave similarly. Additional experiments spanning a wider range of variables including more sources, SO2 concentrations and exposure times, ambient PM locations, as well as more individual samples may be necessary to obtain more conclusive evidence into the role of various metals in catalyzing the conversion of S(IV) to S(VI).

  4. Dispersion measurement as a method of quantifying geologic characterization and defining reservoir heterogeneity. Final report

    SciTech Connect

    Menzie, D.E.

    1995-05-01

    The main objective of this research project is to investigate dispersion as a method of quantifying geological characterization and defining reservoir heterogeneity in order to enhance crude oil recovery. The dispersion of flow of a reservoir rock (dispersion coefficient and dispersivity) was identified as one of the physical properties of a reservoir rock by measuring the mixing of two miscible fluids, one displacing the other in a porous medium. A rock was 100% saturated with a resident fluid and displaced by a miscible fluid of equal viscosity and equal density. Some specific experiments were performed with unequal densities. Produced fluid was analyzed by refractometer, nuclear reaction, electrical conductivity and X-ray scan. Several physical and flow characteristics were measured on the sand rock sample in order to establish correlations with the measured dispersion property. Absolute permeability, effective porosity, relative permeability, capillary pressure, the heterogeneity factor and electrical conductivity were used to better understand the flow system. Linear, transverse, 2-D and 3-D dispersions were measured and used to characterize the rock heterogeneity of the flow system. A new system of measuring dispersion was developed using a gas displacing gas system in a porous medium. An attempt was also made to determine the dispersion property of an actual reservoir from present day well log data on a producing well. 275 refs., 102 figs., 17 tabs.

  5. Geologically-Based Modeling of Unsaturated Flow Through Heterogeneous Alluvial Sediments, Lawrence Livermore National Laboratory, California

    NASA Astrophysics Data System (ADS)

    Martell, S. B.; Weissmann, G. S.; Phanikumar, M. S.; Hyndman, D. W.; Khire, M. V.

    2004-05-01

    Groundwater flow and transport modelers have recently realized the value of incorporating geologically realistic heterogeneities into their models. This study applies the same philosophy to the vadose zone at the Eastern Landing Mat (ELM) site at Lawrence Livermore National Laboratory, California. A series of pneumatic tests were conducted at the ELM site to evaluate approaches to remove high VOC concentrations. The pneumatic data measured during the tests appear to show a heterogeneous distribution of pressure drawdown with distance. Our research examines the role of vadose zone heterogeneities in the development of the measured responses. The pressure drawdown data will be evaluated through numerical simulations of the pneumatic tests. Core and geophysical well log data, along with conceptual facies models, provide (1) a stratigraphic framework for evaluating the site, (2) parameters used to develop Markov chain models of spatial variability, and (3) conditioning data for transition probability geostatistics. Through geostatistics, multiple realizations of facies distributions were developed for the ELM site. These realizations will be used to simulate 3-dimensional vadose zone flow based on the Non-isothermal Unsaturated Flow and Transport (NUFT) code, calibrated to the pneumatic data. We expect to be able to use these methods to locate the high permeability zones that act as short-cut pathways of air flow and mass movement. Such information could then be used to design an optimal remediation strategy such as an efficient soil vapor extraction system.

  6. Photoacoustic Signal Formation in Heterogeneous Multilayer Systems with Piezoelectric Detection

    NASA Astrophysics Data System (ADS)

    Isaiev, Mykola; Andrusenko, Dmytro; Tytarenko, Alona; Kuzmich, Andrey; Lysenko, Vladimir; Burbelo, Roman

    2014-12-01

    A new efficient model describing photoacoustic (PA) signal formation with piezoelectric detection is reported. Multilayer sandwich-like systems: heterogeneous studied structure—buffer layer—piezoelectric transducers are considered. In these systems, the buffer layer is used for spatial redistribution of thermoelastic force moments generated in the investigated structure. Thus, mechanical properties of this layer play a crucial role to ensure perfect control of the detected voltage formed on a piezoelectric transducer by contribution of different regions of the studied structure. In particular, formation of the voltage signal strongly depends on the point at which the thermoelastic source is applied. Therefore, use of relatively simple linear Green's functions introduced in frames of the Kirchhoff-Love theory is chosen as an efficient approach for the PA signal description. Moreover, excellent agreement between the theoretical model and measured results obtained on a heterogeneous "porous silicon-bulk Si substrate" structure is stated. Furthermore, resolving of the inverse problem with fitting of the experimental curves by the developed model allows reliable evaluation of the thermal conductivity of the nanostructured porous silicon layer.

  7. Calibrating a distributed hydrological model in a basin with heterogeneous geology

    NASA Astrophysics Data System (ADS)

    McMillan, H. K.; Clark, M. P.; Ibbitt, R. P.

    2007-12-01

    Calibrating distributed hydrological models is a challenging task because of the large number of model parameters (multiple model parameters for multiple sub-basins). A common approach is to apply a set of "parameter multipliers" to the model parameters in each sub-basin. This significantly reduces the dimensionality of the optimization problem, but can result in a spatial distribution of model parameters that is inconsistent with spatial differences in hydrological processes. More thoughtful calibration strategies are needed, especially in river basins where the geology is heterogeneous. This paper reports on our experience calibrating a distributed hydrological model for the Rangitaiki River basin in New Zealand. The Rangitaiki is an interesting river in that the geology of the western half of the river basin is pumice, which responds slowly to rain events; while the geology of the eastern half of the river basin is greywacke, which responds rapidly to rain events. Several different calibration strategies were tested, each of which modifies the frequency distribution that describes the a-priori parameters assigned to sub-catchments throughout the river basin. The spatial parameters are modified en masse, or modified in clusters according to geographic location or sub-catchment geology. Results show that spatial variability in model parameters is necessary to produce realistic streamflow simulations both at the basin outlet and at interior points in the basin. The required complexity of the calibration strategy depends on the reasonableness of a-priori parameter estimates--if a-priori model parameters are constant across all sub-catchments, then more complex calibration methods are needed to reproduce spatial variability in runoff responses. The results of the analysis are currently being used to design a methodology to estimate model parameters for all river basins throughout New Zealand.

  8. Geologic Maps Geology 200

    E-print Network

    Kammer, Thomas

    Geologic Maps Geology 200 Geology for Environmental Scientists #12;Geologic Map of the US #12;Symbols found on geologic maps #12;Horizontal Strata #12;Geologic map of part of the Grand Canyon. Each color represents a different formation. #12;Inclined Strata #12;Dome #12;Geologic map of the Black Hills

  9. Geology of the Biwabik Iron Formation and Duluth Complex

    USGS Publications Warehouse

    Jirsa, M.A.; Miller, J.D., Jr.; Morey, G.B.

    2008-01-01

    The Biwabik Iron Formation is a ???1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern-most extent by ???1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in iron-formation along the eastern part of what is known as the Mesabi Iron Range, and their potential liberation by iron mining has raised environmental health concerns. We describe here the geologic setting and mineralogic composition of the Biwabik Iron Formation in and adjacent to the contact metamorphic aureole of the Duluth Complex. The effects of metamorphism are most pronounced within a few kilometers of the contact, and decrease progressively away from it. The contact aureole has been divided into four metamorphic zones-each characterized by the composition and crystal structure of the metamorphic minerals it contains. The recrystallization of iron-formation to iron-rich amphibole minerals (grunerite and cummingtonite) and iron-pyroxene minerals (hedenbergite and ferrohypersthene) is best developed in zones that are most proximal to the Duluth Complex contact. ?? 2007 Elsevier Inc. All rights reserved.

  10. Geology of the Biwabik Iron Formation and Duluth Complex.

    PubMed

    Jirsa, Mark A; Miller, James D; Morey, G B

    2008-10-01

    The Biwabik Iron Formation is a approximately 1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern-most extent by approximately 1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in iron-formation along the eastern part of what is known as the Mesabi Iron Range, and their potential liberation by iron mining has raised environmental health concerns. We describe here the geologic setting and mineralogic composition of the Biwabik Iron Formation in and adjacent to the contact metamorphic aureole of the Duluth Complex. The effects of metamorphism are most pronounced within a few kilometers of the contact, and decrease progressively away from it. The contact aureole has been divided into four metamorphic zones-each characterized by the composition and crystal structure of the metamorphic minerals it contains. The recrystallization of iron-formation to iron-rich amphibole minerals (grunerite and cummingtonite) and iron-pyroxene minerals (hedenbergite and ferrohypersthene) is best developed in zones that are most proximal to the Duluth Complex contact. PMID:17997209

  11. Geologically based model of heterogeneous hydraulic conductivity in an alluvial setting

    NASA Astrophysics Data System (ADS)

    Fogg, Graham E.; Noyes, Charles D.; Carle, Steven F.

    Information on sediment texture and spatial continuity are inherent to sedimentary depositional facies descriptions, which are therefore potentially good predictors of spatially varying hydraulic conductivity (K). Analysis of complex alluvial heterogeneity in Livermore Valley, California, USA, using relatively abundant core descriptions and field pumping-test data, demonstrates a depositional-facies approach to characterization of subsurface heterogeneity. Conventional textural classifications of the core show a poor correlation with K; however, further refinement of the textural classifications into channel, levee, debris-flow, and flood-plain depositional facies reveals a systematic framework for spatial modeling of K. This geologic framework shows that most of the system is composed of very low-K flood-plain materials, and that the K measurements predominantly represent the other, higher-K facies. Joint interpretation of both the K and geologic data shows that spatial distribution of K in this system could not be adequately modeled without geologic data and analysis. Furthermore, it appears that K should not be assumed to be log-normally distributed, except perhaps within each facies. Markov chain modeling of transition probability, representing spatial correlation within and among the facies, captures the relevant geologic features while highlighting a new approach for statistical characterization of hydrofacies spatial variability. The presence of fining-upward facies sequences, cross correlation between facies, as well as other geologic attributes captured by the Markov chains provoke questions about the suitability of conventional geostatistical approaches based on variograms or covariances for modeling geologic heterogeneity. Résumé Les informations sur la texture des sédiments et leur continuité spatiale font partie des descriptions de faciès sédimentaires de dépôt. Par conséquent, ces descriptions sont d'excellents prédicteurs potentiels des variations spatiales de la conductivité hydraulique (K). L'analyse de l'hétérogénéité des alluvions complexes de la vallée de Livermore (Californie, États-Unis), sur la base de descriptions de carottes relativement nombreuses et de données d'essais de pompage, montre que l'hétérogénéité souterraine peut être caractérisée par une approche des faciès de dépôt. Des classifications conventionnelles de la texture de la carotte montrent une corrélation médiocre avec K; toutefois, une amélioration ultérieure des classifications de texture en faciès de dépôt de chenal, de levée d'inondation, de coulée boueuse et de plaine d'inondation a fourni un cadre systématique pour une modélisation spatiale de K. Ce cadre géologique montre que le système est composé pour l'essentiel par des matériaux d'inondation à très faible perméabilité ceci laisse envisager qu'on ne peut pas supposer que K suit une distribution log-normal, sauf peut-être à l'intérieur de chaque faciès. Une modélisation par chaîne de Markov de la probabilité de passage, représentant la corrélation spatiale dans les faciès et entre eux, prend en compte les faits géologiques intéressants tout en fournissant une approche nouvelle pour une caractérisation statistique de la variabilité spatiale des faciès. La présence de séquences à faciès tronqués vers le haut, d'une corrélation croisée entre faciès, ainsi que d'autres caractères géologiques pris en compte par les chaînes de Markov conduisent à se poser des questions sur l'adéquation des approches géostatistiques conventionnelles utilisant les variogrammes ou les covariances pour modéliser l'hétérogénéité géologique. Resumen La información respecto a la textura de los sedimentos y la continuidad espacial es inherente a las descripciones de las facies deposicionales sedimentarias. De este modo, estas descripciones se convierten en excelentes predictores potenciales de las variaciones espaciales de la conductividad hidráulica (K). El análisis de la heterogeneidad en un aluvial en el Valle de L

  12. Estimation of hydrologic properties of heterogeneous geologic media with an inverse method based on iterated function systems

    SciTech Connect

    Doughty, C.A.

    1996-05-01

    The hydrologic properties of heterogeneous geologic media are estimated by simultaneously inverting multiple observations from well-test data. A set of pressure transients observed during one or more interference tests is compared to the corresponding values obtained by numerically simulating the tests using a mathematical model. The parameters of the mathematical model are varied and the simulation repeated until a satisfactory match to the observed pressure transients is obtained, at which point the model parameters are accepted as providing a possible representation of the hydrologic property distribution. Restricting the search to parameters that represent fractal hydrologic property distributions can improve the inversion process. Far fewer parameters are needed to describe heterogeneity with a fractal geometry, improving the efficiency and robustness of the inversion. Additionally, each parameter set produces a hydrologic property distribution with a hierarchical structure, which mimics the multiple scales of heterogeneity often seen in natural geological media. Application of the IFS inverse method to synthetic interference-test data shows that the method reproduces the synthetic heterogeneity successfully for idealized heterogeneities, for geologically-realistic heterogeneities, and when the pressure data includes noise.

  13. Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation.

    PubMed

    Rajendran, Ranjith; Sherry, Leighann; Lappin, David F; Nile, Chris J; Smith, Karen; Williams, Craig; Munro, Carol A; Ramage, Gordon

    2014-12-01

    BackgroundBiofilm formation by Candida albicans has shown to be highly variable and is directly associated with pathogenicity and poor clinical outcomes in patients at risk. The aim of this study was to test the hypotheses that the extracellular DNA release by C. albicans is strain dependent and is associated with biofilm heterogeneity.ResultsInitially, biofilm formed by C. albicans high biofilm formers (HBF) or low biofilm formers (LBF) were treated with DNase to find whether eDNA play a role in their biofilm formation. Digestion of biofilm eDNA significantly reduced the HBF biofilm biomass by five fold compared to untreated controls. In addition, quantification of eDNA over the period of biofilm formation by SYBR green assay demonstrate a significantly higher level of 2 to 6 fold in HBF compared to LBF. Biochemical and transcriptional analyses showed that chitinase activity and mRNA levels of chitinase genes, a marker of autolysis, were upregulated in 24 h biofilm formation by HBF compared to LBF, indicating autolysis pathway possibly involved in causing variation. The biofilm biomass and eDNA release by single (¿cht2, ¿cht3) and double knockout (¿cht2/¿cht3) chitinase mutants were significantly less compared to their parental strain CA14, confirming the role of chitinases in eDNA release and biofilm formation. Correlation analysis found a positive correlation between chitinases and HWP1, suggesting eDNA may release during the hyphal growth. Finally, we showed a combinational treatment of biofilms with DNase or chitinase inhibitor (acetazolamide) plus amphotericin B significantly improved antifungal susceptibility by 2 to 8 fold.ConclusionsCollectively, these data show that eDNA release by C. albicans clinical isolates is variable and is associated with differential biofilm formation. Digestion of biofilm eDNA by DNase may provide a novel therapeutic strategies to destabilise biofilm growth and improves antifungal sensitivity. PMID:25476750

  14. Modeling fine-scale geological heterogeneity--examples of sand lenses in tills.

    PubMed

    Kessler, Timo Christian; Comunian, Alessandro; Oriani, Fabio; Renard, Philippe; Nilsson, Bertel; Klint, Knud Erik; Bjerg, Poul Løgstrup

    2013-01-01

    Sand lenses at various spatial scales are recognized to add heterogeneity to glacial sediments. They have high hydraulic conductivities relative to the surrounding till matrix and may affect the advective transport of water and contaminants in clayey till settings. Sand lenses were investigated on till outcrops producing binary images of geological cross-sections capturing the size, shape and distribution of individual features. Sand lenses occur as elongated, anisotropic geobodies that vary in size and extent. Besides, sand lenses show strong non-stationary patterns on section images that hamper subsequent simulation. Transition probability (TP) and multiple-point statistics (MPS) were employed to simulate sand lens heterogeneity. We used one cross-section to parameterize the spatial correlation and a second, parallel section as a reference: it allowed testing the quality of the simulations as a function of the amount of conditioning data under realistic conditions. The performance of the simulations was evaluated on the faithful reproduction of the specific geological structure caused by sand lenses. Multiple-point statistics offer a better reproduction of sand lens geometry. However, two-dimensional training images acquired by outcrop mapping are of limited use to generate three-dimensional realizations with MPS. One can use a technique that consists in splitting the 3D domain into a set of slices in various directions that are sequentially simulated and reassembled into a 3D block. The identification of flow paths through a network of elongated sand lenses and the impact on the equivalent permeability in tills are essential to perform solute transport modeling in the low-permeability sediments. PMID:23252428

  15. Determining resistivity of a geological formation using circuitry located within a borehole casing

    DOEpatents

    Vail III, William Banning

    2006-01-17

    Geological formation resistivity is determined. Circuitry is located within the borehole casing that is adjacent to the geological formation. The circuitry can measure one or more voltages across two or more voltage measurement electrodes associated with the borehole casing. The measured voltages are used by a processor to determine the resistivity of the geological formation. A common mode signal can also be reduced using the circuitry.

  16. COMMENT ON 'AN ADVECTION-DIFFUSION CONCEPT FOR SOLUTE TRANSPORT IN HETEROGENEOUS UNCONSOLIDATED GEOLOGICAL DEPOSITS' BY GILLHAM ET AL

    EPA Science Inventory

    The article is a technical commentary relating to the article, 'An Advection-Diffusion Concept for Solute Transport in Heterogenous Unconsolidated Geological Deposits,' by Gillham, et al, Water Resources Research 20(3):369-378, 1984. The authors principal comments relate to the c...

  17. Sulfuric Acid Monohydrate: Formation and Heterogeneous Chemistry in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Zhang, Renyi; Leu, Ming-Taun; Keyser, Leon F.

    1995-01-01

    We have investigated some thermodynamic properties (i.e., freezing/melting points) and heterogeneous chemistry of sulfuric acid monohydrate (SAM, H2SO4.H2O), using a fast flow reactor coupled to a quadrupole mass spectrometer. The freezing point observations of thin liquid sulfuric acid films show that for acid contents between 75 and 85 wt % the monohydrate crystallizes readily at temperatures between 220 and 240 K on a glass substrate. Once formed, SAM can be thermodynamically stable in the H2O partial pressure range of (1-4) x 10(exp -4) torr and in the temperature range of 220-240 K. For a constant H2O partial pressure, lowering the temperature causes SAM to melt when the temperature and water partial pressure conditions are out of its stability regime. The reaction probability measurements indicate that the hydrolysis of N2O5 is significantly suppressed owing to the formation of crystalline SAM: The reaction probability on water-rich SAM (with higher relative humidity, or RH) is of the order of 10(exp -3) at 210 K and decreases by more than an order of magnitude for the acid-rich form (with lower RH). The hydrolysis rate of ClONO2 on water-rich SAM is even smaller, of the order of 10(exp -4) at 195 K. These reported values on crystalline SAM are much smaller than those on liquid solutions. No enhancement of these reactions is observed in the presence of HCl vapor at the stratospheric concentrations. In addition, Brunauer, Emmett, and Teller analysis of gas adsorption isotherms and photomicrography have been performed to characterize the surface roughness and porosities of the SAM substrate. The results suggest the possible formation of SAM in some regions of the middle- or low-latitude stratosphere and, consequently, much slower heterogeneous reactions on the frozen aerosols.

  18. Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity. [Jurassic Smackover Formation

    SciTech Connect

    Mancini, E.A.

    1990-01-01

    The objective of this project is to augment the National Reservoir Database (TORIS database), to increase our understanding of geologic heterogeneities that affect the recoveries of oil and gas from carbonate reservoirs in the State of Alabama, and to identify resources that are producible at moderate cost. This objective will be achieved through detailed geological, geostatistical, and engineering characterization of typical Jurassic Smackover Formation hydrocarbon, and engineering characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the state of Alabama. The results of these studies will be used to develop and test mathematical models for prediction of the effects of reservoir heterogeneities in hydrocarbon production. Work to date has focused on completion of Subtasks 1, 2, and 3 of this project. Work on Subtask 4 began in this quarter, and substantial additional work has been accomplished on Subtask 2. Subtask 1 included the survey and tabulation of available reservoir engineering and geological data. Subtask 2 comprises the geologic and engineering characterization of smackover reservoir lithofacies. Subtask 3 includes the geologic modeling of reservoir heterogeneities. Subtask 4 includes the development of reservoir exploitation methodologies for strategic infill drilling. 1 fig.

  19. Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones

    SciTech Connect

    Brown, Stephen R.

    2003-06-01

    Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones Stephen Brown, Gregory Boitnott, and Martin Smith New England Research In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. For sedimentary materials the length scales are: the pore scale (irregularities in grain surface roughness and cementation), the scale of grain packing faults (and the resulting correlated porosity structures), the scale dominated by sorting or winnowing due to depositional processes, and the scale of geomorphology at the time of deposition. We are studying the heterogeneity and anisotropy in geometry, permeability, and geophysical response from the pore (microscopic), laboratory (mesoscopic), and backyard field (macroscopic) scales. In turn these data are being described and synthesized for development of mathematical models. Eventually, we will perform parameter studies to explore these models in the context of transport in the vadose and saturated zones. We have developed a multi-probe physical properties scanner which allows for the mapping of geophysical properties on a slabbed sample or core. This device allows for detailed study of heterogeneity at those length scales most difficult to quantify using standard field and laboratory practices. The measurement head consists of a variety of probes designed to make local measurements of various properties, including: gas permeability, acoustic velocities (compressional and shear), complex electrical impedance (4 electrode, wide frequency coverage), and ultrasonic reflection (ultrasonic impedance and permeability). We can thus routinely generate detailed geophysical maps of a particular sample. With the exception of the acoustic velocity, we are testing and modifying these probes as necessary for use on soil samples. As a baseline study we have been characterizing the heterogeneity of a bench-size Berea Sandstone block. Berea Sandstone has long been regarded as a laboratory standard in rock properties studies, owing to its uniformity and ''typical'' physical properties. We find that both permeability and velocity exhibit complex heterogeneity at the centimeter scale. While some correlation with the outcropping of the bedding is apparent, much of the heterogeneity is not clearly associated with visual features. We are developing software tools to examine simultaneously pixel by pixel correlations among geophysical measurements, transport properties, and visual (photographic) texture and the dependence of these correlations on measurement scale. We find that certain pairs of physical quantities, such as P velocity and permeability for example, are distinctly correlated with one another at certain scales, but less obviously at other scales. Preliminary analyses of the Berea Sandstone data show that by simultaneous consideration of several physical properties the data can be separated into clusters of like properties which can be considered distinct facies. Apparently, identification of these facies, which could represent a limited range of fluid permeability, may be made by making joint geophysical measurements. Given various physical models for the dependence of the geophysical and transport properties on pore size, we expect that these observed correlations will provide conditioning and constraints to inversions for stochastic models of the internal structure of a specimen. For the study of soil heterogeneity at a wide range of scales, we are focusing on a local glacial deposit. This deposit is a glacial kame terrace of fluvial origin with multi-scale sedimentary structures comprised of unconsolidated sands, clays, and gravels. There are also many joints and faults in the unconsolidated sediments, allowing study of these as potential fluid flow conduits or barriers. We have obtained undisturbed soil samples from this site, allowing detailed laboratory study using similar methods to those described for the sandstone bl

  20. Geologic framework of the Jurassic (Oxfordian) Smackover Formation the Alabama coastal waters area

    Microsoft Academic Search

    B. H. Tew; E. A. Mancini; Mink R. M; S. D. Mann

    1993-01-01

    The Jurassic (Oxfordian) Smackover Formation is a prolific hydrocarbon-producing geologic unit in the onshore Gulf of Mexico area, including southwest Alabama. However, no Smackover strata containing commercial accumulations of oil or gas have thus far been discovered in the Alabama state coastal waters area (ACW). This study of the regional geologic framework of the Smackover Formation was done to characterize

  1. Stochastic Inversion of Pneumatic Cross-hole Tests and Barometric Pressure Fluctuations in Heterogeneous Unsaturated Formations

    NASA Astrophysics Data System (ADS)

    Ni, C.-F.; Yeh, T.-C. J.; Hsu, H.-H.; Deng, Y.-T.

    2009-04-01

    The distributions of permeability and porosity are key factors that control airflow and gas phase transport in unsaturated formations. To understand the behavior of flow and transport in such formations, characterization procedure is a typical approach that has been widely applied to laboratories and fields. As is recognized by most investigations, this approach relies on accurate measurements, and more importantly, an adequate tool to interpret those measurements from experiments. This study presents a pneumatic inverse model that is capable to estimate the distributions of permeability (Ka) and porosity (n) with high resolution in heterogeneous unsaturated formations. Based on the concept of sequential successive linear estimator (SSLE), the developed model accounts for compressibility and density of air and estimates the geologic parameters using air pressure measurements from sequential cross-hole pneumatic pumping or injection tests. Four synthetic examples, including a one-dimensional well-posed, a horizontally two-dimensional, and two three-dimensional problems, are used to evaluate the developed model in estimating the distributions of permeability and porosity in unsaturated formations. Results of the numerical experiments are promising. The developed pneumatic inverse model can reconstruct the property (i.e., permeability and porosity) fields if the well-defined conditions are met. With relatively small number of available measurements, the proposed model can accurately capture the patterns and the magnitudes of estimated properties for unsaturated formations. Results of two complex three-dimensional examples show that the proposed model can map the fracture connectivity using relatively small number of subsurface pressure measurements and estimate and in shallow soil layers using spatial variations of barometric pressure.

  2. Stochastic inversion of pneumatic cross-hole tests and barometric pressure fluctuations in heterogeneous unsaturated formations

    NASA Astrophysics Data System (ADS)

    Ni, Chuen-Fa; Yeh, Tian-Chyi Jim

    2008-12-01

    The distributions of permeability and porosity are key factors that control airflow and gas phase transport in unsaturated formations. To understand the behavior of flow and transport in such formations, characterization procedure is a typical approach that has been widely applied to laboratories and fields. As is recognized by most investigations, this approach relies on accurate measurements, and more importantly, an adequate tool to interpret those measurements from experiments. This study presents a pneumatic inverse model that is capable to estimate the distributions of permeability ( k) and porosity ( ?) with high resolution in heterogeneous unsaturated formations. Based on the concept of sequential successive linear estimator (SSLE), the developed model accounts for compressibility and density of air and estimates the geologic parameters using air pressure measurements from sequential cross-hole pneumatic pumping or injection tests. Four synthetic examples, including a one-dimensional well-posed, a horizontally two-dimensional, and two three-dimensional problems, are used to evaluate the developed model in estimating the distributions of permeability and porosity in unsaturated formations. Results of the numerical experiments are promising. The developed pneumatic inverse model can reconstruct the property (i.e., permeability and porosity) fields if the well-defined conditions are met. With a relatively small number of available measurements, the proposed model can accurately capture the patterns and the magnitudes of estimated properties for unsaturated formations. Results of two complex three-dimensional examples show that the proposed model can map the fracture connectivity using a small number of subsurface pressure measurements and estimate k and ? in shallow soil layers using spatial variations of barometric pressure.

  3. Geologic heterogeneity recognition using discrete wavelet transformation for subsurface flow solute transport simulations

    NASA Astrophysics Data System (ADS)

    Mustapha, Hussein; Chatterjee, Snehamoy; Dimitrakopoulos, Roussos; Graf, Thomas

    2013-04-01

    Subsurface flow and solute transport simulations are performed using different scenarios of permeability fields generated from the sequential Gaussian simulation method (SGS), the multiple-point FILTERSIM algorithm and a new multiple-point wavelet-based simulation method (SWS). The SWS method is a multiple-point pattern-based simulation method which uses discrete wavelet transformation for the representation of geologic heterogeneity. For pattern-based simulation, patterns are generated by scanning a training image with a spatial template. The pattern classifications were performed after reducing the dimension of patterns by wavelet decomposition at the suitable scale and by taking only scaling components of wavelet decomposed patterns. The simulation is performed in a sequential manner by finding the best-matched class corresponding to the conditioning data and by randomly sampling a pattern from the best-matched class. The developed method is compared with two other multi-point simulation algorithms, FLTERSIM and SIMPAT. The comparative results revealed that the proposed method is computationally faster than the other two methods while the simulation maps are comparable. Numerical simulations of two flow problems are performed using SGS, SWS and FILTERSIM realizations. The numerical results show a superiority of the SWS method over SGS and FILTERSIM in terms of reproduction of the reference images main features, and agreement with flow and transport results obtained on reference images.

  4. Approaches to identifying reservoir heterogeneity and reserve growth opportunities from subsurface data: The Oficina Formation, Budare field, Venezuela

    SciTech Connect

    Hamilton, D.S.; Raeuchle, S.K.; Holtz, M.H. [Bureau of Economic Geology, Austin, TX (United States)] [and others

    1997-08-01

    We applied an integrated geologic, geophysical, and engineering approach devised to identify heterogeneities in the subsurface that might lead to reserve growth opportunities in our analysis of the Oficina Formation at Budare field, Venezuela. The approach involves 4 key steps: (1) Determine geologic reservoir architecture; (2) Investigate trends in reservoir fluid flow; (3) Integrate fluid flow trends with reservoir architecture; and (4) Estimate original oil-in-place, residual oil saturation, and remaining mobile oil, to identify opportunities for reserve growth. There are three main oil-producing reservoirs in the Oficina Formation that were deposited in a bed-load fluvial system, an incised valley-fill, and a barrier-strandplain system. Reservoir continuity is complex because, in addition to lateral facies variability, the major Oficina depositional systems were internally subdivided by high-frequency stratigraphic surfaces. These surfaces define times of intermittent lacustrine and marine flooding events that punctuated the fluvial and marginal marine sedimentation, respectively. Syn and post depositional faulting further disrupted reservoir continuity. Trends in fluid flow established from initial fluid levels, response to recompletion workovers, and pressure depletion data demonstrated barriers to lateral and vertical fluid flow caused by a combination of reservoir facies pinchout, flooding shale markers, and the faults. Considerable reserve growth potential exists at Budare field because the reservoir units are highly compartment by the depositional heterogeneity and structural complexity. Numerous reserve growth opportunities were identified in attics updip of existing production, in untapped or incompletely drained compartments, and in field extensions.

  5. Statistical characterisation and stochastic parameterisation of sedimentary geological formations on their reaction capacity for sustainable groundwater quality management

    NASA Astrophysics Data System (ADS)

    Griffioen, J.; Vermooten, S.; Keijzer, T.; Bakr, M.; Valstar, J.

    2012-04-01

    The fate of contaminants in groundwater aquifers is determined by the buffering capacity of those aquifers together with the composition of inflowing groundwater. A nationwide characterisation of the environmental geochemistry of the shallow subsurface (down to 30 m below surface) has been started in the Netherlands. This covers: 1. the reaction capacity of sediments as buffer for contamination, and 2. typical elemental composition of geological formations and the association between trace elements and major minerals. For this purpose, the Netherlands is subdivided into 27 so-called geotop regions each having a unique geological build-up of the shallow subsurface. Here, four types are recognised based on vertical hydrogeological build-up. The regions are statistically characterised on their geochemical composition using combinations of lithological class and geological formation as strata. The statistical data are subsequently coupled with a geological voxel model of the subsurface to stochastically parameterise the geological units on reaction capacity. This combined approach will be illustrated for the Dutch province Zeeland. Reaction capacity is considered as a series of geochemical characteristics that control acid/base condition, redox condition and sorption capacity. Five primary reaction capacity variables are characterised: 1. pyrite, 2. non-pyrite, reactive iron (oxides, siderite and glauconite), 3. clay fraction, 4. organic matter and 5. Ca-carbonate. Important reaction capacity variables that are determined by more than one solid compound are also deduced: 1. potential reduction capacity (PRC) by pyrite and organic matter, 2. cation-exchange capacity (CEC) by organic matter and clay content, 3. carbonate buffering upon pyrite oxidation (CPBO) by carbonate and pyrite. A statistical investigation of several hunderds of sediment analyses is performed that provides the geochemical properties of the sediments. Here, classification based on sedimentary facies may provide additional insight on spatial heterogeneity within lithological classes. A two-step stochastic algoritm is established for parameterisation of a geological voxel model. First, the cumulative frequency distribution (cfd) functions are calculated for the geochemical strata. Next, all voxels are classified into the geochemical strata and the cfd functions are used to put random reaction capacity variables into the geological voxel model. The result is a heterogeneous geochemical reaction capacity model of the subsurface having grid cells of 100x100x0.5 m. This model can be used in e.g. groundwater transport models or other instruments for groundwater quality management.

  6. Geology

    SciTech Connect

    Reidel, Stephen P.

    2008-01-17

    This chapter summarizes the geology of the single-shell tank (SST) farms in the context of the region’s geologic history. This chapter is based on the information in the geology data package for the SST waste management areas and SST RFI Appendix E, which builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.

  7. Quantification of rock heterogeneities by structural geological field studies combined with laboratory analyses

    NASA Astrophysics Data System (ADS)

    Reyer, Dorothea; Afsar, Filiz; Philipp, Sonja

    2013-04-01

    Heterogeneous rock properties in terms of layering and complex infrastructure of fault zones are typical in sedimentary successions. The knowledge of in-situ mechanical rock properties is crucial for a better understanding of processes such as fracturing and fluid transport in fractured reservoirs. To estimate in situ rock properties at different depths it is important to understand how rocks from outcrops differ from rocks at depth, for example due to alteration and removal of the overburden load. We aim at quantifying these properties by performing structural geological field studies in outcrop analogues combined with laboratory analyses of outcrop samples and drill-cores. The field studies focus on 1) fault zone infrastructure and 2) host rock fracture systems in two different study areas with different lithologies, the North German and the Bristol Channel Basin. We analyse quantitatively the dimension, geometry, persistence and connectivity of fracture systems. The field studies are complemented by systematic sampling to obtain the parameters Young's modulus, compressive and tensile strengths and elastic strain energy (also referred to as destruction work) from which we estimate rock and fracture toughnesses. The results show that in rocks with distinctive layering fractures are often restricted to individual layers, that is, stratabound. The probability of arrest seems to depend on the stiffness contrast between two single layers as well as on the thickness of the softer layer. The results also show that there are clear differences between fault zones in the different lithologies in terms of damage zone thicknesses and fracture system parameters. The results of laboratory analyses show that the mechanical properties vary considerably and for many samples there are clear directional differences. That is, samples taken perpendicular to layering commonly have higher stiffnesses and strengths than those taken parallel to layering. We combine the results of laboratory analyses and field measurements to specify the mechanical heterogeneities of typical sedimentary rocks and of the mechanical units of fault zones. The results from drill-core sample analyses are then compared with the results from the outcrop samples. Another approach is to analyse how rock mechanical properties correlate with petrographic properties (e.g., mineral content, cementation, fabric) to use this knowledge to extrapolate the data to depth. Acknowledgements The authors appreciate the support of 'Niedersächsisches Ministerium für Wissenschaft und Kultur' and 'Baker Hughes' within the gebo research project (http://www.gebo-nds.de). The project "Fracture propagation and reservoir permeability in limestone-marl alternations" is funded by the Deutsche Forschungsgemeinschaft (German Research Foundation, http://www.dfg.de).

  8. Mesozoic marine tetrapod diversity: mass extinctions and temporal heterogeneity in geological megabiases affecting vertebrates.

    PubMed

    Benson, Roger B J; Butler, Richard J; Lindgren, Johan; Smith, Adam S

    2010-03-22

    The fossil record is our only direct means for evaluating shifts in biodiversity through Earth's history. However, analyses of fossil marine invertebrates have demonstrated that geological megabiases profoundly influence fossil preservation and discovery, obscuring true diversity signals. Comparable studies of vertebrate palaeodiversity patterns remain in their infancy. A new species-level dataset of Mesozoic marine tetrapod occurrences was compared with a proxy for temporal variation in the volume and facies diversity of fossiliferous rock (number of marine fossiliferous formations: FMF). A strong correlation between taxic diversity and FMF is present during the Cretaceous. Weak or no correlation of Jurassic data suggests a qualitatively different sampling regime resulting from five apparent peaks in Triassic-Jurassic diversity. These correspond to a small number of European formations that have been the subject of intensive collecting, and represent 'Lagerstätten effects'. Consideration of sampling biases allows re-evaluation of proposed mass extinction events. Marine tetrapod diversity declined during the Carnian or Norian. However, the proposed end-Triassic extinction event cannot be recognized with confidence. Some evidence supports an extinction event near the Jurassic/Cretaceous boundary, but the proposed end-Cenomanian extinction is probably an artefact of poor sampling. Marine tetrapod diversity underwent a long-term decline prior to the Cretaceous-Palaeogene extinction. PMID:19923126

  9. Episodic and long-lived river incision along geologically heterogeneous passive margins

    NASA Astrophysics Data System (ADS)

    Harbor, D. J.; Gunnell, Y.; Hancock, G. S.

    2011-12-01

    Hillslopes and river profiles in the southern and central Appalachians and the Eastern Ghats of India do not display the characteristics of dynamic equilibrium expected for Mesozoic passive margins. Escarpments, gorges, and river knickpoints characterize many portions of the margin highlands and continental interior. Bedrock resistance is a first-order control on topography, but it is significantly altered by the history of erosion. A conceptual model of episodic drainage rearrangement and subsequent incision in these spatially varied geologic settings underscores the potential erosional heterogeneity of these long-eroding margins. Waves of heightened river incision extend deep into the margin, yielding steep topography on comparatively weak bedrock, and regional escarpments and plateau remnants that cross lithologic boundaries. Correlating major incision events through the landscape is possible using basin-wide analysis of river profile shape, but it is complicated by many factors including 1) the effects of rock resistance on rate and style of incision, 2) river dynamics that depend on sediment load, and 3) meander bend cutoffs. Knickpoint migration rates determined from terrace ages, in-channel erosion rate, and basin-wide correlations suggest that incision migrates upriver over millions of years. Renewed Quaternary incision by the James River, which has a large drainage basin likely captured during the Neogene, occurs by further knickpoint retreat that could be a response to erosional unloading and uplift, or simply to climate change. In one Appalachian drainage basin, modern channel morphology plus integration of erosion over the long term suggests that episodic, nonuniform erosion accounts for the majority of late Quaternary incision.

  10. Nitrate reduction in geologically heterogeneous catchments--a framework for assessing the scale of predictive capability of hydrological models.

    PubMed

    Refsgaard, Jens Christian; Auken, Esben; Bamberg, Charlotte A; Christensen, Britt S B; Clausen, Thomas; Dalgaard, Esben; Effersø, Flemming; Ernstsen, Vibeke; Gertz, Flemming; Hansen, Anne Lausten; He, Xin; Jacobsen, Brian H; Jensen, Karsten Høgh; Jørgensen, Flemming; Jørgensen, Lisbeth Flindt; Koch, Julian; Nilsson, Bertel; Petersen, Christian; De Schepper, Guillaume; Schamper, Cyril; Sørensen, Kurt I; Therrien, Rene; Thirup, Christian; Viezzoli, Andrea

    2014-01-15

    In order to fulfil the requirements of the EU Water Framework Directive nitrate load from agricultural areas to surface water in Denmark needs to be reduced by about 40%. The regulations imposed until now have been uniform, i.e. the same restrictions for all areas independent of the subsurface conditions. Studies have shown that on a national basis about 2/3 of the nitrate leaching from the root zone is reduced naturally, through denitrification, in the subsurface before reaching the streams. Therefore, it is more cost-effective to identify robust areas, where nitrate leaching through the root zone is reduced in the saturated zone before reaching the streams, and vulnerable areas, where no subsurface reduction takes place, and then only impose regulations/restrictions on the vulnerable areas. Distributed hydrological models can make predictions at grid scale, i.e. at much smaller scale than the entire catchment. However, as distributed models often do not include local scale hydrogeological heterogeneities, they are typically not able to make accurate predictions at scales smaller than they are calibrated. We present a framework for assessing nitrate reduction in the subsurface and for assessing at which spatial scales modelling tools have predictive capabilities. A new instrument has been developed for airborne geophysical measurements, Mini-SkyTEM, dedicated to identifying geological structures and heterogeneities with horizontal and lateral resolutions of 30-50 m and 2m, respectively, in the upper 30 m. The geological heterogeneity and uncertainty are further analysed by use of the geostatistical software TProGS by generating stochastic geological realisations that are soft conditioned against the geophysical data. Finally, the flow paths within the catchment are simulated by use of the MIKE SHE hydrological modelling system for each of the geological models generated by TProGS and the prediction uncertainty is characterised by the variance between the predictions of the different models. PMID:23953482

  11. Estimation of hydrologic properties of heterogeneous geologic media with an inverse method based on iterated function systems

    SciTech Connect

    Doughty, C [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1995-12-01

    The highly heterogeneous nature of most geologic media, coupled with the restricted view of the subsurface available through boreholes, makes it difficult to determine the spatial distribution of subsurface hydrologic properties. Without such a description one cannot predict how fluid flow or solute transport will occur through permeable geologic media, and these predictions are critically needed to address many important environmental problems, including toxic chemical spills, leaking underground storage tanks, and long-term radioactive waste isolation. A common concern of these problems is the possible existence of high-permeability pathways connecting the problem to the biosphere. An understanding of flow and transport behavior is also necessary to optimize energy extraction from petroleum or geothermal reservoirs, where identifying low-permeability barriers that compartmentalize reservoirs and hamper efficient resource utilization is a key problem. The present work describes the development and application of a new inverse method for determining the spatial distribution of hydrologic properties (permeability and specific storage) in heterogeneous geologic media, using pressure transients from interference well tests. The method employs fractal concepts to improve efficiency and reliability. It is applicable to any sort of heterogeneous geologic medium in which wells communicate with each other, whether it be porous, fractured, or a combination thereof. Application to field data from a shallow aquifer at Kesterson Reservoir agrees well with an independent analysis using traditional well-test analysis methods. Application to a series of interference tests conducted at the Gypsy Pilot Site produces a detailed picture of the subsurface, which compares favorably with cross-well seismic imaging studies. 53 refs.

  12. Evaluating variable switching and flash methods in modeling carbon sequestration in deep geologic formations

    E-print Network

    Mills, Richard

    µ p - Wgz , (3) where formation permeability is denoted by k, relative permeability by k, fluid formations using PFLOTRAN Chuan Lu1, Peter C Lichtner2, Glenn E Hammond3 and Richard T Mills4 1 Energy of supercritical CO2 in deep geologic formations. Two different methods of solution to the governing partial

  13. Modeling CO2 distribution in a heterogeneous sandstone reservoir: the Johansen Formation, northern North Sea

    NASA Astrophysics Data System (ADS)

    Sundal, Anja; Miri, Rohaldin; Petter Nystuen, Johan; Dypvik, Henning; Aagaard, Per

    2013-04-01

    The last few years there has been broad attention towards finding permanent storage options for CO2. The Norwegian continental margin holds great potential for storage in saline aquifers. Common for many of these reservoir candidates, however, is that geological data are sparse relative to thoroughly mapped hydrocarbon reservoirs in the region. Scenario modeling provides a method for estimating reservoir performances for potential CO2 storage sites and for testing injection strategies. This approach is particularly useful in the evaluation of uncertainties related to reservoir properties and geometry. In this study we have tested the effect of geological heterogeneities in the Johansen Formation, which is a laterally extensive sandstone and saline aquifer at burial depths of 2 - 4 km, proposed as a suitable candidate for CO2 storage by Norwegian authorities. The central parts of the Johansen Formation are underlying the operating hydrocarbon field Troll. In order not to interfere with ongoing gas production, a potential CO2 injection well should be located at a safe distance from the gas reservoir, which consequently implies areas presently without well control. From 3D seismic data, prediction of spatial extent of sandstone is possible to a certain degree, whereas intra-reservoir flow baffles such as draping mudstone beds and calcite cemented layers are below seismic resolution. The number and lateral extent of flow baffles, as well as porosity- and permeability distributions are dependent of sedimentary facies and diagenesis. The interpretation of depositional environment and burial history is thus of crucial importance. A suite of scenario models was established for a potential injection area south of the Troll field. The model grids where made in Petrel based on our interpretations of seismic data, wire line logs, core and cuttings samples. Using Eclipse 300 the distribution of CO2 is modeled for different geological settings; with and without the presence of pervasive low permeability draping mudstone layers, and with varying lateral extent of potential calcite cemented layers in 8 to 15 intra-reservoir depth levels. The modeled area covers 10 x 15.8 km, with a thickness of 110 m at the injection point. Simulations were run with an injection phase of 30 years plus 100 years of migration. The presence of meso-scale flow baffles causes a reduction in vertical permeability in addition to the facies related variation on the micro-scale. Scenarios including potential flow baffles as separate layers in the model grids were compared to scenarios in which the effect of flow baffles were included using harmonic mean average of vertical permeability. The subsequent differences in CO2 distribution are important in estimating the contact area between the plume front and reservoir brine. A heterogeneous reservoir with internal flow baffles is not necessarily a disadvantage as long as sufficient injectivity is maintained within individual sandstone bodies. In each scenario we aim to adapt a suitable injection strategy with respect to utilizing local effects such as the delimitation of gravitational flow, in order to increase reservoir sweep and maximize the effect of trapping mechanisms (i.e. residual, stratigraphic, mineral and dissolution).

  14. Predicting 87Sr/86Sr in surface water using bedrock geology: Understanding geologic heterogeneity and scale to improve isoscapes and animal migration reconstruction

    NASA Astrophysics Data System (ADS)

    Hegg, J. C.; Fremier, A. K.; Kennedy, B. P.

    2012-12-01

    Recent advances in reconstructing location and movement patterns using isotopic tracers have revolutionized the study of migration across taxa. Strontium ratio (87Sr/86Sr) in particular has allowed unprecedented temporal and spatial resolution in migration studies. The development of 87Sr/86Sr isoscapes for surface water has been hindered, however, by the difficulty in predicting 87Sr/86Sr variation across the landscape. The abundance of strontium isotopes is tightly linked to the underlying geology; inviting the possibility that 87Sr/86Sr could be predicted directly from bedrock geology. Accurate predictive models would increase spatial resolution in studies of migration, but previous attempts to predict 87Sr/86Sr in stream water have produced limited success and are not easily generalized across the landscape. Using data from the Snake River of Idaho we present a method for accurately predicting stream water 87Sr/86Sr from bedrock. We further show that our predictions can be used to accurately determine the origin of fish based upon the distinct 87Sr/86Sr signatures in their otoliths. We discuss the importance of understanding the affects of geologic heterogeneity and scale for improving our ability to generalize predictions in future models.

  15. 2006 Proc. Annu. Conf. SEAFWA Geologic Analyses for EvaluatingWatershed Heterogeneity

    E-print Network

    Harbor, David

    (Micropterus dolomieu) from the Maury and James rivers (Virginia). Cluster analysis of multivariate geologic of otolith chemistry in riverine smallmouth bass (Micropterus dolomieu) populations. Trace element concen

  16. High Performance Simulation of Environmental Tracers in Heterogeneous Formations

    NASA Astrophysics Data System (ADS)

    Gardner, P.; Hammond, G. E.; Lichtner, P. C.; Arnold, B. W.

    2013-12-01

    Environmental tracers provide information on fluid flux, yielding important information for use in groundwater studies. Currently environmental tracer interpretation has been limited by computational expense. Here we use a scalable, massively parallel, flow and reactive transport code PFLOTRAN to simulate the concentrations of 3H, 3He, CFC-11, CFC-12, CFC-113, SF6, 39Ar, 81Kr , 4He and the mean groundwater age in 2D and 3D heterogeneous fields on grids with an excess of 10 million nodes. We utilize this computational platform to simulate the spatial distribution of environmental tracer concentration, tracer derived ages and modeled mean ground water age in heterogeneous aquifers. Modeled concentrations are then used to calculate tracer derived ages. The deviation of the tracer derived age distribution from the true groundwater age distribution increases with increasing heterogeneity of the system. The separation between the apparent age derived from different tracers also increases with increasing system heterogeneity. Age distributions in 3D aquifers differ significantly from 2D simulations with similar spatial statistics. The addition of the 3rd dimension increases connectivity, decreasing mean age and reducing age variability. High performance computation allows for investigation of tracer and groundwater age spatial distribution in unprecedented detail, providing a foundation for the next generation of environmental tracer interpretation.

  17. Geological and biological heterogeneity of the Aleutian margin (1965–4822 m)

    Microsoft Academic Search

    A. E. Rathburn; L. A. Levin; M. Tryon; J. M. Gieskes; J. B. Martin; M. E. Pérez; F. J. Fodrie; C. Neira; G. J. Fryer; G. Mendoza; P. A. McMillan; J. Kluesner; J. Adamic; W. Ziebis

    2009-01-01

    Geological, biological and biogeochemical characterization of the previously unexplored margin off Unimak Island, Alaska between 1965 and 4822m water depth was conducted to examine: (1) the geological processes that shaped the margin, (2) the linkages between depth, geomorphology and environmental disturbance in structuring benthic communities of varying size classes and (3) the existence, composition and nutritional sources of methane seep

  18. Heterogeneous Response to Marine Reserve Formation: A Sorting Model approach

    Microsoft Academic Search

    Junjie Zhang; Martin D. Smith

    2011-01-01

    The bioeconomic impacts of spatial fisheries management hinge on how fishing vessels reallocate their effort over space. However,\\u000a empirical studies face two challenges: heterogeneous behavioral responses and unobservable resource abundance. This paper\\u000a addresses these two problems simultaneously by using an unusual data set and an estimation technique developed in the industrial\\u000a organization literature. We apply the methods to location and

  19. Transport in Heterogeneous Porous Formations: Spatial Moments, Ergodicity, and Effective Dispersion

    Microsoft Academic Search

    Gedeon Dagan

    1990-01-01

    Transport of inert solutes in natural porous formations is dominated by convection and by the large-scale heterogeneity of permeability. A solute body inserted in the formation spreads because of the variation of velocity among and along the stream tubes which cross the plume. With neglect of the slow effect of pore-scale dispersion the solute particles preserve their initial concentration, but

  20. Bacterial interactions and transport in geological formation of alumino-silica clays.

    PubMed

    Vu, Kien; Yang, Guang; Wang, Boya; Tawfiq, Kamal; Chen, Gang

    2015-01-01

    Bacterial transport in the subsurface is controlled by their interactions with the surrounding environment, which are determined by the surface properties of the geological formation and bacterial surfaces. In this research, surface thermodynamic properties of Escherichia coli and the geological formation of alumino-silica clays were characterized based on contact angle measurements, which were utilized to quantify the distance-dependent interactions between E. coli and the geological formation according to the traditional and extended Derjaguin, Landau, Verwey and Overbeek (DLVO) theory. E. coli attachment to alumino-silica clays was evaluated in laboratory columns under saturated and steady-state flow conditions. E. coli deposition coefficient and desorption coefficient were simulated using convection-dispersion transport models against E. coli breakthrough curves, which were then linked to interactions between E. coli and the geological formation. It was discovered that E. coli deposition was controlled by the long-ranged electrostatic interaction and E. coli desorption was attributed to the short-ranged Lifshitz-van der Waals and Lewis acid-base interactions. E. coli transport in three layers of different alumino-silica clays was further examined and the breakthrough curve was simulated using E. coli deposition coefficient and desorption coefficient obtained from their individual column experiments. The well-fitted simulation confirmed that E. coli transport observations were interaction-dependent phenomena between E. coli and the geological formation. PMID:25437062

  1. Fundamental Study on the Dynamics of Heterogeneity-Enhanced CO2 Gas Evolution in the Shallow Subsurface During Possible Leakage from Deep Geologic Storage Sites

    NASA Astrophysics Data System (ADS)

    Plampin, M. R.; Lassen, R. N.; Sakaki, T.; Pawar, R.; Jensen, K.; Illangasekare, T. H.

    2013-12-01

    A concern for geologic carbon sequestration is the potential for CO2 stored in deep geologic formations to leak upward into shallow freshwater aquifers where it can have potentially detrimental impacts to the environment and human health. Understanding the mechanisms of CO2 exsolution, migration and accumulation (collectively referred to as 'gas evolution') in the shallow subsurface is critical to predict and mitigate the environmental impacts. During leakage, CO2 can move either as free-phase or as a dissolved component of formation brine. CO2 dissolved in brine may travel upward into shallow freshwater systems, and the gas may be released from solution. In the shallow aquifer, the exsolved gas may accumulate near interfaces between soil types, and/or create flow paths that allow the gas to escape through the vadose zone to the atmosphere. The process of gas evolution in the shallow subsurface is controlled by various factors, including temperature, dissolved CO2 concentration, water pressure, background water flow rate, and geologic heterogeneity. However, the conditions under which heterogeneity controls gas phase evolution have not yet been precisely defined and can therefore not yet be incorporated into models used for environmental risk assessment. The primary goal of this study is to conduct controlled laboratory experiments to help fill this knowledge gap. With this as a goal, a series of intermediate-scale laboratory experiments were conducted to observe CO2 gas evolution in porous media at multiple scales. Deionized water was saturated with dissolved CO2 gas under a specified pressure (the saturation pressure) before being injected at a constant volumetric flow rate into the bottom of a 1.7 meter-tall by 5.7 centimeter-diameter column or a 2.4 meter-tall by 40 centimeter-wide column that were both filled with sand in various heterogeneous packing configurations. Both test systems were initially saturated with fresh water and instrumented with soil moisture sensors to monitor the evolution of gas phase through time by measuring the average water content in small sampling volumes of soil. Tensiometers allowed for observation of water pressure through space and time in the test systems, and a computer-interfaced electronic scale continuously monitored the outflow of water from the top of the two test columns. Several packing configurations with five different types of sands were used in order to test the effects of various pore size contrasts and interface shapes on the evolution of the gas phase near soil texture transitions in the heterogeneous packings. Results indicate that: (1) heterogeneity affects gas phase evolution patterns within a predictable range of conditions quantified by the newly introduced term 'oversaturation,' (2) soil transition interfaces where less permeable material overlies more permeable material have a much more pronounced effect on gas evolution than interfaces with opposite orientations, and (3) anticlines (or stratigraphic traps) cause significantly greater gas accumulation than horizontal interfaces. Further work is underway to apply these findings to more realistic, two-dimensional scenarios, and to assess how well existing numerical models can capture these processes.

  2. A Standard-Driven Data Dictionary for Data Harmonization of Heterogeneous Datasets in Urban Geological Information Systems

    NASA Astrophysics Data System (ADS)

    Liu, G.; Wu, C.; Li, X.; Song, P.

    2013-12-01

    The 3D urban geological information system has been a major part of the national urban geological survey project of China Geological Survey in recent years. Large amount of multi-source and multi-subject data are to be stored in the urban geological databases. There are various models and vocabularies drafted and applied by industrial companies in urban geological data. The issues such as duplicate and ambiguous definition of terms and different coding structure increase the difficulty of information sharing and data integration. To solve this problem, we proposed a national standard-driven information classification and coding method to effectively store and integrate urban geological data, and we applied the data dictionary technology to achieve structural and standard data storage. The overall purpose of this work is to set up a common data platform to provide information sharing service. Research progresses are as follows: (1) A unified classification and coding method for multi-source data based on national standards. Underlying national standards include GB 9649-88 for geology and GB/T 13923-2006 for geography. Current industrial models are compared with national standards to build a mapping table. The attributes of various urban geological data entity models are reduced to several categories according to their application phases and domains. Then a logical data model is set up as a standard format to design data file structures for a relational database. (2) A multi-level data dictionary for data standardization constraint. Three levels of data dictionary are designed: model data dictionary is used to manage system database files and enhance maintenance of the whole database system; attribute dictionary organizes fields used in database tables; term and code dictionary is applied to provide a standard for urban information system by adopting appropriate classification and coding methods; comprehensive data dictionary manages system operation and security. (3) An extension to system data management function based on data dictionary. Data item constraint input function is making use of the standard term and code dictionary to get standard input result. Attribute dictionary organizes all the fields of an urban geological information database to ensure the consistency of term use for fields. Model dictionary is used to generate a database operation interface automatically with standard semantic content via term and code dictionary. The above method and technology have been applied to the construction of Fuzhou Urban Geological Information System, South-East China with satisfactory results.

  3. Aquifer Testing in Fractured Rock: Conceptual Similarities in Aquifer Heterogeneity From Varied Geologic Settings

    NASA Astrophysics Data System (ADS)

    Shapiro, A. M.; Hsieh, P. A.

    2001-12-01

    A survey of time-drawdown records from aquifer tests conducted in bedded sedimentary rocks, such as dolomite, sandstone and shale, and in glaciated and unglaciated igneous and metamorphic rocks has shown unexpected similarities. The tests were conducted with a single highly permeable fracture or fracture zone isolated in the pumped borehole, and monitored intervals in observation boreholes had either one or no highly permeable fractures or fracture zones. This was accomplished using boreholes with open intervals at selected elevations or with packers isolating discrete intervals in the pumped and observation boreholes. The results of these aquifer tests showed that multiple monitored intervals in different observation boreholes had essentially the same time-drawdown history regardless of their distance to the pumped interval. This type of aquifer test response is anticipated in bedded sedimentary rocks, where bedding plane partings act as highly permeable zones that are connected hydraulically by fractures in the massive rock between bedding planes. Observation intervals intersecting a given bedding plane during aquifer testing respond similarly because of the high permeability of the bedding plane. Aquifer tests conducted in the Silurian dolomite in New York and Illinois, and in the sandstone and shale beds of formations in the Newark Basin serve as examples. In igneous and metamorphic rocks, in both glaciated and unglaciated terrain, fracturing tends to be considerably more complex than in sedimentary rocks, however, the aquifer test response also showed groups of monitored intervals in observation boreholes with nearly identical drawdown responses. Aquifer tests conducted in the igneous and metamorphic rock in New Hampshire and Georgia, and igneous rock in Sweden serve as examples. A detailed investigation at a bedrock site in central New Hampshire suggest that highly permeable fractures of various orientations form subhorizontal zones that are embedded within a network of less-permeable fractures. The similarity of drawdown responses in monitored intervals of observation boreholes regardless of distance to the pumped borehole suggests a model of aquifer heterogeneity where areally extensive, highly permeable zones are hydraulically connected by rock with less-permeable fractures. Interpretation of these aquifer tests can be conducted by hypothesizing zones of high permeability embedded in less-permeable aquifer material, the hydraulic properties of which can be estimated by methods of parameter estimation used in conjunction with standard ground-water flow models.

  4. GEODYN: A Geological Formation\\/Drillstring Dynamics Computer Program

    Microsoft Academic Search

    J. A. Baird; B. C. Caskey; M. A. Tinianow; C. M. Stone

    1984-01-01

    This paper describes the initial development phase of a finite element computer program, GEODYN, capable of simulating the three-dimensional transient, dynamic response of a polycrystalline diamond compact (PDC) bit interacting with a non-uniform formation. The ability of GEODYN to simulate response variations attributable to hole size, hole bottom surface shapes, and formation material non-uniformities is demonstrated. Planned developmental phases will

  5. Geology of the Grand Canyon: Interpreting its rock layers and formation

    NSDL National Science Digital Library

    In this culminating activity, students will be assessed on what they have learned during the Geology unit of their Earth Science class. After conducting classroom and field studies on geology students will utilize this knowledge to interpret the rock layers and formation of the Grand Canyon. Outside of class students will read/review a website and complete a study guide to be reviewed by the teacher to assess students' learning. Following teacher review of study guides, the next class period(s) will be a discussion and questioning session(s) on the formation of the Grand Canyon.

  6. River-aquifer interactions, geologic heterogeneity, and low-flow management

    USGS Publications Warehouse

    Fleckenstein, J.H.; Niswonger, R.G.; Fogg, G.E.

    2006-01-01

    Low river flows are commonly controlled by river-aquifer exchange, the magnitude of which is governed by hydraulic properties of both aquifer and aquitard materials beneath the river. Low flows are often important ecologically. Numerical simulations were used to assess how textural heterogeneity of an alluvial system influences river seepage and low flows. The Cosumnes River in California was used as a test case. Declining fall flows in the Cosumnes River have threatened Chinook salmon runs. A ground water-surface water model for the lower river basin was developed, which incorporates detailed geostatistical simulations of aquifer heterogeneity. Six different realizations of heterogeneity and a homogenous model were run for a 3-year period. Net annual seepage from the river was found to be similar among the models. However, spatial distribution of seepage along the channel, water table configuration and the level of local connection, and disconnection between the river and aquifer showed strong variations among the different heterogeneous models. Most importantly, the heterogeneous models suggest that river seepage losses can be reduced by local reconnections, even when the regional water table remains well below the riverbed. The percentage of river channel responsible for 50% of total river seepage ranged from 10% to 26% in the heterogeneous models as opposed to 23% in the homogeneous model. Differences in seepage between the models resulted in up to 13 d difference in the number of days the river was open for salmon migration during the critical fall months in one given year. Copyright ?? 2006 The Author(s).

  7. Permafrost on Mars: distribution, formation, and geological role

    NASA Technical Reports Server (NTRS)

    Nummedal, D.

    1984-01-01

    The morphology of channels, valleys, chaotic and fretted terrains and many smaller features on Mars is consistent with the hypothesis that localized deterioration of thick layers of ice-rich permafrost was a dominant geologic process on the Martian surface. Such ground ice deterioration gave rise to large-scale mass movement, including sliding, slumping and sediment gravity flowage, perhaps also catastropic floods. In contrast to Earth, such mass movement processes on Mars lack effective competition from erosion by surface runoff. Therefore, Martian features due to mass movement grew to reach immense size without being greatly modified by secondary erosional processes. The Viking Mission to Mars in 1976 provided adequate measurements of the relevant physical parameters to constrain models for Martian permafrost.

  8. Use and Features of Basalt Formations for Geologic Sequestration

    SciTech Connect

    McGrail, B. Peter; Ho, Anita M.; Reidel, Steve P.; Schaef, Herbert T.

    2003-01-01

    Extrusive lava flows of basalt are a potential host medium for geologic sequestration of anthropogenic CO2. Flood basalts and other large igneous provinces occur worldwide near population and power-producing centers and could securely sequester a significant fraction of global CO2 emissions. We describe the location, extent, and general physical and chemical characteristics of large igneous provinces that satisfy requirements as a good host medium for CO2 sequestration. Most lava flows have vesicular flow tops and bottoms as well as interflow zones that are porous and permeable and serve as regional aquifers. Additionally, basalt is iron-rich, and, under the proper conditions of groundwater pH, temperature, and pressure, injected CO2 will react with iron released from dissolution of primary minerals in the basalt to form stable ferrous carbonate minerals. Conversion of CO2 gas into a solid form was confirmed in laboratory experiments with supercritical CO2 in contact with basalt samples from Washington state.

  9. GEOGYN - a geological formation/drill string dynamics computer program

    SciTech Connect

    Caskey, B.

    1984-09-16

    This paper describes the initial development phase of a finite element computer program, GEODYN, capable of simulating the three-dimensional transient, dynamic response of a polycrystalline diamond compact (PDC) bit interacting with a non-uniform formation. The ability of GEODYN to simulate response variations attributable to hole size, hole bottom surface shapes, and formation material non-uniformities is demonstrated. Planned developmental phases will address the detailed response of a bottom-hole assembly (BHA), a drill ahead (rock penetration and removal) simulation, and ultimately, the response of the entire string.

  10. GEODYN: A geological formation/drillstring dynamics computer program

    SciTech Connect

    Baird, J.A.; Caskey, B.C.; Stone, C.M.; Tinianow, M.A.

    1984-09-01

    This paper describes the initial development phase of a finite element computer program, GEODYN, capable of simulating the three-dimensional transient dynamic response of a polycrystalline diamond compact (PDC) bit interacting with a non-uniform formation. The ability of GEODYN to simulate response variations attributable to hole size, hole bottom surface shapes, and formation material non-uniformities is demonstrated. Planned developmental phases will address the detailed response of a bottom-hole assembly (BHA), a drill ahead (rock penetration and removal) simulation, and ultimately, the response of the entire string.

  11. Simulation of Dispersion in Heterogeneous Porous Formations: Statistics, First-Order Theories, Convergence of Computations

    Microsoft Academic Search

    Alberto Bellin; Paolo Salandin; Andrea Rinaldo

    1992-01-01

    This paper discusses the results of numerical analysis of dispersion of passive solutes in two-dimensional heterogeneous porous formations. Statistics of flow and transport variables, the accuracy and the role of approximations implicit in existing first-order theories, and the convergence of computational results are investigated. The results suggest that quite different rates of convergence with Monte Carlo runs hold for different

  12. Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media

    SciTech Connect

    Ababou, R.

    1991-08-01

    This report develops a broad review and assessment of quantitative modeling approaches and data requirements for large-scale subsurface flow in radioactive waste geologic repository. The data review includes discussions of controlled field experiments, existing contamination sites, and site-specific hydrogeologic conditions at Yucca Mountain. Local-scale constitutive models for the unsaturated hydrodynamic properties of geologic media are analyzed, with particular emphasis on the effect of structural characteristics of the medium. The report further reviews and analyzes large-scale hydrogeologic spatial variability from aquifer data, unsaturated soil data, and fracture network data gathered from the literature. Finally, various modeling strategies toward large-scale flow simulations are assessed, including direct high-resolution simulation, and coarse-scale simulation based on auxiliary hydrodynamic models such as single equivalent continuum and dual-porosity continuum. The roles of anisotropy, fracturing, and broad-band spatial variability are emphasized. 252 refs.

  13. Method and device with adjustable focusing for measuring the electric resistivity of geological formations

    SciTech Connect

    Desbrandes, R.

    1983-10-25

    The method of the invention comprises determining the variation of the electric potential on both sides of a central electrode in a borehole, detecting the two levels of the borehole where the potential gradient is zero, and measuring the electric resistivity of the geological formation between these two levels.

  14. Natural iodine in a clay formation: Implications for iodine fate in geological disposals

    E-print Network

    Paris-Sud XI, Université de

    1 Natural iodine in a clay formation: Implications for iodine fate in geological disposals F. Corresponding author: f.claret@brgm.fr To be submitted to Geochimica Acta Abstract Iodine is one of the most to considerable debate. The present study aims at providing new insights into this aspect of the iodine problem

  15. Stratigraphy, structural geology and metamorphism of the Inwood Marble Formation, northern Manhattan, NYC, NY

    E-print Network

    Merguerian, Charles

    Stratigraphy, structural geology and metamorphism of the Inwood Marble Formation, northern, Hofstra University, Hempstead, NY 11549 Introduction Field studies of the Inwood Marble in the type of recrystallized dolomite and subordinate calcite marble the Inwood Marble was used for quarrying and mineral

  16. A geological approach to characterizing aquifer heterogeneity. Completion report, 1990--1994

    SciTech Connect

    Phillips, F.; Wilson, J.; Gutjahr, A.

    1998-07-31

    Spatial variations of hydraulic conductivity have generally been recognized as the dominant medium-independent control on the transport and dispersion of contaminants in groundwater. Mathematical models that use statistical descriptions of the hydraulic conductivity spatial distribution are available to predict contaminant transport. Such models are expected to be major tools in dealing with contamination problems at DOE sites. Unfortunately, the statistical parameters needed for such models can usually only be obtained through geostatistical analysis of very large numbers of hydraulic conductivity measurements, with associated large costs and often-significant human risk at highly contaminated sites. More accurate and realistic conceptual models for the actual distribution of hydraulic conductivity, requiring fewer field data, would increase the reliability of contaminant transport predictions while decreasing their cost. The objectives of the project can therefore be summarized in the following question: How can the data requirements for geostatistical analysis of hydraulic parameters be reduced by incorporation of geological expertise and macroscopic proxy information into new mathematical models. Specifically, the authors proposed to combine intensive geological field observations with permeability measurements to discover relationships between sediment depositional processes, geological structures, and the geostatistics of the permeability distributions that result.

  17. Sedimentological and Petrophysical Heterogeneity of Glaciogenic Paleovalley, Late Ordovician Sarah Formation, Central Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Razzaq, Waseem; Abdullatif, Osman; Sahin, Ali; Hariri, Mustafa

    2014-05-01

    The Late Ordovician Sarah Formation deposited in glaciogenic environment, mainly dominated by braided river outwash system. Compared to the subsurface, the Sarah formation is considered as important tight gas sandstone reservoir at southern and northern parts of Saudi Arabia. Ten outcrops from Al-Ilb paleochannel were studied in detail to identify the heterogeneity in terms of the types and distribution of facies and related petrophysical properties. The Sarah Formation shows highly heterogeneous behavior at all scales. The main facies observed at Al-Ilb paleovalley are 64% trough-cross bedded sandstone, 23% horizontally stratified sandstone facies, and 2% massive conglomerates are observed at the proximal, medial and distal parts of the paleovalley. The remaining facies are trough-cross bedded sandstone facies that is laterally changes to horizontally stratified sandstone facies and in some cases to planner cross-bedded sandstone facies. The petrophysical analysis revealed good quality of porosity present in all parts of paleovalley. On the other hand the permeability values are high and ranging between 53mD to 5D. The descriptive statistics clearly indicate the normal distribution of porosity values for proximal, medial and distal parts of paleovalley and can be described as homogeneous. For permeability the distribution is heterogeneous as it is log-normally distributed. The scatter plots of porosity versus horizontal and vertical permeability shows very poor correlation for each part of paleochannel. This heterogeneity is attributed to depositional and post-depositional viabilities. These variables are grain size and shape distribution, sorting, packing, distribution of matrix and cementing material, and the presence of clays like kaolinite, smectite, and palygorskite. These observations further indicate that Sarah Formation is affected by shallow burial conditions during diagenesis. However, Sarah Formation shows highly heterogeneous behavior at outcrop scale that might be unpredictable and challenging in the subsurface.

  18. A geological and engineering reservoir characterization of the Caballos Formation (Cretaceous), Puerto Colon field Putumayo basin, Colombia

    E-print Network

    Ruiz Castellanos, Hector

    1994-01-01

    A GEOLOGICAL AND ENGINEERING RESERVOIR CHARACTERIZATION OF THE CABALLOS FORMATION (CRETACEOUS), PUERTO COLON FIELD, PUTUMAYO BASIN, COLOMBIA A Thesis by HECTOR RUIZ CASTELLANOS Submitted to Texas A&M University in partial fulfillment...: Petroleum Engineering ABSTRACT A Geological and Engineering Reservoir Characterization of the Caballos Formation (Cretaceous), Puerto Colon Field Putumayo Basin Colombia. (December 1994) Hector Ruiz Castellanos, B. S. , Universidad Industrial de...

  19. Geologic heterogeneity and a comparison of two geostatistical models: Sequential Gaussian and transition probability-based geostatistical simulation

    NASA Astrophysics Data System (ADS)

    Lee, Si-Yong; Carle, Steven F.; Fogg, Graham E.

    2007-09-01

    A covariance-based model-fitting approach is often considered valid to represent field spatial variability of hydraulic properties. This study examines the representation of geologic heterogeneity in two types of geostatistical models under the same mean and spatial covariance structure, and subsequently its effect on the hydraulic response to a pumping test based on 3D high-resolution numerical simulation and field data. Two geostatistical simulation methods, sequential Gaussian simulation (SGS) and transition probability indicator simulation (TPROGS) were applied to create conditional realizations of alluvial fan aquifer systems in the Lawrence Livermore National Laboratory (LLNL) area. The simulated K fields were then used in a numerical groundwater flow model to simulate a pumping test performed at the LLNL site. Spatial connectivity measures of high- K materials (channel facies) captured connectivity characteristics of each geostatistical model and revealed that the TPROGS model created an aquifer (channel) network having greater lateral connectivity. SGS realizations neglected important geologic structures associated with channel and overbank (levee) facies, even though the covariance model used to create these realizations provided excellent fits to sample covariances computed from exhaustive samplings of TPROGS realizations. Observed drawdown response in monitoring wells during a pumping test and its numerical simulation shows that in an aquifer system with strongly connected network of high- K materials, the Gaussian approach could not reproduce a similar behavior in simulated drawdown response found in TPROGS case. Overall, the simulated drawdown responses demonstrate significant disagreement between TPROGS and SGS realizations. This study showed that important geologic characteristics may not be captured by a spatial covariance model, even if that model is exhaustively determined and closely fits the exponential function.

  20. Thermal state and complex geology of a heterogeneous salty crust of Jupiter's satellite, Europa

    USGS Publications Warehouse

    Prieto-Ballesteros, O.; Kargel, J.S.

    2005-01-01

    The complex geology of Europa is evidenced by many tectonic and cryomagmatic resurfacing structures, some of which are "painted" into a more visible expression by exogenic alteration processes acting on the principal endogenic cryopetrology. The surface materials emplaced and affected by this activity are mainly composed of water ice in some areas, but in other places there are other minerals involved. Non-ice minerals are visually recognized by their low albedo and reddish color either when first emplaced or, more likely, after alteration by Europan weathering processes, especially sublimation and alteration by ionizing radiation. While red chromophoric material could be due to endogenic production of solid sulfur allotropes or other compounds, most likely the red substance is an impurity produced by radiation alteration of hydrated sulfate salts or sulphuric acid of mainly internal origin. If the non-ice red materials or their precursors have a source in the satellite interior, and if they are not merely trace contaminants, then they can play an important role in the evolution of the icy crust, including structural differentiation and the internal dynamics. Here we assume that these substances are major components of Europa's cryo/hydrosphere, as some models have predicted they should be. If this is an accurate assumption, then these substances should not be neglected in physical, chemical, and biological models of Europa, even if major uncertainties remain as to the exact identity, abundance, and distribution of the non-ice materials. The physical chemical properties of the ice-associated materials will contribute to the physical state of the crust today and in the geological past. In order to model the influence of them on the thermal state and the geology, we have determined the thermal properties of the hydrated salts. Our new lab data reveal very low thermal conductivities for hydrated salts compared to water ice. Lower conductivities of salty ice would produce steeper thermal gradients than in pure ice. If there are salt-rich layers inside the crust, forming salt beds over the seafloor or a briny eutectic crust, for instance, the high thermal gradients may promote endogenic geological activity. On the seafloor, bedded salt accumulations may exhibit high thermochemical gradients. Metamorphic and magmatic processes and possible niches for thermophilic life at shallow suboceanic depths result from the calculated thermal profiles, even if the ocean is very cold. ?? 2004 Elsevier Inc. All rights reserved.

  1. Geological study of uranium potential of the Kingston Peak Formation, Death Valley Region, California

    SciTech Connect

    Carlisle, D.; Kettler, R.M.; Swanson, S.C.

    1980-09-01

    The results of a geological survey of the Kingston Peak Formation on the western slope of the Panamint Range near Death Valley are discussed. The geology of the Panamint mountains was mapped on topographic base maps of the Telescope Peak and Manly Peak quadrangles. Radiometric suveys of the area were conducted using gamma ray spectrometers. Samples of the conglomerate were analyzed using delayed neutron, neutron activation, atomic absorption, and LECO analysis. It is concluded that uranium mineralization in the Favorable Submember is significant and further exploration is warranted. The monazite-fenotime related uranium and thorium mineralization in the Mountain Girl quartz pebble conglomerate is of no economic interest. (DMC)

  2. Geology

    NSDL National Science Digital Library

    Jennifer Bergman

    2009-08-03

    With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on the many different kinds of geological exploration. The elements that make up minerals and the different ways minerals are developed, The special characteristics of minerals, like physical properties, is explained. Earths tectonic plates, the reasons they move, and the effects of the shifting are also given. Also featured is fossils and how they are developed and are found, as well as why fossils are useful tools for scientists.

  3. Heterogeneous formation of polar stratospheric clouds - Part 2: Nucleation of ice on synoptic scales

    NASA Astrophysics Data System (ADS)

    Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Hoyle, C. R.; Grooß, J.-U.; Dörnbrack, A.; Peter, T.

    2013-04-01

    This paper provides unprecedented evidence for the importance of heterogeneous nucleation, likely on solid particles of meteoritic origin, and of small-scale temperature fluctuations, for the formation of ice particles in the Arctic stratosphere. During January 2010, ice PSCs (Polar Stratospheric Clouds) were shown by CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) to have occurred on a synoptic scale (~ 1000 km dimension). CALIPSO observations also showed widespread PSCs containing nitric acid trihydrate (NAT) particles in December 2009, prior to the occurrence of synoptic-scale regions of ice PSCs during mid-January 2010. We demonstrate by means of detailed microphysical modeling along air parcel trajectories that the formation of these PSCs is not readily reconciled with expectations from the conventional understanding of PSC nucleation mechanisms. The measurements are at odds with the previous laboratory-based understanding of PSC formation, which deemed direct heterogeneous nucleation of NAT and ice on preexisting solid particles unlikely. While a companion paper (Part 1) addresses the heterogeneous nucleation of NAT during December 2009, before the existence of ice PSCs, this paper shows that also the large-scale occurrence of stratospheric ice in January 2010 cannot be explained merely by homogeneous ice nucleation but requires the heterogeneous nucleation of ice, e.g. on meteoritic dust or preexisting NAT particles. The required efficiency of the ice nuclei is surprisingly high, namely comparable to that of known tropospheric ice nuclei such as mineral dust particles. To gain model agreement with the ice number densities inferred from observations, the presence of small-scale temperature fluctuations, with wavelengths unresolved by the numerical weather prediction models, is required. With the derived rate parameterization for heterogeneous ice nucleation we are able to explain and reproduce CALIPSO observations throughout the entire Arctic winter 2009/2010.

  4. Heterogeneous formation of polar stratospheric clouds - Part 2: Nucleation of ice on synoptic scales

    NASA Astrophysics Data System (ADS)

    Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Hoyle, C. R.; Grooß, J.-U.; Dörnbrack, A.; Peter, T.

    2013-11-01

    This paper provides compelling evidence for the importance of heterogeneous nucleation, likely on solid particles of meteoritic origin, and of small-scale temperature fluctuations, for the formation of ice particles in the Arctic stratosphere. During January 2010, ice PSCs (polar stratospheric clouds) were shown by CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) to have occurred on a synoptic scale (~1000 km dimension). CALIPSO observations also showed widespread PSCs containing NAT (nitric acid trihydrate) particles in December 2009, prior to the occurrence of synoptic-scale regions of ice PSCs during mid-January 2010. We demonstrate by means of detailed microphysical modeling along air parcel trajectories that the formation of these PSCs is not readily reconciled with expectations from the conventional understanding of PSC nucleation mechanisms. The measurements are at odds with the previous laboratory-based understanding of PSC formation, which deemed direct heterogeneous nucleation of NAT and ice on preexisting solid particles unlikely. While a companion paper (Part 1) addresses the heterogeneous nucleation of NAT during December 2009, before the existence of ice PSCs, this paper shows that also the large-scale occurrence of stratospheric ice in January 2010 cannot be explained merely by homogeneous ice nucleation but requires the heterogeneous nucleation of ice, e.g. on meteoritic dust or preexisting NAT particles. The required efficiency of the ice nuclei is surprisingly high, namely comparable to that of known tropospheric ice nuclei such as mineral dust particles. To gain model agreement with the ice number densities inferred from observations, the presence of small-scale temperature fluctuations, with wavelengths unresolved by the numerical weather prediction models, is required. With the derived rate parameterization for heterogeneous ice nucleation we are able to explain and reproduce CALIPSO observations throughout the entire Arctic winter 2009/2010.

  5. SOA formation from partitioning and heterogeneous reactions: model study in the presence of inorganic species.

    PubMed

    Jang, Myoseon; Czoschke, Nadine M; Northcross, Amanda L; Cao, Gang; Shaof, David

    2006-05-01

    A predictive model for secondary organic aerosol (SOA) formation by both partitioning and heterogeneous reactions was developed for SOA created from ozonolysis of alpha-pinene in the presence of preexisting inorganic seed aerosols. SOA was created in a 2 m3 polytetrafluoroethylene film indoor chamber under darkness. Extensive sets of SOA experiments were conducted varying humidity, inorganic seed compositions comprising of ammonium sulfate and sulfuric acid, and amounts of inorganic seed mass. SOA mass was decoupled into partitioning (OM(P)) and heterogeneous aerosol production (OM(H)). The reaction rate constant for OM(H) production was subdivided into three categories (fast, medium, and slow) to consider different reactivity of organic products for the particle phase heterogeneous reactions. The influence of particle acidity on reaction rates was treated in a previous semiempirical model. Model OM(H) was developed with medium and strong acidic seed aerosols, and then extrapolated to OM(H) in weak acidic conditions, which are more relevant to atmospheric aerosols. To demonstrate the effects of preexisting glyoxal derivatives (e.g., glyoxal hydrate and dimer) on OM(H), SOA was created with a seed mixture comprising of aqueous glyoxal and inorganic species. Our results show that heterogeneous SOA formation was also influenced by preexisting reactive glyoxal derivatives. PMID:16719105

  6. The Impact of Geologic Heterogeneity on CO2 Injection with Simultaneous Brine Extraction and Economic Uncertainty for Large-Scale CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Kobos, P. H.; Heath, J. E.; Roach, J. D.; McKenna, S. A.; Dewers, T. A.; Gutierrez, K.

    2011-12-01

    Performance assessment of CO2 sequestration opportunities at the scale of the United States presents challenges for coping with geologic and economic uncertainties. Inaccurate estimation of suitable flow properties could result in drilling wells in parts of a formation that could not physically accommodate the needed injection rates and storage volumes. Data paucity and heterogeneity in geologic properties necessitates probabilistic approaches for estimating CO2 injection and simultaneous brine extraction rates (for beneficial use such as power-plant cooling or pressure management) and associated costs. We present an Integrated Assessment Model (IAM) that assesses CO2 injection rates with or without simultaneous brine extraction for the saline reservoirs identified in the National Carbon Sequestration Database (NatCarb). We have linked NatCarb reservoirs to injectivity rock types. We define these rock types quantitatively by probability distribution functions (PDFs) of permeability and porosity, and spatial correlation models. Thus, IAM has flexibility in calculating CO2 injectivity and brine productivity while coping with heterogeneity, and then determining the uncertainty in well-associated costs. For computational efficiency, IAM performs injectivity and productivity calculations with analytical solutions that have been validated by numerical simulation and comparison to available field data. The solutions incorporate spatially varying properties through PDFs that are based on upscaling of geostatistical realizations of the injectivity rock types. A key method of the geostatistics is linear coregionalization, which defines the linear relationship between porosity and log permeability with a specified correlation coefficient, r, of the regression while maintaining the spatial correlation of each variable. The major finding is high sensitivity of well-associated costs to permeability. Error in field prediction of an order of magnitude in permeability may be the difference between an economically and physically viable or unfeasible site due to potentially order of magnitude change in the number of required injection wells. Finally, we present the affects of varying the correlation between permeability and porosity on injectivity and productivity estimates. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. Paleomagnetic dating of continental geological formations: Strong diachronism evidenced in the Saharan platform and geodynamical implications

    NASA Astrophysics Data System (ADS)

    Henry, B.; Derder, M. E. M.; Amenna, M.; Maouche, S.; Bayou, B.; Ouabadi, A.; Bouabdallah, H.; Beddiaf, M.; Ayache, M.; Bestandji, R.

    2014-11-01

    The paleomagnetism is a powerful tool to date formations that have age not constrained by paleontological, stratigraphical or radiochronological data. It was applied, on the western border of the Murzuq basin in Algeria (Saharan platform), to the Zarzaïtine formation, attributed to a Middle-Upper Triassic-Lower Jurassic age. Comparison of the obtained paleomagnetic pole with previous poles from the same geological formation outcropping in another basin and from other Carboniferous to Lower Mesozoic African formations yielded a clearly older age (Late Permian) than expected. That evidences a strong diachronism (at least 40 My) of the deposition of this formation on the Saharan platform. The post-Hercynian structural evolution was therefore different according to the parts of this platform, with significant differential vertical tectonic movements. The latter were at the origin of erosion, hiatus or sediments deposition according to areas.

  8. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

    DOEpatents

    Vail, W.B. III.

    1991-08-27

    Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the differential current conducted into the formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas are present. Lithological characteristics of the formation such as the presence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes. 48 figures.

  9. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

    DOEpatents

    Vail, W.B. III.

    1989-11-21

    Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas are present. Lithological characteristics of the formation such as the presence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes. 48 figs.

  10. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

    DOEpatents

    Vail, III, William B. (Bothell, WA)

    1991-01-01

    Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas present. Lithological characteristics of the formation such as the pressence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes.

  11. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

    DOEpatents

    Vail, III, William B. (Bothell, WA)

    1989-01-01

    Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas are present. Lithological characteristics of the formation such as the presence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes.

  12. Methods and apparatus for measurement of the resistivity of geological formations from within cased boreholes

    DOEpatents

    Vail, W.B. III.

    1989-04-11

    Methods and apparatus are disclosed which allow measurement of the resistivity of a geological formation through borehole casing which may be surrounded by brine saturated cement. A.C. current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. The A.C. voltage difference is measured between two additional vertically disposed electrodes on the interior of the casing which provides a measure of the resistivity of the geological formation. A calibration and nulling procedure is presented which minimizes the influence of variations in the thickness of the casing. The procedure also minimizes the influence of inaccurate placements of the additional vertically disposed electrodes. 3 figs.

  13. Methods and apparatus for measurement of the resistivity of geological formations from within cased boreholes

    DOEpatents

    Vail, III, William B. (Bothell, WA)

    1989-01-01

    Methods and apparatus are disclosed which allow measurement of the resistivity of a geological formation through borehole casing which may be surrounded by brine saturated cement. A.C. current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. The A.C. voltage difference is measured between two additional vertically disposed electrodes on the interior of the casing which provides a measure of the resistivity of the geological formation. A calibration and nulling procedure is presented which minimizes the influence of variations in the thickness of the casing. The procedure also minimizes the influence of inaccurate placements of the additional vertically disposed electrodes.

  14. Method for controlling a producing zone of a well in a geological formation

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Byerly, Kent A. (Inventor); Amini, B. Jon (Inventor)

    2005-01-01

    System and methods for transmitting and receiving electromagnetic pulses through a geological formation. A preferably programmable transmitter having an all-digital portion in a preferred embodiment may be operated at frequencies below 1 MHz without loss of target resolution by transmitting and over sampling received long PN codes. A gated and stored portion of the received signal may be correlated with the PN code to determine distances of interfaces within the geological formation, such as the distance of a water interfaces from a wellbore. The received signal is oversampled preferably at rates such as five to fifty times as high as a carrier frequency. In one method of the invention, an oil well with multiple production zones may be kept in production by detecting an approaching water front in one of the production zones and shutting down that particular production zone thereby permitting the remaining production zones to continue operating.

  15. Evaluation of the geological relationships to gas hydrate formation and stability

    SciTech Connect

    Not Available

    1986-01-01

    Although there are many publications pertaining to gas hydrates, their formation and stability in various geological conditions are poorly known. Therefore, for the same reasons and because of the very broad scope of our research, limited amount and extremely dispersed information, the study regions are very large. Moreover, almost without exception the geological environments controlling gas hydrates formation and stability of the studied regions are very complex. The regions studied (completed and partially completed - total 17 locations) during the reporting period, particularly the Gulf of Mexico and the Middle America Trench, are the most important in this entire research project. In the past, both of these regions have been extensively studied, the presence of gas hydrates confirmed and samples recovered. In our investigation it was necessary not only to review all previous data and interpretations, but to do a thorough analysis of the basins, and a critical evaluation of an previously reported and publicly available but not published information.

  16. Multiple scale physical and numerical modeling for improved understanding of mechanisms of trapping and leakage of CO2 in deep geologic formations

    NASA Astrophysics Data System (ADS)

    Illangasekare, T.; Plampin, M.; Trevisan, L.; Agartan, E.; Mori, H.; Sakaki, T.; Cihan, A.; Birkholzer, J.; Zhou, Q.; Pawar, R.; Zyvoloski, G.

    2012-04-01

    The fundamental processes associated with trapping and leakage of CO2 in deep geologic formations are complex. Formation heterogeneity manifested at all scales is expected to affect capillary and dissolution trapping and leakage of gaseous CO2 to the shallow subsurface. Research is underway to improve our fundamental understanding of trapping and leakage. This research involves experimentation in multiple scales and modeling focusing on effects of formation heterogeneity. The primary hypothesis that drives this research is that when the effects of heterogeneity on entrapment and leakage are understood, it will be possible to design more effective and safe storage schemes. Even though field investigations have some value in understanding issues related to large scale behavior and performance assessment, a fundamental understanding of how the heterogeneity affects trapping is difficult or impossible to obtain in field settings. Factors that contribute to these difficulties are the inability to fully characterize the formation heterogeneity at all scales of interest and lack of experimental control at very high depths. Intermediate scale physical model testing provides an attractive alternative to investigate these processes in the laboratory. Heterogeneities can be designed using soils with known properties in test tanks and the experiments can be conducted under controlled conditions to obtain accurate data. Conducting laboratory experiments under ambient pressure and temperature conditions to understand the processes that occur in deep formations poses many challenges. This research attempts to address such challenges and demonstrates how this testing approach could be used to generate useful data. The experiments involve the use of test systems of hierarchy of scales from small to intermediate scale tanks (~ 5 m) and long columns (~ 4.5 m). These experiments use surrogate fluids to investigate both capillary and solubility trapping in homogeneous and heterogeneous systems. A traversing x-ray scanning system is used to monitor the advancement of the plume during and after injection and to measure the residual (trapped) CO2 saturation. Dissolution of a surrogate non-wetting fluid in a surrogate wetting fluid is analyzed in small and large tanks. We test the numerical models that are capable of simulating two-phase flow and density driven flow as a result of dissolution by using the experimental data. Verified models are used to further evaluate the effect of capillary and solubility trapping in complex heterogeneous environments. During leakage, under different pressure and temperature conditions, dissolved CO2 may come back out of solution (exsolve), but the fundamental triggering mechanisms of this process in porous media are not yet well understood. An extensive series of column experiments has been conducted to investigate the factors that control the rates of CO2 gas bubble nucleation, growth, and migration. Results indicate that the saturation pressure (i.e. the amount of CO2 dissolved into the injected water) and heterogeneity both significantly affect the gas formation and migration, whereas the injection rate has less of an effect. These column experiments will soon be upscaled to an intermediate-scale two-dimensional tank to investigate the behaviour of the CO2 gas-water-soil system in more complex geological environments.

  17. Universitt StuttgartInstitut fr Wasserbau, Lehrstuhl fr Hydromechanik und Hydrosystemmodellierung Workshop on Numerical Models for Carbon Dioxide Storage in Geological Formations

    E-print Network

    Cirpka, Olaf Arie

    Hydrosystemmodellierung Workshop on Numerical Models for Carbon Dioxide Storage in Geological Formations 1/16 Modelling April 2008 Workshop on Numerical Models for Carbon Dioxide Storage in Geological Formations #12 on Numerical Models for Carbon Dioxide Storage in Geological Formations 2/16 CO2 leakage mitigation using

  18. Modulation format identification in heterogeneous fiber-optic networks using artificial neural networks.

    PubMed

    Khan, Faisal Nadeem; Zhou, Yudi; Lau, Alan Pak Tao; Lu, Chao

    2012-05-21

    We propose a simple and cost-effective technique for modulation format identification (MFI) in next-generation heterogeneous fiber-optic networks using an artificial neural network (ANN) trained with the features extracted from the asynchronous amplitude histograms (AAHs). Results of numerical simulations conducted for six different widely-used modulation formats at various data rates demonstrate that the proposed technique can effectively classify all these modulation formats with an overall estimation accuracy of 99.6% and also in the presence of various link impairments. The proposed technique employs extremely simple hardware and digital signal processing (DSP) to enable MFI and can also be applied for the identification of other modulation formats at different data rates without necessitating hardware changes. PMID:22714229

  19. Intrinsic formation of nanocrystalline neptunium dioxide under neutral aqueous conditions relevant to deep geological repositories.

    PubMed

    Husar, Richard; Hübner, René; Hennig, Christoph; Martin, Philippe M; Chollet, Mélanie; Weiss, Stephan; Stumpf, Thorsten; Zänker, Harald; Ikeda-Ohno, Atsushi

    2015-01-25

    The dilution of aqueous neptunium carbonate complexes induces the intrinsic formation of nanocrystalline neptunium dioxide (NpO2) particles, which are characterised by UV/Vis and X-ray absorption spectroscopies and transmission electron microscopy. This new route of nanocrystalline NpO2 formation could be a potential scenario for the environmental transport of radionuclides from the waste repository (i.e. under near-field alkaline conditions) to the geological environment (i.e. under far-field neutral conditions). PMID:25479067

  20. Geological Carbon Sequestration in the Ohio River Valley: An Evaluation of Possible Target Formations

    NASA Astrophysics Data System (ADS)

    Dalton, T. A.; Daniels, J. J.

    2009-12-01

    The development of geological carbon sequestration within the Ohio River Valley is of major interest to the national electricity and coal industries because the Valley is home to a heavy concentration of coal-burning electricity generation plants and the infrastructure is impossible to eliminate in the short-term. It has been determined by Ohio's politicians and citizenry that the continued use of coal in this region until alternative energy supplies are available will be necessary over the next few years. Geologic sequestration is the only possible means of keeping the CO2 out of the atmosphere in the region. The cost of the sequestration effort greatly decreases CO2 emissions by sequestering CO2 directly on site of these plants, or by minimizing the distance between fossil-fueled generation and sequestration (i.e., by eliminating the cost of transportation of supercritical CO2 from plant to sequestration site). Thus, the practicality of CO2 geologic sequestration within the Ohio River Valley is central to the development of such a commercial effort. Though extensive work has been done by the Regional Partnerships of the DOE/NETL in the characterization of general areas for carbon sequestration throughout the nation, few projects have narrowed their focus into a single geologic region in order to evaluate the sites of greatest commercial potential. As an undergraduate of the Earth Sciences at Ohio State, I have engaged in thorough research to obtain a detailed understanding of the geology of the Ohio River Valley and its potential for commercial-scale carbon sequestration. Through this research, I have been able to offer an estimate of the areas of greatest interest for CO2 geologic sequestration. This research has involved petrological, mineralogical, geochemical, and geophysical analyses of four major reservoir formations within Ohio—the Rose Run, the Copper Ridge, the Clinton, and the Oriskany—along with an evaluation of the possible effects of injection into these saline reservoirs.

  1. FOREWORD: Heterogenous nucleation and microstructure formation—a scale- and system-bridging approach Heterogenous nucleation and microstructure formation—a scale- and system-bridging approach

    NASA Astrophysics Data System (ADS)

    Emmerich, H.

    2009-11-01

    Scope and aim of this volume. Nucleation and initial microstructure formation play an important role in almost all aspects of materials science [1-5]. The relevance of the prediction and control of nucleation and the subsequent microstructure formation is fully accepted across many areas of modern surface and materials science and technology. One reason is that a large range of material properties, from mechanical ones such as ductility and hardness to electrical and magnetic ones such as electric conductivity and magnetic hardness, depend largely on the specific crystalline structure that forms in nucleation and the subsequent initial microstructure growth. A very demonstrative example for the latter is the so called bamboo structure of an integrated circuit, for which resistance against electromigration [6] , a parallel alignment of grain boundaries vertical to the direction of electricity, is most favorable. Despite the large relevance of predicting and controlling nucleation and the subsequent microstructure formation, and despite significant progress in the experimental analysis of the later stages of crystal growth in line with new theoretical computer simulation concepts [7], details about the initial stages of solidification are still far from being satisfactorily understood. This is in particular true when the nucleation event occurs as heterogenous nucleation. The Priority Program SPP 1296 'Heterogenous Nucleation and Microstructure Formation—a Scale- and System-Bridging Approach' [8] sponsored by the German Research Foundation, DFG, intends to contribute to this open issue via a six year research program that enables approximately twenty research groups in Germany to work interdisciplinarily together following this goal. Moreover, it enables the participants to embed themselves in the international community which focuses on this issue via internationally open joint workshops, conferences and summer schools. An outline of such activities can be found in [8]. Furthermore, the honorable invitation to publish a special issue in Journal of Physics: Condensed Matter dedicated to the Priority Program's topic allows the obtained results to be communicated to relevant international colleagues, which stimulates further interest and encourages future collaborations. The issue comprises the research results of the participants during the first two year period of the Priority Program as well as that of the international referees of the program. Now, what precisely is the research concept of the Priority Program and thus, what are the articles in this special issue dedicated to? Ever since the pioneering work of Volmer and Weber [9], Becker and Döring [10] as well as Turnbull and Fisher [11] nucleation has been modelled more or less phenomenologically. These traditional models describe nucleation by stochastic processes of single atoms, respectively, molecules, which attach at primary droplets. Those thereby growing droplets become stable by reaching a critical size. This concept has largely been employed to model thermal activated first-order phase transformations. However it contains basic weak points, which raises the question of its physical justification. For instance, the dependence of the interfacial free energy on the critical size of a nucleus is—from the point of view of recent experiments—not considered adequately. In the past years, several advances have been performed to put the modelling of nucleation and microstructure formation on a wider base [12-15]. Figure 1 Figure 1. Illustration of the interdisciplinary approach in the Research Priority Program 'Nucleation and Growth Kinetics in Colloids and Metals—Steps towards a Scale- and System-Bridging Understanding' [8]: to advance towards a system- and scale-bridging detailed understanding of the energetics and kinetics of heterogeneous nucleation and micro-structure formation, two different experimental (binary colloids and binary metallic alloys) model systems are investigated jointly by experimental scientists working with different experimental tech

  2. Process and device for the determination of the characteristics of the geological formations traversed by a borehole

    Microsoft Academic Search

    J. Bard; P. Morlier; R. Pelet; J. Sarda

    1981-01-01

    A description is given of a process for determining characteristics of the geological formations traversed by a borehole, making use of a sonde by means of which the intensity of the gamma rays naturally radiated from the formations is measured. Both longitudinal and transversal acoustic waves are transmitted to the formations, their travel time and their attenuation between two receivers

  3. Experiences with the Application of Services Oriented Approaches to the Federation of Heterogeneous Geologic Data Resources

    NASA Astrophysics Data System (ADS)

    Cervato, C.; Fils, D.; Bohling, G.; Diver, P.; Greer, D.; Reed, J.; Tang, X.

    2006-12-01

    The federation of databases is not a new endeavor. Great strides have been made e.g. in the health and astrophysics communities. Reviews of those successes indicate that they have been able to leverage off key cross-community core concepts. In its simplest implementation, a federation of databases with identical base schemas that can be extended to address individual efforts, is relatively easy to accomplish. Efforts of groups like the Open Geospatial Consortium have shown methods to geospatially relate data between different sources. We present here a summary of CHRONOS's (http://www.chronos.org) experience with highly heterogeneous data. Our experience with the federation of very diverse databases shows that the wide variety of encoding options for items like locality, time scale, taxon ID, and other key parameters makes it difficult to effectively join data across them. However, the response to this is not to develop one large, monolithic database, which will suffer growth pains due to social, national, and operational issues, but rather to systematically develop the architecture that will enable cross-resource (database, repository, tool, interface) interaction. CHRONOS has accomplished the major hurdle of federating small IT database efforts with service-oriented and XML-based approaches. The application of easy-to-use procedures that allow groups of all sizes to implement and experiment with searches across various databases and to use externally created tools is vital. We are sharing with the geoinformatics community the difficulties with application frameworks, user authentication, standards compliance, and data storage encountered in setting up web sites and portals for various science initiatives (e.g., ANDRILL, EARTHTIME). The ability to incorporate CHRONOS data, services, and tools into the existing framework of a group is crucial to the development of a model that supports and extends the vitality of the small- to medium-sized research effort that is essential for a vibrant scientific community. This presentation will directly address issues of portal development related to JSR-168 and other portal API's as well as issues related to both federated and local directory-based authentication. The application of service-oriented architecture in connection with ReST-based approaches is vital to facilitate service use by experienced and less experienced information technology groups. Application of these services with XML- based schemas allows for the connection to third party tools such a GIS-based tools and software designed to perform a specific scientific analysis. The connection of all these capabilities into a combined framework based on the standard XHTML Document object model and CSS 2.0 standards used in traditional web development will be demonstrated. CHRONOS also utilizes newer client techniques such as AJAX and cross- domain scripting along with traditional server-side database, application, and web servers. The combination of the various components of this architecture creates an environment based on open and free standards that allows for the discovery, retrieval, and integration of tools and data.

  4. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site

    SciTech Connect

    Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan

    2011-11-29

    Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington State (USA) was investigated by analyzing samples recovered from depths of 9 to 52 m. Approximately 8000 near full-length 16S rRNA gene sequences were analyzed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units at the 97% identity level), respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (ca. 90%) of Proteobacteria. The Bacterial community in the oxic sediments contained not only members of 9 well-recognized phyla but also an unusually high proportion of 3 candidate divisions (GAL15, NC10, and SPAM). Additionally, novel phylogenetic orders were identified within the Delta-proteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site.

  5. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site.

    PubMed

    Lin, Xueju; Kennedy, David; Fredrickson, Jim; Bjornstad, Bruce; Konopka, Allan

    2012-02-01

    Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington state (USA) was investigated by analysing 21 samples recovered from depths of 9-52?m. Approximately 8000 near full-length 16S rRNA gene sequences were analysed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (operational taxonomic units at the 97% identity level) respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (>?700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (c. 90%) of Proteobacteria. The bacterial community in the oxic sediments contained not only members of nine well-recognized phyla but also an unusually high proportion of three candidate divisions (GAL15, NC10 and SPAM). Additionally, 13 novel phylogenetic orders were identified within the Deltaproteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site. PMID:22122741

  6. Geologic Explorations

    NSDL National Science Digital Library

    Alec Bodzin

    2002-04-01

    Geologic Explorations allows learners to explore a variety of unique geological formations of Utah using Quicktime Virtual Reality (QTVR) panoramas and digital still imagery. Spectacular panoramas and striking images capture Utah's unique geology and invite students to explore and learn interesting facts and concepts central to the study of geology.

  7. Impacts of transport mechanisms and plume history on tailing of sorbing plumes in heterogeneous porous formations

    NASA Astrophysics Data System (ADS)

    Maghrebi, Mahdi; Jankovic, Igor; Allen-King, Richelle M.; Rabideau, Alan J.; Kalinovich, Indra; Weissmann, Gary S.

    2014-11-01

    This work investigated the impacts of permeability and sorption heterogeneity on contaminant transport in groundwater using simulation experiments designed to elucidate the causes of tailing. The effects of advection, diffusion and sorption mechanisms and plume history were explored. A simple conceptual model consisting of a single inclusion (heterogeneity) of uniform hydraulic conductivity K and sorption distribution coefficient Kd was adopted. The 3D inclusion, shaped as a horizontal oblate ellipsoid of variable thickness, was placed in a homogeneous anisotropic background of different hydraulic conductivity and sorption distribution coefficient. The background represents average K and Kd of a heterogeneous porous formation. A closed-form analytic flow solution for uniform flow past the inclusion was coupled with a numerical transport solution to simulate contaminant migration for a wide range of transport parameters and two distinct source conditions. Over 2600 numerical simulations were performed in parallel. Transport results were presented in terms of travel time distributions at a control plane downstream of the inclusion and used to quantify tailing for a wide range of transport parameters, in order to separate advection-dominated from diffusion-dominated transport regime and to investigate effects of inclusion shape, diffusion, sorption and plume history on tailing.

  8. Physical Constraints on Geologic CO2 Sequestration in Low-Volume Basalt Formations

    SciTech Connect

    Ryan M. Pollyea; Jerry P. Fairley; Robert K. Podgorney; Travis L. McLing

    2014-03-01

    Deep basalt formations within large igneous provinces have been proposed as target reservoirs for carbon capture and sequestration on the basis of favorable CO2-water-rock reaction kinetics that suggest carbonate mineralization rates on the order of 102–103 d. Although these results are encouraging, there exists much uncertainty surrounding the influence of fracture-controlled reservoir heterogeneity on commercial-scale CO2 injections in basalt formations. This work investigates the physical response of a low-volume basalt reservoir to commercial-scale CO2 injections using a Monte Carlo numerical modeling experiment such that model variability is solely a function of spatially distributed reservoir heterogeneity. Fifty equally probable reservoirs are simulated using properties inferred from the deep eastern Snake River Plain aquifer in southeast Idaho, and CO2 injections are modeled within each reservoir for 20 yr at a constant mass rate of 21.6 kg s–1. Results from this work suggest that (1) formation injectivity is generally favorable, although injection pressures in excess of the fracture gradient were observed in 4% of the simulations; (2) for an extensional stress regime (as exists within the eastern Snake River Plain), shear failure is theoretically possible for optimally oriented fractures if Sh is less than or equal to 0.70SV; and (3) low-volume basalt reservoirs exhibit sufficient CO2 confinement potential over a 20 yr injection program to accommodate mineral trapping rates suggested in the literature.

  9. Method of detecting leakage from geologic formations used to sequester CO.sub.2

    DOEpatents

    White, Curt (Pittsburgh, PA); Wells, Arthur (Bridgeville, PA); Diehl, J. Rodney (Pittsburgh, PA); Strazisar, Brian (Venetia, PA)

    2010-04-27

    The invention provides methods for the measurement of carbon dioxide leakage from sequestration reservoirs. Tracer moieties are injected along with carbon dioxide into geological formations. Leakage is monitored by gas chromatographic analyses of absorbents. The invention also provides a process for the early leak detection of possible carbon dioxide leakage from sequestration reservoirs by measuring methane (CH.sub.4), ethane (C.sub.2H.sub.6), propane (C.sub.3H.sub.8), and/or radon (Rn) leakage rates from the reservoirs. The invention further provides a method for branding sequestered carbon dioxide using perfluorcarbon tracers (PFTs) to show ownership.

  10. Heterogenous mixed-valence and compound formation in ordered Yb/Ni(100) overlayers

    NASA Astrophysics Data System (ADS)

    Nilsson, A.; Eriksson, B.; Martensson, N.; Andersen, J. N.; Onsgaard, J.

    1987-12-01

    The Yb valence state for ordered Yb/Ni(100) overlayers has been studied by use of photoelectron spectroscopy. At coverages between 50% and 100% of a densely packed Yb layer a c(10×2) surface structure is seen. The ultraviolet photoemission spectroscopy spectrum for this situation reveals both divalent and trivalent 4f emission features, indicating a mixed-valent state. From the observed 4f binding energies it is concluded that the mixed valence is of a heterogenous nature. The results are interpreted in terms of the formation of an epitaxial surface intermetallic compound with Yb distributed over several atomic layers. The results demonstrate the importance of surface compound formation in the present type of systems and offers an alternative explanation to the homogenous mixed-valence recently proposed for related Sm overlayers.

  11. Contrasting the impact of aerosols at northern and southern midlatitudes on heterogeneous ice formation

    NASA Astrophysics Data System (ADS)

    Kanitz, T.; Seifert, P.; Ansmann, A.; Engelmann, R.; Althausen, D.; Casiccia, C.; Rohwer, E. G.

    2011-09-01

    Three cloud data sets, each covering four months of observations, were recently recorded with a lidar at Punta Arenas (53°S), Chile, at Stellenbosch (34°S, near Cape Town), South Africa, and aboard the research vessel Polarstern during three north-south cruises. By comparing these observations with an 11-year cloud data set measured with a lidar at Leipzig (51°N), Germany, the occurrence of heterogeneous ice formation (as a function of cloud top temperature) for very different aerosol conditions in the northern and southern hemisphere is investigated. Large differences in the heterogeneous freezing behavior in the mostly layered clouds are found. For example, <20%, 30%-40% and around 70% of the cloud layers with cloud top temperatures from -15°C to -20°C, showed ice formation over Punta Arenas, Stellenbosch, and Leipzig, respectively. The observed strong contrast reflects the differences in the free tropospheric aerosol conditions at northern midlatitudes, that are controlled by anthropogenic pollution, mineral dust, forest fire smoke, terrestrial biological material and high southern midlatitudes with clean marine conditions.

  12. Heterogeneous formation of polar stratospheric clouds - Part 1: Nucleation of nitric acid trihydrate (NAT)

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-09-01

    Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  13. Heterogeneous formation of polar stratospheric clouds - Part 1: Nucleation of nitric acid trihydrate (NAT)

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-03-01

    Satellite based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarisation (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled the thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed PSCs very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  14. Heterogeneous Formation of Polar Stratospheric Clouds- Part 1: Nucleation of Nitric Acid Trihydrate (NAT)

    NASA Technical Reports Server (NTRS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooss, J.-U.; Peter, T.

    2013-01-01

    Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  15. Influence of Aerosol Chemical Composition on Heterogeneous Ice Formation under Mid-Upper Troposphere Conditions

    NASA Astrophysics Data System (ADS)

    Kanji, Z. A.; Niemand, M.; Saathoff, H.; Möhler, O.; Chou, C.; Abbatt, J.; Stetzer, O.

    2011-12-01

    Aerosols are involved in cooling/warming the atmosphere directly via interaction with incoming solar radiation (aerosol direct effect), or via their ability to act as cloud condensation or ice nuclei (IN) and thus play a role in cloud formation (indirect effect). In particular, the physical properties of aerosols such as size and solubility and chemical composition can influence their behavior and fate in the atmosphere. Ice nucleation taking place via IN is termed as heterogeneous ice nucleation and can take place with via deposition (ice forming on IN directly from the vapor phase), condensation/immersion (freezing via formation of the liquid phase on IN) or condensation (IN colliding with supercooled liquid drops). This presentation shows how the chemical composition and surface area of various tropospherically relevant aerosols influence conditions of temperature (T) and relative humidity (RH) required for heterogeneous ice formation conditions in the mid-upper troposphere regime (253 - 220K)? Motivation for this comes first from, the importance of being able to predict ice formation accurately so as to understand the hydrological cycle since the ice is the primary initiator of precipitation forming clouds. Second, the tropospheric budget of water vapour, an especially active greenhouse gas is strongly influenced by ice nucleation and growth. Third, ice surfaces in the atmosphere act as heterogeneous surfaces for chemical reactions of trace gases (e.g., SO2, O3, NOx and therefore being able to accurately estimate ice formation rates and quantify ice surface concentrations will allow a more accurate calculation of trace gas budgets in the troposphere. Ice nucleation measurements were conducted using a self-developed continuous flow diffusion chamber and static chamber. A number of tropospherically relevant particulates with naturally-varying and laboratory-modified surface chemistry/structure were investigated for their ice formation efficiency based on highest T and lowest RH required for ice formation. The particles investigated were classified into three categories, mineral dust aerosols, hygroscopic and non-hygroscopic particles which included organic and inorganic salts and/or coatings. In addition results ice formation results from ozone aged mineral particles will be presented. It is observed that changing functional groups on the surface of the particles can inhibit ice formation in the deposition mode. The ice forming efficiency of mineral aerosols was observed to be the highest, requiring RH with respect to ice as low as 105% at 233 K. Hydrophobic particles were comparatively weaker at forming ice and required RH close to or above water saturation for ice formation via deposition/condensation mode freezing. The high ice nucleation activity of mineral aerosols suggest that they could play an important role in ice forming and therefore precipitation processes in the troposphere and may have in impact on global and regional climate.

  16. Inherent heterogeneity of sediments in Dhahran, Saudi Arabia — a case study

    Microsoft Academic Search

    Naser A. Al-Shayea

    2000-01-01

    The behavior and properties of sediments depend on their compositional characteristics and formation processes, as well as the environmental conditions during their geological history, i.e. post-formation processes. A vertical cut made in a hill in Dhahran, Saudi Arabia, reveals a vivid picture of the inherent heterogeneity of sediments that have been deposited at different geological ages. A review of the

  17. Geologic framework of the Jurassic (Oxfordian) Smackover Formation the Alabama coastal waters area

    SciTech Connect

    Tew, B.H.; Mancini, E.A. (Univ. of Alabama, Tuscaloosa, AL (United States)); Mink R.M.; Mann, S.D. (Geological Survey of Alabama, Tuscaloosa, AL (United States)); Mancini, E.A.

    1993-09-01

    The Jurassic (Oxfordian) Smackover Formation is a prolific hydrocarbon-producing geologic unit in the onshore Gulf of Mexico area, including southwest Alabama. However, no Smackover strata containing commercial accumulations of oil or gas have thus far been discovered in the Alabama state coastal waters area (ACW). This study of the regional geologic framework of the Smackover Formation was done to characterize the unit in the ACW and to compare strata in the ACW with productive Smackover intervals in the onshore area. In the study area, the Smackover Formation was deposited on a highly modified carbonate associated with pre-Smackover topographic features. In the onshore Alabama, north of the Wiggins arch complex, an inner ramp developed in the area of the Mississippi interior salt basin and the Manila and Conecuh embayments. South of the Wiggins arch complex in extreme southern onshore Alabama and in the ACW, an outer ramp formed that was characterized by a much thicker Smackover section. In the outer ramp setting, four lithofacies associations are recognized: lower, middle, and upper outer ramp lithofacies (ORL) and the coastal dolostone lithofacies. The coastal dolostone lithofacies accounts for most of the reservoir-grade porosity in the outer ramp setting. The lower, middle, and upper ORL, for the most part, are nonporous. Volumetrically, intercrystalline porosity is the most important pore type in the coastal dolostone lithofacies. Numerous data in the ACW area indicate that halokinesis has created structural conditions favorable for accumulation and entrapment of oil and gas in the outer ramp lithofacies of the Smackover. Prolific hydrocarbon source rocks are present in the ACW, as evidenced by the significant natural gas accumulations in the Norphlet Formation. To date, however, reservoir quality rocks of the coastal dolostone lithofacies coincident with favorable structural conditions have not been encountered in the ACW.

  18. Geologic and hydrogeologic characteristics of the Ogallala Formation and White River Group, Belvoir Ranch near Cheyenne, Laramie County, Wyoming

    USGS Publications Warehouse

    Bartos, Timothy T.; Diehl, Sharon F.; Hallberg, Laura L.; Webster, Daniel M.

    2014-01-01

    The geologic and hydrogeologic characteristics of Tertiary lithostratigraphic units (Ogallala Formation and White River Group) that typically compose or underlie the High Plains aquifer system in southeastern Wyoming were described physically and chemically, and evaluated at a location on the Belvoir Ranch in Laramie County, Wyoming. On the basis of this characterization and evaluation, three Tertiary lithostratigraphic units were identified using physical and chemical characteristics determined during this study and previous studies, and these three units were determined to be correlative with three identified hydrogeologic units composing the groundwater system at the study site—a high-yielding aquifer composed of the entire saturated thickness of the heterogeneous and coarse-grained fluvial sediments assigned to the Ogallala Formation (Ogallala aquifer); an underlying confining unit composed primarily of very fine-grained volcaniclastic sediments and mudrocks assigned to the Brule Formation of the White River Group and some additional underlying sediments that belong to either the Brule or Chadron Formation, or both (Brule confining unit); and an underlying low-yielding aquifer composed primarily of poorly sorted fluvial sediments assigned to the Chadron Formation of the White River Group (Chadron aquifer). Despite widely varying sediment heterogeneity and consolidation, some limited hydraulic connection throughout the full vertical extent of the Ogallala aquifer was indicated but not conclusively proven by interpretation of similar chemical and isotopic characteristics, modern apparent groundwater ages, and similar hydraulic-head responses measured continuously in two Ogallala aquifer monitoring wells installed for this study at two different widely separated (83 feet) depth intervals. Additional work beyond the scope of this study, such as aquifer tests, would be required to conclusively determine hydraulic connection within the Ogallala aquifer. Groundwater levels (hydraulic heads) measured continuously using water-level recorders in both monitoring wells completed in the Ogallala aquifer showed a consistent strong upward vertical gradient in the Ogallala aquifer, indicating the potential for water to move from deeper to shallower parts of the aquifer, regardless of the time of year and the presumed effects of pumping of public-supply and industrial wells in the area. Continuous measurement of groundwater levels in the shallowest monitoring well, installed near the water table, and examination of subsequently constructed water-level hydrographs indicated substantial groundwater recharge is likely during the spring of 2009 and 2010 from the ephemeral stream (Lone Tree Creek) located adjacent to the study site that flows primarily in response to spring snowmelt from the adjacent Laramie Mountains and surface runoff from precipitation events. Using the water-table fluctuation method, groundwater recharge was estimated to be about 13 inches for the period beginning in early October 2009 and ending in late June 2010, and about 4 inches for the period beginning in March 2011 and ending in early July 2011. Comparison of previously measured groundwater levels (hydraulic heads) and groundwater-quality characteristics in nearby monitoring wells completed in the Chadron aquifer with those measured in the two monitoring wells installed for this study in the Ogallala aquifer, combined with detailed lithologic characterization, strongly indicated the Brule confining unit hydraulically confines and isolates the Chadron aquifer from the overlying Ogallala aquifer, thus likely limiting hydraulic connection between the two units. Consequently, because of the impermeable nature of the Brule confining unit and resulting hydraulic separation of the Ogallala and Chadron aquifers, and compared with local and regional hydrostratigraphic definitions of the High Plains aquifer system, the groundwater system in Tertiary lithostratigraphic units overlying the Upper Cretaceous Lance Formation at the location studied on the Belvoir Ranch was

  19. Geologic setting, petrophysical characteristics, and regional heterogeneity patterns of the Smackover in southwest Alabama. Draft topical report on Subtasks 2 and 3

    SciTech Connect

    Kopaska-Merkel, D.C.; Mann, S.D.; Tew, B.H.

    1992-06-01

    This is the draft topical report on Subtasks 2 and 3 of DOE contract number DE-FG22-89BC14425, entitled ``Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity.`` This volume constitutes the final report on Subtask 3, which had as its primary goal the geological modeling of reservoir heterogeneity in Smackover reservoirs of southwest Alabama. This goal was interpreted to include a thorough analysis of Smackover reservoirs, which was required for an understanding of Smackover reservoir heterogeneity. This report is divided into six sections (including this brief introduction). Section two, entitled ``Geologic setting,`` presents a concise summary of Jurassic paleogeography, structural setting, and stratigraphy in southwest Alabama. This section also includes a brief review of sedimentologic characteristics and stratigraphic framework of the Smackover, and a summary of the diagenetic processes that strongly affected Smackover reservoirs in Alabama. Section three, entitled ``Analytical methods,`` summarizes all nonroutine aspects of the analytical procedures used in this project. The major topics are thin-section description, analysis of commercial porosity and permeability data, capillary-pressure analysis, and field characterization. ``Smackover reservoir characteristics`` are described in section four, which begins with a general summary of the petrographic characteristics of porous and permeable Smackover strata. This is followed by a more-detailed petrophysical description of Smackover reservoirs.

  20. Formation of Small Gas Phase Carbonyls from Heterogeneous Oxidation of Polyunsaturated Fatty Acids (PUFA)

    NASA Astrophysics Data System (ADS)

    Zhou, S.; Zhao, R.; Lee, A.; Gao, S.; Abbatt, J.

    2011-12-01

    Fatty acids (FAs) are emitted into the atmosphere from gas and diesel powered vehicles, cooking, plants, and marine biota. Field measurements have suggested that FAs, including polyunsaturated fatty acids (PUFA), could make up an important contribution to the organic fraction of atmospheric aerosols. Due to the existence of carbon-carbon double bonds in their molecules, PUFA are believed to be highly reactive towards atmospheric oxidants such as OH and NO3 radicals and ozone, which will contribute to aerosol hygroscopicity and cloud condensation nuclei activity. Previous work from our group has shown that small carbonyls formed from the heterogeneous reaction of linoleic acid (LA) thin films with gas-phase O3. It is known that the formation of small carbonyls in the atmosphere is not only relevant to the atmospheric budget of volatile organic compounds but also to secondary organic aerosol formation. In the present study, using an online proton transfer reaction mass spectrometry (PTR-MS) and off-line gas chromatography-mass spectrometry (GC-MS) we again investigated carbonyl formation from the same reaction system, i.e. the heterogeneous ozonolysis of LA film. In addition to the previously reported carbonyls, malondialdehyde (MDA), a source of reactive oxygen species that is mutagenic, has been identified as a product for the first time. Small dicarbonyls, e.g. glyoxal, are expected to be formed from the further oxidation of MDA. In this presentation, the gas-phase chemistry of MDA with OH radicals using a newly built Teflon chamber in our group will also be presented.

  1. The Vicksburg Formation of Texas: Depositional systems distribution, sequence stratigraphy, and petroleum geology

    SciTech Connect

    Combes, J.M. (Amoco Production Co., Tulsa, OK (United States))

    1993-11-01

    The lower Oligocene Vicksburg Formation of the Gulf Coastal plain contains major petroleum reservoirs in the Rio Grande embayment and is an economically viable target in other areas of Texas. Knowledge of the distribution of Vicksburg depositional systems is essential to understanding sandstone concentrations and, therefore, is fundamental to effective exploration and production of the Vicksburg section. The depositional setting of the Vicksburg reservoirs, their position in a sequence stratigraphic framework, and the influence these factors have on the petroleum geology of the Vicksburg are the focus of this paper. Surface and subsurface geological and geophysical data provided the framework for an analysis of the depositional systems and the petroleum geology of the Vicksburg. The two primary Texas Vicksburg depocenters, the Rio Grande embayment and the Houston embayment, are separated by the San Marcos arch, a deep-rooted structural nose. Within the embayments, sand-rich deltaic complexes merged along strike with barrier/strand plains. Contemporaneous growth faulting controlled depositional patterns of shelf-edge deltas in the Rio Grande embayment, but had only a minor effect on the configuration of the shelfal deltas in the Houston embayment. Smaller wave-dominated shelf delta complexes interspersed with barrier/strand plains extended across the San Marcos arch. Updip of these sandy paralic depocenters, fluvial systems traversed mud-rich coastal plain units. Seaward of the paralic systems, sand and mud deposits prograded across and built up over the relict Jackson shelf and shelf-margin shales. These depositional complexes are contained in the systems tracts of one eustatic (Exxon) sequence. Vicksburg production from each of the three structural regions of Texas is characterized by reservoirs from different systems tracts and of distinct, different depositional origins.

  2. Process and device for the determination of the characteristics of the geological formations traversed by a borehole

    SciTech Connect

    Bard, J.; Morlier, P.; Pelet, R.; Sarda, J.

    1981-12-22

    A description is given of a process for determining characteristics of the geological formations traversed by a borehole, making use of a sonde by means of which the intensity of the gamma rays naturally radiated from the formations is measured. Both longitudinal and transversal acoustic waves are transmitted to the formations, their travel time and their attenuation between two receivers placed in contact with the formations are measured. By combination of the so-obtained values a resulting value is elaborated which is representative of one characteristic of the surveyed formations.

  3. Heterogeneous-nucleation and glass-formation studies of 56Ga2O3-44CaO

    NASA Technical Reports Server (NTRS)

    Ethridge, Edwin C.; Curreri, Peter A.; Pline, David

    1987-01-01

    Glass formation and heterogeneous crystallization are described for the reluctant-glass-forming 56Ga2O3-44CaO eutectic composition. The times and temperatures for nucleation at various cooling rates and experimental conditions were measured and empirical continuous-cooling-crystallization boundaries were constructed for various heterogeneous nucleation processes. A definition for an empirical critical cooling rate to form a glass from reluctant borderline glass formers is proposed, i.e., the cooling rate that results in glass formation in 95 percent of the quenching experiments.

  4. Inter-chromosomal heterogeneity in the formation of radiation induced chromosomal aberrations

    SciTech Connect

    Natarajan, A.T.; Vermeulen, S.; Boei, J.J.W.A. [Leiden Univ. (Netherlands)

    1997-10-01

    it is generally assumed that radiation induced chromosomal lesions are distributed randomly and repaired randomly among the genome. Recent studies using fluorescent in situ hybridization (FISH) and chromosome specific DNA libraries indicate that some chromosomes are more sensitive for radiation induced aberration formation than others. Chromosome No. 4 in human and chromosome No. 8 in Chinese hamster have been found to involve more in exchange aberrations than others, when calculated on the basis of their DNA content. Painting with arm specific chromosome libraries indicate that the frequencies of radiation induced intra-chromosome exchanges (i.e., between the arms of a chromosome, such as centric rings and inversions) are far in excess than one would expect on the basis of the frequencies of observed inter-chromosomal exchanges. The possible factors leading to the observed heterogeneity will be discussed.

  5. Heterogeneity of chemical and physical soil properties of an artificial catchment during initial soil formation

    NASA Astrophysics Data System (ADS)

    Zimmermann, C.; Dümig, A.; Schaaf, W.; Kögel-Knabner, I.

    2009-04-01

    The post-mining landscapes of the Lusatian lignite mining district in Eastern Germany offered the opportunity to construct an artificial catchment to study patterns and processes of ecosystem development from the point zero. The Transregional Collaborative Research Centre (SFB/TRR 38) investigates the structures and processes including their interactions within the 6 ha area of the artificial catchment 'Chicken Creek', which was left to primary succession. Within this study processes of the initial pedogenesis of the sandy quaternary sediment of the catchment are investigated with respect to heterogeneity and dynamics of soil properties like leaching, decalcification, accumulation and formation of stable soil organic matter. To get a first database to answer these questions and to characterize the initial conditions a geostatistical sampling was performed in August 2008. To capture structures certain areas were sampled by randomised selection of spatial higher resolution according to the geostatistical approach of nested sampling. It was supposed that the first centimetres of the substrate surface play a main role in initial soil formation processes. Therefore, we focused our sampling design on the first three centimetres of the surface including the surface crust. At 192 sampling points disturbed and undisturbed samples of the surface soil were taken and all sampling points were documented photographically. This contribution presents first results of soil characteristics in the artificial catchment ‘Chicken Creek' and the heterogeneity of soil parameters like bulk density, soil skeleton content, pH, oxalate-extractable Fe and dithionite-soluble Fe, organic C and N contents and distribution of the natural stable C and N isotopes (?13C; ?15N). To show dynamics in the development of soil properties in the initial phase of pedogenesis it is planned to repeat the sampling every two years.

  6. Structured development of a petrophysics laboratory computer system to aid in formation evaluation and geologic interpretation

    SciTech Connect

    Hoyt, B.R.; Skopec, R.A. (Gearhart Industries, Inc., Fort Worth, TX (USA))

    1987-02-01

    Problem solving, data collection, and analysis in geology require diverse tools and methods. Computers must be convenient and versatile to be useful as laboratory apparatus and as tools for use in formation evaluation and geologic interpretation. Networking and distributed intelligence provide a laboratory with flexibility and power for cost-effective real-time data collection, management, and analysis. Networking facilities toolbox-style programming; improves data compilation, management, and comparison; and increases peripheral effectiveness. Distributed intelligence enhances local instrumentation, uninterrupted real-time data collector, and data analysis. The system presented includes facilities for instrumentation, data collection and management, and interpretation, analysis, and presentation for such systems as mercury injection, rock electrical properties, gas slippage, Klinkenberg correction, gamma-ray logging, cation exchange capacity, thermal neutron capture cross section, and permeability/porosity measurements. The individual systems share central text and graphic hard-copy devices and high-speed mass storage and backup facilities. Modifying the central system updates many of the remote system facilities such as user interfaces and graphic facilities. Individual system configurations include instrumentation, high-resolution color graphics, analog to digital conversion, and variation in computing power.

  7. Sudbury project (University of Muenster-Ontario Geological Survey): Petrology, chemistry, and origin of breccia formations

    NASA Technical Reports Server (NTRS)

    Stoeffler, D.; Deutsch, A.; Avermann, M.; Brockmeyer, P.; Lakomy, R.; Mueller-Mohr, V.

    1992-01-01

    Within the Sudbury Project of the University of Muenster and the Ontario Geological Survey special emphasis was put on the breccia formations exposed at the Sudbury structure (SS) because of their crucial role for the impact hypothesis. They were mapped and sampled in selected areas of the north, east, and south ranges of the SS. The relative stratigraphic positions of these units are summarized. Selected samples were analyzed by optical microscopy, SEM, microprobe, XRF and INAA, Rb-Sr and SM-Nd-isotope geochemistry, and carbon isotope analysis. The results of petrographic and chemical analysis for those stratigraphic units that were considered the main structural elements of a large impact basin are summarized.

  8. A dynamic flow simulation code benchmark study addressing the highly heterogeneous properties of the Stuttgart formation at the Ketzin pilot site

    NASA Astrophysics Data System (ADS)

    Kempka, Thomas; Class, Holger; Görke, Uwe-Jens; Norden, Ben; Kolditz, Olaf; Kühn, Michael; Walter, Lena; Wang, Wenqing; Zehner, Björn

    2013-04-01

    CO2 injection at the Ketzin pilot site located in Eastern Germany (Brandenburg) about 25 km west of Berlin is undertaken since June 2008 with a scheduled total amount of about 70,000 t CO2 to be injected into the saline aquifer represented by the Stuttgart Formation at a depth of 630 m to 650 m until the end of August 2013. The Stuttgart Formation is of fluvial origin determined by high-permeablity sandstone channels embedded in a floodplain facies of low permeability indicating a highly heterogeneous distribution of reservoir properties as facies distribution, porosity and permeability relevant for dynamic flow simulations. Following the dynamic modelling activities discussed by Kempka et al. (2010), a revised geological model allowed us to history match CO2 arrival times in the observation wells and reservoir pressure with a good agreement (Martens et al., 2012). Consequently, the validated reservoir model of the Stuttgart Formation at the Ketzin pilot site enabled us to predict the development of reservoir pressure and the CO2 plume migration in the storage formation by dynamic flow simulations. A benchmark study of industrial (ECLIPSE 100 as well as ECLIPSE 300 CO2STORE and GASWAT) and scientific dynamic flow simulations codes (TOUGH2-MP/ECO2N, OpenGeoSys and DuMuX) was initiated to address and compare the simulator capabilities considering a highly complex reservoir model. Hence, our dynamic flow simulations take into account different properties of the geological model such as significant variation of porosity and permeability in the Stuttgart Formation as well as structural geological features implemented in the geological model such as seven major faults located at the top of the Ketzin anticline. Integration of the geological model into reservoir models suitable for the different dynamic flow simulators applied demonstrated that a direct conversion of reservoir model discretization between Finite Volume and Finite Element flow simulators is not feasible. Hence, the initial hexahedron meshes as applied for the ECLIPSE 100 and TOUGH2-MP/ECO2N simulations had to be converted into tetrahedron meshes to meet the convergence criteria of the Finite Element simulators DuMuX and OpenGeoSys. Our simulation results show a good agreement of reservoir pressure between all simulators, while CO2 arrival times at the observation wells strongly depend on the chosen discretization. In summary, all simulators applied are capable to address the highly complex reservoir properties present in the Stuttgart Formation at the Ketzin pilot site by dynamic flow simulations providing results of sufficient quality for prediction of future site behaviour. References Kempka, T.; Kühn, M.; Class, H.; Frykman, P.; Kopp, A.; Nielsen, C.M.; Probst, P. (2010) Modelling of CO2 arrival time at Ketzin - Part I. International Journal of Greenhouse Gas Control, Special Issue Geological CO2 Storage 4(6):1007-1015. Martens, S.; Kempka, T.; Liebscher, A.; Lüth, S.; Möller, F.; Myrttinen, A.; Norden, B.; Schmidt-Hattenberger, C.; Zimmer, M.; Kühn, M. (2012): Europe's longest-operating on-shore CO2 storage site at Ketzin, Germany: a progress report after three years of injection. Environmental Earth Sciences. 10.1007/s12665-012-1672-5.

  9. Modeling Biogeochemistry and Flow within Heterogeneous Formations in Variably-Saturated Media

    E-print Network

    Arora, Bhavna

    2012-10-19

    heterogeneity on coupled biogeochemical processes across column and landfill scales. Structural heterogeneity in the form of macropore distributions (no macropore, single macropore, and multiple macropores) in experimental soil columns is investigated...

  10. Heterogeneity in a Low-Permeability Formation or Non-Ideal Testing Conditions?

    NASA Astrophysics Data System (ADS)

    Mishra, S.; Deeds, N. E.; Pickens, J. F.; Distinguin, M.; Delay, J.

    2005-12-01

    Hydraulic testing in packer-isolated wellbore intervals in low-permeability formations is often complicated by non-ideal conditions such as thermal expansion of fluid in the test interval, packer squeeze and borehole closure. Such processes lead to fluid accumulation and pressurization within the wellbore during shut-in, and can exert significant effects on the measured borehole pressure response. Unless these conditions are taken into account during test interpretation, it is possible to make inappropriate conclusions regarding formation heterogeneity (e.g., lateral permeability variations) and/or static pressure levels. We have developed a lumped parameter modeling approach by treating the combined effect of these processes as the equivalent of an additional volume of fluid accumulating within the test interval (in addition to the nominal test-interval volume at the time of shut-in). We postulate that the rate of fluid accumulation can be treated in a simple manner as a constant value for the duration of the test. Thus, the fluid accumulation problem can be recast as the equivalent of a constant injection rate into the packed-off volume within the borehole. We show how this surrogate injection rate can be estimated from the measured pressure data by exploiting the analogy between the pressure response during borehole storage dominated conditions and that of a line-source well with an exponentially varying flow rate. Shut-in test sequences (i.e., shut-in period prior to initiation of a pressure pulse test and shut-in period(s) during pulse test(s)) can then be analyzed as effective constant-rate injection periods. The methodology is demonstrated using data from a recent series of hydraulic tests conducted in support of site characterization activities by ANDRA, the French radioactive waste management agency. In many of these tests, the measured pressure response was fitted to a 2-zone radially composite system model. Although the fit was visually excellent, static pressure estimates were found to be significantly different than those obtained from long-term pressure monitoring data from permanently installed borehole pressure gauges that use wireless telemetry for data transmission. These special tools (called EPG tools) provide the highest quality monitoring data for defining true undisturbed formation pressures in very low-permeability formations. In this study, the hydraulic-test data were reanalyzed using the lumped parameter modeling approach with a single-zone homogeneous model constrained to the static pressure bounds indicated by the EPG data. The single-zone analysis yields visual fits comparable to those from the 2-zone radially composite model, and formation parameters that are statistically much more robust (i.e., they do not suffer from over-parameterization and poor parameter identifiability as do the parameter estimates from the 2-zone conceptualization). We conclude that the effects of non-ideal testing conditions can be mistaken as indicators of formational heterogeneities.

  11. 3rd hand smoking; heterogeneous oxidation of nicotine and secondary aerosol formation in the indoor environment

    NASA Astrophysics Data System (ADS)

    Petrick, Lauren; Dubowski, Yael

    2010-05-01

    Tobacco smoking is well known as a significant source of primary indoor air pollutants. However, only recently has it been recognized that the impact of Tobacco smoking may continue even after the cigarette has been extinguished (i.e., third hand smoke) due to the effect of indoor surfaces. These surfaces may affect the fate of tobacco smoke in the form of secondary reactions and pollutants, including secondary organic aerosol (SOA) formation. Fourier Transform Infrared spectrometry with Attenuated Total Reflection (FTIR-ATR) in tandem with a Scanning Mobility Particle Sizing (SMPS) system was used to monitor the ozonation of cellulose sorbed nicotine and resulting SOA formation. SOA formation began at onset of ozone introduction ([O3] = 60 ± 5 ppb) with a size distribution of dp ? 25 nm, and was determined to be a result of heterogeneous reaction (opposed to homogeneous). SOA yield from reacted surface nicotine was on the order of 10 %. Simultaneous to SOA monitoring, FTIR-ATR spectra showed surface changes in the nicotine film as the reaction progressed, revealing a pseudo first-order surface reaction rate of 0.0026 ± 0.0008 min-1. Identified surface oxidation products included: cotinine, myosmine, methylnicotinamide and nicotyrine. Surface reaction rate was found to be partially inhibited at high relative humidity. Given the toxicity of some of the identified products (e.g., cotinine has shown potential mutagenicity and teratogenicity) and that small particles may contribute to adverse health effects, the present study indicates that exposure to 3rd hand smoke ozonation products may pose additional health risks.

  12. Coupled Finite Volume and Discrete-Finite element Methods for Modeling Hydraulic Fracturing in Geologic Formations

    NASA Astrophysics Data System (ADS)

    Johnson, S.; Morris, J.

    2008-12-01

    ABSTRACT: High demand for stimulation treatments of fluid-state hydrocarbon reservoirs is driving increased interest in improved understanding of the fundamentals of hydraulic fracturing of geologic formations. In addition, prediction of caprock integrity under the load of geologically sequestered, pressurized CO2 requires better understanding fluid-rock interactions. The approach described here addresses modeling of hydraulic fracturing at the meso-scale, using a discrete-finite element method code (LDEC) coupled to a modified finite volume method to capture compressible flow in a propagating fracture. Leak-off is also addressed through a model parameterized by flow rate and cumulative flow through the fracture face; this approach is used to better approximate the functional form of the dominant underlying chemo-physical phenomena which lead to permeability loss at the fracture face over typical models, which are often parameterized only by time and calibrated, through a set of parameters, to match experimental data. A simulation of a standard fracture injection test is used to compare the results of the proposed leak-off model with the popular Carter leak-off model and shows excellent agreement between the two models. Also, the finite volume approach is verified against analytical solutions for constant aperture parallel plate flow, and results of a validation study comparing simulation results with an experiment on the propagation of a fracture in a brittle, homogeneous polymer are discussed. ACKNOWLEDGEMENTS: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  13. Geology of the Molina Member of the Wasatch Formation, Piceance Basin, Colorado

    SciTech Connect

    Lorenz, J. [Sandia National Labs., Albuquerque, NM (United States); Nadon, G. [Ohio Univ., Athens, OH (United States); LaFreniere, L. [FD Services Inc., Casper, WY (United States)

    1996-06-01

    The Molina Member of the Wasatch Formation has been cored in order to assess the presence/absence and character of microbial communities in the deep subsurface. Geological study of the Molina Member was undertaken in support of the microbiological tasks of this project, for the purposes of characterizing the host strata and of assessing the potential for post-depositional introduction of microbes into the strata. The Molina Member comprises a sandy fluvial unit within a formation dominated by mudstones. Sandy to conglomeratic deposits of braided and meandering fluvial systems are present on the western and eastern margins of the basin respectively, although the physical and temporal equivalence of these systems cannot be proven. Distal braided facies of planar-horizontal bedded sandstones are recognized on the western margin of the basin. Natural fractures are present in all Molina sandstones, commonly as apparent shear pairs. Core from the 1-M-18 well contains natural fractures similar to those found in outcrops, and has sedimentological affinities to the meandering systems of the eastern margin of the basin. The hydrologic framework of the Molina, and thus any potential post-depositional introduction of microbes into the formation, should have been controlled by approximately east-west flow through the natural fracture system, the geometries and extent of the sandstones in which the fractures occur, and hydraulic gradient. Migration to the well site, from outcropping recharge areas at the edge of the basin, could have started as early as 40 million years ago if the cored strata are connected to the eastern sedimentary system.

  14. Formation of nitroanthracene and anthraquinone from the heterogeneous reaction between NO2 and anthracene adsorbed on NaCl particles.

    PubMed

    Chen, Wenyuan; Zhu, Tong

    2014-08-01

    Oxidative derivatives of polycyclic aromatic hydrocarbons (PAHs), that is, nitro-PAHs and quinones, are classed as hazardous semivolatile organic compounds but their formation mechanism from the heterogeneous reactions of PAHs adsorbed on atmospheric particles is not well understood. The heterogeneous reaction of NO2 with anthracene adsorbed on NaCl particles under different relative humidity (RH 0-60%) was investigated under dark conditions at 298 K. The formation of the major products, 9,10-anthraquinone (9,10-AQ) and 9-nitroanthracene (9-NANT), were determined to be second-order reactions with respect to NO2 concentration. The rate of formation of 9,10-AQ under low RH (0-20%) increased as the RH increased but decreased when the RH was further increased in high RH (40-60%). In contrast, the rate of formation of 9-NANT across the whole RH range (0-60%) decreased significantly with increasing RH. Two different reaction pathways are discussed for the formation of 9,10-AQ and 9-NANT, respectively, and both are considered to be coupled to the predominant reaction of NO2 with the NaCl substrate. These results suggest that relative humidity, which controls the amount of surface adsorbed water on NaCl particles, plays an important role in the heterogeneous reaction of NO2 with adsorbed PAHs. PMID:24950458

  15. Flow and Transport in Highly Heterogeneous Porous Formations: Numerical Experiments Performed Using the Analytic Element Method

    NASA Astrophysics Data System (ADS)

    Jankovic, I.

    2002-05-01

    Flow and transport in porous formations are analyzed using numerical simulations. Hydraulic conductivity is treated as a spatial random function characterized by a probability density function and a two-point covariance function. Simulations are performed for a multi-indicator conductivity structure developed by Gedeon Dagan (personal communication). This conductivity structure contains inhomogeneities (inclusions) of elliptical and ellipsoidal geometry that are embedded in a homogeneous background. By varying the distribution of sizes and conductivities of inclusions, any probability density function and two-point covariance may be reproduced. The multi-indicator structure is selected since it yields simple approximate transport solutions (Aldo Fiori, personal communication) and accurate numerical solutions (based on the Analytic Element Method). The dispersion is examined for two conceptual models. Both models are based on the multi-indicator conductivity structure. The first model is designed to examine dispersion in aquifers with continuously varying conductivity. The inclusions in this model cover as much area/volume of the porous formation as possible. The second model is designed for aquifers that contain clay/sand/gravel lenses embedded in otherwise homogeneous background. The dispersion in both aquifer types is simulated numerically. Simulation results are compared to those obtained using simple approximate solutions. In order to infer transport statistics that are representative of an infinite domain using the numerical experiments, the inclusions are placed in a domain that was shaped as a large ellipse (2D) and a large spheroid (3D) that were submerged in an unbounded homogeneous medium. On a large scale, the large body of inclusions behaves like a single large inhomogeneity. The analytic solution for a uniform flow past the single inhomogeneity of such geometry yields uniform velocity inside the domain. The velocity differs from that at infinity and can be used to infer the effective conductivity of the medium. As many as 100,000 inhomogeneities are placed inside the domain for 2D simulations. Simulations in 3D were limited to 50,000 inclusions. A large number of simulations was conducted on a massively parallel supercomputer cluster at the Center for Computational Research, University at Buffalo. Simulations range from mildly heterogeneous formations to highly heterogeneous formations (variance of the logarithm of conductivity equal to 10) and from sparsely populated systems to systems where inhomogeneities cover 95% of the volume. Particles are released and tracked inside the core of constant mean velocity. Following the particle tracking, various medium, flow, and transport statistics are computed. These include: spatial moments of particle positions, probability density function of hydraulic conductivity and each component of velocity, their two-point covariance function in the direction of flow and normal to it, covariance of Lagrangean velocities, and probability density function of travel times to various break-through locations. Following the analytic nature of the flow solution, all the results are presented in dimensionless forms. For example, the dispersion coefficients are made dimensionless with respect to the mean velocity and size of inhomogeneities. Detailed results will be presented and compared to well known first-order results and the results that are based on simple approximate transport solutions of Aldo Fiori.

  16. Heterogeneous Chemistry of Glyoxal on Acidic Solutions. An Oligomerization Pathway for Secondary Organic Aerosol Formation.

    PubMed

    Gomez, Mario E; Lin, Yun; Guo, Song; Zhang, Renyi

    2014-11-20

    The heterogeneous chemistry of glyoxal on sulfuric acid surfaces has been investigated at various acid concentrations and temperatures, utilizing a low-pressure fast flow laminar reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS). The uptake coefficient (?) of glyoxal ranges from (1.2 ± 0.06) × 10(-2) to (2.5 ± 0.01) × 10(-3) for 60-93 wt % H2SO4 at 253-273 K. The effective Henry's Law constant (H*) ranges from (98.9 ± 4.9) × 10(5) to (1.6 ± 0.1) × 10(5) M atm(-1) for 60-93 wt % at 263-273 K. Both the uptake coefficient and Henry's Law constant increase with decreasing acid concentration and temperature. Our results reveal a reaction mechanism of hydration followed by oligomerization for glyoxal on acidic media, indicating an efficient aqueous reaction of glyoxal on hygroscopic particles leading to secondary organic aerosol formation. PMID:25369518

  17. Heterogeneous diagenetic patterns in the Pleistocene Ironshore Formation of Grand Cayman, British West Indies

    NASA Astrophysics Data System (ADS)

    Li, Rong; Jones, Brian

    2013-08-01

    The Ironshore Formation on Grand Cayman consists of six unconformity-bounded units (A to F) that developed in response to repeated transgressive-regressive cycles during the Middle to Late Pleistocene. Corals and matrices in limestones from the Rogers Wreck Point (RWP), offshore George Town (GT), and western onshore (WO) areas are characterized by complex diagenetic fabrics that reflect marine (bioerosion, micrite envelopes, internal sediments, fibrous high-Mg calcite, acicular aragonite, isopachous prismatic calcite cements), freshwater phreatic (circumgranular cements, even/random blocky calcite cements), and vadose (meniscus calcite cements, blocky calcite cements) diagenesis. Throughout these limestones, the matrices have undergone more meteoric diagenetic alteration than the corals. Overall, however, no systematic stratigraphic patterns exist to the distribution of these diagenetic fabrics and it is generally impossible to link the different phases of diagenesis with specific unconformities that cap each unit. These heterogenous patterns of diagenetic features can be attributed to many intrinsic and extrinsic factors, including the original compositions of the different components in the limestones, the porosity and permeability of the substrate, the nature of the diagenetic fluids, climate, and the duration of exposure during each lowstand. Integration of available data, however, indicates that maximum diagenesis took place during the lowstands denoted by the unconformities at the top of Unit C (Marine Isotope Stage 7) and Unit D (Marine Isotope Stage 5e) when long periods of exposure were accompanied by wet climates with high annual rainfalls.

  18. Integration of Sedimentology,Petrophysics and Statistics for Characterizing the Reservoir Heterogeneity of the Late Ordovician Sarah Formation, Central Saudi Arabia

    NASA Astrophysics Data System (ADS)

    El-Deek, Islam; Abdullatif, Osman; Korvin, Gabor; Al-Ramadan, Khalid

    2014-05-01

    The first glaciogenic event in the Arabian Peninsula is represented by the Late Ordovician Sarah Formation. Sarah Formation is outcropping in areas of central and northern Arabia bordering the Arabian Shield, while it occupies several sub-basinal areas in the subsurface. The glacio-fluvial Sarah Formation is considered as an important tight gas reservoir target. This study uses the outcrop analog of the Sarah Formation to characterize the reservoir heterogeneity of the paleovalleys based on sedimentological, petrophysical, and statistical approaches. Facies types and architectural elements were identified within several paleovalleys of the Sarah Formation. The study indicated variability in texture, composition, sandstone type, facies, geometry and architecture at outcrop scale. Outcrop relationships also showed vertical and lateral facies change with other Paleozoic formations. The integration of field and laboratory data helped identifying the heterogeneity within Sarah paleovalleys. The reservoir quality trends in the Sarah Formation show variations that might be due to the controls of facies, depositional environments, and paleogeography. Three measures of heterogeneity were applied on the petrophysical data for various paleovalleys of the Sarah Formation. Those measures are: the coefficient of variation, Dykstra-Parsons, and Lorenz coefficients.The coefficient of variation values indicate extremely heterogeneous distribution. Dykstra-Parsons coefficient values suggest very to extremely heterogeneous reservoirs. Lorenz coefficients show good correlation with Dykstra-Parsons coefficient for Sarah paleovalleys. The studied heterogeneity measures indicate that Sarah paleovalleys represent very to extremely heterogeneous reservoirs.

  19. Nuclear Waste Disposal in Deep Geological Formations: What are the Major Remaining Scientific Issues?

    SciTech Connect

    Toulhoat, Pierre [Institut des Sciences Analytiques, Universite de Lyon, 43 avenue du 11 novembre 1918, Villeurbanne, 69622 (France); Scientific Direction, INERIS, Parc Technologique ALATA, BP2, Verneuil-en-Halatte, 60550, (France)

    2007-07-01

    For more than thirty years, considerable efforts have been carried out in order to evaluate the possibility of disposing of high level wastes in deep geological formations. Different rock types have been examined, such as water-under-saturated tuffs (USA), granites or crystalline rocks (Canada, Sweden, and Finland), clays (France, Belgium, and Switzerland), rock-salt (Germany). Deep clays and granites, (provided that the most fractured zones are avoided in the second case) are considered to fulfill most allocated functions, either on short term (reversibility) or long term. Chemically reducing conditions favor the immobilization of actinides and most fission products by precipitation, co-precipitation and sorption. If oxidizing conditions prevail, the safety demonstration will mostly rely on the performance of artificial confinement systems. Rock-salt offers limited performance considering the issue of reversibility, which is now perceived as essential, mostly for ethical and sociological reasons. However, several issues would deserve additional research programs, and as a first priority, a clear description of time/space succession of processes during the evolution of the repository. This will allow a better representation of coupled processes in performance assessment, such as the influence of gases (H{sub 2}) generated by corrosion, on the long term dynamics of the re-saturation. Geochemical interactions between the host formation and the engineered systems (packages + barriers) are still insufficiently described. Additional gains in performance could be obtained when taking into account processes such as isotopic exchange. Imaginative solutions, employing ceramic- carbon composite materials could be proposed to replace heavy and gas-generating overpacks, or to accommodate the small but probably significant amount of 'ultimate' wastes that will be inevitably produced by Generation IV reactor systems. (author)

  20. Microbial characterization of basalt formation waters targeted for geological carbon sequestration.

    PubMed

    Lavalleur, Heather J; Colwell, Frederick S

    2013-07-01

    Geological carbon sequestration in basalts is a promising solution to mitigate carbon emissions into the Earth's atmosphere. The Wallula pilot well in Eastern Washington State, USA provides an opportunity to investigate how native microbial communities in basalts are affected by the injection of supercritical carbon dioxide into deep, alkaline formation waters of the Columbia River Basalt Group. Our objective was to characterize the microbial communities at five depth intervals in the Wallula pilot well prior to CO2 injection to establish a baseline community for comparison after the CO2 is injected. Microbial communities were examined using quantitative polymerase chain reaction to enumerate bacterial cells and 454 pyrosequencing to compare and contrast the diversity of the native microbial communities. The deepest depth sampled contained the greatest amount of bacterial biomass, as well as the highest bacterial diversity. The shallowest depth sampled harbored the greatest archaeal diversity. Pyrosequencing revealed the well to be dominated by the Proteobacteria, Firmicutes, and Actinobacteria, with microorganisms related to hydrogen oxidizers (Hydrogenophaga), methylotrophs (Methylotenera), methanotrophs (Methylomonas), iron reducers (Geoalkalibacter), sulfur oxidizers (Thiovirga), and methanogens (Methermicocccus). Thus, the Wallula pilot well is composed of a unique microbial community in which hydrogen and single-carbon compounds may play a significant role in sustaining the deep biosphere. PMID:23418786

  1. Effect of Upscaling on CO2 Storage and Leakage in Heterogeneous Formations

    NASA Astrophysics Data System (ADS)

    Saadatpoor, E.; Bryant, S. L.

    2011-12-01

    In carbon sequestration in saline aquifers, CO2 displaces brine during injection and may continue to migrate by buoyancy after injection ends. During this migration, various modes of trapping occur: residual, dissolution, mineral, and local capillary trapping. The local capillary trapping takes place when a CO2 plume rising through an aquifer encounters a region where capillary entry pressure is locally larger than average, so CO2 accumulates beneath the region. This mode of trapping occurs in heterogeneous domains and can only be seen in fine-scale simulations that use heterogeneous capillary pressure field. Using homogeneous capillary pressure field or even several rock types in a heterogeneous domain fails to capture local capillary trapping. However, fine-scale simulation is always costly and often impractical, and an upscaling method would greatly facilitate assessment of large fields nominated for storage. The challenge, then, is for the coarse-scale model to capture the effect of fine-scale features on the distribution of CO2 and to give similar simulation results that are important from risk analysis point of view. Examples include whether the CO2 reaches the top seal of storage formation, the time it takes for CO2 to reach the top seal, and the amount of CO2 leakage if a presumptive leak develops in the top seal. The main difficulty in upscaling is for nonadditive properties, mainly permeability and multiphase flow properties. One of the important multiphase flow properties, especially in applications like CO2 storage where imbibition occurs, is residual saturation. It strongly affects the mass of CO2 that remains securely as residual phase in storage aquifer. It also affects the mass of escaped CO2 in the case of leakage from the aquifer through a breach in the overlying seal. Incorrect estimation of residual saturation in an upscaled model could lead to disqualification of a candidate aquifer due to wrong estimation of secure storage capacity or approval of a risky candidate aquifer. In this work, first we study the effect of upscaling based on single-phase properties on buoyancy-driven vertical flow of CO2. Porosity and absolute permeability are upscaled, then used to scale the end-point capillary pressures using Leverett scaling group. Relative permeabilities and reference capillary pressure curve are kept unchanged for upscaled model. Different degrees of coarsening are considered and results are analyzed based on average gas saturation and mass of CO2 in storage aquifer. Then, simulation of a leak at the top seal of the aquifer is upscaled, again with the single phase upscaling method, and the results are analyzed. Finally, using a corrected value of residual gas saturation in coarse-grid simulation is shown to give an acceptable result for the mass percent of escaped CO2. A correlation is derived between the upscaled or "effective residual saturation" and a measure of the variance in the permeability field. This method is validated using another synthetic field.

  2. Microbial and Chemical Enhancement of In-Situ Carbon Mineralization in Geological Formation

    SciTech Connect

    Matter, J.; Chandran, K.

    2013-05-31

    Predictions of global energy usage suggest a continued increase in carbon emissions and rising concentrations of CO{sub 2} in the atmosphere unless major changes are made to the way energy is produced and used. Various carbon capture and storage (CCS) technologies are currently being developed, but unfortunately little is known regarding the fundamental characteristics of CO{sub 2}-mineral reactions to allow a viable in-situ carbon mineralization that would provide the most permanent and safe storage of geologically-injected CO{sub 2}. The ultimate goal of this research project was to develop a microbial and chemical enhancement scheme for in-situ carbon mineralization in geologic formations in order to achieve long-term stability of injected CO{sub 2}. Thermodynamic and kinetic studies of CO{sub 2}-mineral-brine systems were systematically performed to develop the in-situ mineral carbonation process that utilizes organic acids produced by a microbial reactor. The major participants in the project are three faculty members and their graduate and undergraduate students at the School of Engineering and Applied Science and at the Lamont-Doherty Earth Observatory at Columbia University: Alissa Park in Earth and Environmental Engineering & Chemical Engineering (PI), Juerg Matter in Earth and Environmental Science (Co-PI), and Kartik Chandran in Earth and Environmental Engineering (Co-PI). Two graduate students, Huangjing Zhao and Edris Taher, were trained as a part of this project as well as a number of graduate students and undergraduate students who participated part-time. Edris Taher received his MS degree in 2012 and Huangjing Zhao will defend his PhD on Jan. 15th, 2014. The interdisciplinary training provided by this project was valuable to those students who are entering into the workforce in the United States. Furthermore, the findings from this study were and will be published in referred journals to disseminate the results. The list of the papers is given at the end of the report for reference.

  3. Evaluation of the Effect of Geological Heterogeneity on the Surfactant Transport by Performing Push-Pull Test in a Physical Aquifer Model (PAM)

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Lim, D.; Park, S.; Hong, U.; Lim, J.; Lee, W.; Kwon, S.

    2009-12-01

    A surfactant flushing process is commonly used to remove light non-aqueous phase liquids (LNAPLs) such as benzene, toluene, ethylbenzene, and xylene (BTEX) by enhancing solubility of the contaminants. Since the surfactant flushing process is significantly affected by the degree of geological heterogeneity, push-pull tests in a physical aquifer model (PAM) was performed to evaluate the surfactant transport and toluene removal efficiency in a lab-scale three layered aquifer. Push-pull tests showed that maximum bromide concentration detected at a sampling port located 15 cm downgradient from an injection port was approximately 95% of average injected bromide concentration in two permeable layers (0.22±0.02 cm/min of hydraulic conductivity) and only 40% in lower permeable layers (0.05±0.02 cm/min of hydraulic conductivity). Through the push-pull tests, we also found the different mass recovery of bromide (58%), toluene (47%) and surfactant (17%) in the PAM, confirming higher absorption characteristics of the surfactant on the soil particle than other solutes. Interestingly, toluene mass recovery in the presence of excessive surfactant decreased, possibly because of adsorption of toluene mass on the surfactant attached to soil particle. Through this work, we proved soil permeability, adsorption rate of surfactant, and amount of injected surfactant should be considered to remove the LNAPL contaminants efficiently by surfactant flushing process from the heterogeneous aquifer.

  4. The Oil Game: Problem-based learning exercise in an Environmental Geology lecture-format class

    NSDL National Science Digital Library

    David Voorhees

    This is an active engagement exercise as a capstone exercise in a unit on energy in an Environmental Geology class of non-science majors combining a 'field-based' simulation and 'office-based' geological modeling. It uses readily available supplies and easily constructed equipment that can take 1 or 2 class meetings.

  5. Saharan dust and heterogeneous ice formation: Eleven years of cloud observations at a central European EARLINET site

    Microsoft Academic Search

    P. Seifert; A. Ansmann; I. Mattis; U. Wandinger; M. Tesche; R. Engelmann; D. Müller; C. Pérez; K. Haustein

    2010-01-01

    More than 2300 observed cloud layers were analyzed to investigate the impact of aged Saharan dust on heterogeneous ice formation. The observations were performed with a polarization\\/Raman lidar at the European Aerosol Research Lidar Network site of Leipzig, Germany (51.3°N, 12.4°E) from February 1997 to June 2008. The statistical analysis is based on lidar-derived information on cloud phase (liquid water,

  6. Morphology and formation ages of mid-sized post-Rheasilvia craters - Geology of quadrangle Tuccia, Vesta

    NASA Astrophysics Data System (ADS)

    Kneissl, T.; Schmedemann, N.; Reddy, V.; Williams, D. A.; Walter, S. H. G.; Neesemann, A.; Michael, G. G.; Jaumann, R.; Krohn, K.; Preusker, F.; Roatsch, T.; Le Corre, L.; Nathues, A.; Hoffmann, M.; Schäfer, M.; Buczkowski, D.; Garry, W. B.; Yingst, R. A.; Mest, S. C.; Russell, C. T.; Raymond, C. A.

    2014-12-01

    A variety of geologic landforms and features are observed within quadrangle Av-13 Tuccia in the southern hemisphere of Vesta. The quadrangle covers parts of the highland Vestalia Terra as well as the floors of the large Rheasilvia and Veneneia impact basins, which results in a substantial elevation difference of more than 40 km between the northern and the southern portions of the quadrangle. Measurements of crater size-frequency distributions within and surrounding the Rheasilvia basin indicate that gravity-driven mass wasting in the interior of the basin has been important, and that the basin has a more ancient formation age than would be expected from the crater density on the basin floor alone. Subsequent to its formation, Rheasilvia was superimposed by several mid-sized impact craters. The most prominent craters are Tuccia, Eusebia, Vibidia, Galeria, and Antonia, whose geology and formation ages are investigated in detail in this work. These impact structures provide a variety of morphologies indicating different sorts of subsequent impact-related or gravity-driven mass wasting processes. Understanding the geologic history of the relatively young craters in the Rheasilvia basin is important in order to understand the even more degraded craters in other regions of Vesta.

  7. The Carancas meteorite impact crater, Peru: Geologic surveying and modeling of crater formation and atmospheric passage

    NASA Astrophysics Data System (ADS)

    Kenkmann, T.; Artemieva, N. A.; Wünnemann, K.; Poelchau, M. H.; Elbeshausen, D.; Núñez Del Prado, H.

    2009-08-01

    The recent Carancas meteorite impact event caused a worldwide sensation. An H4-5 chondrite struck the Earth south of Lake Titicaca in Peru on September 15, 2007, and formed a crater 14.2 m across. It is the smallest, youngest, and one of two eye-witnessed impact crater events on Earth. The impact violated the hitherto existing view that stony meteorites below a size of 100 m undergo major disruption and deceleration during their passage through the atmosphere and are not capable of producing craters. Fragmentation occurs if the strength of the meteoroid is less than the aerodynamic stresses that occur in flight. The small fragments that result from a breakup rain down at terminal velocity and are not capable of producing impact craters. The Carancas cratering event, however, demonstrates that meter-sized stony meteoroids indeed can survive the atmospheric passage under specific circumstances. We present results of a detailed geologic survey of the crater and its ejecta. To constrain the possible range of impact parameters we carried out numerical models of crater formation with the iSALE hydrocode in two and three dimensions. Depending on the strength properties of the target, the impact energies range between approximately 100-1000 MJ (0.024- 0.24 t TNT). By modeling the atmospheric traverse we demonstrate that low cosmic velocities (12- 14 kms-1) and shallow entry angles (<20°) are prerequisites to keep aerodynamic stresses low (<10 MPa) and thus to prevent fragmentation of stony meteoroids with standard strength properties. This scenario results in a strong meteoroid deceleration, a deflection of the trajectory to a steeper impact angle (40-60°), and an impact velocity of 350-600 ms-1, which is insufficient to produce a shock wave and significant shock effects in target minerals. Aerodynamic and crater modeling are consistent with field data and our microscopic inspection. However, these data are in conflict with trajectories inferred from the analysis of infrasound signals.

  8. Formation and evolution of the midlands of Venus: Geological features and structures, stratigraphic relationships and geologic history of the Fredegonde area (V-57)

    NASA Astrophysics Data System (ADS)

    Ivanov, Mikhail A.; Head, James W.

    2012-12-01

    The topographic midlands on Venus comprise about 80% of the surface and an understanding of their mode of formation is essential to unraveling the geologic and geodynamic history of the planet. We explore this question by undertaking a comprehensive geological mapping of the Fredegonde Quadrangle (V-57, 50-75°S, 60-120°E, 1:5M scale) that represents the transition zone from the midlands to the lowlands at the edge of Lada Terra. We report on the geologic units and structures and the sequence of events and, thus, the major stages in the evolution of this region of the midlands. At earlier stages of evolution of the long-wavelength topography, broad (hundreds of kilometers wide) and relatively low (1-1.5 km high) topographic ridges formed due to sequential development of deformation zones, first of contractional ridge belts (NW orientation) and then crosscut by extensional groove belts (NE orientation). Arcuate swarms of graben within groove belts often form the rims of coronae and represent their tectonic component. This suggests that groove belts and coronae within the quadrangle formed simultaneously. Intersections of these deformation zones caused separation of the topography of the region into a series of broad, shallow equidimensional basins many hundreds of kilometers across and currently hundreds of meters up to a kilometer deep. Thus, the principal topographic features within the quadrangle were established near the beginning of its observable geological record. The basins then remained sites of accumulation of successive volcanic plains units such as shield plains (psh) and the lower unit of regional plains (rp1). The flows of the younger plains, such as upper unit of regional plains (rp2) and lobate plains (pl), are less voluminous, and flow down the current topographic gradients. This implies that the major topographic pattern of the Fredegonde quadrangle has been stable since its establishment. Further evidence for this is that the vast volcanic plains units (psh and rp1) that postdate the heavily tectonized units of the deformation zones are only mildly deformed. This suggests that since the emplacement of shield plains, volcanism has been the primary geologic process and that the time of formation of unit psh corresponds to a major change from the earlier regime dominated by tectonics to the later volcanically dominated regime. Consistent age relationships among the main volcanic units within the quadrangle from older shield plains, through regional plains, to lobate plains, documents an evolution in volcanic style. Shield plains were formed from small eruptions from ubiquitous small shield volcanoes and are interpreted to be derived from broadly distributed and shallow magmatic sources. The lower unit of regional plains is widely distributed but vents and flow fronts are rare; this unit is interpreted to represent massive and probably short-lived flood basalts-like eruptions that filled in the lowlands basins. The upper unit of regional plains (rp2) and lobate plains (pl) are associated with localized and distinctive sources, such as late-stage volcanic activity at coronae. Thus, the tectonic stage of evolution of coronae (formation of the rims) and the volcanic stage when coronae served as magmatic centers and sourced lava flows, were separated in time by the emplacement of the shield and lower regional plains. How and when did the major components of Venus midland topography form? Clearly, in the Fredegonde quadrangle, regional deformation produced the deformation belts and groove belts/coronae in the earliest phases, and this topography formed the basis for the next, volcanic stage of emplacement (filling of the basins), with coronae-associated volcanism following this phase. The broad topography resulting from this early phase has persisted until the present. We compare this tectonic-volcanic sequence and history of topography in the Fredegonde quadrangle with other areas on Venus and find that the sequence has widespread application globally, and that the history of topography may be similar planet-w

  9. Composite catalyst surfaces: Effect of inert and active heterogeneities on pattern formation

    SciTech Connect

    Baer, M. [Max-Planck-Institut fuer Physik komplexer Systeme, Dresden (Germany)] [Max-Planck-Institut fuer Physik komplexer Systeme, Dresden (Germany); Bangia, A.K.; Kevrekidis, I.G. [Princeton Univ., NJ (United States)] [Princeton Univ., NJ (United States); Haas, G.; Rotermund, H.H.; Ertl, G. [Fritz-Haber-Instiut der Max-Planck-Gesellschaft, Berlin (Germany)] [Fritz-Haber-Instiut der Max-Planck-Gesellschaft, Berlin (Germany)

    1996-12-05

    Spatiotemporal dynamics in reaction-diffusion systems can be altered through the properties (reactivity, diffusivity) of the medium in which they occur. We construct active heterogeneous media (composite catalytic surfaces with inert as well as active illusions) using microelectronics fabrication techniques and study the spatiotemporal dynamics of heterogeneous catalytic reactions on these catalysts. In parallel, we perform simulations as well as numerical stability and bifurcation analysis of these patterns using mechanistic models. At the limit of large heterogeneity `grain size` (compared to the wavelength of spontaneously arising structures) the interaction patterns with inert or active boundaries dominates (e.g., pinning, transmission, and boundary breakup of spirals, interaction of pulses with corners, `pacemaker` effects). At the opposite limit of very small or very finely distributed heterogeneity, effective behavior is observed (slight modulation of pulses, nearly uniform oscillations, effective spirals). Some representative studies of transitions between the two limits are presented. 48 refs., 11 figs.

  10. Heterogeneous Catalysis.

    ERIC Educational Resources Information Center

    Miranda, R.

    1989-01-01

    Described is a heterogeneous catalysis course which has elements of materials processing embedded in the classical format of catalytic mechanisms and surface chemistry. A course outline and list of examples of recent review papers written by students are provided. (MVL)

  11. Stress heterogeneity observed in Barnett Shale, TX, and its relation to the distribution of clay-rich ductile formations

    NASA Astrophysics Data System (ADS)

    Sone, H.; Zoback, M. D.

    2010-12-01

    An FMI image log from a vertical well in Barnett Shale, Fort Worth Basin, TX shows that the state of stress is locally perturbed at depth ranges around the shale formation (8260-8740 ft). Above the Barnett Shale, drilling-induced tensile fractures (DITFs) are parallel to the vertical wellbore axis, indicating that the vertical principal stress is essentially parallel to the wellbore axis. However, inside the Barnett Shale, DITFs deviate from the wellbore axis, forming en-echelon patterns. The inclination of these inclined DITFs averages around 10 degrees, which we have been able to model as a westward tilt of the “vertical” principal stress by at least 5 degrees from the true vertical direction. Also, the angular spans of the inclined DITFs around the wellbore circumference vary between 0-100 degrees, indicating that the stress state fluctuates frequently within the Barnett Shale. We postulate that such stress heterogeneity is caused by the ductility and the mechanical heterogeneity of the organic-rich shale layer. Laboratory experiments using core samples show that Barnett Shale rocks may have relatively low effective viscosities with respect to that of the overburden formations which could lead to the rotation of the principal stress axes known as “stress refraction”. Rocks within the Barnett Shale are also found to be quite heterogeneous in terms of its mineralogy where, for instance, clay content varies between 5-50% by volume. Laboratory experiments show that the degree of ductility, as seen by creep deformation, varies by a factor of 3 for these rocks and that the ductility is dependent on the sample clay content. Because ductile deformation causes differential stresses to relax (thus raising the magnitude of minimum principal stress), it is possible that the stress heterogeneity is ultimately the result of lithological heterogeneity within the Barnett Shale. We attempt to explain the observed stress heterogeneity using analytical and numerical models acknowledging stress refractions and ductile deformation. The implication of establishing such connection between stress and lithological heterogeneity is that one may be able to infer the state of stress by studying the distribution of rock types and its mechanical properties. This could help identify regions within hydrocarbon reservoirs with stress states favorable for hydraulic fracturing, or provide insights into the distribution of stress states around major fault zones.

  12. Challenges in conditioning a stochastic geological model of a heterogeneous glacial aquifer to a comprehensive soft data set

    NASA Astrophysics Data System (ADS)

    Koch, J.; He, X.; Jensen, K. H.; Refsgaard, J. C.

    2014-08-01

    In traditional hydrogeological investigations, one geological model is often used based on subjective interpretations and sparse data availability. This deterministic approach usually does not account for any uncertainties. Stochastic simulation methods address this problem and can capture the geological structure uncertainty. In this study the geostatistical software TProGS is utilized to simulate an ensemble of realizations for a binary (sand/clay) hydrofacies model in the Norsminde catchment, Denmark. TProGS can incorporate soft data, which represent the associated level of uncertainty. High-density (20 m × 20 m × 2 m) airborne geophysical data (SkyTEM) and categorized borehole data are utilized to define the model of spatial variability in horizontal and vertical direction, respectively, and both are used for soft conditioning of the TProGS simulations. The category probabilities for the SkyTEM data set are derived from a histogram probability matching method, where resistivity is paired with the corresponding lithology from the categorized borehole data. This study integrates two distinct data sources into the stochastic modeling process that represent two extremes of the conditioning density spectrum: sparse borehole data and abundant SkyTEM data. In the latter the data have a strong spatial correlation caused by its high data density, which triggers the problem of overconditioning. This problem is addressed by a work-around utilizing a sampling/decimation of the data set, with the aim to reduce the spatial correlation of the conditioning data set. In the case of abundant conditioning data, it is shown that TProGS is capable of reproducing non-stationary trends. The stochastic realizations are validated by five performance criteria: (1) sand proportion, (2) mean length, (3) geobody connectivity, (4) facies probability distribution and (5) facies probability-resistivity bias. In conclusion, a stochastically generated set of realizations soft-conditioned to 200 m moving sampling of geophysical data performs most satisfactorily when balancing the five performance criteria. The ensemble can be used in subsequent hydrogeological flow modeling to address the predictive uncertainty originating from the geological structure uncertainty.

  13. Laboratory investigations of the effects of geologic heterogeneity on groundwater salinization and flush-out times from a tsunami-like event

    NASA Astrophysics Data System (ADS)

    Vithanage, M.; Engesgaard, P.; Jensen, K. H.; Illangasekare, T. H.; Obeysekera, J.

    2012-08-01

    This intermediate scale laboratory experimental study was designed to improve the conceptual understanding of aquifer flushing time associated with diffuse saltwater contamination of coastal aquifers due to a tsunami-like event. The motivation comes from field observations made after the tsunami in December, 2004 in South Asia. The focus is on the role and effects of heterogeneity on flushing effectiveness. A scheme that combines experimentation in a 4.8 m long laboratory tank and numerical modeling was used. To demonstrate the effects of geologic heterogeneity, plume migration and flushing times were analyzed in both homogeneous and layered media and under different boundary conditions (ambient flow, saltwater infiltration rate, freshwater recharge). Saltwater and freshwater infiltrations imitate the results of the groundwater salinization from the tsunami and freshening from the monsoon rainfall. The saltwater plume behavior was monitored both through visual observations (digital photography) of the dyed salt water and using measurements taken from several electrical conductivity sensors installed through the tank walls. The variable-density, three dimensional code HST3D was used to simulate the tank experiments and understand the fate and movement of the saltwater plume under field conditions. The results from the tank experiments and modeling demonstrated that macro-scale heterogeneity significantly influenced the migration patterns and flushing times of diffuse saltwater contamination. Ambient flow had a direct influence on total flush-out time, and heterogeneity impacted flush-out times for the top part of the tank and total flush-out times. The presence of a continuous low-permeability layer caused a 40% increase in complete flush-out time due to the slower flow of salt water in the low-permeability layer. When a relatively small opening was introduced in the low-permeability layer, salt water migrated quickly into a higher-permeable layer below causing a reduction in flush-out time. Freshwater recharge caused an early dilution of salt water in the top part of the tank in the case of a layered media, but also pushed the saltwater plume into the low-permeability layer which led to increased total flush-out times.

  14. Evidence for Regional Basin Formation in Early Post-Tessera Venus History: Geology of the Lavinia Planitia Area (V55)

    NASA Technical Reports Server (NTRS)

    Head, J. W.; Ivanov, M. A.

    1995-01-01

    On Venus, global topography shows the presence of highs and lows including regional highly deformed plateaus (tesserae), broad rifted volcanic rises, linear lows flanking uplands, and more equidimensional lowlands (e.g. Lavinia and Atalanta planitiae) Each of these terrain types on Venus has relatively distinctive characteristics, but origins are uncertain in terms of mode of formation, time of formation, and potential evolutionary links. There is a high level of uncertainty about the formation and evolution of lowlands on Venus. We have undertaken the mapping of a specific lowlands region of Venus to address several of these major questions. Using geologic mapping we have tried to establish: What is the sequence of events in the formation and evolution of large-scale equidimensional basins on Venus? When do the compressional features typical of basin interiors occur? What is the total volume of lava that occurs in the basins and is this similar to other non-basin areas? How much subsidence and downwarping has occurred after the last major plains units? WE have undertaken an analysis of the geology of the V55 Lavinia Planitia quadrangle in order to address many of these issues and we report on the results here.

  15. Comparison between a vertical equilibrium model and a three-dimensional multiphase flow model for CO2 sequestration in geologic formations

    NASA Astrophysics Data System (ADS)

    Jung, Byeongju; Tian, Liang; Niemi, Auli

    2014-05-01

    The vertical equilibrium (VE) approach, assuming pore fluid pressure equilibrium in a vertical direction, becomes more popular within the CO2 geosequestration research community due to its computational efficiency compared to three-dimensional multiphase flow models. However, the accuracy of this simplified pseudo 3-D numerical method has not fully verified for basin-scale geologic CO2 storage applications. To address this problem, we have compared CO2 plume migration in a homogeneous aquifer for benchmarking, calculated by both VE approach and 3-D model implemented by TOUGH2/ECO2N code. Then further comparison on injected fluid pressure and CO2 transport was performed using a more complicated numerical grid having a realistic reservoir topology. Preliminary results show that the VE model is generally in good agreement with the 3-D model in terms of overpressure ratio, whose values are similar and reach ~60% at the injection well installed in the reservoir with permeability of 4.0 x 10-14m2 and porosity of 15%. The migration distance of CO2 plume estimated by both models also matched closely, showing ~10 km dispersion along with flow path after 0.5 MtCO2/year injection for 50 years. The results also suggest that the VE approach can be an efficient alternative method for CO2 storage modeling, especially when reservoir formations have relatively small vertical heterogeneity.

  16. Assessment of the Geologic Carbon Dioxide Storage Resources of the Clinton, Medina, and Tuscarora Formations in the Appalachian Basin

    NASA Astrophysics Data System (ADS)

    Doolan, C.

    2013-12-01

    The U.S. Geological Survey (USGS) has completed an assessment of the geologic carbon dioxide (CO2) storage potential within the Appalachian Basin. This assessment was performed as part of the USGS national assessment of geologic CO2 storage resources in which individual sedimentary basins are divided into storage assessment units (SAUs) based on geologic characteristics such as lithology, porosity, permeability, reservoir depth, formation water salinity, and the presence of a regional sealing formation. This study focuses on the assessment of the Clinton, Medina and Tuscarora Formations storage assessment unit (SAU) that covers an area of 48.9 million acres in eastern Kentucky and Ohio, West Virginia, northern and western Pennsylvania, and southwestern New York. The areal extent of the SAU is defined on the western boundary by the 100 foot isopach contour of the combined Rochester and Rose Hill Shales that acts as the regional sealing formation and is defined by the 3,000 foot depth to top contour of the Clinton and Tuscarora Formations elsewhere. Depth-to-top and isopach contours were derived from IHS Energy Group, 2011 data for over 25,000 unique boreholes located throughout the area of the SAU. The Clinton, Medina and Tuscarora Formations SAU is composed of the porous intervals of the Lower to Middle Silurian strata that is bounded by the underlying Ordovician age Queenston Shale, and the overlying Silurian age Rochester and Rose Hill Shales. Porous intervals were deposited in a variety of wave and tidal dominated environments as a result of a Lower Silurian shoreline that prograded southeast to northwest. Porous units in the Tuscarora Formation in southwestern and central Pennsylvania and West Virginia are predominantly fine to medium grained sands of alluvial plain facies and those of the Clinton and Medina Formations in southwestern New York, northeastern Pennsylvania, eastern Ohio and northeastern Kentucky are typically fine grained quartzarenites deposited in littoral, deltaic, and offshore marine environments. The mean total thickness and thickness of the net porous interval, determined from geophysical logs, are 200 and 100 feet respectively at depths between 3,000 and 13,000 feet. Input parameters used to calculate the volume of technically available storage resources in the Clinton, Medina and Tuscarora Formations SAU include the area and net porous thickness of the SAU, a mean porosity of 9% for the net porous interval, and a permeability of 13 millidarcys for the net porous interval. Both the mean porosity and permeability used as input parameters for the SAU were determined by examining reported porosity and permeability values for petroleum reservoirs throughout the study area. Buoyant trapping pore volumes were determined by examining reported pore volumes of known petroleum plays within the SAU and extrapolating into areas where CO2 storage potential may exist in the absence of petroleum resources. The Clinton, Medina and Tuscarora Formations SAU has geologic storage resources to hold a mean of 32.1 megatons (Mt) of CO2, with 31Mt as buoyant trapping storage resources and 1.1 Mt as residual trapping storage resources.

  17. DIGITAL CHROMATOGRAPHY AND THE FORMA-TION OF HETEROGENEOUS DROPLET LIBRARIES

    E-print Network

    Basu, Amar S.

    DIGITAL CHROMATOGRAPHY AND THE FORMA- TION OF HETEROGENEOUS DROPLET LIBRARIES USING of micro- droplet systems in high-throughput screening (HTS). This paper presents microfrac- tionation. (b) Droplet library formed in a 1.5 mm ID tube. this paper introduces microfractionation in droplets

  18. Formation of indoor nitrous acid (HONO) by light-induced NO2 heterogeneous reactions with white wall paint.

    PubMed

    Bartolomei, Vincent; Sörgel, Matthias; Gligorovski, Sasho; Alvarez, Elena Gómez; Gandolfo, Adrien; Strekowski, Rafal; Quivet, Etienne; Held, Andreas; Zetzsch, Cornelius; Wortham, Henri

    2014-08-01

    Gaseous nitrogen dioxide (NO2) represents an oxidant that is present in relatively high concentrations in various indoor settings. Remarkably increased NO2 levels up to 1.5 ppm are associated with homes using gas stoves. The heterogeneous reactions of NO2 with adsorbed water on surfaces lead to the generation of nitrous acid (HONO). Here, we present a HONO source induced by heterogeneous reactions of NO2 with selected indoor paint surfaces in the presence of light (300 nmformation of HONO is much more pronounced at elevated relative humidity. In the presence of light (5.5 W m(-2)), an increase of HONO production rate of up to 8.6·10(9) molecules cm(-2) s(-1) was observed at [NO2]=60 ppb and 50% relative humidity (RH). At higher light intensity of 10.6 (W m(-2)), the HONO production rate increased to 2.1·10(10) molecules cm(-2) s(-1). A high NO2 to HONO conversion yield of up to 84% was observed. This result strongly suggests that a light-driven process of indoor HONO production is operational. This work highlights the potential of paint surfaces to generate HONO within indoor environments by light-induced NO2 heterogeneous reactions. PMID:24723352

  19. Heterogeneous porous media in hydrology

    NASA Astrophysics Data System (ADS)

    Ababou, Rachid

    In natural geologic formations, flow and transport-related processes are perturbed by multidimensional and anisotropic material heterogeneities of diverse sizes, shapes, and origins (bedding, layering, inclusions, fractures, grains, for example). Heterogeneity tends to disperse and mix transported quantities and may initiate new transfer mechanisms not seen in ideally homogeneous porous media. Effective properties such as conductivity and dispersivity may not be simple averages of locally measured quantities.The special session, “Effective Constitutive Laws for Heterogeneous Porous Media,” convened at AGU's 1992 Fall Meeting in San Francisco, addressed these issue. Over forty-five contributions, both oral and poster, covering a broad range of physical phenomena were presented. The common theme was the macroscale characterization and modeling of flow and flow-related processes in geologic media that are heterogeneous at various scales (from grain size or fracture aperture, up to regional scales). The processes analyzed in the session included coupled hydro-mechanical processes; Darcy-type flow in the saturated, unsaturated, or two-phase regimes; tracer transport, dilution, and dispersion. These processes were studied for either continuous (porous) or discontinuous (fractured) media.

  20. The Enigmatic Longevity of Granular Materials on Mars: The Case for Geologically Episodic Dune Formation

    NASA Technical Reports Server (NTRS)

    Marshall, J.

    1999-01-01

    Martian sand dunes are concentrated in vast sand seas in the circumpolar belt of the planet's northern hemisphere, but they are also pervasive over the whole planet. Their occurrence is to be expected on a super-arid planetary surface subjected to boundary layer drag from a continually active atmosphere. Whilst their occurrence is to be expected, their survival is enigmatic. But the enigma only arises if the martian system is considered similar to Earth's --where sand is moved highly frequently, more or less on a seasonal basis. Experimentally it is readily demonstrated that active sand will soon wear down to small grains and eventually diminish to below the critical sand size required to sustain dune formation. According to conventional wisdom, sand moves at higher speeds on Mars than on Earth, and if it were to move as frequently as it does on Earth, then the dune-forming sand population should have long since disappeared, given the great longevity of the martian aeolian system (Sagan coined the term "kamikaze" grains to express this disappearance). No supply of sand could keep pace with this depletion, especially in light of the fact that Mars does not have very active weathering, nor significant crustal differentiation. On Earth, plate tectonics, magmatic activity, and general crustal differentiation over geological time have produced great concentrations of quartz crystals in the continental crustal masses. Not only are these quartz grains chemically and mechanically resilient, they are about the right size for being transported by either wind or water. Add to this, the geologically recent contribution of glacial grinding, and it is easy to see why there are dune field on Earth. So what are the martian dunes composed of, and how does the material survive the eons of attrition? In addition to experimental demonstrations of sand comminution in laboratory aeolian simulations, the problem can be approached from first principles. Sagan showed that by simple considerations of material strength versus mechanical work applied to the material, comminution to sub-sand size would be inevitable. Another semi-analytical approach might be taken by considering that the archetypal aeolian sand surface texture is an irregularly pitted ("frosted") surface composed of chipping hollows approximately 10 microns in diameter, 5 microns deep. Their volume = about 250 cubic microns, or about 1/25000 of the volume of a 100 micron diameter dune grain. Because a saltating grain always strikes another grain, then two surfaces are impacted. Thus each grain undergoes two impacts for every one saltation leap, when the impact statistics are considered for a closed dune system (it can be calculated that a grain can never undergo <1 impact, and never >2 per saltation leap). Hence, if we conservatively assume that there is damage to a grain each time it bounces, but with the minimum damage of only 2 microscopic craters per impact, then approximately 12,500 impacts are required to completely eliminate the grain. Of course, it would require only a fraction of this amount to reduce the grain to below sand size. A grain will make only several tens of saltation leaps on the stoss side of a dune before becoming buried on the lee slope. The dune then has to move its full length before the grain is exhumed again for abrasion. Even with this hiatus in transport, it is easy to see that terrestrial dunes need resupplying with sand in order to survive. In recent theoretical work it has been shown that martian aeolian transport may be initiated with high-speed grains, but this converts to a lower energy dynamic transport equilibrium in which a reptation population dominates grain transport (on Earth, at least half of the flux is by reptation and creep). On Mars, therefore, average grain speeds may be lower than those on Earth, or at least comparable. This would permit greater longevity for martian sands, but it would not go far enough to solve the survival problem. It may, however, explain why martian dunes are about the same size as terr

  1. Innate neural stem cell heterogeneity determines the patterning of glioma formation in children.

    PubMed

    Lee, Da Yong; Gianino, Scott M; Gutmann, David H

    2012-07-10

    The concept that gliomas comprise a heterogeneous group of diseases distinguished by their developmental origin raises the intriguing possibility that neural stem cells (NSCs) from different germinal zones have differential capacities to respond to glioma-causing genetic changes. We demonstrate that lateral ventricle subventricular zone NSCs are molecularly and functionally distinct from those of the third ventricle. Consistent with a unique origin for pediatric low-grade glioma, third ventricle, but not lateral ventricle, NSCs hyperproliferate in response to mutations characteristic of childhood glioma. Finally, we demonstrate that pediatric optic gliomas in Nf1 genetically engineered mice arise from the third ventricle. Collectively, these observations establish the importance of innate brain region NSC heterogeneity in the patterning of gliomagenesis in children and adults. PMID:22789544

  2. Pore size and pore throat types in a heterogeneous dolostone reservoir, Devonian Grosmont formation, western Canada sedimentary basin

    SciTech Connect

    Luo, P.; Machel, H. G. [Univ. of Alberta, Edmonton, Alberta (Canada)

    1995-11-01

    The Devonian Grosmont Formation in northeastern Alberta, Canada, is a giant heavy-oil reservoir. The main reservoir rocks are dolomitized and karstified platform and ramp carbonates, and the best reservoir facies occur in the upper Grosmont (UGM) units 3 and 2. In these units, reservoir properties are highly heterogeneous. Hand specimen, thin section, UV, and SEM petrography, as well as grading scales, mercury capillary pressure curve analysis, and statistics, have been used to characterize reservoir heterogeneity. Our investigation led to a new pore size classification for carbonate reservoirs; this new classification has four pore sizes: microporosity (pore diameters <1 {mu}m), mesoporosity (pore diameters 1-1000 {mu}m), macroporosity (pore diameters 1-256 mm), and megaporosity (pore diameters >256 mm). A combination of microscopic observations and capillary pressure curve characteristics led to the recognition of four pore throat texture types on the microporosity scale, and to five types on the mesoporosity scale. Microporosity pore types include (1) intracrystal dissolution porosity, (2) pervasive intercrystal and intracrystal dissolution porosity, (3) intergranular and/or intercrystal porosity in grainstones, and (4) primary or solution microporosity in mud matrix (only in limestones). Mesoporosity pore types include (1) intercrystal porosity, (2) solution-enhanced intercrystal porosity, (3) oversized porosity, (4) intragranular solution porosity, and (5) intergranular solution porosity. Some of these types are homogeneous (e.g., non-fabric selective dissolution porosity and intercrystal primary porosity), whereas others are heterogeneous. Generally, hydrocarbon recovery efficiency is good in the homogeneous pore throat types, but poor in the heterogeneous types.

  3. Heterogeneities of a low permeability exhumed petroleum reservoir, El Abra Formation, Sierra el Abra, NE Mexico

    Microsoft Academic Search

    Sean T. Brennan

    1996-01-01

    Characterization of heterogeneities in low-permeability petroleum reservoirs is typically problematic, mostly due to the lack of research on three dimensional reservoir analogs. In the Sierra el Abra of northeastern Mexico there is an exhumed petroleum reservoir exposing mid-Cretaceous Abra Limestone. This unit is the reservoir for the famous Golden Lane fields of northeast Mexico. This study focused on three-dimensional exposures

  4. Multiscale heterogeneity characterization of tidal channel, tidal delta and foreshore facies, Almond Formation outcrops, Rock Springs uplift, Wyoming

    SciTech Connect

    Schatzinger, R.A.; Tomutsa, L. [BDM Petroleum Technologies, Bartlesville, OK (United States)

    1997-08-01

    In order to accurately predict fluid flow within a reservoir, variability in the rock properties at all scales relevant to the specific depositional environment needs to be taken into account. The present work describes rock variability at scales from hundreds of meters (facies level) to millimeters (laminae) based on outcrop studies of the Almond Formation. Tidal channel, tidal delta and foreshore facies were sampled on the eastern flank of the Rock Springs uplift, southeast of Rock Springs, Wyoming. The Almond Fm. was deposited as part of a mesotidal Upper Cretaceous transgressive systems tract within the greater Green River Basin. Bedding style, lithology, lateral extent of beds of bedsets, bed thickness, amount and distribution of depositional clay matrix, bioturbation and grain sorting provide controls on sandstone properties that may vary more than an order of magnitude within and between depositional facies in outcrops of the Almond Formation. These features can be mapped on the scale of an outcrop. The products of diagenesis such as the relative timing of carbonate cement, scale of cemented zones, continuity of cemented zones, selectively leached framework grains, lateral variability of compaction of sedimentary rock fragments, and the resultant pore structure play an equally important, although less predictable role in determining rock property heterogeneity. A knowledge of the spatial distribution of the products of diagenesis such as calcite cement or compaction is critical to modeling variation even within a single facies in the Almond Fin. because diagenesis can enhance or reduce primary (depositional) rock property heterogeneity. Application of outcrop heterogeneity models to the subsurface is greatly hindered by differences in diagenesis between the two settings. The measurements upon which this study is based were performed both on drilled outcrop plugs and on blocks.

  5. Heterogeneous formation of polar stratospheric clouds-nucleation of nitric acid trihydrate (NAT) in the arctic stratosphere

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-05-01

    Satellite based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current theory, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid December 2009, a heterogeneous nucleation mechanism is required, occurring on the surface of dust or meteoritic particles. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along tens of thousands of trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarisation (CALIOP) observation points. Comparing the optical properties of the modelled NAT PSCs with these observations enables the thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory and is simple to implement in models. It is shown that the new method is capable of reproducing observed PSCs very well, despite the varied conditions experienced by air parcels travelling along the different trajectories.

  6. Exploring Geology

    NASA Astrophysics Data System (ADS)

    Geissman, John W.

    2008-09-01

    I am willing to bet a nice bottle of chardonnay that much of the Eos readership has lugged around, fondled, and fumbled through an introductory physical geology textbook of some form or another, once upon a time. Mine, in 1970, was Physical Geology, by Longwell, Flint, and Sanders, which I still have, by the way. Most of us know how ``classical'' physical geology textbooks have been organized: first, a broad overview of Earth processes, then several sections devoted to groups of more specific subjects (e.g., mineralogy, sedimentary rocks, and environments, with one chapter per subject), then several sections devoted to a synthesis of geologic processes in the context of plate tectonics, and finally, typically, a discussion of Earth resources and environment- related issues. Some relatively new textbooks have ventured into new pedagogical formats, for example, emphasizing how we know what we know (e.g., How Does Earth Work: Physical Geology and the Process of Science by Smith and Pun).

  7. Efficient SOA Formation from Heterogeneous Oxidation of Organic Surfaces by OH Radicals

    NASA Astrophysics Data System (ADS)

    Wilson, K. R.; Smith, J. D.; Ahmed, M.; Leone, S. R.

    2007-05-01

    Currently, there is much interest in the formation rates and mechanisms of secondary organic aerosols (SOA) from ozone reactions with both biogenic and anthropogenic precursors. However, with the exception of isoprene (1), little work has been done to understand SOA formation from OH radical reactions with other volatile organic compounds. Using a coated flow tube reactor, rapid secondary organic aerosol (SOA) formation is observed when an organic film (such as stearic acid) is exposed to OH radicals. In addition to films, we have also observed that OH oxidation of submicron organic particles also leads to similar SOA formation. These results suggest an entirely new, and very efficient, formation mechanism of SOA via OH radical oxidation of organic surfaces. Analysis of these SOA particles, via VUV photoionization mass spectrometry, suggests that these particles are chemically complex and perhaps oligomeric in nature. We suggest a potential mechanism for this process in which gas phase products, such as semi-volatile aldehydes and carboxylic acids, evolve from the oxidation of the organic films. Subsequent reactions of these volatile products with OH in the gas phase results in efficient SOA formation. This mechanism is supported by the observation that OH radical reactions with gas phase hexanal and nonanal leads to strong SOA formation. These results provide a direct link between volatile organic compounds produced by particle oxidation and SOA formation. References 1. M. Claeys et al., Science 303, 1173 (2004).

  8. Heterogeneous chemistry: a mechanism missing in current models to explain secondary inorganic aerosol formation during the January 2013 haze episode in North China

    NASA Astrophysics Data System (ADS)

    Zheng, B.; Zhang, Q.; Zhang, Y.; He, K. B.; Wang, K.; Zheng, G. J.; Duan, F. K.; Ma, Y. L.; Kimoto, T.

    2015-02-01

    Severe regional haze pollution events occurred in eastern and central China in January 2013, which had adverse effects on the environment and public health. Extremely high levels of particulate matter with aerodynamic diameter of 2.5 ?m or less (PM2.5) with dominant components of sulfate and nitrate are responsible for the haze pollution. Although heterogeneous chemistry is thought to play an important role in the production of sulfate and nitrate during haze episodes, few studies have comprehensively evaluated the effect of heterogeneous chemistry on haze formation in China by using the 3-D models due to of a lack of treatments for heterogeneous reactions in most climate and chemical transport models. In this work, the WRF-CMAQ model with newly added heterogeneous reactions is applied to East Asia to evaluate the impacts of heterogeneous chemistry and the meteorological anomaly during January 2013 on regional haze formation. As the parameterization of heterogeneous reactions on different types of particles is not well established yet, we arbitrarily selected the uptake coefficients from reactions on dust particles and then conducted several sensitivity runs to find the value that can best match observations. The revised CMAQ with heterogeneous chemistry not only captures the magnitude and temporal variation of sulfate and nitrate, but also reproduces the enhancement of relative contribution of sulfate and nitrate to PM2.5 mass from clean days to polluted haze days. These results indicate the significant role of heterogeneous chemistry in regional haze formation and improve the understanding of the haze formation mechanisms during the January 2013 episode.

  9. The secondary formation of inorganic aerosols in the droplet mode through heterogeneous aqueous reactions under haze conditions

    NASA Astrophysics Data System (ADS)

    Wang, Xinfeng; Wang, Wenxing; Yang, Lingxiao; Gao, Xiaomei; Nie, Wei; Yu, Yangchun; Xu, Pengju; Zhou, Yang; Wang, Zhe

    2012-12-01

    Secondary inorganic aerosols play important roles in visibility reduction and in regional haze pollution. To investigate the characteristics of size distributions of secondary sulfates and nitrates as well as their formation mechanisms under hazes, size-resolved aerosols were collected using a Micro-Orifice Uniform Deposit Impactor (MOUDI) at an urban site in Jinan, China, in all four seasons (December 2007-October 2008). In haze episodes, the secondary sulfates and nitrates primarily formed in fine particles, with elevated concentration peaks in the droplet mode (0.56-1.8 ?m). The fine sulfates and nitrates were completely neutralized by ammonia and existed in the forms of (NH4)2SO4 and NH4NO3, respectively. The secondary formation of sulfates, nitrates and ammonium (SNA) was found to be related to heterogeneous aqueous reactions and was largely dependent on the ambient humidity. With rising relative humidity, the droplet-mode SNA concentration, the ratio of droplet-mode SNA to the total SNA, the fraction of SNA in droplet-mode particles and the mass median aerodynamic diameter of SNA presented an exponential, logarithmic or linear increase. Two heavily polluted multi-day haze episodes in winter and summer were analyzed in detail. The secondary sulfates were linked to heterogeneous uptake of SO2 followed by the subsequent catalytic oxidation by oxygen together with iron and manganese in winter. The fine nitrate formation was strongly associated with the thermodynamic equilibrium among NH4NO3, gaseous HNO3 and NH3, and showed different temperature-dependences in winter and summer.

  10. Combined isotope and enantiomer analysis to assess the fate of phenoxy acids in a heterogeneous geologic setting at an old landfill.

    PubMed

    Milosevic, N; Qiu, S; Elsner, M; Einsiedl, F; Maier, M P; Bensch, H K V; Albrechtsen, H-J; Bjerg, P L

    2013-02-01

    Phenoxy acid herbicides and their potential metabolites represent industrial or agricultural waste that impacts groundwater and surface waters through leaching from old landfills throughout the world. Fate assessment of dichlorprop and its putative metabolite 4-CPP (2-(4-chlorophenoxy)propionic acid) is frequently obstructed by inconclusive evidence from redox conditions, heterogeneous geologic settings (e.g. clay till) and ambiguous parent-daughter relationships (i.e. 4-CPP may be daughter product or impurity of dichlorprop). For the first time, a combination of four methods was tested to assess transformation of phenoxy acids at a contaminated landfill (Risby site): analysis of (i) parent and daughter compound concentrations, (ii) enantiomer ratios (iii) compound-specific isotope analysis and (iv) enantiomer-specific isotope analysis. Additionally, water isotopes and chloride were used as conservative tracers to delineate two distinct groundwater flow paths in the clay till. Metabolite concentrations and isotope ratios of chlorinated ethenes demonstrated dechlorination activity in the area with highest leachate concentrations (hotspot) indicating favorable conditions also for dechlorination of dichlorprop to 4-CPP and further to phenoxypropionic acid. Combined evidence from concentrations, enantiomer ratios and isotope ratios of dichlorprop and 4-CPP confirmed their dechlorination in the hotspot and gave evidence for further degradation of 4-CPP downgradient of the hotspot. A combination of 4-CPP enantiomer and isotope analysis indicated different enantioselectivity and isotope fractionation, i.e. different modes of 4-CPP degradation, at different locations. This combined information was beyond the reach of any of the methods applied alone demonstrating the power of the new combined approach. PMID:23168311

  11. Petrological and geochemical study of the Late Cretaceous ophiolite of Khoy (NW Iran), and related geological formations

    NASA Astrophysics Data System (ADS)

    Khalatbari-Jafari, Morteza; Juteau, Thierry; Cotten, Joseph

    2006-09-01

    This paper, based on 113 new whole rock analyses and about 3500 electron microprobe analyses of the mineral phases, is dedicated to the petrography and geochemistry of the Khoy ophiolites and related formations, NW Iran. It is complementary to a previous paper published in this Journal, where we gave a detailed description of the geology of the Khoy area, including various geological field sections, two geological maps in colour, new micropaleontological data and 27 new 40K- 40Ar datings (Khalatbari-Jafari, M., Juteau, T., Bellon, H., Whitechurch, H., Cotten, J., Emami, H., 2004. New geological, geochronological and geochemical investigations on the Khoy ophiolites and related formations, NW Iran. J. Asian Earth Sci. 23, 507-535). Our conclusions are: (a) The petrographic study confirms the field data showing the existence of two ophiolite complexes in the region of Khoy. (b) The Late Cretaceous ophiolitic lavas of the Khoy region exhibit very homogeneous T-MORB-type multi-element plots, suggesting that they were formed at oceanic spreading centers, by partial melting of a depleted mantle source, probably contaminated by one or several regional mantle plumes, responsible for their moderate enrichment in LREE. They do not show any negative anomaly for Nb, Zr or Ti, which allows us to exclude a genesis in a 'supra-subduction' environment. (c) The Late Cretaceous ophiolite of Khoy was created at a slow-spreading oceanic ridge. (d) Cryptic variations along extrusive and layered gabbros sections suggest frequent replenishment and magma mixing events in the magma chambers. (e) The 'supra-ophiolitic turbiditic series' overlying the Late Cretaceous ophiolite was accumulated in a subduction trench running along the northwestern margin of the Iran Block. This trench was fed with detrital volcanic fragments from both sides: T-MORB basalt fragments from the ocean-side, and arc-type basalts from the continent-side. (f) The meta-ophiolites of Khoy probably also represent slow-spreading conditions, and the porphyroclastic to mylonitic tectonites preserved in these metamorphic slices attest to extreme conditions of ductile shearing, characteristic of oceanic fracture zones.

  12. Petroleum geology of the Norphlet formation (Upper Jurassic), S. W. and offshore Alabama

    Microsoft Academic Search

    E. A. Mancini; R. M. Mink; B. L. Bearden

    1984-01-01

    Recent successful gas test in the Norphlet formation (up to 26 million CF\\/day) at depths exceeding 20,500 ft in the Mobile Bay area demonstrate a high potential for hydrocarbon production in the Alabama offshore area. In addition, wells drilled in the upper Mobile Bay area could encounter gas condensate in the Norphlet formation; gas condensate is being produced from wells

  13. Geological and geochemical model of formation of oil and gas accumulations in the South Caspian basin

    SciTech Connect

    Narimanov, A.A.

    1991-08-01

    The South Caspian Sea, Azerbaijan, has been a major petroleum producer since 1848 and is still one of the premier prospective areas for oil and gas in the Soviet Union. Many years of research studies suggest oil and gas in the Soviet Union. Many years of research studies suggest an area of increased prospectivity in the deeper part of the Caspian Sea. Geologic history recorded that a trough developed during the Mesozoic through the Tertiary. The sedimentary sequence is up to 23 km thick. The Pliocene sequence is the major proven productive and prospective interval. Multiple stages of active sedimentation and tectonism took place starting in the early Pliocene and ending in the late Pliocene. Traps were formed and destroyed during the early to late Pliocene. The final tectonic events during the late Pliocene trapped the remigrated oil. Gas and gas condensate probably are within the lower reaches of the basin. Because of the rapid deposition, mud volcanoes were also active. Many are still active today and can be noted in proximity to hydrocarbon deposits. Rapid subsidence and deposition, and anomalously low geothermal regime, and a low maturity of sampled organic matter from the Pliocene section leads to the hypothesis of hydrocarbon generation at depth from older sedimentary rocks. With this proposed geological and geochemical model, the prospectivity for oil and gas deposits is greatly enhanced in aerial extent and possibly to a depth of 9 km.

  14. Chemical composition and geologic history of saline waters in Aux Vases and Cypress Formations, Illinois Basin

    USGS Publications Warehouse

    Demir, I.; Seyler, B.

    1999-01-01

    Seventy-six samples of formation waters were collected from oil wells producing from the Aux Vases or Cypress Formations in the Illinois Basin. Forty core samples of the reservoir rocks were also collected from the two formations. Analyses of the samples indicated that the total dissolved solids content (TDS) of the waters ranged from 43,300 to 151,400 mg/L, far exceeding the 35,400 mg/mL of TDS found in typical seawater. Cl-Br relations suggested that high salinities in the Aux Vases and Cypress formation waters resulted from the evaporation of original seawater and subsequent mixing of the evaporated seawater with concentrated halite solutions. Mixing with the halite solutions increased Na and Cl concentrations and diluted the concentration of other ions in the formation waters. The elemental concentrations were influenced further by diagenetic reactions with silicate and carbonate minerals. Diagenetic signatures revealed by fluid chemistry and rock mineralogy delineated the water-rock interactions that took place in the Aux Vases and Cypress sandstones. Dissolution of K-feldspar released K into the solution, leading to the formation of authigenic illite and mixed-layered illite/smectite. Some Mg was removed from the solution by the formation of authigenic chlorite and dolomite. Dolomitization, calcite recrystallization, and contribution from clay minerals raised Sr levels significantly in the formation waters. The trend of increasing TDS of the saline formation waters with depth can be explained with density stratification. But, it is difficult to explain the combination of the increasing TDS and increasing Ca/Na ratio with depth without invoking the controversial 'ion filtration' mechanism.

  15. The formation and functional consequences of heterogeneous mitochondrial distributions in skeletal muscle

    PubMed Central

    Pathi, B.; Kinsey, S. T.; Howdeshell, M. E.; Priester, C.; McNeill, R. S.; Locke, B. R.

    2012-01-01

    SUMMARY Diffusion plays a prominent role in governing both rates of aerobic metabolic fluxes and mitochondrial organization in muscle fibers. However, there is no mechanism to explain how the non-homogeneous mitochondrial distributions that are prevalent in skeletal muscle arise. We propose that spatially variable degradation with dependence on O2 concentration, and spatially uniform signals for biogenesis, can account for observed distributions of mitochondria in a diversity of skeletal muscle. We used light and transmission electron microscopy and stereology to examine fiber size, capillarity and mitochondrial distribution in fish red and white muscle, fish white muscle that undergoes extreme hypertrophic growth, and four fiber types in mouse muscle. The observed distributions were compared with those generated using a coupled reaction-diffusion/cellular automata (CA) mathematical model of mitochondrial function. Reaction-diffusion analysis of metabolites such as oxygen, ATP, ADP and PCr involved in energy metabolism and mitochondrial function were considered. Coupled to the reaction-diffusion approach was a CA approach governing mitochondrial life cycles in response to the metabolic state of the fiber. The model results were consistent with the experimental observations and showed higher mitochondrial densities near the capillaries because of the sometimes steep gradients in oxygen. The present study found that selective removal of mitochondria in the presence of low prevailing local oxygen concentrations is likely the primary factor dictating the spatial heterogeneity of mitochondria in a diversity of fibers. The model results also suggest decreased diffusional constraints corresponding to the heterogeneous mitochondrial distribution assessed using the effectiveness factor, defined as the ratio of the reaction rate in the system with finite rates of diffusion to that in the absence of any diffusion limitation. Thus, the non-uniform distribution benefits the muscle fiber by increasing the energy status and increasing sustainable metabolic rates. PMID:22573766

  16. The formation and functional consequences of heterogeneous mitochondrial distributions in skeletal muscle.

    PubMed

    Pathi, B; Kinsey, S T; Howdeshell, M E; Priester, C; McNeill, R S; Locke, B R

    2012-06-01

    Diffusion plays a prominent role in governing both rates of aerobic metabolic fluxes and mitochondrial organization in muscle fibers. However, there is no mechanism to explain how the non-homogeneous mitochondrial distributions that are prevalent in skeletal muscle arise. We propose that spatially variable degradation with dependence on O(2) concentration, and spatially uniform signals for biogenesis, can account for observed distributions of mitochondria in a diversity of skeletal muscle. We used light and transmission electron microscopy and stereology to examine fiber size, capillarity and mitochondrial distribution in fish red and white muscle, fish white muscle that undergoes extreme hypertrophic growth, and four fiber types in mouse muscle. The observed distributions were compared with those generated using a coupled reaction-diffusion/cellular automata (CA) mathematical model of mitochondrial function. Reaction-diffusion analysis of metabolites such as oxygen, ATP, ADP and PCr involved in energy metabolism and mitochondrial function were considered. Coupled to the reaction-diffusion approach was a CA approach governing mitochondrial life cycles in response to the metabolic state of the fiber. The model results were consistent with the experimental observations and showed higher mitochondrial densities near the capillaries because of the sometimes steep gradients in oxygen. The present study found that selective removal of mitochondria in the presence of low prevailing local oxygen concentrations is likely the primary factor dictating the spatial heterogeneity of mitochondria in a diversity of fibers. The model results also suggest decreased diffusional constraints corresponding to the heterogeneous mitochondrial distribution assessed using the effectiveness factor, defined as the ratio of the reaction rate in the system with finite rates of diffusion to that in the absence of any diffusion limitation. Thus, the non-uniform distribution benefits the muscle fiber by increasing the energy status and increasing sustainable metabolic rates. PMID:22573766

  17. Geologic and well-construction data for the H-10 borehole complex near the proposed Waste Isolation Pilot Plant site, southeastern New Mexico. [Rustler and Salado formations

    SciTech Connect

    Wells, J.G.; Drellack, S.L. Jr.

    1983-01-01

    The H-10 borehole complex, a group of three closely spaced boreholes, is located 4 miles southeast of the proposed Waste Isolation Pilot Plant site in west-central Lea County, New Mexico. The holes were drilled during August and October 1979 to obtain geologic and hydrologic data to better define the regional ground-water-flow system. The geologic data presented in this report are part of a site-characterization study for the possible storage of defense-associated radioactive wastes within salt beds of the Salado Formation of Permian age. The geologic data include detailed descriptions of cores, cuttings, and geophysical logs. Each borehole was designed to penetrate a distinct water-bearing zone: H-10a (total depth 1318 feet) was completed just below the Magenta Dolomite Member of the Rustler Formation of Permian age; H-10b (total depth 1398 feet) was completed just below the Culebra Dolomite Member of the Rustler Formation; and H-10c (total depth 1538 feet) was completed below the Rustler Formation-Salado Formation contact. The geologic units penetrated in borehole H-10c are surficial alluvium and eolian sand of Holocene age (0 to 5 feet); the Mescalero caliche (5 to 9 feet) and the Gatuna Formation (9 to 90 feet) of Pleistocene age: formations in the Dockum Group (Chinle Formation, 90 to 482 feet and Santa Rosa Sandstone, 482 to 658 feet) of Late Triassic age; and the Dewey Lake Red Beds (658 to 1204 feet), the Rustler Formation (1204 to 1501 feet), and part of the Salado Formation (1501 to 1538 feet), all of Permian age. The sections of the Rustler and Salado Formations penetrated by borehole H-10c are complete and contain little or no evidence of dissolution of halite and associated rocks, indicating that the eastward-moving dissolution within the Rustler or on top of the Salado, found west of the Waste Isolation Pilot Plant site, has not reached the H-10 site.

  18. Spontaneous Formation of Tumorigenic Hybrids between Breast Cancer and Multipotent Stromal Cells Is a Source of Tumor Heterogeneity

    PubMed Central

    Rappa, Germana; Mercapide, Javier; Lorico, Aurelio

    2012-01-01

    Breast cancer progression involves cancer cell heterogeneity, with generation of invasive/metastatic breast cancer cells within populations of nonmetastatic cells of the primary tumor. Sequential genetic mutations, epithelial-to-mesenchymal transition, interaction with local stroma, and formation of hybrids between cancer cells and normal bone marrow–derived cells have been advocated as tumor progression mechanisms. We report herein the spontaneous in vitro formation of heterotypic hybrids between human bone marrow–derived multipotent stromal cells (MSCs) and two different breast carcinoma cell lines, MDA-MB-231 (MDA) and MA11. Hybrids showed predominantly mesenchymal morphological characteristics, mixed gene expression profiles, and increased DNA ploidy. Both MA11 and MDA hybrids were tumorigenic in immunodeficient mice, and some MDA hybrids had an increased metastatic capacity. Both in culture and as xenografts, hybrids underwent DNA ploidy reduction and morphological reversal to breast carcinoma–like morphological characteristics, while maintaining a mixed breast cancer–mesenchymal expression profile. Analysis of coding single-nucleotide polymorphisms by RNA sequencing revealed genetic contributions from both parental partners to hybrid tumors and metastasis. Because MSCs migrate and localize to breast carcinoma, our findings indicate that formation of MSC–breast cancer cell hybrids is a potential mechanism of the generation of invasive/metastatic breast cancer cells. Our findings reconcile the fusion theory of cancer progression with the common observation that breast cancer metastases are generally aneuploid, but not tetraploid, and are histopathologically similar to the primary neoplasm. PMID:22542847

  19. Effects on the mobility of metals from acidification caused by possible CO? leakage from sub-seabed geological formations.

    PubMed

    de Orte, Manoela Romanó; Sarmiento, Aguasanta M; Basallote, Maria Dolores; Rodríguez-Romero, Araceli; Riba, Inmaculada; Delvalls, Angel

    2014-02-01

    Carbon dioxide capture and storage (CCS) in submarine geological formations has been proposed as a mitigation measure for the prevention of global warming. However, leakage of CO2 to overlying sediments may occur over time, leading to various effects on ecosystems. Laboratory-scale experiments were performed, involving direct release of carbon dioxide into sediment, inside non-pressurized chambers, in order to provide data on the possible effects of CO2 leakage from geological storage sites on the fate of several metals. Marine sediments from three sites with different levels of contamination were sampled and submitted to acidification by means of CO2 injection. The experiment lasted 10 days and sediment samples were collected at the beginning and end of the experiment and pore water was extracted for metal analysis. The results revealed that mobility of metals from sediment to pore water depends on the site, metal and length of time exposed. Mobilization of the metals Al, Fe, Zn, Co, Pb and Cu increases with acidification, and this response generally increases with time of exposure to CO2 injection. The geochemical model applied suggests that acidification also influences the speciation of metals, transforming metals and metalloids, like As, into species much more toxic to biota. The data obtained from this study will be useful for calculating the potential risk of CCS activities to the marine environment. PMID:24144940

  20. Heterogeneous mechanisms governing formation of droplets in atomizing superheated liquid by a spray atomizer

    NASA Astrophysics Data System (ADS)

    Sorokin, V. V.

    2015-03-01

    The effects of increasing the jet expansion angle, decreasing droplet sizes, and forming a bimodal spectrum of droplets in atomizing superheated liquid by a spray atomizer are discussed. Condensation is adopted to be the mechanism governing the formation of a smaller-size fraction, and atomization enhanced by superheating is adopted to be the mechanism governing the formation of a larger-size fraction. Formulas for calculating the droplet diameter and the jet expansion angle are obtained. It is demonstrated that the calculated and experimentally determined droplet sizes are in satisfactory agreement with each other.

  1. Studies of the formation, chemical reactivity, and properties of small clusters: Application to an understanding of aerosol formation and heterogeneous chemistry

    SciTech Connect

    Castleman, A.W. Jr.

    1990-01-01

    The small cluster program involves (1) studies of reactions related to formation and growth of heteromolecular clusters and their thermochemical properties, (2) studies of photoinitiated processes in clusters, (3) investigations related to heterogeneous reactions including the influence of reaction centers on the interconversion, and (4) theoretical calculations of properties, dynamics, and structure. A major thrust of the work during the past year has been devoted to a study of the role of ionization and the presence of ions on reactions and energetics. During the past few months, particular attention has been paid to systems having varying proton affinities. From the data, we can determine the influence of these values on the nature of the reactions and ascertain the ultimate chemical nature of the ionization center formed as a result of the reactions. 83 refs., 12 figs., 2 tabs.

  2. Simulating Geologic Co-sequestration of Carbon Dioxide and Hydrogen Sulfide in a Basalt Formation

    SciTech Connect

    Bacon, Diana H.; Ramanathan, Ramya; Schaef, Herbert T.; McGrail, B. Peter

    2014-01-15

    Co-sequestered CO2 with H2S impurities could affect geologic storage, causing changes in pH and oxidation state that affect mineral dissolution and precipitation reactions and the mobility of metals present in the reservoir rocks. We have developed a variable component, non-isothermal simulator, STOMP-COMP (Water, Multiple Components, Salt and Energy), which simulates multiphase flow gas mixtures in deep saline reservoirs, and the resulting reactions with reservoir minerals. We use this simulator to model the co-injection of CO2 and H2S into brecciated basalt flow top. A 1000 metric ton injection of these supercritical fluids, with 99% CO2 and 1% H2S, is sequestered rapidly by solubility and mineral trapping. CO2 is trapped mainly as calcite within a few decades and H2S is trapped as pyrite within several years.

  3. Heterogeneous Earth Accretion and Incomplete Metal-Silicate Reequilibration at High Pressure During Core Formation

    Microsoft Academic Search

    D. C. Rubie; U. Mann; D. J. Frost; P. Kegler; A. Holzheid; H. Palme

    2007-01-01

    We present a new model of core formation, based on the partitioning of siderophile elements, that involves accreting the Earth through a series of collisions with smaller bodies that had already differentiated at low pressure. Each impact results in a magma ocean in which the core of the impactor reequilibrates with silicate liquid at high pressure before merging with the

  4. An allometric model of home range formation explains the structuring of animal communities exploiting heterogeneous resources

    E-print Network

    Nathan, Ran

    , animal physiology, behavior, intra- and inter- specific interactions structures animal populations106 An allometric model of home range formation explains the structuring of animal communities is a central challenge in ecology. An important structural property of animal communities is the distribution

  5. Inventory of Shale Formations in the US, Including Geologic, Hydrological, and Mechanical Characteristics

    SciTech Connect

    Dobson, Patrick; Houseworth, James

    2013-11-22

    The objective of this report is to build upon previous compilations of shale formations within many of the major sedimentary basins in the US by developing GIS data delineating isopach and structural depth maps for many of these units. These data are being incorporated into the LANL digital GIS database being developed for determining host rock distribution and depth/thickness parameters consistent with repository design. Methods were developed to assess hydrological and geomechanical properties and conditions for shale formations based on sonic velocity measurements.

  6. Geological Sequestration of CO2 by Hydrous Carbonate Formation with Reclaimed Slag

    SciTech Connect

    Von L. Richards; Kent Peaslee; Jeffrey Smith

    2008-02-06

    The concept of this project is to develop a process that improves the kinetics of the hydrous carbonate formation reaction enabling steelmakers to directly remove CO2 from their furnace exhaust gas. It is proposed to bring the furnace exhaust stream containing CO2 in contact with reclaimed steelmaking slag in a reactor that has an environment near the unit activity of water resulting in the production of carbonates. The CO2 emissions from the plant would be reduced by the amount sequestered in the formation of carbonates. The main raw materials for the process are furnace exhaust gases and specially prepared slag.

  7. Leveraging Regional Exploration to Develop Geologic Framework for CO2 Storage in Deep Formations in Midwestern United States

    SciTech Connect

    Neeraj Gupta

    2009-09-30

    Obtaining subsurface data for developing a regional framework for geologic storage of CO{sub 2} can require drilling and characterization in a large number of deep wells, especially in areas with limited pre-existing data. One approach for achieving this objective, without the prohibitive costs of drilling costly standalone test wells, is to collaborate with the oil and gas drilling efforts in a piggyback approach that can provide substantial cost savings and help fill data gaps in areas that may not otherwise get characterized. This leveraging with oil/gas drilling also mitigates some of the risk involved in standalone wells. This collaborative approach has been used for characterizing in a number of locations in the midwestern USA between 2005 and 2009 with funding from U.S. Department of Energy's National Energy Technology Laboratory (DOE award: DE-FC26-05NT42434) and in-kind contributions from a number of oil and gas operators. The results are presented in this final technical report. In addition to data collected under current award, selected data from related projects such as the Midwestern Regional Carbon Sequestration Partnership (MRCSP), the Ohio River Valley CO{sub 2} storage project at and near the Mountaineer Plant, and the drilling of the Ohio Stratigraphic well in Eastern Ohio are discussed and used in the report. Data from this effort are also being incorporated into the MRCSP geologic mapping. The project activities were organized into tracking and evaluation of characterization opportunities; participation in the incremental drilling, basic and advanced logging in selected wells; and data analysis and reporting. Although a large number of opportunities were identified and evaluated, only a small subset was carried into the field stage. Typical selection factors included reaching an acceptable agreement with the operator, drilling and logging risks, and extent of pre-existing data near the candidate wells. The region of study is primarily along the Ohio River Valley corridor in the Appalachian Basin, which underlies large concentrations of CO{sub 2} emission sources. In addition, some wells in the Michigan basin are included. Assessment of the geologic and petrophysical properties of zones of interest has been conducted. Although a large number of formations have been evaluated across the geologic column, the primary focus has been on evaluating the Cambrian sandstones (Mt. Simon, Rose Run, Kerbel) and carbonates layers (Knox Dolomite) as well as on the Silurian-Devonian carbonates (Bass Island, Salina) and sandstones (Clinton, Oriskany, Berea). Factors controlling the development of porosity and permeability, such as the depositional setting have been explored. In northern Michigan the Bass Islands Dolomite appears to have favorable reservoir development. In west central Michigan the St. Peter sandstone exhibits excellent porosity in the Hart and Feuring well and looks promising. In Southeastern Kentucky in the Appalachian Basin, the Batten and Baird well provided valuable data on sequestration potential in organic shales through adsorption. In central and eastern Ohio and western West Virginia, the majority of the wells provided an insight to the complex geologic framework of the relatively little known Precambrian through Silurian potential injection targets. Although valuable data was acquired and a number of critical data gaps were filled through this effort, there are still many challenges ahead and questions that need answered. The lateral extent to which favorable potential injection conditions exist in most reservoirs is still generally uncertain. The prolongation of the characterization of regional geologic framework through partnership would continue to build confidence and greatly benefit the overall CO{sub 2} sequestration effort.

  8. An aqueous rechargeable formate-based hydrogen battery driven by heterogeneous Pd catalysis.

    PubMed

    Bi, Qing-Yuan; Lin, Jian-Dong; Liu, Yong-Mei; Du, Xian-Long; Wang, Jian-Qiang; He, He-Yong; Cao, Yong

    2014-12-01

    The formate-based rechargeable hydrogen battery (RHB) promises high reversible capacity to meet the need for safe, reliable, and sustainable H2 storage used in fuel cell applications. Described herein is an additive-free RHB which is based on repetitive cycles operated between aqueous formate dehydrogenation (discharging) and bicarbonate hydrogenation (charging). Key to this truly efficient and durable H2 handling system is the use of highly strained Pd nanoparticles anchored on graphite oxide nanosheets as a robust and efficient solid catalyst, which can facilitate both the discharging and charging processes in a reversible and highly facile manner. Up to six repeated discharging/charging cycles can be performed without noticeable degradation in the storage capacity. PMID:25382034

  9. Geological formation - drill string dynamic interaction finite-element program (GEODYN). Phase 1. Theoretical description

    SciTech Connect

    Baird, J.A.; Apostal, M.C.; Rotelli, R.L. Jr.; Tinianow, M.A.; Wormley, D.N.

    1984-06-01

    The Theoretical Description for the GEODYN interactive finite-element computer program is presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit-Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates nonlinear, time-dependent, loading and boundary conditions.

  10. Phase 1 user instruction manual. A geological formation - drill string dynamic interaction finite element program (GEODYN)

    SciTech Connect

    Tinianow, M.A.; Rotelli, R.L. Jr.; Baird, J.A.

    1984-06-01

    User instructions for the GEODYN Interactive Finite Element Computer Program are presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit - Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates non-linear, time dependent, loading and boundary conditions.

  11. Phase 1 user instruction manual. A geological formation - drill string dynamic interaction finite element program (GEODYN)

    Microsoft Academic Search

    M. A. Tinianow; R. L. Jr. Rotelli; J. A. Baird

    1984-01-01

    User instructions for the GEODYN Interactive Finite Element Computer Program are presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit - Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates non-linear, time dependent, loading and boundary conditions.

  12. Geological formation - drill string dynamic interaction finite-element program (GEODYN). Phase 1. Theoretical description

    Microsoft Academic Search

    J. A. Baird; M. C. Apostal; R. L. Jr. Rotelli; M. A. Tinianow; D. N. Wormley

    1984-01-01

    The Theoretical Description for the GEODYN interactive finite-element computer program is presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit-Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates nonlinear, time-dependent, loading and boundary conditions.

  13. Norphlet formation (Upper Jurassic) of southwestern and offshore Alabama: environments of deposition and petroleum geology

    Microsoft Academic Search

    E. A. Mancini; B. L. Bearden; R. M. Mink; R. P. Wilkerson

    1985-01-01

    Upper Jurassic Norphlet sediments in southwestern and offshore Alabama accumulated under arid climatic conditions. The Appalachian Mountains of the eastern United States extended into southwestern Alabama to provide a barrier for air and water circulation during the deposition of the Norphlet Formation. These mountains produced topographic conditions that contributed to the arid climate, and they affected sedimentation. Norphlet paleogeography in

  14. Planetary and Space Science 56 (2008) 289302 Periods of active permafrost layer formation during the geological

    E-print Network

    Marchant, David R.

    2008-01-01

    ). Muller (1947) defined permafrost on Earth as a soil or rock layer in which temperatures are belowPlanetary and Space Science 56 (2008) 289­302 Periods of active permafrost layer formation during, Providence, RI 02912, USA b Earth and Planetary Sciences, University of California, Santa Cruz, Santa Cruz

  15. Evaluation of the geological relationships to gas hydrate formation and stability

    SciTech Connect

    Krason, J.; Finley, P.

    1988-01-01

    The summaries of regional basin analyses document that potentially economic accumulations of gas hydrates can be formed in both active and passive margin settings. The principal requirement for gas hydrate formation in either setting is abundant methane. Passive margin sediments with high sedimentation rates and sufficient sedimentary organic carbon can generate large quantities of biogenic methane for hydrate formation. Similarly, active margin locations near a terrigenous sediment source can also have high methane generation potential due to rapid burial of adequate amounts of sedimentary organic matter. Many active margins with evidence of gas hydrate presence correspond to areas subject to upwelling. Upwelling currents can enhance methane generation by increasing primary productivity and thus sedimentary organic carbon. Structural deformation of the marginal sediments at both active and passive sites can enhance gas hydrate formation by providing pathways for migration of both biogenic and thermogenic gas to the shallow gas hydrate stability zone. Additionally, conventional hydrocarbon traps may initially concentrate sufficient amounts of hydrocarbons for subsequent gas hydrate formation.

  16. Geology and hydrocarbon potential of Dawson Bay Formation carbonate unit (Middle Devonian), Williston basin, North Dakota

    SciTech Connect

    Pound, W.

    1988-07-01

    The Middle Devonian Dawson Bay Formation carbonate unit is present in the subsurface of North Dakota except where truncated by postdepositional erosion. The carbonate unit thickens from the erosional limit to a maximum thickness of 47.5 m (156 ft) in Renville County and reaches a maximum depth of 3798 m (12,460 ft) below the surface in McKenzie County. In North Dakota, a submarine hardground separates the carbonate unit from the underlying second red bed member of the Dawson Bay Formation. The upper contact with the Souris River Formation is conformable except in those areas where the Dawson Bay Formation was exposed to subaerial erosion prior to deposition of the Souris River sediments. The Dawson Bay carbonate unit is predominantly dolomitic and fossiliferous limestone or fossiliferous dolostone. The carbonate unit can be subdivided into five lithofacies on the basis of characteristic fossil fauna, flora, and other lithologic features. Lithofacies analysis of the Dawson Bay carbonates suggests a shallowing-upward succession of depositional environments and associated energy zones as follows: shallow epeiric sea (very low energy), stromatoporoid biostrome/bioherm (low energy), very shallow epeiric sea (very low energy), restricted shallow epeiric sea (extremely low energy), and shallow epeiric sea shoreline (variable energy). Eogenetic diagenesis includes color-mottling, dolomitization of micrite to microcrystalline dolomite with penecontemporaneous anhydrite replacement of cryptalgal mudstones and boundstones, cementation by sparry calcite, and vuggy porosity development. Mesogenetic diagenesis includes formation of mosaic dolomites, cementation by blocky equant calcite, neomorphism, pressure-solution, fracturing, halite cementation, and hydrocarbon emplacement.

  17. Non-data-aided joint bit-rate and modulation format identification for next-generation heterogeneous optical networks

    NASA Astrophysics Data System (ADS)

    Khan, Faisal Nadeem; Zhou, Yudi; Sui, Qi; Lau, Alan Pak Tao

    2014-03-01

    A novel and cost-effective technique for simultaneous bit-rate and modulation format identification (BR-MFI) in next-generation heterogeneous optical networks is proposed. This technique utilizes an artificial neural network (ANN) in conjunction with asynchronous delay-tap plots (ADTPs) to enable low-cost joint BR-MFI at the receivers as well as at the intermediate network nodes without requiring any prior information from the transmitters. The results of numerical simulations demonstrate successful identification of several commonly-used bit-rates and modulation formats with estimation accuracies in excess of 99.7%. The effectiveness of proposed technique under different channel conditions i.e. optical signal-to-noise ratio (OSNR) in the range of 14-28 dB, chromatic dispersion (CD) in the range of -500 to 500 ps/nm and differential group delay (DGD) in the range of 0-10 ps, is investigated and it has been shown that the proposed technique is robust against all these impairments.

  18. Influence of iron and copper oxides on polychlorinated diphenyl ether formation in heterogeneous reactions.

    PubMed

    Liu, Wenxia; Shen, Lianfeng; Zhang, Fawen; Liu, Wenbin; Zheng, Minghui; Yang, Xitian

    2013-08-01

    Polychlorinated diphenyl ether (PCDE) has attracted great attention recently as an important type of environmental pollutant. The influence of iron and copper oxides on formation of PCDEs was investigated using laboratory-scale flow reactors under air and under nitrogen at 350 °C, a temperature corresponding to the post-combustion zone of a municipal solid waste incinerator. The results show that the 2,2',3,4,4',5,5',6-otachlorodiphenyl ether (OCDE) formed from the condensation of pentachlorophenol (PCP) and 1,2,4,5-tetrachlorobenzene (Cl4Bz) is the predominant congener formed on the SiO2/Fe2O3 surface with and without oxygen. This indicated that HCl elimination between PCP and 1,2,4,5-Cl4Bz molecules formed 2,2',3,4,4',5,5',6-OCDE in the presence of Fe2O3. On the other hand, decachlorodiphenyl ether, nonachlorodiphenyl ether, and OCDE were the dominant products on the SiO2/CuO surface without oxygen, although the 2,2',3,4,4',5,5',6-OCDE was the dominant product on the SiO2/CuO surface with oxygen. Therefore, the presence of Fe2O3 and CuO influences the formation and homologue distribution of PCDEs, which shifted towards the lower chlorinated species. Fe2O3 can promote both the condensation and dechlorination reaction without oxygen. On the contrary, with oxygen, Fe2O3 suppresses the condensation of chlorobenzene and chlorophenol to form PCDEs and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). CuO can increase the formation of lower chlorinated PCDEs and PCDDs without oxygen. In conclusion, the different fly ash components have a major influence on PCDE emissions. PMID:23440438

  19. Petroleum geology of the Norphlet formation (Upper Jurassic), S. W. and offshore Alabama

    SciTech Connect

    Mancini, E.A.; Mink, R.M.; Bearden, B.L.

    1984-07-16

    Recent successful gas test in the Norphlet formation (up to 26 million CF/day) at depths exceeding 20,500 ft in the Mobile Bay area demonstrate a high potential for hydrocarbon production in the Alabama offshore area. In addition, wells drilled in the upper Mobile Bay area could encounter gas condensate in the Norphlet formation; gas condensate is being produced from wells in Hatter's Pond field about 14 miles north of Mobile Bay and 45 miles north of the Lower Mobile Bay-Mary Ann field. With continued petroleum exploration, additional Norphlet petroleum fields should be discovered in southwestern and offshore Alabama in the years ahead. In light of the recent discoveries in Escambia County and in the lower Mobile Bay area, Mobile, Baldwin, and Escambia counties and Mobile Bay appear to be the most prospective hydrocarbon areas.

  20. Characteristics of China’s oil and gas pool formation in latest geological history

    Microsoft Academic Search

    Chengzao Jia; Dengfa He; Xin Shi; Geng Yang; Chaojun Zhang

    2006-01-01

    The structural activities took place extensively in the Asia continent during the Cenozoic era owing to the strong continent-to-continent\\u000a collision and continuous compression between the India Plate and the Eurasia Plate. Huang Jiqing called such structural activities\\u000a Himalayan movement. China’s sedimentary basins developed and took shape mainly during the Himalayan movement period. It is\\u000a also the main period for formation

  1. User instruction manual for GEODYN2: A geological formation--bottom hole assembly

    SciTech Connect

    Apostal, M.C.; Baird, J.A. (Jordan, Apostal, Ritter Associates, Inc., Davisville, RI (USA))

    1987-06-01

    User instructions for the GEODYN2 Interactive Finite Element Computer Program are presented along with the required data file utilization and naming conventions. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a bottom hole assembly (BHA) and Polycrystalline Diamond Compact Bit arising from the intermittent contact of the BHA with the downhole rock formations. The program accommodates nonlinear, time dependent, loading and boundary conditions. 19 refs., 38 figs., 14 tabs.

  2. A geological formation: Drill string dynamic interaction finite element program (GEODYN2)

    SciTech Connect

    Baird, J.A.; Apostal, M.C. (Jordan, Apostal, Ritter Associates, Inc., Davisville, RI (USA)); Wormley, D.N. (Massachusetts Inst. of Tech., Cambridge, MA (USA))

    1989-12-01

    The Theoretical Description for the GEODYN2 Interactive Finite Element Computer Program is presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit-BHA finite element model arising from the intermittent contact of the PDC Bit-BHA System with the downhole rock formations. The program accommodates nonlinear, time dependent, loading and boundary conditions. 15 refs., 28 figs., 2 tabs.

  3. Thermal Decomposition of Gaseous Ammonium Nitrate at Low Pressure: Kinetic Modeling of Product Formation and Heterogeneous Decomposition of Nitric Acid

    NASA Astrophysics Data System (ADS)

    Park, J.; Lin, M. C.

    2009-10-01

    The thermal decomposition of ammonium nitrate, NH4NO3 (AN), in the gas phase has been studied at 423-56 K by pyrolysis/mass spectrometry under low-pressure conditions using a Saalfeld reactor coated with boric acid. The sublimation of NH4NO3 at 423 K was proposed to produce equal amounts of NH3 and HNO3, followed by the decomposition reaction of HNO3, HNO3 + M ? OH + NO2 + M (where M = third-body and reactor surface). The absolute yields of N2, N2O, H2O, and NH3, which can be unambiguously measured and quantitatively calibrated under a constant pressure at 5-6.2 torr He are kinetically modeled using the detailed [H,N,O]-mechanism established earlier for the simulation of NH3-NO2 (Park, J.; Lin, M. C. Technologies and Combustion for a Clean Environment. Proc. 4th Int. Conf. 1997, 34-1, 1-5) and ADN decomposition reactions (Park, J.; Chakraborty, D.; Lin, M. C. Proc. Combust. Inst. 1998, 27, 2351-2357). Since the homogeneous decomposition reaction of HNO3 itself was found to be too slow to account for the consumption of reactants and the formation of products, we also introduced the heterogeneous decomposition of HNO3 in our kinetic modeling. The heterogeneous decomposition rate of HNO3, HNO3 + (B2O3/SiO2) ? OH + NO2 + (B2O3/SiO2), was determined by varying its rate to match the modeled result to the measured concentrations of NH3 and H2O; the rate could be represented by k2b = 7.91 × 107 exp(-12 600/T) s-1, which appears to be consistent with those reported by Johnston and co-workers (Johnston, H. S.; Foering, L.; Tao, Y.-S.; Messerly, G. H. J. Am. Chem. Soc. 1951, 73, 2319-2321) for HNO3 decomposition on glass reactors at higher temperatures. Notably, the concentration profiles of all species measured could be satisfactorily predicted by the existing [H,N,O]-mechanism with the heterogeneous initiation process.

  4. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2003-09-25

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling that utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 3 of the project has been reservoir characterization, 3-D modeling, testing of the geologic-engineering model, and technology transfer. This effort has included six tasks: (1) the study of seismic attributes, (2) petrophysical characterization, (3) data integration, (4) the building of the geologic-engineering model, (5) the testing of the geologic-engineering model and (6) technology transfer. This work was scheduled for completion in Year 3. Progress on the project is as follows: geoscientific reservoir characterization is completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been completed. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been made. Petrophysical and engineering property characterization has been completed. Porosity and permeability data at Appleton and Vocation Fields have been analyzed, and well performance analysis has been conducted. Data integration is up to date, in that, the geological, geophysical, petrophysical and engineering data collected to date for Appleton and Vocation Fields have been compiled into a fieldwide digital database. 3-D geologic modeling of the structures and reservoirs at Appleton and Vocation Fields has been completed. The models represent an integration of geological, petrophysical and seismic data. 3-D reservoir simulation of the reservoirs at Appleton and Vocation Fields has been completed. The 3-D geologic models served as the framework for the simulations. The geologic-engineering models of the Appleton and Vocation Field reservoirs have been developed. These models are being tested. The geophysical interpretation for the paleotopographic feature being tested has been made, and the study of the data resulting from drilling of a well on this paleohigh is in progress. Numerous presentations on reservoir characterization and modeling at Appleton and Vocation Fields have been made at professional meetings and conferences and a short course on microbial reservoir characterization and modeling based on these fields has been prepared.

  5. Pore-scale study of capillary trapping mechanism during CO2 injection in geological formations

    SciTech Connect

    Bandara, Uditha C.; Tartakovsky, Alexandre M.; Palmer, Bruce J.

    2011-11-01

    Geological sequestration of CO{sub 2} gas emerged as a promising solution for reducing amount of green house gases in atmosphere. A number of continuum scale models are available to describe the transport phenomena of CO{sub 2} sequestration. These models rely heavily on a phenomenological description of subsurface transport phenomena and the predictions can be highly uncertain. Pore-scale models provide a better understanding of fluid displacement processes, nonetheless such models are rare. In this work we use a Smoothed Particle Hydrodynamics (SPH) model to study pore-scale displacement and capillary trapping mechanisms of super-critical CO{sub 2} in the subsurface. Simulations are carried out to investigate the effects of gravitational, viscous, and capillary forces in terms of Gravity, Capillary, and Bond numbers. Contrary to the other published continuum scale investigations, we found that not only Gravity number but also Capillary number plays an important role on the fate of injected CO{sub 2}. For large Gravity numbers (on the order of 10), most of the injected CO{sub 2} reaches the cap-rock due to gravity segregation. A significant portion of CO{sub 2} gets trapped by capillary forces when Gravity number is small (on the order of 0.1). When Gravity number is moderately high (on the order of 1), trapping patterns are heavily dependent on Capillary number. If Capillary number is very small (less than 0.001), then capillary forces dominate the buoyancy forces and a significant fraction of injected CO{sub 2} is trapped by the capillary forces. Conversely, if Capillary number is high (higher than 0.001), capillary trapping is relatively small since buoyancy dominates the capillary forces. In addition, our simulations reveal different types of capillary trapping and flow displacement mechanisms during and after injection. In gravity dominated cases leave behind was the widespread trapping mechanism. Division was the primary trapping mechanism in viscous dominated cases. In capillary dominated cases, snap-off of the CO{sub 2} plume is the most commonly observed displacement mechanism. Large CO{sub 2} blobs are created due to coalescence mechanism.

  6. Geology of the Hanna Formation, Hanna Underground Coal Gasification Site, Hanna, Wyoming

    SciTech Connect

    Oliver, R.L.; Youngberg, A.D.

    1984-01-01

    The Hanna Underground Coal Gasification (UCG) study area consists of the SW1/4 of Section 29 and the E1/2SE1/4 of Section 30 in Township 22 North, Range 81 West, Wyoming. Regionally, this is located in the coal-bearing Hanna Syncline of the Hanna Basin in southeast Wyoming. The structure of the site is characterized by beds dipping gently to the northeast. An east-west fault graben complex interrupts this basic trend in the center of the area. The target coal bed of the UCG experiments was the Hanna No. 1 coal in the Hanna Formation. Sedimentary rocks comprising the Hanna Formation consist of a sequence of nonmarine shales, sandstones, coals and conglomerates. The overburden of the Hanna No. 1 coal bed at the Hanna UCG site was divided into four broad local stratigraphic units. Analytical studies were made on overburden and coal samples taken from cores to determine their mineralogical composition. Textural and mineralogical characteristics of sandstones from local stratigraphic units A, B, and C were analyzed and compared. Petrographic analyses were done on the coal including oxides, forms of sulfur, pyrite types, maceral composition, and coal rank. Semi-quantitative spectrographic and analytic geochemical analyses were done on the overburden and coal and relative element concentrations were compared. Trends within each stratigraphic unit were also presented and related to depositional environments. The spectrographic analysis was also done by lithotype. 34 references, 60 figures, 18 tables.

  7. Heterogeneous immunoassays in microfluidic format using fluorescence detection with integrated amorphous silicon photodiodes

    PubMed Central

    Pereira, A. T.; Novo, P.; Prazeres, D. M. F.; Chu, V.; Conde, J. P.

    2011-01-01

    Miniaturization of immunoassays through microfluidic technology has the potential to decrease the time and the quantity of reactants required for analysis, together with the potential of achieving multiplexing and portability. A lab-on-chip system incorporating a thin-film amorphous silicon (a-Si:H) photodiode microfabricated on a glass substrate with a thin-film amorphous silicon-carbon alloy directly deposited above the photodiode and acting as a fluorescence filter is integrated with a polydimethylsiloxane-based microfluidic network for the direct detection of antibody-antigen molecular recognition reactions using fluorescence. The model immunoassay used consists of primary antibody adsorption to the microchannel walls followed by its recognition by a secondary antibody labeled with a fluorescent quantum-dot tag. The conditions for the flow-through analysis in the microfluidic format were defined and the total assay time was 30 min. Specific molecular recognition was quantitatively detected. The measurements made with the a-Si:H photodiode are consistent with that obtained with a fluorescence microscope and both show a linear dependence on the antibody concentration in the nanomolar-micromolar range. PMID:21403847

  8. Heterogeneous immunoassays in microfluidic format using fluorescence detection with integrated amorphous silicon photodiodes.

    PubMed

    Pereira, A T; Novo, P; Prazeres, D M F; Chu, V; Conde, J P

    2011-01-01

    Miniaturization of immunoassays through microfluidic technology has the potential to decrease the time and the quantity of reactants required for analysis, together with the potential of achieving multiplexing and portability. A lab-on-chip system incorporating a thin-film amorphous silicon (a-Si:H) photodiode microfabricated on a glass substrate with a thin-film amorphous silicon-carbon alloy directly deposited above the photodiode and acting as a fluorescence filter is integrated with a polydimethylsiloxane-based microfluidic network for the direct detection of antibody-antigen molecular recognition reactions using fluorescence. The model immunoassay used consists of primary antibody adsorption to the microchannel walls followed by its recognition by a secondary antibody labeled with a fluorescent quantum-dot tag. The conditions for the flow-through analysis in the microfluidic format were defined and the total assay time was 30 min. Specific molecular recognition was quantitatively detected. The measurements made with the a-Si:H photodiode are consistent with that obtained with a fluorescence microscope and both show a linear dependence on the antibody concentration in the nanomolar-micromolar range. PMID:21403847

  9. GEODYN2: a bottom hole assembly. Geological formation dynamic interaction computer program

    SciTech Connect

    Baird, J.A.; Caskey, B.C.; Wormley, D.N.; Stone, C.M.

    1985-01-01

    This paper describes the current development of a three-dimensional transient dynamic finite element computer program, GEODYN2, capable of simulating the behavior of a rotating bottom hole assembly (BHA) interacting with a non-uniform formation. The GEODYN2 Program facilitates a very detailed analysis/simulation of the behavior of a BHA with a polycrystalline diamond compact (PDC) bit and various stabilizer designs. The basic drill string mechanics implemented within the program, the overall algorithm, and the more pertinent modeling features which permit this level of analysis are briefly outlined. The implementation of these features and how they allow calculation of the response behavior of a bottom hole assembly are demonstrated. Although the development and enhancement of modeling capabilities within GEODYN2 is ongoing, it is anticipated that the preliminary verification results thus far generated will further the understanding of the response behavior of BHAs. 9 refs., 16 figs.

  10. Thermal-transport properties of Cenozoic and Mesozoic geological formations in the Northeast German Basin

    NASA Astrophysics Data System (ADS)

    Fuchs, Sven; Förster, Andrea

    2010-05-01

    Thermal properties of sedimentary formations are first-order controls on the thermal structure of basins. In order to overcome the limiting factor of the availability of drill core samples along the borehole profile and provide continuous thermal-conductivity profiles, standard petrophysical wireline logs and high-precision temperature logs can be used. As part of this approach, thermal conductivity was measured in the laboratory on Mesozoic sandstones from eight wells (predominantly geothermal boreholes) of the Northeast German Basin (NEGB). The measurements were made on drill core using the optical scanning method. Bulk thermal conductivities of sandstones, corrected for in situ thermal conditions, range between 2.1 and 3.8 W/m/K. In general, the Mesozoic sandstones show a large effective porosity typically ranging between 16 % and 30 %. Matrix thermal conductivity ranges from 3.4 to 7.4 W/m/K. The higher values are a reflection of large quartz content in some of the sandstones. Based on the in situ thermal conductivity and corresponding interval temperature gradient, obtained from high-precision temperature logs measured under thermal borehole equilibrium, interval heat-flow values were computed for two borehole locations in the Middle Buntsandstein section of the Stralsund area, at a depth between 1405 and 1521 m. The heat flow at that depth averages to 74 mW/m2 (Gt Ss 1/85 borehole) and 78 mW/m2 (Gt Ss 2/85 borehole), which is in good correspondence with previously reported heat-flow values for the NEGB. Based on the interval heat flow and a temperature gradient log, thermal conductivity was indirectly calculated for those parts of the section lacking measured laboratory values. Thus the Cenozoic and Mesozoic section of the Stralsund area, near the northern basin margin, show formation thermal conductivities between 1.5 and 3.8 W/m/K. Further work has to verify whether these values also qualify for other locations in the NEGB.

  11. Reservoir heterogeneity and hydrocarbon production in mixed dolomitic-clastic sequence: Escandalosa Formation, Barinas-Apure basin, southwestern Venezuela

    SciTech Connect

    Escalona, N.; Abud, J.

    1989-03-01

    Widespread dedolomitization and differential leaching occur in the Turonian O Member of the Escandalosa Formation, Barinas-Apure basin. Within this dolostone-dominated succession, calcite was developed through a dedolomitization process occurring in deeply buried dolomitized lime sediments previously deposited on a carbonate platform as well as dedolomitization on the associated glauconitic-quartzose sandstones of small-scale channels that scoured the platform. The dolomitized intervals have a strata-bound nature, and their original fabric is totally obliterated. The dolomitization process generated a sucrose-textured mosaic of saddle dolomite. Initial dolomite was of the scattered type, but progressive replacement of the host produced a mosaic dolostone with both idiotopic and xenotopic textures. A general increase occurred in the iron and manganese content, and goethite was exsolved from the curved rhombs of saddle dolomite. Calcite usually postdates dolomitization, except in the highly fossiliferous packstones; calcite veins develop in both dolostones and limestones. Leaching is restricted essentially to glauconitic sandstones where calcite and some clay have been leached. This has produced very low intercrystalline porosity within the dolostones and partially dissolved, corroded and floating grains with oversized pores in the sandstones. These sandy intervals exhibit maximum potential for hydrocarbon storage, due to contrasting diagenetic influence associated with reservoir heterogeneity.

  12. Norphlet formation (Upper Jurassic) of southwestern and offshore Alabama: environments of deposition and petroleum geology

    SciTech Connect

    Mancini, E.A.; Bearden, B.L.; Mink, R.M.; Wilkerson, R.P.

    1985-06-01

    Upper Jurassic Norphlet sediments in southwestern and offshore Alabama accumulated under arid climatic conditions. The Appalachian Mountains of the eastern United States extended into southwestern Alabama to provide a barrier for air and water circulation during the deposition of the Norphlet Formation. These mountains produced topographic conditions that contributed to the arid climate, and they affected sedimentation. Norphlet paleogeography in southwestern Alabama was dominated by a broad desert plain, rimmed to the north and east by the Appalachians and to the south by a developing shallow sea. The desert plain extended westward into eastern and central Mississippi. Norphlet hydrocarbon potential in southwestern and offshore Alabama is excellent; six oil and gas fields already have been established. Petroleum traps discovered to date are primarily structural traps involving salt anticlines, faulted salt anticlines, and extensional fault traps associated with salt movement. Reservoir rocks consist primarily of quartz-rich sandstones that are eolian, wadi, and marine in origin. Porosity is principally secondary (dissolution) with some intergranular porosity. Smackover algal carbonate mudstones were probably the source for the Norphlet hydrocarbons. Jurassic oil generation and migration probably were initiated in the Early Cretaceous.

  13. Relationship between Mineralogy and Porosity in Subsurface Formations Relevant to Geologic CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Cole, D. R.; Swift, A.; Sheets, J.; Welch, S.; Anovitz, L. M.; Rother, G.; Vlcek, L.

    2013-12-01

    Porosity and permeability are the key variables that link the thermal, hydrological, geochemical and geomechanical processes that redistribute mass and energy in response to injection of CO2 into the subsurface. The size, shape, distribution and connectivity of rock pores dictate how fluids migrate into and through these micro- and nanoenvironments, wet and react with the solid. The link between pore size distribution and connectivity and pore-wall mineralogy is still poorly constrained for both reservoir and caprocks.. The objectives of this effort are to characterize the nano- to macropore features, quantify mineral-specific reactive surface areas in both pore and fracture networks, and determine how pores and fractures evolve in reacted systems at temperature-pressure-composition conditions relevant to CO2 injection. Representative caprocks and reservoir rocks associated with CO2 injection activities (e.g. shallow buried quartz arenites from the St. Peter Sandstone and the deeper Mt. Simon sandstone in Ohio as well as the Eau Claire Formation shale and mudrocks) are being interrogated with an array of complementary methods - e.g. SEM, TEM, neutron scattering, X-ray CT, neutron tomography as well as conventional petrophysics. (Ultra)small-angle neutron scattering and autocorrelations derived from BSE imaging provide a powerful method of quantifying pore structures in a statistically significant manner from the nanometer to the centimeter scale. Results will be described comparing shale and mudrocks that indicate there are significant variations not only in terms of total nano- to micro-porosity and pore interconnectivity, but also in terms of pore surface fractal (roughness) and mass fractal (pore distributions) dimensions as well as size distributions. For tight formations we have observed that: (a) total porosity exhibiting bimodality may be typical of shale and mudstones, (b) connected porosity exhibiting bimodal tendencies may not be uncommon in shale and mudstone caprocks, (c) as expected, fissile shale contains far greater abundance of nanopores than do mudstones, (d) connected porosity also mimics the bimodal total porosity trends with connected nanopores observed below about 400 nm and connected micropores between 50 and 100 microns, (e) pore mineralogy (hence potential reactive surface area) is generally very different than the bulk mineralogy, especially for mudstones where phases present in minor abundances in the bulk may contribute more to the connected pore network. The data on sandstones suggest that nano- and microporosity are more prevalent in nominally coarse-grained lithologies and may play a more important role than previously thought in fluid/rock interactions. Information from imaging and scattering are being used to constrain computer-generated, random, three-dimensional porous structures. The results integrate various sources of experimental information and are statistically compatible with the real rock. These computerized porous matrices will then be used in CO2 sorption MD simulations.

  14. Geologic uses of formation microscanner (FMS) in Antelope Shale Cymric field, San Joaquin Valley, California

    SciTech Connect

    White, R.E.

    1989-04-01

    A comparison between formation microscanner (FMS) log and core from the Cymric field was made to determine the effectiveness of the FMS in characterizing the Antelope Shale. Comparisons of the FMS log and core were based on a detailed core description, petrography, scanning electron microscopy (SEM), and mineralogical analysis. Results indicate that the FMS log in the Antelope Shale is useful for (1) distinguishing between certain rock types, (2) determining bed thickness and bedding-plane orientations, and (3) detecting some fractures and determining some fracture-plane orientations. However, the FMS log shows some ambiguous responses that can be interpreted only by comparison with the core or other wireline logs. Based on resistivity contrasts, three rock-type groups can be distinguished. From least to most resistive, they are (1) mudstone, (2) argillaceous diatomite/Porcelanite, and (3) sandstone, dolostone, clay-poor porcelanite, and chert. A bed thickness of 1 cm or greater can be resolved using the FMS. Bedding-plane orientations can also be determined and provide a means to orient the core. Detection of fractures in the Antelope Shale is generally limited to those fractures within rock type that display intermediate ranges of resistivity and to the large-scale fractures. Fracture-plane orientations of some fractures can be determined; however, because of poor fracture development in the majority of Antelope Shale rock types, fractures are commonly not visible on both FMS-pad images. This makes determination of fracture-plane orientation difficult, if not impossible, for many of these fractures.

  15. High-resolution photo geologic mapping of the Tuscan Formation cliffs in the BCCER and Upper Bidwell Park, Chico CA

    NASA Astrophysics Data System (ADS)

    gonzalez, M.; Greene, T.

    2013-12-01

    The Tuscan Formation rocks make up the uppermost cliffs of the Big Chico Creek Ecological Reserve (BCCER) and Upper Bidwell Park. These rocks are composed of 3.2 to 1.8 million year old tuffs, conglomerate and sandstone dominated by volcanic clasts, as well as siltstone and mudstone mostly derived from the ancient Mt. Yana volcanic complex near Lake Almanor. This study attempts to investigate stratal geometries of Tuscan deposits in the BCCER and Upper Bidwell Park by mapping stratigraphic sections and using high resolution aerial geologic photomosaics of the Tuscan rocks. In order to obtain the best perspective of the rocks, the photos have been taken directly perpendicular to the cliff face using a helicopter and high resolution photography. With these photos, detailed layering and features of the Tuscan, both in the breccia units and the interbedded fluvial units, can be detected. These 'head on' photos are the best way to see erosional surfaces, pinch-outs, and individual flow units. They can also be used to document how well these features correlate down-canyon. Additionally, aerial photos provide a foundation for recognizing larger scale features and trends which would otherwise go unnoticed (channel flow direction, cross-cutting flows). One example of these larger scale features are two larger debris flows at the top of the unit that are best seen by the aerial photos. By foot, these debris flows can be difficult to access because of steep terrain and vegetation cover. These photos will not only aid in the study of the Tuscan deposits, but will potentially benefit other research focused on the hydrology, ecology, or archeology of Upper Bidwell Park and the BCCER. The Tuscan Formation. Debris Flow layers can easily be mapped from high-resolution photos

  16. Phased Array Approach To Retrieve Gases, Liquids, Or Solids From Subsurface And Subaqueous Geologic Or Man-Made Formations

    DOEpatents

    Rynne, Timothy M. (Long Beach, CA); Spadaro, John F. (Huntington Beach, CA); Iovenitti, Joe L. (Pleasant Hill, CA); Dering, John P. (Lakewood, CA); Hill, Donald G. (Walnut Creek, CA)

    1998-10-27

    A method of enhancing the remediation of contaminated soils and ground water, production of oil and gas, and production of any solid, gas, and/or liquid from subsurface geologic and man-made formations including the steps of estimating the geometric boundaries of the region containing the material to be recovered, drilling a recovery well(s) into subsurface in a strategic location to recover the material of interest, establishing multiple sources of acoustical power in an array about and spaced-apart from the surface or at various depths below the surface in a borehole(s) and/or well(s), directing a volume of acoustical excitation from the sources into the region containing the material to be recovered, the excitation in the form of either controllable sinusoidal, square, pulsed, or various combinations of these three waveforms, and controlling the phasing, frequency, power, duration, and direction of these waveforms from the sources to increase and control the intensity of acoustical excitation in the region of the material to be recovered to enhance. the recovery of said material from the recovery well(s). The invention will augment any technology affecting the removal of materials from the subsurface.

  17. An integrative geologic, geochronologic and geochemical study of Gorgona Island, Colombia: Implications for the formation of the Caribbean Large Igneous Province

    NASA Astrophysics Data System (ADS)

    Serrano, Lina; Ferrari, Luca; Martínez, Margarita López; Petrone, Chiara Maria; Jaramillo, Carlos

    2011-09-01

    The genesis of the Caribbean Large Igneous Province (CLIP) has been associated to the melting of the Galapagos plume head at ~ 90 Ma or to the interaction between the plume and the Caribbean slab window. Gorgona Island, offshore western Colombia, is an accreted fragment of the CLIP and its highly heterogeneous igneous suite, ranging from enriched basalts to depleted komatiites and picrites, was assumed to have formed at ~ 89 Ma from different part of the plume. Here we present new geologic, geochronologic and geochemical data of Gorgona with significant implications for the formation of the CLIP. A new set of 40Ar- 39Ar ages documents a magmatic activity spanning the whole Late Cretaceous (98.7 ± 7.7 to 64.4 ± 5 Ma) followed by a shallower, picritic pyroclastic eruption in the Paleocene. Trace element and isotope geochemistry confirm the existence of an enriched (EDMM: La/Sm N ? 1 and ?Nd i of 5.7 to 7.8) and a depleted (DMM: La/Sm N < 1 and ?Nd i of 9.5 to 11.3) mantle sources. A progressive increase in the degree of melting and melt extraction with time occurred in both groups. Petrologic modeling indicates that low but variable degrees of wet melting (< 5%) of an EDMM can produce the LREE-enriched rocks. Higher degree of melting (> 10%) of a mixed DMM + EDMM (40 to 60%) may reproduce the more depleted rocks with temperatures in the range of ambient mantle in absence of plumes. Our results contradict the notion that the CLIP formed by melting of a plume head at ~ 90 Ma. Multiple magmatic pulses over several tens of Ma in small areas like Gorgona, also recognized in other CLIP areas, suggest a long period of diffuse magmatism without a clear pattern of migration. The age span of this magmatism is broadly concurrent with the Caribbean slab window. During this time span the Farallon oceanic lithosphere (later becoming the Caribbean plate) advanced eastward ~ 1500 km, overriding the astenosphere feeding the proto-Caribbean spreading ridge. This hotter mantle flowed westward into, and mixed with, the opening mantle wedge, promoting increasing melting with time. The fortuitous occurrence of a plume passing through the slab gap area cannot be excluded but not required to produce the observed composition and degree of melting.

  18. Natural heterogeneity and evolving geochemistry of Lower Tuscaloosa Formation brine in response to continuing CO2 injection at Cranfield EOR site, Mississippi, USA

    NASA Astrophysics Data System (ADS)

    Thordsen, J. J.; Kharaka, Y. K.; Thomas, B.; Abedini, A. A.; Conaway, C. H.; Manning, M. A.; Lu, J.

    2012-12-01

    Geochemical monitoring of Lower Tuscaloosa Formation (LTF) brine continues at the Cranfield CO2-enhanced oil recovery (EOR) and sequestration site to investigate the potential for the geologic storage of large volumes of CO2 in saline aquifers and depleted reservoirs. Cranfield oil field is a domal depleted oil and gas reservoir in the Mississippi Interior Salt Basin, with production in heterogeneous fluvial sandstones of the LTF (depth ~3000 m). CO2 flood began in July 2008. Brine samples were collected from selected production wells in March and December 2009, April 2010, and November 2011. Intensive sampling also was conducted for the first 18 days of a CO2 injection experiment below the oil-water contact (December 2009) at the Detailed Area of Study (DAS) 3-well array. The sampling objectives are to define the geochemical composition of the pre-injection brine, and to understand the geochemical changes resulting from interactions between the injected CO2, brine, and reservoir minerals. Results show that Tuscaloosa brine is Na-Ca-Cl type with total salinity ranging from ~140 to 160 g/L TDS (50 samples). Relatively large variations are observed in major divalent cations (Ca ~7,500-14,000 mg/L, Mg ~800-1,250 mg/L, Sr ~475-750 mg/L). Significant positive correlations are noted amongst Ca, Mg, Sr, Ba, and Br, whereas these solutes all trend negatively with Na and Cl. These results may be interpreted as possible binary mixing between two end-member waters: (1) high Na-Cl (51 and 97 g/L, respectively), low Ca, Mg, Sr, and Br (~7500, 800, 475, 280 mg/L, respectively); and (2) low Na-Cl (40 and 86 g/L), high Ca, Mg, Sr, and Br (~14,000, 1250, 750, 480 mg/L). This apparent binary mixing has no obvious correlation to CO2 injection, which suggests that observed variations are due to natural heterogeneities in LTF brine within the Cranfield dome. The variations may indicate vertical and/or lateral proximity to a halite source (i.e. salt dome), with the high Na-Cl, low Br endmember water being more proximal to the halite source. The high salinity and large natural variations in major solutes (Ca, Mg, Sr) in LTF brine mask the signal of enhanced water-rock reactions due to CO2 injection. However, other parameters such as pH, alkalinity (HCO3), and Fe are more sensitive indicators of CO2 injection. Results from the first 13 months of sampling, including the DAS, indicate only modest water-rock interaction due to CO2 flooding, with a decrease in surface-measured pH (from ~5.7 to 5.0) and increases in HCO3 (from ~375 to 500 mg/L) and Fe (from ~90 to 120 mg/L). The modest extent of change was imputed to low-reactivity well tubing, and the limited reaction potential of the dominant reservoir minerals (quartz, chlorite, kaolinite), and low abundances of carbonates. However, results from the most recent (November, 2011) re-sampling of four mature production wells indicate significant increases in HCO3 (averages from 460 to 875 mg/L) and Fe (averages from 120 to 230 mg/L), and overall significant positive HCO3-Fe correlation (R2=0.89; 46 samples). Water-rock interactions may be increasing with continuing CO2 injection in the mature production wells. However, brine-CO2 reactions with anthropogenic production materials, such as well tubing, also are an important consideration.

  19. U.S. Department of Energy's site screening, site selection, and initial characterization for storage of CO2 in deep geological formations

    USGS Publications Warehouse

    Rodosta, T.D.; Litynski, J.T.; Plasynski, S.I.; Hickman, S.; Frailey, S.; Myer, L.

    2011-01-01

    The U.S. Department of Energy (DOE) is the lead Federal agency for the development and deployment of carbon sequestration technologies. As part of its mission to facilitate technology transfer and develop guidelines from lessons learned, DOE is developing a series of best practice manuals (BPMs) for carbon capture and storage (CCS). The "Site Screening, Site Selection, and Initial Characterization for Storage of CO2 in Deep Geological Formations" BPM is a compilation of best practices and includes flowchart diagrams illustrating the general decision making process for Site Screening, Site Selection, and Initial Characterization. The BPM integrates the knowledge gained from various programmatic efforts, with particular emphasis on the Characterization Phase through pilot-scale CO2 injection testing of the Validation Phase of the Regional Carbon Sequestration Partnership (RCSP) Initiative. Key geologic and surface elements that suitable candidate storage sites should possess are identified, along with example Site Screening, Site Selection, and Initial Characterization protocols for large-scale geologic storage projects located across diverse geologic and regional settings. This manual has been written as a working document, establishing a framework and methodology for proper site selection for CO2 geologic storage. This will be useful for future CO2 emitters, transporters, and storage providers. It will also be of use in informing local, regional, state, and national governmental agencies of best practices in proper sequestration site selection. Furthermore, it will educate the inquisitive general public on options and processes for geologic CO2 storage. In addition to providing best practices, the manual presents a geologic storage resource and capacity classification system. The system provides a "standard" to communicate storage and capacity estimates, uncertainty and project development risk, data guidelines and analyses for adequate site characterization, and guidelines for reporting estimates within the classification based on each project's status. ?? 2011 Published by Elsevier Ltd.

  20. Evaluation of the geological relationships to gas hydrate formation and stability. Second annual technical progress report, October 1, 1985--September 30, 1986

    SciTech Connect

    Not Available

    1986-12-31

    Although there are many publications pertaining to gas hydrates, their formation and stability in various geological conditions are poorly known. Therefore, for the same reasons and because of the very broad scope of our research, limited amount and extremely dispersed information, the study regions are very large. Moreover, almost without exception the geological environments controlling gas hydrates formation and stability of the studied regions are very complex. The regions studied (completed and partially completed - total 17 locations) during the reporting period, particularly the Gulf of Mexico and the Middle America Trench, are the most important in this entire research project. In the past, both of these regions have been extensively studied, the presence of gas hydrates confirmed and samples recovered. In our investigation it was necessary not only to review all previous data and interpretations, but to do a thorough analysis of the basins, and a critical evaluation of an previously reported and publicly available but not published information.

  1. Heterogeneous distribution of solar and cosmogenic noble gases in CM chondrites and implications for the formation of CM parent bodies

    NASA Astrophysics Data System (ADS)

    Nakamura, Tomoki; Nagao, Keisuke; Metzler, Knut; Takaoka, Nobuo

    1999-01-01

    Distribution of solar, cosmogenic, and primordial noble gases in thin slices of Murchison, Murray, and Nogoya CM carbonaceous chondrites was determined by the laser microprobe analysis so as to put some constraints on the parent-body processes in the CM chondrite formation. The main lithological units of the three meteorite slices were located by electron microscope observations and classified into clastic matrix and clasts of primary accretionary rocks (PARs) based on the classification scheme of texture of CM chondrites. All sample slices contain both clastic matrix and PARs. Clastic matrix shows a comminuted texture formed by fragmentation and mechanical mixing of rocks due to impacts, whereas PARs preserve the original textures prior to the mechanical disruption. Solar-type noble gases are detected in all sample slices. They are located preferentially in clastic matrix. The distribution of solar gases is similar to that in ordinary chondrites where these gases reside in clastic dark portions of these meteorites. The heterogeneous distribution of solar gases in CM chondrites suggests that these gases were acquired not in a nebular accretion process but in parent body processes. Solar energetic particles (SEP) are predominant in CM chondrites. The low abundance of low energy solar wind (SW) component relative to SEP suggests preferential loss of SW from minerals comprising the clastic matrix, due to aqueous alteration in the parent bodies. Cosmogenic noble gases are also enriched in some portions in clastic matrix, indicating that some parts of clastic matrix were exposed to solar and galactic cosmic rays prior to the final consolidation of the CM parent bodies. Primordial noble gases are rich in fine-grained rims around chondrules in all three meteorites. However, average concentrations of heavy primordial gases in the rims differ among meteorites and correlate inversely to the degree of aqueous alteration that the meteorites have experienced. This appears to have been caused by aqueous alteration reactions between fluids and carbonaceous carrier phases of noble gases.

  2. Dispersion measurement as a method of quantifying geologic characterization and defining reservoir heterogeneity. Annual report, July 12, 1990--September 12, 1991

    SciTech Connect

    Menzie, D.E.

    1992-04-01

    Since reservoirs are heterogeneous, nonuniform, and anisotropic, the success or failure of many enhanced oil recovery techniques rests on our prediction of internal variability and the paths of fluid flow in the reservoir. The main objective of this project is to develop a greater understanding of reservoir heterogeneities through dispersion measurement. In this annual report, an approach to ways to estimate the dispersivities of reservoir rocks from well logs is presented. From a series of rock property measurements and dispersion tests the following studies have been made: A measure of rock heterogeneity is developed by using the effluent concentration at one pore volume injection in a matched viscosity miscible displacement. By this approach, a heterogeneity factor is determined from the measured S-shaped dispersion curve. The parameter f in the Coats-Smith capacitance model is redefined as the dispersion fraction f{sub d} (or mechanical mixing fraction). At the f{sub d} pore volume injection, the dynamic miscible displacement efficiency reaches maximum. Reflected on the dispersion curve, this number corresponds to the peak of the first derivative of concentration. With the concept of dispersion fraction, a unique solution to the capacitance model is obtained, and then an equivalent dispersivity is defined. Through experimental data on Berea and Brown sandstone samples, it has been found that the equivalent dispersivity is an exponential function of the heterogeneity factor and can be used as a reservoir characteristic. Through a key parameter of tortuosity, dispersivity is related to rock petrophysical properties. This semi-theoretical relationship forms the basis for determining dispersivities from well logs. The approach is validated through experimental studies on Berea and Brown sandstone samples. It has been found that the equivalent dispersivity is an exponential function of the heterogeneity factor and can be used as a reservoir characteristic.

  3. A Study of the Geology of the Rocks of the Huntington Formation in the Izee and Olds Ferry Terrains of the Blue Mountains Region

    NSDL National Science Digital Library

    This winning entry in the museum's Young Naturalist Awards 1999 by Matthew, a 17 year old student from Idaho, takes a look at the geology of the rocks of the Huntington Formation. His essay discusses the hypothetical series of events that explains how the Izee and Olds Ferry terrains were formed over hundreds of millions of years, the 10 rock specimens he collected there and the metamorphoses they have each undergone.

  4. Geological SciencesGeological Sciences Geological EngineeringGeological Engineering

    E-print Network

    Ellis, Randy

    Geological SciencesGeological Sciences Geological EngineeringGeological Engineering Geosciences Careers in the ik ou ve n ver see t b f rel e y ' e n i e o ! Department of Geological Sciences and Geological Engineering Queen's University See the World Geological Sciences Arts and Science Faculty

  5. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2001-09-14

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 1 of the project has been reservoir description and characterization. This effort has included four tasks: (1) geoscientific reservoir characterization, (2) the study of rock-fluid interactions, (3) petrophysical and engineering characterization and (4) data integration. This work was scheduled for completion in Year 1. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been initiated. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been made. Petrophysical and engineering property characterization is progressing. Data on reservoir production rate and pressure history at Appleton and Vocation Fields have been tabulated, and porosity data from core analysis has been correlated with porosity as observed from well log response. Data integration is on schedule, in that, the geological, geophysical, petrophysical and engineering data collected to date for Appleton and Vocation Fields have been compiled into a fieldwide digital database for reservoir characterization, modeling and simulation for the reef and carbonate shoal reservoirs for each of these fields.

  6. Geologic and hydrologic data for the Rustler Formation near the Waste Isolation Pilot Plant, southeastern New Mexico

    USGS Publications Warehouse

    Richey, Steven F.

    1989-01-01

    The U.S. Geological Survey is investigating the geohydrology in the vicinity of the Waste Isolation Pilot Plant in southeastern New Mexico. Data presented were compiled in support of a regional groundwater flow model. The data include water level measurements obtained from the U.S. Geological Survey 's Groundwater Site-Inventory and OMNIANA data bases and stratigraphic information interpreted from commercial geophysical logs. (USGS)

  7. Identification of discharge zones and quantification of contaminant mass discharges into a local stream from a landfill in a heterogeneous geologic setting

    NASA Astrophysics Data System (ADS)

    Milosevic, N.; Thomsen, N. I.; Juhler, R. K.; Albrechtsen, H.-J.; Bjerg, P. L.

    2012-06-01

    SummaryContaminants from Risby Landfill (Denmark) are expected to leach through the underlying geologic strata and eventually reach the local Risby Stream. Identification of the groundwater discharge zone was conducted systematically by an array of methods including studies on site geology and hydrogeology, ground- and surface water flows and landfill leachate tracing from April 2009 to December 2010. Chemical profiling by driven wells and gradients in streambed temperatures was an efficient method to identify the contaminant discharge area. A considerable variation of leachate indicators, redox parameters and xenobiotic organic compounds were revealed in this area because of a complex geological setting with clay till (interbedded sand lenses) and deposits of sand and peat. Concentrations of leachate indicators decreased from the landfill to the stream, implying attenuation processes. Xenobiotic organic compounds were mainly phenoxy acid herbicides, while petroleum hydrocarbons and chlorinated solvents were found at very few boreholes. Findings of putative metabolites of phenoxy acid herbicides suggest degradation under the anaerobic conditions, which dominated inside and beneath the landfill. The groundwater discharge was quantified by two methods: direct collection of discharged groundwater by seepage meters and calculations from measurement of streambed temperature gradients. The landfill impacted the stream seasonally during dry periods when concentrations in the stream reached groundwater concentration levels. A comparison between mass balance for selected stream stretches and upscaled measurements of the contaminant discharge from groundwater into the stream indicated that only a small part of the actual contaminant discharge of the stream could be explained by the inflowing contaminant discharge from groundwater. Surface runoff and seepage from ponds along the stream impacted by landfill interflow may be important pathways as well. The placement of Risby Landfill near a stream and the complex source and geology causing a large spatial variability of leachate compounds are typical for landfill sites so the approaches and findings from Risby Landfill can be applied to other landfill sites. The study highlights that landfills may pose a risk to surface waters and future studies should be directed towards evaluation of both chemical and ecological risk.

  8. Formation of nitro-PAHs from the heterogeneous reaction of ambient particle-bound PAHs with N2O5/NO3/NO2

    PubMed Central

    Zimmermann, Kathryn; Jariyasopit, Narumol; Massey Simonich, Staci L.; Tao, Shu; Atkinson, Roger; Arey, Janet

    2014-01-01

    Reactions of ambient particles collected from four sites within the Los Angeles, CA air basin and Beijing, China with a mixture of N2O5, NO2, and NO3 radicals were studied in an environmental chamber at ambient pressure and temperature. Exposures in the chamber system resulted in the degradation of particle-bound PAHs and formation of molecular weight (mw) 247 nitropyrenes (NPYs) and nitrofluoranthenes (NFLs), mw 273 nitrotriphenylenes (NTPs), nitrobenz[a]anthracenes (NBaAs), and nitrochrysene (NCHR), and mw 297 nitrobenzo[a]pyrene (NBaP). The distinct isomer distributions resulting from exposure of filter-adsorbed deuterated fluoranthene to N2O5/NO3/NO2 and that collected from the chamber gas-phase suggest that formation of NFLs in ambient particles did not occur by NO3 radical-initiated reaction, but from reaction of N2O5, presumably subsequent to its surface adsorption. Accordingly, isomers known to result from gas-phase radical-initiated reactions of parent PAHs, such as 2-NFL and 2- and 4-NPY, were not enhanced from the exposure of ambient particulate matter to N2O5/NO3/NO2. The reactivity of ambient particles toward nitration by N2O5/NO3/NO2, defined by relative 1-NPY formation, varied significantly, with the relative amounts of freshly emitted particles versus aged particles (particles that had undergone atmospheric chemical processing) affecting the reactivity of particle-bound PAHs toward heterogeneous nitration. Analyses of unexposed ambient samples suggested that, in nighttime samples where NO3 radical-initiated chemistry had occurred, heterogeneous formation of 1-NPY on ambient particles may have contributed to the ambient 1-NPY concentrations at downwind receptor sites. These results, together with observations that 2-NFL is consistently the dominant particle-bound nitro-PAH measured in ambient atmospheres, suggest that for PAHs that exist in both the gas- and particle-phase, the heterogeneous formation of particle-bound nitro-PAHs is a minor formation route compared to gas-phase formation. PMID:23865889

  9. Formation of nitro-PAHs from the heterogeneous reaction of ambient particle-bound PAHs with N2O5/NO3/NO2.

    PubMed

    Zimmermann, Kathryn; Jariyasopit, Narumol; Massey Simonich, Staci L; Tao, Shu; Atkinson, Roger; Arey, Janet

    2013-08-01

    Reactions of ambient particles collected from four sites within the Los Angeles, CA air basin and Beijing, China with a mixture of N2O5, NO2, and NO3 radicals were studied in an environmental chamber at ambient pressure and temperature. Exposures in the chamber system resulted in the degradation of particle-bound PAHs and formation of molecular weight (mw) 247 nitropyrenes (NPYs) and nitrofluoranthenes (NFLs), mw 273 nitrotriphenylenes (NTPs), nitrobenz[a]anthracenes (NBaAs), nitrochrysene (NCHR), and mw 297 nitrobenzo[a]pyrene (NBaP). The distinct isomer distributions resulting from exposure of filter-adsorbed deuterated fluoranthene to N2O5/NO3/NO2 and that collected from the chamber gas-phase suggest that formation of NFLs in ambient particles did not occur by NO3 radical-initiated reaction but from reaction of N2O5, presumably subsequent to its surface adsorption. Accordingly, isomers known to result from gas-phase radical-initiated reactions of parent PAHs, such as 2-NFL and 2- and 4-NPY, were not enhanced from the exposure of ambient particulate matter to N2O5/NO3/NO2. The reactivity of ambient particles toward nitration by N2O5/NO3/NO2, defined by relative 1-NPY formation, varied significantly, with the relative amounts of freshly emitted particles versus aged particles (particles that had undergone atmospheric chemical processing) affecting the reactivity of particle-bound PAHs toward heterogeneous nitration. Analyses of unexposed ambient samples suggested that, in nighttime samples where NO3 radical-initiated chemistry had occurred, heterogeneous formation of 1-NPY on ambient particles may have contributed to the ambient 1-NPY concentrations at downwind receptor sites. These results, together with observations that 2-NFL is consistently the dominant particle-bound nitro-PAH measured in ambient atmospheres, suggest that for PAHs that exist in both the gas- and particle-phase, the heterogeneous formation of particle-bound nitro-PAHs is a minor formation route compared to gas-phase formation. PMID:23865889

  10. Advances in Planetary Geology

    NASA Technical Reports Server (NTRS)

    Woronow, A. (editor)

    1982-01-01

    Advances in Planetary Geology is a new series intended to serve the planetary geology community with a form for quick and thorough communications. There are no set lists of acceptable topics or formats, and submitted manuscripts will not undergo a formal review. All submissions should be in a camera ready form, preferably spaced, and submitted to the editor.

  11. Marine Geological Discoveries

    NSDL National Science Digital Library

    This site by a Norwegian researcher features descriptions of marine geological formations: pockmarks, mud volcanoes, deep-water coral reefs, and gas hydrates. Using ROV technology, he has taken photos of these deep seafloor features, and compares them to geological structures seen on land, and even on the moon.

  12. Geologic Time Online Edition

    NSDL National Science Digital Library

    This tutorial will help students learn and understand the concepts of geologic time and the age of the Earth. They will investigate the geologic time scale and learn about the use of index fossils and radiometric dating to determine the age of rock formations and fossils.

  13. Non-Darcian flow in low-permeability media: key issues related to geological disposal of high-level nuclear waste in shale formations

    NASA Astrophysics Data System (ADS)

    Liu, Hui-Hai

    2014-05-01

    In clay or other low-permeability media, water flow becomes non-Darcian and characterized by the non-linear relationship between water flux and hydraulic gradient. This work is devoted to addressing a number of key issues related to geological disposal of high-level nuclear waste in clay/shale formations. It is demonstrated that water flow velocity in the damaged zone (often considered as a potential preferential advection paths in a repository) surrounding the tunnel is extremely small, as a result of non-Darcian flow behavior, such that solute transport is dominated by diffusion, rather than advection. The finding is also consistent with the often-observed existence of persistent abnormal pressures in shale formations. While relative permeability is the key parameter for modeling the unsaturated flow process, without incorporating non-Darcian flow behavior, significant errors can occur in the determination of relative permeability values from traditional measurement methods. An approach for dealing with temperature impact on non-Darcian flow and a formulation to calculate non-Darcian water flux in an anisotropic medium are presented, taking into consideration that a geological repository is subject to temperature evolution in the near field as a result of heat generated by nuclear waste, and that shale formations are generally anisotropic.

  14. Methods and apparatus for measurement of the resistivity of geological formations from within cased wells in presence of acoustic and magnetic energy sources

    DOEpatents

    Vail, W.B. III.

    1991-08-27

    Methods and apparatus are provided for measuring the acoustically modulated electronic properties of geological formations and cement layers adjacent to cased boreholes. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. Voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the leakage current conducted into formation in the vicinity of those electrodes. Simultaneously subjecting the casing and formation to an acoustic source acoustically modulates the leakage current measured thereby providing a measure of the acoustically modulated electronic properties of the adjacent formation. Similarly, methods and apparatus are also described which measure the leakage current into formation while simultaneously subjecting the casing to an applied magnetic field which therefore allows measurement of the magnetically modulated electronic properties of the casing and the adjacent formation. 9 figures.

  15. Methods and apparatus for measurement of the resistivity of geological formations from within cased wells in presence of acoustic and magnetic energy sources

    DOEpatents

    Vail, III, William B. (Bothell, WA)

    1991-01-01

    Methods and apparatus are provided for measuring the acoustically modulated electronic properties of geological formations and cement layers adjacent to cased boreholes. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. Voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the leakage current conducted into formation in the vicinity of those electrodes. Simultaneously subjecting the casing and formation to an acoustic source acoustically modulates the leakage current measured thereby providing a measure of the acoustically modulated electronic properties of the adjacent formation. Similarly, methods and apparatus are also described which measure the leakage current into formation while simultaneously subjecting the casing to an applied magnetic field which therefore allows measurement of the magnetically modulated electronic properties of the casing and the adjacent formation.

  16. Devil's Tower Geology

    NSDL National Science Digital Library

    National Park Service (NPS)

    This site from the National Park Service briefly addresses the geology of Devil's Tower. The evolution of various theories on the formation of the tower are discussed. A slide show of the emplacement of the tower is also available.

  17. Investigating the Geologic History of Southeast Minnesota by Constructing a Geologic Column

    NSDL National Science Digital Library

    Amanda Ludeman

    This activity is a field investigation where students gather data on rock types and geologic formations to construct a geologic column that will help them to interpret the geologic history of the Cannon Falls area.

  18. A noniterative technqiue for the direct implementation of well bore boundary conditions in three-dimensional heterogeneous formations

    Microsoft Academic Search

    E. A. Sudicky; A. J. A. Unger; S. Lacombe

    1995-01-01

    A noniterative algorithm for handling prescribed well bore boundary conditions while pumping or injecting fluid in a three-dimensional heterogeneous aquifer is described. The algorithm is formulated by superimposing conductive one-dimensional line elements representing the well screen onto the three-dimensional matrix elements representing the aquifer. Storage in the well casing is also naturally accommodated by the superposition of the line elements.

  19. Geologic Map of New Jersey

    NSDL National Science Digital Library

    This map displays the sedimentary rocks of the Cenozoic, Mesozoic, and Paleozoic eras as well as the igneous and metamorphic rocks of the Mesozoic and Precambrian eras. There is a pagesize copy of the geologic map, a brief description of the geology and physiographic provinces of New Jersey, and information on bedrock geologic maps of New Jersey (in CD-ROM format).

  20. Geologic mapping as a method for the construction of a detailed and testable lithostratigraphic model for the Upper Triassic Chinle Formation of Petrified Forest National Park, Arizona

    NASA Astrophysics Data System (ADS)

    Skinner, L. A.; Martz, J. W.; Parker, W.; Raucci, J.; Umhoefer, P. J.

    2010-12-01

    The Upper Triassic Chinle Formation in Petrified Forest National Park represents some of the most intensively studied Upper Triassic strata in western North America. Five stratigraphic members are exposed within the park, from oldest to youngest: the Mesa Redondo, Blue Mesa, Sonsela, Petrified Forest, and Owl Rock Members. Despite numerous stratigraphic studies of the Chinle Formation and two attempts at mapping the park over the past sixty years, sandstone marker beds in the Sonsela Member at the north and south ends of the park were still poorly mapped and correlated. Studies in the years 2002 and 2006 claimed that two sandstones which previous workers had considered to lie at different stratigraphic levels (the Jasper Forest Bed and the Flattops One sandstones in the Martha’s Butte beds) were actually correlative. This correlation resulted in a three-part division of the Sonsela Member and had a major impact on vertebrate biostratigraphy. In a recent attempt to resolve confusions regarding Chinle Formation lithostratigraphy and biostratigraphy, we have completely walked out lithologic contacts through most of the park. The resulting new geologic map, revised lithostratigraphic model, and associated data resolves the 2002 and 2006 miscorrelations by demonstrating that the Jasper Forest Bed capping Blue Mesa and Agate Mesa and Flattops One sandstones (Martha’s Butte beds) are stratigraphically distinct, resulting in a thicker and more complex five-part model for the Sonsela Member, and considerably modifying the vertebrate biostratigraphy. New geologic mapping also resulted in a detailed lithostratigraphic framework for the northern park which has previously been poorly understood, and several important new marker beds, including a purple-gray bed that represents the base of the Owl Rock Member. The revised geologic map is an ArcGIS product that includes an updated lithostratigraphic model for the Chinle Formation, fossil localities, and hyperlinks to labeled photographs of measured sections. A pre-existing ArcGIS product created by workers at Northern Arizona University was used for the creation of this map and thus the final product includes some mapping, mostly Quaternary alluvium, dunes, and sandsheets, from that study. The cumulative effect of these revisions is to emphasize the importance of thoroughly exploring stratigraphic contacts, extensively documenting lithostratigraphic models, making georeferenced GIS maps, and accurately locating critical fossil localities. These methods and the new map make lithostratigraphic, biostratigraphic, and paleoecologic and paleoclimate models scientifically testable to future researchers at this classic Chinle Formation location.

  1. Strontium isotope tracking of groundwater-CO2 interactions in Chimayo, New Mexico, and implications for carbon storage in geologic formations

    NASA Astrophysics Data System (ADS)

    Gardiner, J.; Stewart, B. W.; Capo, R.; Hakala, J.

    2009-12-01

    James Gardiner1, Brian Stewart1, Rosemary Capo1, J. Alexandra Hakala2 1Department of Geology and Planetary Sciences, University of Pittsburgh 2National Energy Technology Laboratory, Pittsburgh, PA The storage of carbon dioxide in geologic formations requires sensitive monitors of the geochemical and mineralogical interactions of storage units, their formation waters, and associated aquifers potentially affected by subsurface CO2. High CO2 subsurface environments can serve as natural analogues for conditions following CO2 injection and provide sites to develop and optimize geochemical tools that can characterize subsurface reactions and identify and track brine and groundwater interactions. Wells in Chimayó, NM tap groundwater from the Tesuque sandstone aquifer, which is crosscut by faults that act as conduits for naturally occurring, deeply sourced CO2. This provides an opportunity for geochemical and isotopic characterization of groundwaters potentially influenced by interaction with CO2. Well waters in the region have 87Sr/86Sr ratios ranging from 0.7176 for CO2-charged brackish water to 0.7098 for a low-TDS groundwater, making the Sr isotope system a potentially sensitive tracer for groundwater-rock interactions. Preliminary strontium isotopic and geochemical data lead to the following observations: (1) Strontium isotope ratios and Sr concentrations in groundwaters sampled within the basin suggest a complex mixing between deep- and shallow-sourced waters, possibly combined with reactions of aquifer carbonate cement or local limestone. (2) Adjacent wells with identical 87Sr/86Sr but significantly different CO2 and alkaline earth concentrations imply CO2 migration from depth into a shallow aquifer, followed by dissolution of carbonate cement. (3) Sr isotope mixing models, when used in conjunction with other geochemical data, can be a strong indicator of decoupling between CO2 and its carrier fluid. Conservative isotope tracers such as 87Sr/86Sr could be an essential tool in monitoring CO2 -groundwater-brine interactions related to geologic carbon sequestration.

  2. Geologic assessment of undiscovered oil and gas resources: Oligocene Frio and Anahuac Formations, United States Gulf of Mexico coastal plain and State waters

    USGS Publications Warehouse

    Swanson, Sharon M.; Karlsen, Alexander W.; Valentine, Brett J.

    2013-01-01

    The Oligocene Frio and Anahuac Formations were assessed as part of the 2007 U.S. Geological Survey (USGS) assessment of Tertiary strata of the U.S. Gulf of Mexico Basin onshore and State waters. The Frio Formation, which consists of sand-rich fluvio-deltaic systems, has been one of the largest hydrocarbon producers from the Paleogene in the Gulf of Mexico. The Anahuac Formation, an extensive transgressive marine shale overlying the Frio Formation, contains deltaic and slope sandstones in Louisiana and Texas and carbonate rocks in the eastern Gulf of Mexico. In downdip areas of the Frio and Anahuac Formations, traps associated with faulted, rollover anticlines are common. Structural traps commonly occur in combination with stratigraphic traps. Faulted salt domes in the Frio and Anahuac Formations are present in the Houston embayment of Texas and in south Louisiana. In the Frio Formation, stratigraphic traps are found in fluvial, deltaic, barrier-bar, shelf, and strandplain systems. The USGS Tertiary Assessment Team defined a single, Upper Jurassic-Cretaceous-Tertiary Composite Total Petroleum System (TPS) for the Gulf Coast basin, based on previous studies and geochemical analysis of oils in the Gulf Coast basin. The primary source rocks for oil and gas within Cenozoic petroleum systems, including Frio Formation reservoirs, in the northern, onshore Gulf Coastal region consist of coal and shale rich in organic matter within the Wilcox Group (Paleocene–Eocene), with some contributions from the Sparta Sand of the Claiborne Group (Eocene). The Jurassic Smackover Formation and Cretaceous Eagle Ford Formation also may have contributed substantial petroleum to Cenozoic reservoirs. Modeling studies of thermal maturity by the USGS Tertiary Assessment Team indicate that downdip portions of the basal Wilcox Group reached sufficient thermal maturity to generate hydrocarbons by early Eocene; this early maturation is the result of rapid sediment accumulation in the early Tertiary, combined with the reaction kinetic parameters used in the models. A number of studies indicate that the migration of oil and gas in the Cenozoic Gulf of Mexico basin is primarily vertical, occurring along abundant growth faults associated with sediment deposition or along faults associated with salt domes. The USGS Tertiary assessment team developed a geologic model based on recurring regional-scale structural and depositional features in Paleogene strata to define assessment units (AUs). Three general areas, as described in the model, are found in each of the Paleogene stratigraphic intervals assessed: “Stable Shelf,” “Expanded Fault,” and “Slope and Basin Floor” zones. On the basis of this model, three AUs for the Frio Formation were defined: (1) the Frio Stable Shelf Oil and Gas AU, containing reservoirs with a mean depth of about 4,800 feet in normally pressured intervals; (2) the Frio Expanded Fault Zone Oil and Gas AU, containing reservoirs with a mean depth of about 9,000 feet in primarily overpressured intervals; and (3) the Frio Slope and Basin Floor Gas AU, which currently has no production but has potential for deep gas resources (>15,000 feet). AUs also were defined for the Hackberry trend, which consists of a slope facies stratigraphically in the middle part of the Frio Formation, and the Anahuac Formation. The Frio Basin Margin AU, an assessment unit extending to the outcrop of the Frio (or basal Miocene), was not quantitatively assessed because of its low potential for production. Two proprietary, commercially available databases containing field and well production information were used in the assessment. Estimates of undiscovered resources for the five AUs were based on a total of 1,734 reservoirs and 586,500 wells producing from the Frio and Anahuac Formations. Estimated total mean values of technically recoverable, undiscovered resources are 172 million barrels of oil (MMBO), 9.4 trillion cubic feet of natural gas (TCFG), and 542 million barrels of natural gas liquids for all of the Frio and Anahuac AUs. Of the five units asse

  3. Effects of layered heterogeneity in subsurface geologic materials on solute transport under field conditions: A case study from northeastern Iowa, USA

    NASA Astrophysics Data System (ADS)

    Iqbal, Mohammad Z.

    2000-06-01

    In the Cedar River watershed of northeastern Iowa, USA, water quality in 17 out of 20 private wells indicates that groundwater is contaminated with nitrate from agricultural leachates. In nine of the wells, nitrate concentration exceeds the US Environmental Protection Agency recommended maximum contaminant level (MCL) of 45 mg/L (as NO3 -) for drinking purposes. Solute-transport investigations determined that the surficial loam sediments, the Quaternary sand and gravel deposits, and the glacial till deposits form layered heterogeneity in the subsurface. The resulting conductivity contrast causes a capillary barrier, thereby altering the mechanisms of vertical tracer movement. Storm-water tracing with potassium bromide, corn fertilizer, and fluorescein dye indicates that macropore flow occurs only within the upper 0.9 m of loamy sediments. An average breakthrough concentration of 204 mg/L bromide at 0.3 m depth on day 3 after the storm event supports the hypothesis of macropore flow in the surficial soils. Fluorescein dye was recovered at a depth of 0.3 m with a peak concentration of 650 ?g/L at approximately 5 days after the storm event. The loamy sediment layer is underlain by the Iowan Pebble Band, a pebbly layer admixed with sand, developed in post-glacial time. In the field experiments, preferential flow of the tracers was predominantly vertical within the loamy sediments but rapidly changed to a horizontal matrix flow upon entering the materials of higher saturated hydraulic conductivity in the Pebble Band. The Pebble Band is underlain by low-conductivity deposits of pre-Illinoian till. Even though the upper oxidized portion of the glacial till is reported to have macropores, the Pebble Band prevented deeper infiltration of storm water by maintaining a strong component of horizontal hydraulic gradient. Chemical data indicate that the Pebble Band is a hydraulic-conductivity boundary that abruptly changes the unsaturated-flow mechanism from macropore flow to matrix flow.

  4. Dispersion measurement as a method of quantifying geologic characterization and defining reservoir heterogeneity. Annual report, July 12, 1992--July 12, 1993

    SciTech Connect

    Menzie, D.E.

    1994-01-01

    Dispersion of fluids flowing through porous media is an important phenomenon in miscible displacement. Much of the research involving dispersion and dispersivity as a property of reservoir rock has focused on miscible liquid-liquid displacement processes. This study addresses the measurement of dispersion in a gas-gas displacement system. It will enlarge the understanding of the characteristics of dispersivity and flow systems of reservoir rocks. New experimental methods and apparatus for gas-gas dispersion were developed in this study. Twenty eight gas-gas miscible displacement measurements under different flowrates and pressures were conducted on three Berea sandstone cores of varying lengths and physical properties. A gas chromatograph was utilized and modified to measure the concentration of gas at the outlet of the cores. Nitrogen was used as the displacing gas, while helium was used as the displaced gas. The experimental results were illustrated using S-shaped effluent breakthrough curves. The effect of flowrate and pressure on gas-gas dispersion, dispersion coefficient, dispersivity, and dispersion factor were determined from these curves. Gas effective diffusion coefficients were obtained by graphical methods using the dispersion coefficients under low velocities. A new method to determine the total flowing pore volume by dispersion measurement was proposed in this study. The heterogeneity of reservoir rock can be studied by this method. An increase in displacing velocity was found to decrease the mixing or dispersion of gases in porous media under low pressure (15, 30 and 40 psig). The presumption was made that a critical velocity exists for a given displacement, below which the increase of velocity results in a decrease in dispersion, and above which an increase in dispersion occurs. An increase in pressure will decrease the mixing of gases when the displacement velocity remains constant.

  5. Inversion of synthetic geodetic data for dip-slip faults: clues to the effects of lateral heterogeneities and data distribution in geological environments typical of the Apennines (Italy)

    NASA Astrophysics Data System (ADS)

    Amoruso, A.; Barba, S.; Crescentini, L.; Megna, A.

    2013-02-01

    The inversion of geodetic data to obtain earthquake parameters is often performed by assuming that the medium is isotropic, elastic and either homogeneous or layered. The layered medium often offers the best estimate of the structure of the crust; however, predicted displacements and observed data may differ beyond the measurement errors. The slip distribution on the fault plane is usually obtained by dividing the best uniform slipping fault into an arbitrarily large number of subfaults and minimizing a cost function that includes a smoothness (Laplacian) term and a data misfit term. The smoothing factor controls the trade-off between the smoothness and the goodness-of-fit. The main focus of this work is the determination and effect of the smoothing parameter. We conducted several inversion tests of noiseless synthetic surface displacement due to faults embedded in media with properties consistent with the geology of the Central Apennines (Italy), where the 2009 April 6, L'Aquila earthquake occurred. We used the following three-step procedure: (i) global optimization with no smoothness constraint for a fault divided into a small number of equally sized equal-rake subfaults; (ii) selection of the best fault parameters using information criteria and (iii) evaluation of the slip amplitude distribution on an expanded fault after choosing the smoothing factor from trade-off curves or from cross-validation for different numbers of subfaults. We show that all of the fault features obtained by the inversion procedure, including the slip distribution, agree with those (`true') used in the forward modelling when the data cover the majority of the displacement field. Notable departures from the true slip distribution occur when a suboptimal smoothing factor (obtained from the trade-off curves or cross-validation) is used. If different crustal stratifications are used in the inversions, the best results are obtained for the stratification that is the closest to the true crustal structure. When we use more realistic GPS distributions, prominent spurious slip patches can be obtained. Modellers should use synthetic tests and sensitivity analyses as an initial step in the data inversion for source parameters.

  6. CO2 injection modeling in large scale heterogeneous aquifers

    NASA Astrophysics Data System (ADS)

    Audigane, P. D.; Michel, A.; Trenty, L.; Yamamoto, H.; Gabalda, S.; Anciaux Sedrakian, A.; Chiaberge, C.

    2011-12-01

    Numerical modeling of CO2 injection in heterogeneous media remains a challenging issue with actual computing facilities when considering large size models. In addition, the lack of data available for modeling calibration induces a large degree of uncertainties on the reservoir heterogeneity estimates. We propose here the study of three scenarios using different geological context. The first case is based on the Tenth SPE Comparative Solution Project Model 2. This fine-scale geological model contains 1.1 million cells with a top part representative of a prograding near shore environment while the lower part is fluvial. Simulated CO2 injection has been conducted considering the possibility of water re-injection to maintain the overpressure below the fracture pressure. The second case is based on the French Paris Basin geological context. The area covers a 100 km by 100 km domain (South East of Paris) in which data from about 70 wells and seismic grid have been used to build a 3D grid containing the Dogger carbonate formation as well as the lower part of the Oxfordian clay formation (the caprock) and the upper part of the Aalenian (below the Dogger). Major faults of the geological system have also been incorporated in the structural scheme. Petrophysical properties have been generated using stochastic approach. Porosity variability is simulated for each facies and correlated to permeability. Injection point has been selected in order to avoid fault reactivation. The last case is a representative of the Trias geological formation in France. The 3D regular Cartesian grid contains facies variability built using process based method to represent fluvial deposit architecture. The high geothermal gradient identified in this geological formation allows for the consideration of geothermal production. In this context, we performed CO2 injection simulation to evaluate the mass flow and heat extraction rates from enhanced geothermal injection-production systems using CO2 as heat transmission fluid. Two numerical codes have been used to perform the simulation and handling the high computing demand: (i) TOUGH2-MP, a parallel version of the TOUGH2 code; and (ii) COORES, a black oil reservoir simulator developed at IFPEN. From this study, the limitations of flow simulator to provide pertinent evaluation of overpressure, and plume migration with regard to the considered scale and the role of reservoir heterogeneities on the CO2 storage performance and security is discussed and analyzed.

  7. Geological summary of the Busidima Formation (Plio-Pleistocene) at the Hadar paleoanthropological site, Afar Depression, Ethiopia.

    PubMed

    Campisano, Christopher J

    2012-03-01

    The Hadar paleoanthropological site in Ethiopia preserves a record of hominin evolution spanning from approximately 3.45 Ma to 0.8 Ma. An angular unconformity just above the ca. 2.95 Ma BKT-2 complex divides the sediments into the Hadar Formation (ca. 3.8-2.9Ma) and the Busidima Formation (ca. 2.7-0.15 Ma). The unconformity is likely a response to a major tectonic reorganization in the Afar Depression, and activation of the As Duma fault near the Ethiopian Escarpment (west of Hadar) created a half-graben in which the Busidima Formation was deposited. The pattern and character of sedimentation in the region changed dramatically above the unconformity, as cut-and-fill channel conglomerates and silt-dominated paleosols that comprise the Busidima Formation stand in sharp contrast to the underlying deposits of the Hadar Formation. Conglomerate deposition has been related to both the perennial, axial paleo-Awash and ephemeral, escarpment-draining tributaries. Overbank silts have yielded fossils attributed to early Homo and Oldowan stone tools. Numerous tuffaceous deposits exist within the Busidima Formation, but they are often spatially limited, fine-grained, and reworked. Recent work on the tephrostratigraphic framework of the Busidima Formation at Hadar has identified at least 12 distinct vitric tephras and established the first geochemical-based correlations between Hadar and the neighboring project areas of Gona and Dikika. Compared to Gona and Dikika, where Busidima Formation sediments are exposed over large areas, the highly discontinuous sediments at Hadar comprise less than 40 m in composite section and are exposed over an area of <20 km(2), providing only snapshots into the 2.7-0.15 Ma window. The stratigraphic record at Hadar confirms the complex depositional history of the Busidima Formation, and also provides important details on regional stratigraphic correlations and the pattern of deposition and erosion in the lower Awash Valley reflective of its tectonic history. PMID:21762952

  8. An integrated multi-scale hydrogeological model for performance and safety assessment of French geological high level and long live radwaste disposal in clay formation

    NASA Astrophysics Data System (ADS)

    Benabderrahmane, H.; Cornaton, F. J.; Kerrou, J.

    2009-12-01

    A deep geological repository of high level and long live radwaste requires sound understanding of the far field and near field groundwater flow and transport properties. Andra, French National radioactive waste management Agency is developing since last 15 years, an integrated multi-scale hydrogeological model of whole Paris basin of 200'000 Km2 area (regional scale) to produce a regional flow field associated to groundwater behavior. It includes locally the Meuse / Haute Marne clay site of about 250 Km2 area in the eastern part of Paris basin that was chosen for the emplacement of a repository. Callovo-Oxfordian as host formation is a clay layer characterized by very low permeability, a mean thickness of 130 m at about 500 m depth and is embedded by calcareous formations as aquifers (Dogger and Oxfordian). The hydrogeological conceptual model is based on stratigraphic and petrophysic modeling of the Paris basin and is accounting for the sound structural, geological, hydrogeological and geochemical data in an integrated way. At Paris basin scale, the model is a multilayer system of 27 layers (hydrogeological units) from Trias to Tertiary. A refinement at local scale of the site defines 27 hydro-geological units from Trias to Portlandian within an area of 1800 Km2. Based on sound data acquisition from borehole and seismic campaigns performed by Andra, regional faults, minor and diffuse fractures are considered. A structural and petrophysical representation of the transition zone between the Paris basin scale and site scale, as well as a better handling of surface flow boundary conditions are considered. Finite element flow and transport simulator Ground Water code (GW) is used to solve for groundwater flow at steady-state in a 1.8 Million nodes model, considering current climatic conditions. The model is calibrated against about 1250 hydraulic head measurements, and results in maximum absolute hydraulic head differences of 20 meters at the regional scale and 5 meters at the local scale. The calibrated reference model includes transmissive major faults as well as structures acting as barrier to flow. Advective-dispersive age solutions are also carried out and compared to available age dates of pore water within the two main calcareous aquifers (Dogger and Oxfordian) that embed Callovo-Oxfordian host formation, to consolidate calibration of flow and to analyze internal water mixing processes and hydraulic behavior of major faults. Lifetime expectancy solutions combined with age solutions are also used to map in the 3-D space the low- and high-speed flow zones at the local scale.

  9. Formation of gas-phase carbonyls from heterogeneous oxidation of polyunsaturated fatty acids at the air-water interface and of the sea surface microlayer

    NASA Astrophysics Data System (ADS)

    Zhou, S.; Gonzalez, L.; Leithead, A.; Finewax, Z.; Thalman, R.; Vlasenko, A.; Vagle, S.; Miller, L. A.; Li, S.-M.; Bureekul, S.; Furutani, H.; Uematsu, M.; Volkamer, R.; Abbatt, J.

    2014-02-01

    Motivated by the potential for reactive heterogeneous chemistry occurring at the ocean surface, gas-phase products were observed when a reactive sea surface microlayer (SML) component, i.e. the polyunsaturated fatty acids (PUFA) linoleic acid (LA), was exposed to gas-phase ozone at the air-seawater interface. Similar oxidation experiments were conducted with SML samples collected from two different oceanic locations, in the eastern equatorial Pacific Ocean and from the west coast of Canada. Online proton-transfer-reaction mass spectrometry (PTR-MS) University of Colorado light-emitting diode cavity-enhanced differential optical absorption spectroscopy (LED-CE-DOAS) were used to detect oxygenated gas-phase products from the ozonolysis reactions. The LA studies indicate that oxidation of a PUFA monolayer on seawater gives rise to prompt and efficient formation of gas-phase aldehydes. The products are formed via the decomposition of primary ozonides which form upon the initial reaction of ozone with the carbon-carbon double bonds in the PUFA molecules. In addition, two highly reactive dicarbonyls, malondialdehyde (MDA) and glyoxal, were also generated, likely as secondary products. Specific yields relative to reactant loss were 78%, 29%, 4% and < 1% for n-hexanal, 3-nonenal, MDA and glyoxal, respectively, where the yields for MDA and glyoxal are likely lower limits. Heterogeneous oxidation of SML samples confirm for the first time that similar carbonyl products are formed via ozonolysis of environmental samples.

  10. Banded iron-formations of late Proterozoic age in the central eastern desert, Egypt: geology and tectonic setting.

    USGS Publications Warehouse

    Sims, P.K.; James, H.L.

    1984-01-01

    Iron-formation occurs as stratigraphic units within a layered andesite-basalt sequence. The sequence is metamorphosed to greenschist facies, intruded by syntectonic granodiorite and post-tectonic granite, and complexly deformed and grossly fragmented; the rocks are allochthonous along thrust faults. The iron deposits are chemical precipitates, accumulated during lulls in volcanism, apparently in an intraoceanic island-arc environment. The deposits are of the Algoma type of iron-formation.-G.J.N.

  11. Mining geology of the Pond Creek seam, Pikeville Formation, Middle Pennsylvanian, in part of the Eastern Kentucky Coal Field, USA

    USGS Publications Warehouse

    Greb, S.F.; Popp, J.T.

    1999-01-01

    The Pond Creek seam is one of the leading producers of coal in the Eastern Kentucky Coal Field. The geologic factors that affect mining were investigated in several underground mines and categorized in terms of coal thickness, coal quality, and roof control. The limits of mining and thick coal are defined by splitting along the margin of the coal body. Within the coal body, local thickness variation occurs because of (1) leader coal benches filling narrow, elongated depressions, (2) rider coal benches coming near to or merging with the main bench, (3) overthrust coal benches being included along paleochannel margins, (4) cutouts occuring beneath paleochannels, and (5) very hard and unusual rock partings occuring along narrow, elongated trends. In the study area, the coal is mostly mined as a compliance product: sulfur contents are less than 1% and ash yields are less than 10%. Local increases in sulfur occur beneath sandstones, and are inferred to represent post-depositional migration of fluids through porous sands into the coal. Run-of-mine quality is also affected by several mine-roof conditions and trends of densely concentrated rock partings, which lead to increased in- and out-of-seam dilution and overall ash content of the mined coal. Roof control is largely a function of a heterolithic facies mosaic of coastal-estuarine origin, regional fracture trends, and unloading stress related to varying mine depth beneath the surface. Lateral variability of roof facies is the rule in most mines. The largest falls occur beneath modern valleys and parallel fractures, along paleochannel margins, within tidally affected 'stackrock,' and beneath rider coals. Shale spalling, kettlebottoms, and falls within other more isolated facies also occur. Many of the lithofacies, and falls related to bedding weaknesses within or between lithofacies, occur along northeast-southwest trends, which can be projected in advance of mining. Fracture-related falls occur independently of lithofacies trends along northwest-southeast trends, especially beneath modern valleys where overburden thickness decreases sharply. Differentiating roof falls related to these trends can aid in predicting roof quality in advance of mining.The Pond Creek-Lower Elkhorn seam has been an important exploration target because it typically has very low sulfur contents and ash yields. Geologic research in several large Pond Creek mines suggested variability in roof quality and coal thickness. Due to mine access, geologic problems encountered during mining are documented and described.

  12. YOUNG GEOLOGY GEOLOGY OF THE

    E-print Network

    Seamons, Kent E.

    YOUNG GEOLOGY UNIVERSITY May, 1962 GEOLOGY OF THE SOUTHERN WASATCH MOUNTAINS AND VICIN~IM,UTAH C O ....................J. Keith Rigby 80 Economic Geology of North-Central Utah ...,............... Kcnneth C.Bdodc 85 Rod Log ........................Lehi F. Hintze, J. Ka# Ri&, & ClydeT. Hardy 95 Geologic Map of Southern

  13. The geologic mapping of asteroid Vesta

    NASA Astrophysics Data System (ADS)

    Williams, D.; Yingst, A.; Garry, B.

    2014-07-01

    As part of NASA's Dawn mission [1,2] we conducted a geologic mapping campaign to provide a systematic, cartography-based initial characterization of the global and regional geology of asteroid Vesta. The goal of geological maps is to place observations of surface features into their stratigraphic context to develop a geologic history of the evolution of planetary surfaces. Geologic mapping reduces the complexity of heterogeneous planetary surfaces into comprehensible portions, defining and characterizing discrete material units based upon physical attributes related to the geologic processes that produced them, and enabling identification of the relative roles of various processes (impact cratering, tectonism, volcanism, erosion and deposition) in shaping planetary surfaces [3,4]. The Dawn Science Team produced cartographic products of Vesta from the Framing Camera images, including global mosaics as well as 15 regional quadrangles [5], which served as bases for the mapping. We oversaw the geologic mapping campaign during the Nominal Mission, including production of a global geologic map at scale 1:500,000 using images from the High Altitude Mapping Orbit [6] and 15 quadrangle geologic maps at scale 1:250,000 using images from the Low Altitude Mapping Orbit [7]. The goal was to support the Dawn Team by providing geologic and stratigraphic context of surface features and supporting the analysis of data from the Visible and Infrared Spectrometer (VIR) and the Gamma Ray and Neutron Detector (GRaND). Mapping was done using ArcGIS™ software, in which quadrangle mapping built on interpretations derived from the global geologic map but were updated and modified to take advantage of the highest spatial resolution data. Despite challenges (e.g., Vesta's highly sloped surface [8] deforms impact craters and produces mass movements that buries contacts), we were successfully able to map the whole surface of Vesta and identify a geologic history as represented in our maps and the resulting time-stratigraphic system and geologic timescale. Key results from the geologic mapping of Vesta include: 1) surface units are dominated by features and materials produced by two major impact events, the older Veneneia and younger Rheasilvia impacts at the south pole 2) both impacts produced a ridge-and-trough terrain as a tectonic response to the impacts, mapped as the Saturnalia Fossae and the Divalia Fossae Formations, respectively 3) stratigraphic analysis of Vesta's heavily cratered terrains show that portions of the original crust are preserved and predate the Veneneia impact 4) the Marcia impact event marks the beginning of Vesta's final stratigraphic period, including exposure of fresh bright and dark material and preservation of young bright-rayed and dark-rayed craters. We conclude that a geologic mapping campaign, including both global and regional mapping, can be conducted during the limited planetary nominal mission timeline, and is an excellent way to engage younger team members (graduate students and postdocs) in mission data analysis activities.

  14. CO{sub 2} Sequestration Capacity and Associated Aspects of the Most Promising Geologic Formations in the Rocky Mountain Region: Local-Scale Analyses

    SciTech Connect

    Laes, Denise; Eisinger, Chris; Morgan, Craig; Rauzi, Steve; Scholle, Dana; Scott, Phyllis; Lee, Si-Yong; Zaluski, Wade; Esser, Richard; Matthews, Vince; McPherson, Brian

    2013-07-30

    The purpose of this report is to provide a summary of individual local-­?scale CCS site characterization studies conducted in Colorado, New Mexico and Utah. These site-­? specific characterization analyses were performed as part of the “Characterization of Most Promising Sequestration Formations in the Rocky Mountain Region” (RMCCS) project. The primary objective of these local-­?scale analyses is to provide a basis for regional-­?scale characterization efforts within each state. Specifically, limits on time and funding will typically inhibit CCS projects from conducting high-­? resolution characterization of a state-­?sized region, but smaller (< 10,000 km{sup 2}) site analyses are usually possible, and such can provide insight regarding limiting factors for the regional-­?scale geology. For the RMCCS project, the outcomes of these local-­?scale studies provide a starting point for future local-­?scale site characterization efforts in the Rocky Mountain region.

  15. Stress heterogeneity observed in Barnett Shale, TX, and its relation to the distribution of clay-rich ductile formations

    Microsoft Academic Search

    H. Sone; M. D. Zoback

    2010-01-01

    An FMI image log from a vertical well in Barnett Shale, Fort Worth Basin, TX shows that the state of stress is locally perturbed at depth ranges around the shale formation (8260-8740 ft). Above the Barnett Shale, drilling-induced tensile fractures (DITFs) are parallel to the vertical wellbore axis, indicating that the vertical principal stress is essentially parallel to the wellbore

  16. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2004-02-25

    The University of Alabama, in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company, has undertaken an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary goal of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. Geoscientific reservoir property, geophysical seismic attribute, petrophysical property, and engineering property characterization has shown that reef (thrombolite) and shoal reservoir lithofacies developed on the flanks of high-relief crystalline basement paleohighs (Vocation Field example) and on the crest and flanks of low-relief crystalline basement paleohighs (Appleton Field example). The reef thrombolite lithofacies have higher reservoir quality than the shoal lithofacies due to overall higher permeabilities and greater interconnectivity. Thrombolite dolostone flow units, which are dominated by dolomite intercrystalline and vuggy pores, are characterized by a pore system comprised of a higher percentage of large-sized pores and larger pore throats. Rock-fluid interactions (diagenesis) studies have shown that although the primary control on reservoir architecture and geographic distribution of Smackover reservoirs is the fabric and texture of the depositional lithofacies, diagenesis (chiefly dolomitization) is a significant factor that preserves and enhances reservoir quality. The evaporative pumping mechanism is favored to explain the dolomitization of the thrombolite doloboundstone and dolostone reservoir flow units at Appleton and Vocation Fields. Geologic modeling, reservoir simulation, and the testing and applying the resulting integrated geologic-engineering models have shown that little oil remains to be recovered at Appleton Field and a significant amount of oil remains to be recovered at Vocation Field through a strategic infill drilling program. The drive mechanisms for primary production in Appleton and Vocation Fields remain effective; therefore, the initiation of a pressure maintenance program or enhanced recovery project is not required at this time. The integrated geologic-engineering model developed for a low-relief paleohigh (Appleton Field) was tested for three scenarios involving the variables of present-day structural elevation and the presence/absence of potential reef thrombolite lithofacies. In each case, the predictions based upon the model were correct. From this modeling, the characteristics of the ideal prospect in the basement ridge play include a low-relief paleohigh associated with dendroidal/chaotic thrombolite doloboundstone and dolostone that has sufficient present-day structural relief so that these carbonates rest above the oil-water contact. Such a prospect was identified from the modeling, and it is located northwest of well Permit No. 3854B (Appleton Field) and south of well No. Permit No.11030B (Northwest Appleton Field).

  17. Geologic Map Database of Texas

    USGS Publications Warehouse

    Stoeser, Douglas B.; Shock, Nancy; Green, Gregory N.; Dumonceaux, Gayle M.; Heran, William D.

    2005-01-01

    The purpose of this report is to release a digital geologic map database for the State of Texas. This database was compiled for the U.S. Geological Survey (USGS) Minerals Program, National Surveys and Analysis Project, whose goal is a nationwide assemblage of geologic, geochemical, geophysical, and other data. This release makes the geologic data from the Geologic Map of Texas available in digital format. Original clear film positives provided by the Texas Bureau of Economic Geology were photographically enlarged onto Mylar film. These films were scanned, georeferenced, digitized, and attributed by Geologic Data Systems (GDS), Inc., Denver, Colorado. Project oversight and quality control was the responsibility of the U.S. Geological Survey. ESRI ArcInfo coverages, AMLs, and shapefiles are provided.

  18. Petroleum systems and geologic assessment of undiscovered oil and gas, Cotton Valley group and Travis Peak-Hosston formations, East Texas basin and Louisiana-Mississippi salt basins provinces of the northern Gulf Coast region. Chapters 1-7.

    USGS Publications Warehouse

    U.S. Geological Survey

    2006-01-01

    The purpose of the U.S. Geological Survey's (USGS) National Oil and Gas Assessment is to develop geologically based hypotheses regarding the potential for additions to oil and gas reserves in priority areas of the United States. The USGS recently completed an assessment of undiscovered oil and gas potential of the Cotton Valley Group and Travis Peak and Hosston Formations in the East Texas Basin and Louisiana-Mississippi Salt Basins Provinces in the Gulf Coast Region (USGS Provinces 5048 and 5049). The Cotton Valley Group and Travis Peak and Hosston Formations are important because of their potential for natural gas resources. This assessment is based on geologic principles and uses the total petroleum system concept. The geologic elements of a total petroleum system include hydrocarbon source rocks (source rock maturation, hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy and petrophysical properties), and hydrocarbon traps (trap formation and timing). The USGS used this geologic framework to define one total petroleum system and eight assessment units. Seven assessment units were quantitatively assessed for undiscovered oil and gas resources.

  19. Advances in Planetary Geology

    NASA Technical Reports Server (NTRS)

    Grant, John A., III; Nedell, Susan S.

    1987-01-01

    The surface of Mars displays a broad range of channel and valley features. There is as great a range in morphology as in scale. Some of the features of Martian geography are examined. Geomorphic mapping, crater counts on selected surfaces, and a detailed study of drainage basins are used to trace the geologic evolution of the Margaritifer Sinus Quandrangle. The layered deposits in the Valles Marineris are described in detail and the geologic processes that could have led to their formation are analyzed.

  20. Kinetic Monte Carlo simulation of surface heterogeneity in graphite anodes for lithium-ion batteries: Passive layer formation

    Microsoft Academic Search

    Ravi N. Methekar; Paul W. C. Northrop; Kejia Chen; Richard D. Braatz; Venkat R. Subramanian

    2011-01-01

    The properties and chemical composition of the solid-electrolyte-interface (SEI) layer have been a subject of intense research due to their importance in the safety, capacity fade, and cycle life of Li-ion secondary batteries. Kinetic Monte Carlo (KMC) simulation is applied to explore the formation of the passive SEI layer in the tangential direction of the lithium- ion intercalation in a

  1. Evaluation of the geological relationships to gas hydrate formation and stability. Progress report, June 16--September 30, 1988

    SciTech Connect

    Krason, J.; Finley, P.

    1988-12-31

    The summaries of regional basin analyses document that potentially economic accumulations of gas hydrates can be formed in both active and passive margin settings. The principal requirement for gas hydrate formation in either setting is abundant methane. Passive margin sediments with high sedimentation rates and sufficient sedimentary organic carbon can generate large quantities of biogenic methane for hydrate formation. Similarly, active margin locations near a terrigenous sediment source can also have high methane generation potential due to rapid burial of adequate amounts of sedimentary organic matter. Many active margins with evidence of gas hydrate presence correspond to areas subject to upwelling. Upwelling currents can enhance methane generation by increasing primary productivity and thus sedimentary organic carbon. Structural deformation of the marginal sediments at both active and passive sites can enhance gas hydrate formation by providing pathways for migration of both biogenic and thermogenic gas to the shallow gas hydrate stability zone. Additionally, conventional hydrocarbon traps may initially concentrate sufficient amounts of hydrocarbons for subsequent gas hydrate formation.

  2. The geological significance of the boundary between the Fort Sill and Signal Mountain Formations in the lower Arbuckle Group (Cambrian)

    SciTech Connect

    Hosey, R.; Donovan, R.N. (Texas Christian Univ., Ft Worth, TX (United States). Geology Dept.)

    1993-02-01

    During the upper Cambrian, a transgression inundated the Southern Oklahoma aulacogen enveloping a landscape that consisted of hills of Cambrian-aged rhyolite up to 350 m in height. Initial deposits on this topography--the Reagan Formation--consist of siliciclastics that were deposited as alluvium and succeeding tidally-influenced marine sandstones and shales. The siliciclastics grains are made up of local rhyolite, quartz and authigenic glauconite. The overlying Honeycreek Formation is defined by the addition of carbonated detritus in the form of tidally-influenced pelmatozoan grainstones. The passage from the Honeycreek to the overlying Fort Sill Formation of the Arbuckle Group is marked by the incoming of beds of lime mudstone and the gradual disappearance of grainstones and siliciclastics. The contact between the Fort Sill and the overlying thinly-bedded dark grey bioclastic limestones of the Signal Mountain Formation is one of the most distinctive horizons in the Arbuckle Group. The contact evidently marks a substantial change in depositional environment. In detail the contact is sharp and shows evidence of minor erosion, although no karsting has been detected. The authors suggest that the contact surface records a regression, perhaps associated with dolomitization and followed by some erosion. A regression is also indicated by the local occurrence of a laminated tidal flat unit with traces of evaporites that outcrops in the far west of the Slick Hills immediately below the formation contact. They suggest that the Signal Mountains as a transgressive unit, incorporating siliciclastics transported into the area during the regression. It has been suggested that the unconformity reflects localized tectonism associated with the evolution of the Southern Oklahoma aulacogen. On the other hand the surface may correlate with a craton--wide Sauxian' hiatus.

  3. National Geologic Map Database

    NSDL National Science Digital Library

    1997-01-01

    The National Geologic Map Database (NGMDB) is an Internet-based system for query and retrieval of earth-science map information, created as a collaborative effort between the USGS and the Association of American State Geologists. Its functions include providing a catalog of available map information; a data repository; and a source for general information on the nature and intended uses of the various types of earth-science information. The map catalog is a comprehensive, searchable catalog of all geoscience maps of the United States, in paper or digital format. It includes maps published in geological survey formal series and open-file series, maps in books, theses and dissertations, maps published by park associations, scientific societies, and other agencies, as well as publications that do not contain a map but instead provide a geological description of an area (for example, a state park). The geologic-names lexicon (GEOLEX) is a search tool for lithologic and geochronologic unit names. It now contains roughly 90% of the geologic names found in the most recent listing of USGS-approved geologic names. Current mapping activities at 1:24,000- and 1:100,000-scale are listed in the Geologic Mapping in Progress Database. Information on how to find topographic maps and list of geology-related links is also available.

  4. Geologic structure generated by large-impact basin formation observed at the South Pole-Aitken basin on the Moon

    NASA Astrophysics Data System (ADS)

    Ohtake, Makiko; Uemoto, Kisara; Yokota, Yasuhiro; Morota, Tomokatsu; Yamamoto, Satoru; Nakamura, Ryosuke; Haruyama, Junichi; Iwata, Takahiro; Matsunaga, Tsuneo; Ishihara, Yoshiaki

    2014-04-01

    The South Pole-Aitken (SPA) basin is the largest clearly recognized basin on the lunar surface. Determining the composition and structure of the SPA basin interior provides critical constraints on the deep crustal and/or mantle composition of the Moon and improves our understanding of large-basin-forming impact processes. Here we present a new mineralogical map of the SPA basin interior, based on high-spatial-resolution reflectance spectra using the SELENE (Kaguya) multiband imager, which is combined with topographic data in order to interpret the geologic context. The derived mineralogical map suggests extensive distribution of ejected low-Ca pyroxene-dominant mantle material with the presence of purest anorthosite crustal materials surrounding a possible melt pool of 0.26 to 0.33 of the basin diameter near the basin center, which is significantly smaller than that suggested by the crater-scaling law. The absence of clear evidence of lower crustal material is consistent with recent impact simulation results.

  5. Geology of the reservoirs from interval I of the Oficina formation, Greater Oficina area, eastern Venezuela Basin

    SciTech Connect

    Rivero, C.A.; Scherer, W. [Intevep, S.A., Los Teques (Venezuela)

    1996-08-01

    In order to determine the geologic features of the reservoirs and their areal statistical distribution and geometry, a study was made of a selected interval where the sands present less coalescence and the reservoirs are clearly defined. The study area comprises 1900 km{sup 2} of the Greater Oficina area; core samples, logs and reservoir maps were used. It was found that interval I consists of interbedded sandstones, shales, some siltstone, and occasionally lignites. Based upon lithologic mesoscopic features, eight (8) characteristic lithofacies could be defined. Rocks classified as sub-litharenites, sub-arkoses, arkoses lithic sandstones and graywackes could be inferred as belonging to a fluvio-deltaic system sourced on the Pre-Cambrian Guayana shield. The diagenetic level reached by the sequence corresponds to the intermediate stage, where significant processes of cementation by oxides, carbonates and silica are of equal intensity and magnitude to the lixiviation of feldspars and other detritic particles, giving these rooks good potential reservoir qualities. Descriptive statistical evaluation was performed on 140 reservoirs representing all lithofacies populations in this interval. Based on this analysis reservoirs were statistically grouped in classes which are a function of their geometry, spatial location and type of hydrocarbon content.

  6. Measuring resistivity changes from within a first cased well to monitor fluids injected into oil bearing geological formations from a second cased well while passing electrical current between the two cased wells

    DOEpatents

    Vail, III, William B. (Bothell, WA)

    1993-01-01

    A.C. current is conducted through geological formations separating two cased wells in an oil field undergoing enhanced oil recovery operations such as water flooding operations. Methods and apparatus are disclosed to measure the current leakage conducted into a geological formation from within a first cased well that is responsive to fluids injected into formation from a second cased well during the enhanced oil production activities. The current leakage and apparent resistivity measured within the first cased well are responsive to fluids injected into formation from the second cased well provided the distance of separation between the two cased wells is less than, or on the order of, a Characteristic Length appropriate for the problem.

  7. Measuring resistivity changes from within a first cased well to monitor fluids injected into oil bearing geological formations from a second cased well while passing electrical current between the two cased wells

    DOEpatents

    Vail, W.B. III.

    1993-02-16

    A.C. current is conducted through geological formations separating two cased wells in an oil field undergoing enhanced oil recovery operations such as water flooding operations. Methods and apparatus are disclosed to measure the current leakage conducted into a geological formation from within a first cased well that is responsive to fluids injected into formation from a second cased well during the enhanced oil production activities. The current leakage and apparent resistivity measured within the first cased well are responsive to fluids injected into formation from the second cased well provided the distance of separation between the two cased wells is less than, or on the order of, a Characteristic Length appropriate for the problem.

  8. Geological images

    NSDL National Science Digital Library

    Marli Bryant Miller

    This site from Marli Bryant Miller, a professor at the University of Oregon, presents images of geological features from around the world. Photographs of glacial features, igneous and metamorphic rocks and processes, and structural geology are featured.

  9. Structural Geology

    NSDL National Science Digital Library

    Created by the University of Nebraska-Lincoln, this site describes the basics of structural geology with text and images. The page includes the discussion of stress, strain, strike and dip, faults, folds, mountain building, erosion, economic geology, and environmental geology. This is a nice introduction to the basic topics in geology. Images from the field help to enhance the topics on the site. Instructors can use this resource to help create or simply enhance their curriculum.

  10. Radionuclide migration in clayrock host formations for deep geological disposal of radioactive waste: advances in process understanding and up-scaling methods resulting from the EC integrated project `Funmig

    Microsoft Academic Search

    S. Altmann; C. Tournassat; F. Goutelard; J. C. Parneix; T. Gimmi; N. Maes

    2009-01-01

    One of the `pillars' supporting Safety Cases for deep geological disposal of radioactive waste in clayrock formations is the knowledge base regarding radionuclide (Rn) retention by sorption and diffusion-driven transport which is why the EC integrated project `Funmig' focused a major part of its effort on advancing understanding of these two macroscopic phenomena. This talk presents some of the main

  11. Geological Time

    NSDL National Science Digital Library

    "Why do engineers need to know about geologic time?" That question is answered in this resource from the University of Saskatchewan's Department of Civil and Geological Engineering. Provided here is a discussion of the concepts of geological time; relative dating methods, such as correlation; and absolute dating methods, such as radiometric methods. Diagrams and charts are included to demonstrate these complex concepts.

  12. Geological cycles

    Microsoft Academic Search

    B. P. Hageman

    1972-01-01

    During the last hundred years, intensive studies have been made on the geological indications of the so called “Ice Ages”;. Already Penck and Bruckner discovered, around the end of the nineteenth century, the cyclic character of these phenomena and distinguished at least four cycles in the Alps area. In fact these geological cycles are controlled by climatic conditions. The geological

  13. Structural Geology

    NSDL National Science Digital Library

    This site contains a variety of resources for faculty members who teach undergraduate structural geology. You will find links to activities and assignments, internet and computer resources, useful articles and maps, presentations from the summer 2004 workshop on teaching structural geology, working groups and a discussion forum, and lots of creative ideas for teaching structural geology.

  14. Geology and petrology of the Hormuz dolomite, Infra-Cambrian: Implications for the formation of the salt-cored Halul and Shraouh islands, Offshore, State of Qatar

    NASA Astrophysics Data System (ADS)

    Nasir, Sobhi; Al-Saad, Hamad; Alsayigh, Abudlrazak; Weidlich, Oliver

    2008-08-01

    Geological investigations of the Halul and the Shraouh islands, offshore Qatar, indicate that most of their calcareous rocks, which display abundant stromatolitic bedding, belong to the Infra-Cambrian Hormuz Series. Mineralogical, petrological, and geochemical analyses show that these calcareous rocks consist dominantly of dolomite and have formed in a reducing depositional environment. Faint laminations and small streaks of organic matter furnish evidence for the involvement of algal mats in their genesis and indicate their formation in an intertidal to supratidal setting. The Halul and Shraouh dolomites experienced extensive recrystallization and sulfatization during the emplacement of the Halul and Shraouh salt domes that form the cores of the islands. During mobilization and ascent of the salt, the dolomite recrystallized, and its Sr initial ratios were abnormally enhanced by the incorporation of 87Sr from a source, which is more radiogenic than the attendant seawater at the time of the dolomite formation near the Proterozoic-Cambrian boundary. Geochemical analysis show that Si, Al, Ti Zr, and % of insoluble residue are highly correlative, suggesting the presence of detrital minerals such as rutile and zircon. A paleosabkha model may well agree with this chemical signature. However, the Infra-Cambrian age of the Hormuz rocks and the presence of stromatolitic layers containing organic materials in the studied rocks, suggest that organogenic dolomitization could be an alternative dolomitization model.

  15. GeoTemp™ 1.0: A MATLAB-based program for the processing, interpretation and modelling of geological formation temperature measurements

    NASA Astrophysics Data System (ADS)

    Ricard, Ludovic P.; Chanu, Jean-Baptiste

    2013-08-01

    The evaluation of potential and resources during geothermal exploration requires accurate and consistent temperature characterization and modelling of the sub-surface. Existing interpretation and modelling approaches of 1D temperature measurements are mainly focusing on vertical heat conduction with only few approaches that deals with advective heat transport. Thermal regimes are strongly correlated to rock and fluid properties. Currently, no consensus exists for the identification of the thermal regime and the analysis of such dataset. We developed a new framework allowing the identification of thermal regimes by rock formations, the analysis and modelling of wireline logging and discrete temperature measurements by taking into account the geological, geophysical and petrophysics data. This framework has been implemented in the GeoTemp software package that allows the complete thermal characterization and modelling at the formation scale and that provides a set of standard tools for the processing wireline and discrete temperature data. GeoTempTM operates via a user friendly graphical interface written in Matlab that allows semi-automatic calculation, display and export of the results. Output results can be exported as Microsoft Excel spreadsheets or vector graphics of publication quality. GeoTemp™ is illustrated here with an example geothermal application from Western Australia and can be used for academic, teaching and professional purposes.

  16. The Geology of the Terrestrial Planets

    NASA Technical Reports Server (NTRS)

    Carr, M. H. (editor); Saunders, R. S.; Strom, R. G.; Wilhelms, D. E.

    1984-01-01

    The geologic history of the terrestrial planets is outlined in light of recent exploration and the revolution in geologic thinking. Among the topics considered are planet formation; planetary craters, basins, and general surface characteristics; tectonics; planetary atmospheres; and volcanism.

  17. The relationship of dynamical heterogeneity to the Adam-Gibbs and random first-order transition theories of glass formation.

    PubMed

    Starr, Francis W; Douglas, Jack F; Sastry, Srikanth

    2013-03-28

    We carefully examine common measures of dynamical heterogeneity for a model polymer melt and test how these scales compare with those hypothesized by the Adam and Gibbs (AG) and random first-order transition (RFOT) theories of relaxation in glass-forming liquids. To this end, we first analyze clusters of highly mobile particles, the string-like collective motion of these mobile particles, and clusters of relative low mobility. We show that the time scale of the high-mobility clusters and strings is associated with a diffusive time scale, while the low-mobility particles' time scale relates to a structural relaxation time. The difference of the characteristic times for the high- and low-mobility particles naturally explains the well-known decoupling of diffusion and structural relaxation time scales. Despite the inherent difference of dynamics between high- and low-mobility particles, we find a high degree of similarity in the geometrical structure of these particle clusters. In particular, we show that the fractal dimensions of these clusters are consistent with those of swollen branched polymers or branched polymers with screened excluded-volume interactions, corresponding to lattice animals and percolation clusters, respectively. In contrast, the fractal dimension of the strings crosses over from that of self-avoiding walks for small strings, to simple random walks for longer, more strongly interacting, strings, corresponding to flexible polymers with screened excluded-volume interactions. We examine the appropriateness of identifying the size scales of either mobile particle clusters or strings with the size of cooperatively rearranging regions (CRR) in the AG and RFOT theories. We find that the string size appears to be the most consistent measure of CRR for both the AG and RFOT models. Identifying strings or clusters with the "mosaic" length of the RFOT model relaxes the conventional assumption that the "entropic droplets" are compact. We also confirm the validity of the entropy formulation of the AG theory, constraining the exponent values of the RFOT theory. This constraint, together with the analysis of size scales, enables us to estimate the characteristic exponents of RFOT. PMID:23556792

  18. The relationship of dynamical heterogeneity to the Adam-Gibbs and random first-order transition theories of glass formation

    PubMed Central

    Starr, Francis W.; Douglas, Jack F.; Sastry, Srikanth

    2013-01-01

    We carefully examine common measures of dynamical heterogeneity for a model polymer melt and test how these scales compare with those hypothesized by the Adam and Gibbs (AG) and random first-order transition (RFOT) theories of relaxation in glass-forming liquids. To this end, we first analyze clusters of highly mobile particles, the string-like collective motion of these mobile particles, and clusters of relative low mobility. We show that the time scale of the high-mobility clusters and strings is associated with a diffusive time scale, while the low-mobility particles' time scale relates to a structural relaxation time. The difference of the characteristic times for the high- and low-mobility particles naturally explains the well-known decoupling of diffusion and structural relaxation time scales. Despite the inherent difference of dynamics between high- and low-mobility particles, we find a high degree of similarity in the geometrical structure of these particle clusters. In particular, we show that the fractal dimensions of these clusters are consistent with those of swollen branched polymers or branched polymers with screened excluded-volume interactions, corresponding to lattice animals and percolation clusters, respectively. In contrast, the fractal dimension of the strings crosses over from that of self-avoiding walks for small strings, to simple random walks for longer, more strongly interacting, strings, corresponding to flexible polymers with screened excluded-volume interactions. We examine the appropriateness of identifying the size scales of either mobile particle clusters or strings with the size of cooperatively rearranging regions (CRR) in the AG and RFOT theories. We find that the string size appears to be the most consistent measure of CRR for both the AG and RFOT models. Identifying strings or clusters with the “mosaic” length of the RFOT model relaxes the conventional assumption that the “entropic droplets” are compact. We also confirm the validity of the entropy formulation of the AG theory, constraining the exponent values of the RFOT theory. This constraint, together with the analysis of size scales, enables us to estimate the characteristic exponents of RFOT. PMID:23556792

  19. Formation of gas-phase carbonyls from heterogeneous oxidation of polyunsaturated fatty acids at the air-water interface and of the sea surface microlayer

    NASA Astrophysics Data System (ADS)

    Zhou, S.; Gonzalez, L.; Leithead, A.; Finewax, Z.; Thalman, R.; Vlasenko, A.; Vagle, S.; Miller, L.; Li, S.-M.; Bureekul, S.; Furutani, H.; Uematsu, M.; Volkamer, R.; Abbatt, J.

    2013-07-01

    Motivated by the potential for reactive heterogeneous chemistry occurring at the ocean surface, gas-phase products were observed when a reactive sea surface microlayer (SML) component, i.e. the polyunsaturated fatty acid (PUFA) linoleic acid (LA), was exposed to gas-phase ozone at the air-seawater interface. Similar oxidation experiments were conducted with SML samples collected from two different oceanic locations, in the eastern equatorial Pacific Ocean and from the west coast of Canada. Online proton-transfer-reaction mass spectrometry (PTR-MS) and light-emitting diode cavity enhanced differential optical absorption spectroscopy (LED-CE-DOAS) were used to detect oxygenated gas-phase products from the ozonolysis reactions. The LA studies indicate that oxidation of a PUFA monolayer on seawater gives rise to prompt and efficient formation of gas phase aldehydes. The products are formed via the decomposition of primary ozonides which form upon the initial reaction of ozone with the carbon-carbon double bonds in the PUFA molecules. In addition, two highly reactive di-carbonyls, malondialdehyde (MDA) and glyoxal, were also generated, likely as secondary products. Specific yields relative to reactant loss were 78%, 29%, 4% and <1% for n-hexanal, 3-nonenal, MDA and glyoxal, respectively, where the yields for MDA and glyoxal are likely lower limits. Heterogeneous oxidation of SML samples confirm for the first time that similar carbonyl products are formed via ozonolysis of environmental samples. The potential impact of such chemistry on the atmosphere of the marine boundary layer is discussed.

  20. Geologic Reconnaissance of the Antelope-Ashwood Area, North-Central Oregon: With Emphasis on the John Day Formation of Late Oligocene and Early Miocene Age

    USGS Publications Warehouse

    Peck, Dallas L.

    1964-01-01

    This report briefly describes the geology of an area of about 750 square miles in Jefferson, Wasco, Crook, and Wheeler Counties, Oregon. About 16,000 feet of strata that range in age from pre-Tertiary to Quaternary are exposed. These include the following units: pre-Tertiary slate, graywacke, conglomerate, and meta-andesite; Clarno Formation of Eocene age - lava flows, volcanic breccia, tuff, and tuffaceous mudstone, chiefly of andesitic composition; John Day Formation of late Oligocene and early Miocene age - pyroclastic rocks, flows, and domes, chiefly of rhyolitic composition; Columbia River Basalt of middle Miocene age - thick, columnar jointed flows of very fine grained dense dark-gray basalt; Dalles Formation of Pliocene age - bedded tuffaceous sandstone, siltstone, and conglomerate; basalt of Pliocene or Pleistocene age - lava flows of porous-textured olivine basalt; and Quaternary loess, landslide debris, and alluvium. Unconformities separate pre-Tertiary rocks and Clarno Formation, Clarno and John Day Formations, John Day Formation and Columbia River Basalt, and Columbia River Basalt and Dalles Formation. The John Day Formation, the only unit studied in detail, consists of about 4,000 feet of tuff, lapilli tuff, strongly to weakly welded rhyolite ash flows, and less abundant trachyandesite flows and rhyolite flows and domes. The formation was divided into nine mappable members in part of the area, primarily on the basis of distinctive ledge-forming welded ash-flow sheets. Most of the sheets are composed of stony rhyolite containing abundant lithophysae and sparse phenocrysts. One sheet contains 10 to 20 percent phenocrysts, mostly cryptoperthitic soda sanidine, but including less abundant quartz, myrmekitic intergrowths of quartz and sanidine, and oligoclase. The rhyolitic ash flows and lava flows were extruded from nearby vents, in contrast to some of the interbedded air-fall tuff and lapilli tuff of dacitic and andesitic composition that may have been derived from vents in an ancestral Cascade Range. The John Day is dated on the basis of a late Oligocene flora near the base of the formation and early Miocene faunas near the top of the formation. The middle Miocene and older rocks in the Antelope-Ashwood area are broadly folded and broken along northeast-trending faults. Over much of the area the rocks dip gently eastward from the crest of a major fold and are broken along a series of steeply dipping antithetic strike faults. Pliocene and Quaternary strata appear to be undeformed. At the Priday agate deposit, chalcedony-filled spherulites (thunder-eggs) occur in the lower part of a weakly welded rhyolitic ash flow. The so-called thunder-eggs are small spheroidal bodies, about 3 inches in average diameter; each consists of a chalcedonic core surrounded by a shell of welded tuff that is altered to radially oriented fibers of cristobalite and alkalic feldspar.

  1. Separation and capture of CO2 from large stationary sources and sequestration in geological formations--coalbeds and deep saline aquifers.

    PubMed

    White, Curt M; Strazisar, Brian R; Granite, Evan J; Hoffman, James S; Pennline, Henry W

    2003-06-01

    The topic of global warming as a result of increased atmospheric CO2 concentration is arguably the most important environmental issue that the world faces today. It is a global problem that will need to be solved on a global level. The link between anthropogenic emissions of CO2 with increased atmospheric CO2 levels and, in turn, with increased global temperatures has been well established and accepted by the world. International organizations such as the United Nations Framework Convention on Climate Change (UNFCCC) and the Intergovernmental Panel on Climate Change (IPCC) have been formed to address this issue. Three options are being explored to stabilize atmospheric levels of greenhouse gases (GHGs) and global temperatures without severely and negatively impacting standard of living: (1) increasing energy efficiency, (2) switching to less carbon-intensive sources of energy, and (3) carbon sequestration. To be successful, all three options must be used in concert. The third option is the subject of this review. Specifically, this review will cover the capture and geologic sequestration of CO2 generated from large point sources, namely fossil-fuel-fired power gasification plants. Sequestration of CO2 in geological formations is necessary to meet the President's Global Climate Change Initiative target of an 18% reduction in GHG intensity by 2012. Further, the best strategy to stabilize the atmospheric concentration of CO2 results from a multifaceted approach where sequestration of CO2 into geological formations is combined with increased efficiency in electric power generation and utilization, increased conservation, increased use of lower carbon-intensity fuels, and increased use of nuclear energy and renewables. This review covers the separation and capture of CO2 from both flue gas and fuel gas using wet scrubbing technologies, dry regenerable sorbents, membranes, cryogenics, pressure and temperature swing adsorption, and other advanced concepts. Existing commercial CO2 capture facilities at electric power-generating stations based on the use of monoethanolamine are described, as is the Rectisol process used by Dakota Gasification to separate and capture CO2 from a coal gasifier. Two technologies for storage of the captured CO2 are reviewed--sequestration in deep unmineable coalbeds with concomitant recovery of CH4 and sequestration in deep saline aquifers. Key issues for both of these techniques include estimating the potential storage capacity, the storage integrity, and the physical and chemical processes that are initiated by injecting CO2 underground. Recent studies using computer modeling as well as laboratory and field experimentation are presented here. In addition, several projects have been initiated in which CO2 is injected into a deep coal seam or saline aquifer. The current status of several such projects is discussed. Included is a commercial-scale project in which a million tons of CO2 are injected annually into an aquifer under the North Sea in Norway. The review makes the case that this can all be accomplished safely with off-the-shelf technologies. However, substantial research and development must be performed to reduce the cost, decrease the risks, and increase the safety of sequestration technologies. This review also includes discussion of possible problems related to deep injection of CO2. There are safety concerns that need to be addressed because of the possibilities of leakage to the surface and induced seismic activity. These issues are presented along with a case study of a similar incident in the past. It is clear that monitoring and verification of storage will be a crucial part of all geological sequestration practices so that such problems may be avoided. Available techniques include direct measurement of CO2 and CH4 surface soil fluxes, the use of chemical tracers, and underground 4-D seismic monitoring. Ten new hypotheses were formulated to describe what happens when CO2 is pumped into a coal seam. These hypotheses provide significant insight into the fundamental chemical, physical, a

  2. Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity

    SciTech Connect

    Mancini, E.A.

    1990-01-01

    The objectives of this project are to augment the National Reservoir Database (TORIS database) and to increase our understanding of geologic heterogeneities that affect the recoveries of oil and gas from carbonate reservoirs in the State of Alabama and to identify those resources that are producible at moderate cost. These objectives will be achieved through detailed geological, engineering, and geostatistical characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the State of Alabama. The results of these studies will be used to develop and test mathematical models for prediction of the effects of reservoir heterogeneities in hydrocarbon production. Work to date has focused on the completion of Subtasks 1, 2, and 3. Subtask 1 included the survey and tabulation of available reservoir engineering and geological data relevant to the Smackover reservoir in southwestern Alabama. Subtask 2 comprises the geological and engineering characterization of Smackover reservoir lithofacies. This has been accomplished through detailed examination and analysis of geophysical well logs, core material, well cuttings, and well-test data from wells penetrating Smackover reservoirs in southwestern Alabama. From these data, reservoir heterogeneities, such as lateral and vertical changes in lithology, porosity, permeability, and diagenetic overprint, have been recognized and used to produce maps, cross sections, graphs, and other graphic representations to aid in interpretation of the geologic parameters that affect these reservoirs. Subtask 3 includes the geologic modeling of reservoir heterogeneities for Smackover reservoirs. This research has been based primarily on the evaluation of key geologic and engineering data from selected Smackover fields. 1 fig.

  3. Hometown Geology

    NSDL National Science Digital Library

    Stacey Cochiara

    Students are introduced to concepts in the course that give them the skills to understand geologic maps. These include structural geology, weathering processes, the geologic time scale, types of rocks and minerals, glacial geology, etc. They also look at several quadrangle maps as lab activities, including the Williamsville Quadrangle from Virginia and the Bright Angel Quadrangle from the Grand Canyon. This independent exercise allows students to further investigate their hometown or other areas of interest, and report on the geologic history. This further prepares them for more advanced courses and also gives them an appreciation of their surroundings, a key part of a geologist's training.

  4. Introduction to Geology

    NSDL National Science Digital Library

    Jagoutz, Oliver

    If you are having difficulty remembering the details of the Earth's geological structure or the nature of major minerals and rock types, you can consult this excellent introductory course offered as part of MIT's OpenCourseWare initiative. The materials are drawn from Professors Perron and Jagoutz's 2011 "Introduction to Geology" course, and they include a number of lecture notes, available for download in PDF file format. The course is designed for undergraduates, though anyone can benefit from examining the materials. Visitors can make their way through lecture notes that cover metamorphic rocks, rock deformation, earthquakes, and the formation of continents.

  5. Geology of the Deer Butte Formation, Malheur county, Oregon: faulting, sedimentation and volcanism in a post-caldera setting

    NASA Astrophysics Data System (ADS)

    Cummings, Michael L.

    1991-11-01

    The Deer Butte Formation accumulated during the middle Miocene in fault-controlled basins in an extensional setting. The basins developed as regional faults asserted influence after eruption of ash-flow sheets and collapse of calderas of the Lake Owyhee volcanic field. The sequences of Hurley Flat, Dry Creek, and Oxbow Basin contain a lower basalt tephradominated unit formed by basalt hydrovolcanism overlain by fine-grained fluvial and lacustrine volcaniclastic sedimentary units. The sequence of Freezeout Creek was deposited in an erosional valley that was incised into older units and cut across the concurrently active Wall Rock Ridge fault zone. The sequence of Hurley Flat and Dry Creek contain alkaline tholeiitic basalt flows and tephra deposits, whereas the sequences of Freezeout Creek and Oxbow Basin contain subalkaline calcalkaline basaltic andesite. The compositional change occurred after local uplift due to faulting along the Wall Rock Ridge fault zone. The youngest unit, well-sorted, medium-grained, muscovite-bearing arkose of the arkose of Dry Creek Buttes, was deposited in a large river that drained westward from source areas in western Idaho. The Deer Butte Formation was deposited between approximately 15 and 12.6 Ma, while basin and range-type faulting dominated regional structural patterns.

  6. Remote sensing of fugitive methane emissions from oil and gas production in North American tight geologic formations

    NASA Astrophysics Data System (ADS)

    Schneising, Oliver; Burrows, John P.; Dickerson, Russell R.; Buchwitz, Michael; Reuter, Maximilian; Bovensmann, Heinrich

    2014-10-01

    In the past decade, there has been a massive growth in the horizontal drilling and hydraulic fracturing of shale gas and tight oil reservoirs to exploit formerly inaccessible or unprofitable energy resources in rock formations with low permeability. In North America, these unconventional domestic sources of natural gas and oil provide an opportunity to achieve energy self-sufficiency and to reduce greenhouse gas emissions when displacing coal as a source of energy in power plants. However, fugitive methane emissions in the production process may counter the benefit over coal with respect to climate change and therefore need to be well quantified. Here we demonstrate that positive methane anomalies associated with the oil and gas industries can be detected from space and that corresponding regional emissions can be constrained using satellite observations. On the basis of a mass-balance approach, we estimate that methane emissions for two of the fastest growing production regions in the United States, the Bakken and Eagle Ford formations, have increased by 990 ± 650 ktCH4 yr-1 and 530 ± 330 ktCH4 yr-1 between the periods 2006-2008 and 2009-2011. Relative to the respective increases in oil and gas production, these emission estimates correspond to leakages of 10.1% ± 7.3% and 9.1% ± 6.2% in terms of energy content, calling immediate climate benefit into question and indicating that current inventories likely underestimate the fugitive emissions from Bakken and Eagle Ford.

  7. Geological setting of oil shales in the Permian phosphoria formation and some of the geochemistry of these rocks

    USGS Publications Warehouse

    Maughan, E.K.

    1983-01-01

    Recent studies of the Meade Peak and the Retort Phosphatic Shale Members of the Phosphoria Formation have investigated the organic carbon content and some aspects of hydrocarbon generation from these rocks. Phosphorite has been mined from the Retort and Meade Peak members in southeastern Idaho, northern Utah, western Wyoming and southwestern Montana. Organic carbon-rich mudstone beds associated with the phosphorite in these two members also were natural sources of petroleum. These mudstone beds were differentially buried throughout the region so that heating of these rocks has been different from place to place. Most of the Phosphoria source beds have been deeply buried and naturally heated to catagenetically form hydrocarbons. Deepest burial was in eastern Idaho and throughout most of the northeastern Great Basin where high ambient temperatures have driven the catagenesis to its limit and beyond to degrade or to destroy the hydrocarbons. In southwest Montana, however, burial in some areas has been less than 2 km, ambient temperatures remained low and the kerogen has not produced hydrocarbons (2). In these areas in Montana, the kerogen in the carbonaceous mudstone has retained the potential for hydrocarbon generation and the carbon-rich Retort Member is an oil shale from which hydrocarbons can be synthetically extracted. The Phosphoria Formation was deposited in a foreland basin between the Cordilleran geosyncline and the North American craton. This foreland basin, which coincides with the area of deposition of the two organic carbon-rich mudstone members of the Phosphoria, has been named the Sublett basin (Maughan, 1979). The basin has a northwest-southeast trending axis and seems to have been deepest in central Idaho where deep-water sedimentary rocks equivalent to the Phosphoria Formation are exceptionally thick. The depth of the basin was increasingly shallower away from central Idaho toward the Milk River uplift - a land area in Montana, the ancestral Rocky Mountains. The basin is composed of land areas in Colorado, the Humboldt highland in northeastern Nevada and intervening carbonate shelves in Utah and Wyoming. The phosphorites and the carbonaceous mudstones were deposited on the foreslope between the carbonate and littoral sand deposits on the shelf and the dominantly cherty mudstone sediments in the axial part of the basin. Paleomagnetic evidence indicates that in the Permian the region would have been within the northern hemispheric trade wind belt; and wind-direction studies determined from studies of sand dunes, indicate that the prevailing winds from the Milk River uplift would have blown offshore across the Phosphoria sea. Offshore winds would have carried surface water away from the shore and generated upwelling in the sea in eastern Idaho and adjacent areas in Montana, Wyoming and Utah. Prior to deposition of the Phosphoria, the region was the site of extensive deposition of shallow-water carbonate sediments. Equivalent rocks in the northern part of the basin are dominantly sandstone derived from the adjacent Milk River uplift and similar sandstone strata in the southeastern sector were derived from the ancestral Rocky Mountains uplift. Tectonic subsidence of the Sublett basin in part of the region seems to have provided a sea-floor profile favorable for upwelling circulation and the shift in deposition from regional carbonates and local sandstone into a more complex depositional pattern that included the accumulation of the mudstone-chert-phosphorite facies that comprises the Phosphoria Formation. High biological productivity and the accumulation of sapropel on the sea floor is associated with contemporary coastal upwelling (1) and similar environmental and depositional conditions are attributed to the rich accumulations of organic matter in the Phosphoria Formation. Sapropelic mudstone and phosphorite composing the Meade Peak Member are approximately 60 m thick near the center of the Sublett basin. The Meade

  8. Nested geological modelling of naturally fractured reservoirs

    Microsoft Academic Search

    M. C. Cacas; J. M. Daniel; J. Letouzey

    2001-01-01

    Because of the multiscaled character of fracture networks and their high degree of heterogeneity, characterization and modelling of fractured reservoirs requires different techniques to the well-established geostatistical methods derived for modelling rock heterogeneity. We have developed a method to improve the geological model used as an input of fractured reservoir fluid flow simulators, either in single or dual permeability simulations,

  9. Heterogeneous atmospheric chemistry

    NASA Technical Reports Server (NTRS)

    Schryer, D. R.

    1982-01-01

    The present conference on heterogeneous atmospheric chemistry considers such topics concerning clusters, particles and microparticles as common problems in nucleation and growth, chemical kinetics, and catalysis, chemical reactions with aerosols, electron beam studies of natural and anthropogenic microparticles, and structural studies employing molecular beam techniques, as well as such gas-solid interaction topics as photoassisted reactions, catalyzed photolysis, and heterogeneous catalysis. Also discussed are sulfur dioxide absorption, oxidation, and oxidation inhibition in falling drops, sulfur dioxide/water equilibria, the evidence for heterogeneous catalysis in the atmosphere, the importance of heterogeneous processes to tropospheric chemistry, soot-catalyzed atmospheric reactions, and the concentrations and mechanisms of formation of sulfate in the atmospheric boundary layer.

  10. Sudbury project (University of Muenster-Ontario Geological Survey): Origin of the polymict, allochthonous breccias of the Onaping Formation

    NASA Technical Reports Server (NTRS)

    Avermann, M. E.

    1992-01-01

    The Sudbury structure has been interpreted as a deeply eroded remnant of a peak-ring basin. The polymict, allochthonous breccias of the Onaping Formation (OF) occur in the central part of the Sudbury structure, which is surrounded by the 1.85-Ga-old 'Sudbury Igneous Complex' (SIC). From bottom to top the OF can be divided into Basal, Gray, Green, and lower and upper Black members. The breccias were mapped in detail in the east range of the structure. The SIC and the lower part of the OF (Basal Member) are interpreted as the impact melt system. The overlying Gray Member is a breccia unit with a clastic matrix and has a sharp contact to the Basal Member. The Green Member is considered as a continuous uniform breccia layer on top of the Gray Member and comprises the former 'chlorite shard horizon'. The uppermost unit of the OF (Black Member) can be subdivided into a lower and an upper Black Member unit. The lower part (100-150 m thick) still shows petrographic features of suevitic breccias, small fragments of basement rocks, melt particles, chloritized particles, and breccia fragments in a dark, clastic matrix.

  11. Structurally caused reservoir heterogeneity - its influence on reservoir performance

    Microsoft Academic Search

    1991-01-01

    Geologic reservoir heterogeneity is the consequence of an original sedimentary framework and diagenetic and structural alterations to that framework. heterogeneity in the fluid system can also occur, due both to original reservoir charging characteristics and to production practices. This paper addresses the structural elements of reservoir heterogeneity - determination of structural reservoir partitioning distribution and its effect on porosity and

  12. Utah Geology

    NSDL National Science Digital Library

    Utah Geological Survey's Web site, Utah Geology, offers a variety of interesting geological information about the state. Good descriptions, illustrations, and photographs can be accessed on earthquakes and hazards, dinosaurs and fossils, rocks and minerals, oil and energy, and more. For example, the Rocks and Minerals page contains everything from how to stake a mining claim to downloadable summaries of mineral activity in the state. There is quite a bit of information within the site, and anyone interested in geology will find themselves exploring these pages for quite a while.

  13. Geology of Jewel Cave

    NSDL National Science Digital Library

    National Park Services (NPS)

    This National Park Service site provides an introduction to the Black Hill's Jewel Cave. The site describes the unique geologic history of the Black Hills, the formation of speleothems as well as unusual crystal growth in the cave. Photographs illustrate the descriptions.

  14. Briefing on geological sequestration

    EPA Science Inventory

    Geological sequestration (GS) is generally recognized as the injection and long-term (e.g., hundreds to thousands of years) trapping of gaseous, liquid or supercritical carbon dioxide (CO2) in subsurface media ? primarily saline formations, depleted or nearly depleted oil and gas...

  15. A primer in lunar geology

    NASA Technical Reports Server (NTRS)

    Greeley, R. (editor); Schultz, P. H. (editor)

    1974-01-01

    Primary topics in lunar geology range from the evolution of the solar system to lunar photointerpretation, impact crater formation, and sampling to analyses on various Apollo lunar landing site geomorphologies.

  16. Novel Nitro-PAH Formation from Heterogeneous Reactions of PAHs with NO2, NO3/N2O5, and OH Radicals: Prediction, Laboratory Studies and Mutagenicity

    PubMed Central

    JARIYASOPIT, NARUMOL; INTOSH, MELISSA MC; ZIMMERMANN, KATHRYN; AREY, JANET; ATKINSON, ROGER; CHEONG, PAUL HA-YEON; CARTER, RICH G.; YU, TIAN-WEI; DASHWOOD, RODERICK H.; SIMONICH, STACI L. MASSEY

    2014-01-01

    The heterogeneous reactions of benzo[a]pyrene-d12 (BaP-d12), benzo[k]fluoranthene-d12 (BkF-d12), benzo[ghi]perylene-d12 (BghiP-d12), dibenzo[a,i]pyrene-d14 (DaiP-d14), and dibenzo[a,l]pyrene (DalP) with NO2, NO3/N2O5, and OH radicals were investigated at room temperature and atmospheric pressure in an indoor Teflon chamber and novel mono NO2-DaiP, and mono NO2-DalP products were identified. Quartz fiber filters (QFF) were used as a reaction surface and the filter extracts were analyzed by GC/MS for nitrated-PAHs (NPAHs) and tested in the Salmonella mutagenicity assay, using Salmonella typhimurium strain TA98 (with and without metabolic activation). In parallel to the laboratory experiments, a theoretical study was conducted to rationalize the formation of NPAH isomers based on the thermodynamic stability of OH-PAH intermediates, formed from OH-radical-initiated reactions. NO2 and NO3/N2O5 were effective oxidizing agents in transforming PAHs to NPAHs, with BaP-d12 being the most readily nitrated. Reaction of BaP-d12, BkF-d12 and BghiP-d12 with NO2 and NO3/N2O5 resulted in the formation of more than one mono-nitro isomer product, while the reaction of DaiP-d14 and DalP resulted in the formation of only one mono-nitro isomer product. The direct-acting mutagenicity increased the most after NO3/N2O5 exposure, particularly for BkF-d12 in which di-NO2-BkF-d10 isomers were measured. The deuterium isotope effect study suggested that substitution of deuterium for hydrogen lowered both the direct and indirect acting mutagenicity of NPAHs and may result in an underestimation of the mutagencity of the novel NPAHs identified in this study. PMID:24350894

  17. Novel nitro-PAH formation from heterogeneous reactions of PAHs with NO2, NO3/N2O5, and OH radicals: prediction, laboratory studies, and mutagenicity.

    PubMed

    Jariyasopit, Narumol; McIntosh, Melissa; Zimmermann, Kathryn; Arey, Janet; Atkinson, Roger; Cheong, Paul Ha-Yeon; Carter, Rich G; Yu, Tian-Wei; Dashwood, Roderick H; Massey Simonich, Staci L

    2014-01-01

    The heterogeneous reactions of benzo[a]pyrene-d12 (BaP-d12), benzo[k]fluoranthene-d12 (BkF-d12), benzo[ghi]perylene-d12 (BghiP-d12), dibenzo[a,i]pyrene-d14 (DaiP-d14), and dibenzo[a,l]pyrene (DalP) with NO2, NO3/N2O5, and OH radicals were investigated at room temperature and atmospheric pressure in an indoor Teflon chamber and novel mono-NO2-DaiP and mono-NO2-DalP products were identified. Quartz fiber filters (QFF) were used as a reaction surface and the filter extracts were analyzed by GC/MS for nitrated-PAHs (NPAHs) and tested in the Salmonella mutagenicity assay, using Salmonella typhimurium strain TA98 (with and without metabolic activation). In parallel to the laboratory experiments, a theoretical study was conducted to rationalize the formation of NPAH isomers based on the thermodynamic stability of OH-PAH intermediates, formed from OH-radical-initiated reactions. NO2 and NO3/N2O5 were effective oxidizing agents in transforming PAHs to NPAHs, with BaP-d12 being the most readily nitrated. Reaction of BaP-d12, BkF-d12, and BghiP-d12 with NO2 and NO3/N2O5 resulted in the formation of more than one mononitro isomer product, while the reaction of DaiP-d14 and DalP resulted in the formation of only one mononitro isomer product. The direct-acting mutagenicity increased the most after NO3/N2O5 exposure, particularly for BkF-d12 in which di-NO2-BkF-d10 isomers were measured. The deuterium isotope effect study suggested that substitution of deuterium for hydrogen lowered both the direct and indirect acting mutagenicity of NPAHs and may result in an underestimation of the mutagencity of the novel NPAHs identified in this study. PMID:24350894

  18. California Geological Survey: Geologic Maps

    NSDL National Science Digital Library

    This index provides access to a selection of geologic maps of California, as well as an overview of geologic and other mapping activities in the state. The index, which can be accessed by clicking on an interactive map of the state, contains lists of selected geologic maps in California prepared by the Regional Geologic Mapping Project (RGMP). The RGMP staff monitors the literature and collects references that contain geologic mapping that may be useful for future compilations. In addition, the site has information about Caltrans Highway Corridor Mapping, The Mineral Resources and Mineral Hazards Mapping Program, North Coast Watersheds Assessment Program, The Timber Harvesting Plan Enforcement Program, and The Seismic Hazards Mapping Program. A set of links is provided to other sources of geologic maps and map information.

  19. North Cascades Geology: Geologic Time

    NSDL National Science Digital Library

    This article describes the period of geologic time spanned by the rocks of the North Cascades area of Washington. Users can access a simplified geologic time scale that provides links to geologic events in the North Cascades region. These include the deposition of various terranes, periods of intrusion and metamorphism, the beginning of the Cascade volcanic arc, and periods of major glaciation. Links to related materials are also provided.

  20. Diffusive leakage of carbon, variable migration rates of solutes, multiple reaction fronts: what happens when CO2 is injected into geologic formations

    NASA Astrophysics Data System (ADS)

    Park, A. J.

    2009-12-01

    A complex set processes occur when CO2-charged water resulting from CO2 injection into a geologic formation interacts with the resident formation water and sediment. First, the sequestration efficiency depends on the rate of CO2 injection and sediment texture (porosity and permeability). Second, acid and bicarbonates resulting from the hydration of CO2 interact with the resident water to create multiple solute migration fronts, and also simultaneously induce complex interactions with the resident minerals. All of these features, and accurate mass-balancing, can be achieved using a new water-rock interaction and reactive-transport simulator Sym.CS. Water-rock interaction and reactive transport modeling is an important tool for deciphering chemical and physical reactions occurring in sediments and rocks that are not accessible for monitoring. Traditional models solve a large set of conservation of mass equations written for aqueous solute species. Typically, reactions are solved separately from mass-transfer equations through loosely coupled sequentially iterated numerical algorithms. Resulting simulators therefore fall short of achieving the full extent of the theoretical accuracy and the nonlinearly of the reactive-transport and water-rock interaction phenomena. A new method is presented that uses conservation equations written for chemical elements, and tight coupling between mass-transfer and reactions. Derivation of the elemental conservation equation from the theoretically correct solute conservation equation involves one parametric conversion. The tight coupling between mass-transfer and reactions entails using explicitly discretized form of mass-transfer terms of the conservation equation when solving for the reactions. This explicitly coupled iteration method allows accurate solution of the conservation equations to be achieved. More importantly, this method allows (1) accurate bookkeeping of mass as effluents are injected and reactions progress among various phases, and (2) capturing the flow-reaction feedback that determines the efficiency of injection practice and reservoir capacity usage. The third component of the model is a composite media petrophysical model that allows the monitoring of changing reservoir characteristics as chemical and textural compositions evolve. The simulator Sym.CS, which includes all of above processes, is used to model interaction between CO2-charged water with formation water in sandstone reservoirs. Results demonstrate the utility of the model that preserves the nonlinearity of mass-transfer and reaction processes. Accurate mass-balance is also achieved and demonstrated. The results also show the importance of diffusive properties of highly reactive solutes, as they form one or more reaction fronts ahead of sweep fronts, as well as significant quantity of carbon to leak out of the reservoir.

  1. SEISMIC DETERMINATION OF RESERVOIR HETEROGENEITY: APPLICATION TO THE CHARACTERIZATION OF HEAVY OIL RESERVOIRS

    SciTech Connect

    Matthias G. Imhof; James W. Castle

    2005-02-01

    The objective of the project was to examine how seismic and geologic data can be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study focused on West Coalinga Field in California. The project initially attempted to build reservoir models based on different geologic and geophysical data independently using different tools, then to compare the results, and ultimately to integrate them all. We learned, however, that this strategy was impractical. The different data and tools need to be integrated from the beginning because they are all interrelated. This report describes a new approach to geostatistical modeling and presents an integration of geology and geophysics to explain the formation of the complex Coalinga reservoir.

  2. Yellowstone Geology

    NSDL National Science Digital Library

    Yellowstone National Park

    This Yellowstone National Park website provides geological information about the Park. Links include geologic highlights, hydrothermal features, reports by park geologists, and scientists' talks (videos). A wide array of information can be found on these links and the webpage is expanding as more topics are added.

  3. Physical geology

    SciTech Connect

    Skinner, B.; Porter, S.

    1987-01-01

    The book integrates current thinking on processes (plate techtonics, chemical cycles, changes throughout geologic time). It is an introduction to investigations into the way the earth works, how mountains are formed, how the atmosphere, hydrosphere, crust and mantle interact with each other. Treatments on climate, paleoclimatology and landscape evolution are included, as is a discussion on how human activity affects geological interactions.

  4. Yosemite Geology

    NSDL National Science Digital Library

    The National Park Service maintains the Yosemite National Park Web site and the corresponding Geology page. This Web site gives an overview of the geologic history of the site, tells how the Sierra Nevada range formed, explains the basics of granitic rock, shows how glaciers carved out the canyons, and much more.[JAB

  5. Engineering Geology

    ERIC Educational Resources Information Center

    Hatheway, Allen W.

    1978-01-01

    Engineering geology remains a potpourri of applied classical geology, and 1977 witnessed an upswing in demand for these services. Traditional foundation-related work was slight, but construction related to national needs increased briskly. Major cities turned to concerns of transit waste-water treatment and solid-waste disposal. (Author/MA)

  6. Geology Major www.geology.pitt.edu/undergraduate/geology.html

    E-print Network

    Jiang, Huiqiang

    Geology Major www.geology.pitt.edu/undergraduate/geology.html Revised: 03/2013 Geology is a scientific discipline that aims to understand every aspect of modern and ancient Earth. A degree in geology the field of geology, environmental and geotechnical jobs exist for people with BS degrees. A master

  7. Geologic controls influencing CO2 loss from a leaking well.

    SciTech Connect

    Hopkins, Polly L.; Martinez, Mario J.; McKenna, Sean Andrew; Klise, Katherine A.

    2010-12-01

    Injection of CO2 into formations containing brine is proposed as a long-term sequestration solution. A significant obstacle to sequestration performance is the presence of existing wells providing a transport pathway out of the sequestration formation. To understand how heterogeneity impacts the leakage rate, we employ two dimensional models of the CO2 injection process into a sandstone aquifer with shale inclusions to examine the parameters controlling release through an existing well. This scenario is modeled as a constant-rate injection of super-critical CO2 into the existing formation where buoyancy effects, relative permeabilities, and capillary pressures are employed. Three geologic controls are considered: stratigraphic dip angle, shale inclusion size and shale fraction. In this study, we examine the impact of heterogeneity on the amount and timing of CO2 released through a leaky well. Sensitivity analysis is performed to classify how various geologic controls influence CO2 loss. A 'Design of Experiments' approach is used to identify the most important parameters and combinations of parameters to control CO2 migration while making efficient use of a limited number of computations. Results are used to construct a low-dimensional description of the transport scenario. The goal of this exploration is to develop a small set of parametric descriptors that can be generalized to similar scenarios. Results of this work will allow for estimation of the amount of CO2 that will be lost for a given scenario prior to commencing injection. Additionally, two-dimensional and three-dimensional simulations are compared to quantify the influence that surrounding geologic media has on the CO2 leakage rate.

  8. Submarine fan reservoir architecture and heterogeneity influence on hard-to-recover reserves. Achimov Fm

    NASA Astrophysics Data System (ADS)

    Kondratyev, A.; Rukavishnikov, V.; Shakirzyanov, L.; Maksyutin, K.

    2015-02-01

    Due to the fact that simulation model calculation is the basic method used for estimating the efficiency of a development strategy, it is necessary to design geological and simulation models within which reservoir properties and heterogeneity are defined. In addition, the estimation of the influence of various kinds of geological uncertainties on reservoir properties will allow defining a more effective development strategy. The Achimov formation of the Vingapur oil field was considered in the current study. The northern part of the field is now quite attractive for the development of this formation. The goal of this paper was the complex investigation of petrophysical properties to make a prognosis for the field and assess the effect of geologic uncertainties on production. The first step implied studying the western part of the field where core data are available, the next stage was developing an algorithm to make a prognosis for properties and the geologic and reservoir simulation models were eventually constructed to study the effect of geologic uncertainties in the northern part. As the result of the sedimentary analysis, a model of deposition was defined within which structural elements were also determined. On the basis of wireline and core data analysis, the petrophysical model of the reservoir was build where the method of Rock Types identification using specific cut-off values for wireline logs was applied for the evaluations. In addition to this, the Hydraulic Flow unit approach was employed, which allowed estimating the less extensively explored areas of the field where core had not been retrieved from. Also, this paper provides the results of the seismic attribute analysis and calculations in order to characterize uncertainty in cumulative oil production under the influence of petrophysical and geological heterogeneity.

  9. Impacts of Anthropogenic Emissions in the Southeastern U.S. on Heterogeneous Chemistry of Isoprene-Derived Epoxides Leading to Secondary Organic Aerosol Formation (Invited)

    NASA Astrophysics Data System (ADS)

    Surratt, J. D.; Pye, H.; Lin, Y.; Budisulistiorini, S.; Zhang, H.; Marth, W.; Cui, T.; Arashiro, M.; Chu, K.; Zhang, Z.; Sexton, K.; Piletic, I.; Xie, Y.; Capps, S. L.; Luecken, D.; Hutzell, W. T.; Jaoui, M.; Canagaratna, M. R.; Croteau, D.; Jayne, J. T.; Worsnop, D. R.; Offenberg, J.; Kleindienst, T. E.; Lewandowski, M.; Edney, E.; Pinder, R. W.; Bartolotti, L.; Gold, A.

    2013-12-01

    Isoprene is a major source of secondary organic aerosol (SOA); however, the exact manner in which it forms SOA remains unclear. Improving our fundamental understanding of isoprene-derived SOA is key to improving existing air quality models, especially in the southeastern U.S. where models currently underestimate observations. By combining organic synthesis, computational calculations, mass spectrometry, smog chamber studies, and field measurements, we show that reactive epoxides, which include methacrylic acid epoxide (MAE) and isomeric isoprene epoxydiols (IEPOX), produced from the photochemical oxidation of isoprene are key to SOA formation. Furthermore, anthropogenic pollutants (NOx and SO2) enhance isoprene-derived epoxides as an SOA source. In the laboratory, we find that the reactive uptake of synthetic IEPOX and MAE standards onto acidified sulfate aerosol yields known isoprene-derived SOA tracers (2-methlytetrols, 2-methylglyceric acid, C5-alkene triols, 3-methyltetrahydrofuran-3,4-diols, dimers and organosulfates) that we measure in fine aerosol collected from multiple sites across the southeastern U.S. using gas chromatography/mass spectrometry (GC/MS) and liquid chromatography coupled to diode array detection and electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (LC/DAD-ESI-QTOFMS). Notably, IEPOX- and MAE-derived SOA tracers account for ~19% of the organic aerosol mass in Yorkville, GA. Moreover, real-time continuous chemical measurements of fine aerosol made using an Aerodyne Aerosol Chemical Speciation Monitor (ACSM) during summer 2011 and summer 2013 in Atlanta, GA, and Look Rock, TN, respectively, resolved an IEPOX-oxygenated organic aerosol (IEPOX-OOA) factor when applying positive matrix factorization (PMF) to the organic mass spectral time series. In Atlanta, this factor is found to account for ~33% of the fine OA mass and is correlated with IEPOX-derived SOA tracers (r2 = 0.6), sulfate (r2 = 0.5), and to some extent with aerosol acidity (measured as nmol H+ m-3, r2 = 0.3). Altogether, the Community Multiscale Air Quality model is updated to predict isoprene aerosol from IEPOX and MAE. The new aqueous aerosol pathways allow for explicit predictions of IEPOX- and MAE-derived SOA tracers that are more consistent with observations than estimates based on semivolatile partitioning, supporting the role of acid-catalyzed heterogeneous reactions leading to SOA formation.

  10. No geology without marine geology

    Microsoft Academic Search

    P. H Kuenen

    2002-01-01

    A brief review is offered of the many problems where knowledge of the ocean floors and of marine processes in shallow water is indispensable for the further advancement of geology. The subject of turbidity currents is treated in greater detail, to demonstrate the interrelation of several aspects of marine geology with sedimentologic and paleogeographic investigations. It is obvious that the

  11. Radon-222 as a Tracer of Water-Air Dynamics in the Unsaturated Zone of Geological Carbonate Formation: Example of an Underground Quarry (Oligocene Aquitain Limestone, France)

    NASA Astrophysics Data System (ADS)

    Loisy, C.; Franceschi, M.; Cerepi, A.

    2006-12-01

    Complex process in the unsaturated zone affect the transfers of fluids. Within the context of an integrated study on the process of the meteoric diagenesis in a carbonate formation, we try to determine the time transit of fluids. The aim of this study is to see whether radon 222 is a good natural tracer of fluids vertical diffusivity. Radon is an inert radioactive gas. It has three isotopes 222Rn, 220Rn, 219Rn. 222Rn comes from the decay of 238U. The 222Rn half-life (3.82 days) allows it to be transported far from its origin (Fleischer et al., 1981). Temporal variations of radon activity in soil gas depend on several factors such as meteorological variables (temperature, rainfall, atmospheric pressure, etc) and geological variables (concentration of radium in the soil, porosity, grain size, tectonic activity, etc.) (Abbad et al., 1993). The radon was measured on an experimental site : soil (0.40 meter thick) is lying on the Oligocene limestone (15 meters thick). This limestone was exploited in underground quarry with several levels (7 meters and 10 meters deep). Radon product comes from soil clays and limons for the major part and quaternary loess trapped in the limestone karstic framework for an other part. In the unsaturated zone, radon moves vertically in the gaseous phase under piston effect of the liquid phase. It moves as well dissolve in the liquid phase. The underground quarry atmosphere of the two levels shows variations of radon concentration in the time. The results show correlation between the maxima of effective precipitations and the maxima ones of radon concentration in the underground quarry atmosphere with a seven months dephasing. Dephasing between the maxima of effective precipitations and the maxima of moisture in the porous rock is only five months. This correlation leads to a diffusion model of radon in the unsaturated zone.

  12. Geologic History

    NSDL National Science Digital Library

    Medina, Philip

    This unit introduces younger students to the concept of relative versus absolute time and how geologists determine the age of geologic events and features. Topics include the laws that determine relative age (superposition, cross-cutting relationships, included fragments, and others), and how to re-construct the geologic history of an area using these relationships. There is also information on geologic correlation and the use of index fossils to determine relative age. The section on absolute time discusses some ways of measurement (tree rings, radioactive dating) and introduces the concepts of natural selection and mass extinctions. A vocabulary and downloadable, printable student worksheets are provided.

  13. Geologic Time

    NSDL National Science Digital Library

    William L. Newman

    1997-01-01

    The Earth is very old -- 4.5 billion years or more -- according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.

  14. Geologic Timeline

    NSDL National Science Digital Library

    2000-01-01

    Dive into the depths of time with this Geologic Timeline. The farther you scroll down, the farther back in time you'll travel. Also, the longer a period is on this page, the longer it lasted in history!

  15. Geology Programs and Disciplinary Accreditation

    NSDL National Science Digital Library

    Robert Corbett

    2001-03-01

    This report raises the question of whether accreditation may be coming to the geology discipline, and attempts to quantify the positions on accreditation of academic department heads/chairs. The study makes a distinction between institutional and specialized (or disciplinary) accreditation and explores attitudes toward both types. Results of the analysis are presented with a discussion of two methods of data interpretation, a multivariate analysis technique and the Chi square test for heterogeneity or independence. The report concludes that there is currently insufficient support for establishing disciplinary accreditation in geology.

  16. Reaction capacity characterization of shallow sedimentary deposits in geologically different regions of the Netherlands.

    PubMed

    Griffioen, Jasper; Klein, Janneke; van Gaans, Pauline F M

    2012-01-01

    Quantitative insight into the reaction capacity of porous media is necessary to assess the buffering capacity of the subsurface against contaminant input via groundwater recharge. Here, reaction capacity is to be considered as a series of geochemical characteristics that control acid/base conditions, redox conditions and sorption intensity. Using existing geochemical analyses, a statistical regional assessment of the reaction capacity was performed for two geologically different areas in the Netherlands. The first area is dominated by Pleistocene aquifer sediments only, in the second area a heterogeneous Holocene confining layer is found on top of the Pleistocene aquifer sediments. Within both areas, two or more regions can be distinguished that have a distinctly different geological build-up of the shallow subsurface. The reactive compounds considered were pyrite, reactive Fe other than pyrite, sedimentary organic matter, carbonate and clay content. This characterization was complemented by the analysis of a dataset of samples newly collected, from two regions within the Pleistocene area, where the sedimentary facies of samples was additionally distinguished. The statistical assessment per area was executed at the levels of region, geological formation and lithology class. For both areas, significant differences in reaction capacities were observed between: 1. different lithology classes within a geological formation in a single region, 2. identical geological formations in different regions and 3. various geological formations within a single region. Here, the reaction capacity is not only controlled by lithostratigraphy, but also by post-depositional diagenesis and paleohydrology. Correlation coefficients among the reactive compounds were generally higher for sand than for clay, but insufficiently high to allow good estimation of reactive compounds from each other. For the sandy Pleistocene aquifer sediments, the content of reactive compounds was frequently observed to be below detection limits. From this, future characterization of sediment reaction capacity is best performed at the sublevel of lithology class, being the geochemically near-uniform unit identifiable for individual geological formations within geographic regions. Additional subdivision on facies provides particular insight in the spatial entity where relatively high reaction capacities may be encountered. To obtain quantitative insight into the reaction capacity of aquifer sediments, non-sandy minor subunits should be well characterised on their reaction capacity as well as their spatial occurrence in the geological formations. A straightforward approach is presented in which the regional statistics on geochemical reactivity become combined with a 3-dimensional geological voxel model. This results into 3-dimensional data fields on reactivity, which are suitable for, for example, groundwater transport modelling. The sedimentological architecture of the deposits becomes well maintained in the geochemical data field, which is an advantage in itself. PMID:21549444

  17. Chapter 7. The GIS project for the geologic assessment of undiscovered oil and gas in the Cotton Valley group and Travis Peak and Hosston formations, East Texas basin and Louisiana-Mississippi salt basins provinces.

    USGS Publications Warehouse

    Biewick, Laura R.H.

    2006-01-01

    A geographic information system (GIS) focusing on the Upper Jurassic-Lower Cretaceous Cotton Valley Group and the Lower Cretaceous Travis Peak and Hosston Formations in the northern Gulf Coast region was developed as a visual-analysis tool for the U.S. Geological Survey's 2002 assessment of undiscovered, technically recoverable oil and natural gas resources in the East Texas Basin and Louisiana-Mississippi Salt Basins Provinces. The Central Energy Resources Team of the U.S. Geological Survey has also developed an Internet Map Service to deliver the GIS data to the public. This mapping tool utilizes information from a database about the oil and natural gas endowment of the United States-including physical locations of geologic and geographic data-and converts the data into visual layers. Portrayal and analysis of geologic features on an interactive map provide an excellent tool for understanding domestic oil and gas resources for strategic planning, formulating economic and energy policies, evaluating lands under the purview of the Federal Government, and developing sound environmental policies. Assessment results can be viewed and analyzed or downloaded from the internet web site, http://energy.cr.usgs.gov/oilgas/noga/ .

  18. Geology - Plate Tectonics

    NSDL National Science Digital Library

    Visitors to this site can learn about the theory of plate tectonics, the history of its development, and the mechanisms that drive the formation, movement, and destruction of continents and tectonic plates. A selection of animations depicts the movements of crustal plates and continents through time. Each animation is accompanied by an interactive time scale that provides links to descriptions of the geology and paleontology of the selected era or period.

  19. Pennsylvania Geology

    NSDL National Science Digital Library

    Three decades after it was published, the Second Geological Survey of Pennsylvania was described as "the most remarkable series of reports ever issued by any survey." Considering the diversity of other geological reports, this was no small compliment. Drawing on support from the Marion and Kenneth Pollock Libraries Program Fund, the Pennsylvania State University Libraries' Digital Preservation Unit was able to digitize not only this fabled Survey, but also the Third and Fourth Surveys as well. Visitors can use the search engine on the homepage to look for items of interest, or they can just browse through the collection at their leisure. The surveys include various maps and illustrations that track mineral deposits and the disposition and location of other natural resources. Additionally, users can look through a miscellaneous set of publications from the early 20th century related to survey work performed by the U.S. Geological Survey.

  20. Teaching Geology

    NSDL National Science Digital Library

    This rather remarkable website contains a great collection of resources for web-based instruction and demonstrations of geology concepts. The collection includes, under Classroom demonstration, the very useful SeisMac 3.0, which is an application for Mac OS X that turns a laptop computer into a " low-resolution strong-motion accelerometer," or a basic seismograph. It works by accessing the computer's Sudden Motion Sensor in order to display real-time, three axis accelerations graphs. Visitors can use the application to watch the seismic waves go up and down just by tapping their feet on the floor nearby. Other resources include Virtual Earth (an "interactive minicourse on thermal convection") and a link to Geology in the news, which collates important news stories with a geological theme.

  1. Heterogeneous catalysis.

    PubMed

    Schlögl, Robert

    2015-03-01

    A heterogeneous catalyst is a functional material that continually creates active sites with its reactants under reaction conditions. These sites change the rates of chemical reactions of the reactants localized on them without changing the thermodynamic equilibrium between the materials. PMID:25693734

  2. Geological flows

    E-print Network

    Yu. N. Bratkov

    2008-11-19

    In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other hand, maps and images of many planets are accessible. Identity of geological flows and high-speed gas dynamics is demonstrated. There is another time scale, and no more. All results, as far as the concept, are new and belong to the author. No formulae, pictures only.

  3. Geologic Time

    NSDL National Science Digital Library

    Timothy Heaton

    This site contains 24 questions on the topic of geologic time, which covers dating techniques and unconformities. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate feedback.

  4. Antarctica Geology

    NSDL National Science Digital Library

    This site contains information about the continent of Antarctica. There is a classroom practice and instructional module. The students will be able to describe the general geology of the land under the Antarctic ice and to explain from where the rocks may have come.

  5. Geology and petrology of the Hormuz dolomite, InfraCambrian: Implications for the formation of the salt-cored Halul and Shraouh islands, Offshore, State of Qatar

    Microsoft Academic Search

    Sobhi Nasir; Hamad Al-Saad; Abudlrazak Alsayigh; Oliver Weidlich

    2008-01-01

    Geological investigations of the Halul and the Shraouh islands, offshore Qatar, indicate that most of their calcareous rocks, which display abundant stromatolitic bedding, belong to the Infra-Cambrian Hormuz Series. Mineralogical, petrological, and geochemical analyses show that these calcareous rocks consist dominantly of dolomite and have formed in a reducing depositional environment. Faint laminations and small streaks of organic matter furnish

  6. Digitizing rocks standardizing the geological description process using workstations

    SciTech Connect

    Saunders, M.R. (EXLOG (Services), Windsor, Berkshire (United Kingdom)); Shields, J.A. (EXLOG North Sea, Aberdeen (United Kingdom)); Taylor, M.R. (EXLOG, Inc., Houston, TX (United States))

    1993-09-01

    The preservation of geological knowledge in a standardized digital form presents a challenge. Data sources, inherently fuzzy, range in scale from the macroscopic (e.g., outcrop) through the mesoscopic (e.g., hand-specimen) core and sidewall core, to the microscopic (e.g., drill cuttings, thin sections, and microfossils). Each scale change results in increased heterogeneity and potentially contradictory data and the providers of such data may vary in experience level. To address these issues with respect to cores and drill cuttings, a geological description workstation has been developed and is undergoing field trials. Over 1000 carefully defined geological attributes are currently available within a depth-indexed, relational database. Attributes are stored in digital form, allowing multiple users to select familiar usage (e.g., diabase vs. dolerite). Data can be entered in one language and retrieved in other languages. The database structure allow groupings of similar elements (e.g., rhyolites in acidic, igneous or volcanics subgroups or the igneous rock group) permitting different uses to analyze details appropriate to the scale of the usage. Data entry uses a graphical user interface, allowing the geologist to make quick, logical selections in a standardized or custom-built format with extensive menus, on-screen graphics and help screens available. Description ranges are permissible. Entries for lithology, petrology, structures (sedimentary, organic and deformational), reservoir characteristics (porosity and hydrocarbon shows), and macrofossils are available. Sampling points for thin sections, core analysis, geochemistry, or micropaleontology studies are also recorded. Using digital data storage, geological logs using graphical, alphanumeric and symbolic depictions are possible. Data can be integrated with drilling and mud gas data, MWD and wireline data and off well-site analyses to produced composite formation evaluation logs and interpretational crossplots.

  7. Mathematical Geology, Vol. 4, No. 3, 1972 Mathematical Techniques for Paleocurrent Analysis

    E-print Network

    Jammalamadaka, S. Rao

    Mathematical Geology, Vol. 4, No. 3, 1972 Mathematical Techniques for Paleocurrent Analysis procedure. Finally, theprocedures for testing the homogeneity of directional data from several geological directions from different geological formations belong to significantly different populations. KEY WORDS

  8. Upper Cenozoic Geologic Map, Yellowstone Plateau Volcanic Field

    NSDL National Science Digital Library

    Christiansen Robert

    This geologic map shows Tertiary and Quaternary rock formations, volcanic and surficial deposits, faults, contacts, and other geologic features in Yellowstone National Park. The map is freely downloadable as a PDF file.

  9. Si-rich layer formation on olivine surfaces during reaction with water and supercritical carbon dioxide under conditions relevant for geologic carbon storage

    NASA Astrophysics Data System (ADS)

    Johnson, N. C.; Jackson, A.; Maher, K.; Bird, D. K.; Brown, G. E.

    2013-12-01

    The reaction of Mg-silicate minerals (i.e. olivine) with carbon dioxide (CO2) is a promising method for secure, long-term, geologic carbon storage. Several technical challenges must be overcome before implementing mineral carbonation technology on a large scale, one of which is slow reaction kinetics. This study probes surface reaction limitations of olivine carbonation, specifically the formation of a passivating, Si-rich layer on olivine surfaces upon exposure to water and CO2 under sequestration conditions (elevated temperature and pressure). A series of batch reactions were performed at 60°C and 100 bar CO2 pressure in Dickson-style rocker bombs, varying the length of reaction and the amount of mixing (rocking). The initial aqueous phase was spiked with 29Si. Fluid samples were taken periodically and analyzed for cation content, alkalinity, and dissolved inorganic carbon. At the end of each experiment, the solid products were analyzed with a Sensitive High Resolution Ion Microprobe Reverse Geometry (SHRIMP-RG) in order to measure the amount of 29Si incorporated into the Si-rich layer on reacted olivine grains. We also cut cross sections of reacted grains from each experiment using a Focused Ion Beam (FIB) which were thinned to <100nm and imaged using Transmission Electron Microscopy (TEM). SHRIMP-RG results show incorporation of 29Si on olivine grain surfaces reacted for 19 days with no mixing, and TEM images of olivine grains from the same experiment show an amorphous, Si-rich layer that is 30nm thick. Similarly, SHRIMP-RG results for olivine grains reacted for 19 days with mixing indicate 29SiO2 precipitation and TEM images reveal a Si-rich layer 60nm thick. In both experiments, EDS (energy dispersive spectroscopy) data show a step change in composition from the bulk rock to the surface layer in addition to the sharp crystalline/amorphous interface visible in the TEM images. Olivine from the unmixed experiment also has a slow decrease in Mg relative to Si before the step change, suggesting that, at least in this experiment, a Si-rich layer precipitated on top of a Mg-depleted layer that formed via a leaching process. SHRIMP-RG data also imply the presence of a precipitated Si-rich layer on top of a leached Si-rich layer, as the 29Si penetration depth is only 25-65% of the total Si-rich layer thickness. The combination of SHRIMP-RG and FIB/TEM analysis leads us to hypothesize that a Si-rich layer forms quickly on olivine surfaces due to preferential Mg removal from the surface (the traditional 'leached' layer), and as the reaction proceeds, amorphous silica reaches saturation in the fluid and precipitates on surfaces inside the reactor (including olivine grains).

  10. GEOLOGY OF THE PALEOCENE SEPULTURA FORMATION, MESA DE LA SEPULTURA, BAJA CALIFORNIA GEOLOGIA DE LA FORMACION SEPULTURA DEL PALEOCENO, EN MESA DE LA SEPULTURA, BAJA CALIFORNIA

    Microsoft Academic Search

    Patrick L. Abbott; Andrew D. Hanson; Celeste N. Thomson; Deirdre L. Logue; Kristine D. Bradshaw; Woody Joe Pollard; Thomas E. Seeliger

    At its Mesa de La Sepultura type area, the upper-lower to upper Paleocene Sepultura Formation lies with apparent disconformity on the lower Maastrichtian, marine upper slope and shelf deposits of the Rosario Formation. In places the uppermost Rosario Formation is marked by a kaolinite-rich paleosol. The Sepultura Formation is a deepening-upward sequence divided into a lower glauconitic-clastic member and an

  11. Geology Fulbrights

    NASA Astrophysics Data System (ADS)

    Fulbright grants in geology for 1988-89 remain open. Specific opportunities are available in Egypt, German Democratic Republic, Hungary, Iceland, Iraq, Kuwait, Morocco, Mozambique, Oman, Poland, Sudan, Syria, Tanzania, Turkey, U.S.S.R., West Bank, Yemen, and Zimbabwe. Other countries are also open to applications in any discipline, and geology is among their preferred fields.The grants are available until awarded and are open only to U.S. citizens. In Central and South America and French-speaking Africa, knowledge of host-country language is required. For more information, contact the Council for International Exchange of Scholars (CIES), 11 Dupont Circle N.W., Suite 300, Washington, DC 20036; tel. 202-939-5401.

  12. Teaching Geology

    NSDL National Science Digital Library

    The study of geology at the University of Colorado has a long and distinguished history, and in recent years they have also become increasingly interested in providing online teaching resources in the field. Educators will be glad to learn about this site's existence, as they can scroll through a list of interactive demonstrations that can be utilized in the classroom. Specifically, these demonstrations include a shaded interactive topographical map of the western United States, a magnetic field of the Earth, and several animated maps of various National Park sites. The site comes to a compelling conclusion with the inclusion of the geology department's slide library, which can be used without a password or registration.

  13. Testing the Injectivity of CO2 in a Sub-surface Heterogeneous Reservoir

    NASA Astrophysics Data System (ADS)

    Sundal, A.; Nystuen, J.; Dypvik, H.; Aagaard, P.

    2011-12-01

    This case study on subsurface reservoir characterization, considers the effect of geological heterogeneities on the storage capacity and injectivity of the Johansen Formation, which is a deep, saline aquifer underlying the Troll Gas Field off the Norwegian coast. The Johansen Formation has been interpreted as a sandy, prograding unit, deposited in a shallow marine environment during Early Jurassic time, and is overlain by a shaly unit; the Amundsen Formation. It appears as a wedge shaped sandstone body, up to 140m thick, with an areal extent in the order of 10 000 km2. The Johansen Formation is currently being considered for large scale CO2 storage from two gas power plants situated on the west coast of Norway, both of which will operate with full scale CO2 handling, as proposed by Norwegian authorities. The storage capacity needed is in the order of 3 Mt CO2/year. With access to a new 3D seismic survey (Gassnova, 2010), and based on existing well log data from 25 penetrating wells, we have studied large scale geometries and intra-formational features, and built a geo-conceptual model of the Johansen Formation. The reservoir is heterogeneous, with distinct permeability zonation within clinothems separated by less permeable layers. In order to obtain better understanding of crucial reservoir parameters and supplement limited data, comparison of data from easily accessible analogue rock units is useful. For this purpose the unit should be well exposed and thoroughly documented, such as the Panther Tongue Member (Star Point Formation, Mesa Verde Group) in Book Cliffs, from which we have collected some comparable permeability estimates for the model. On a micro scale, mineralogy, grain size/shape and pore geometry constitue major controls on reservoir porosity and permeability. Direct geological information is at this point in time limited to a few meters of core, from which detailed mineralogical information has been derived (optical microscopy, SEM, XRD), and some additional data from side wall cores and cuttings. From this we evaluate facies dependence related to observed diagenetic features and compositional variations due to burial depth (2-4km), mainly considering chlorite coatings (preserving porosity) and cementation (calcite and quartz). Using Schlumberger soft-wares; Petrel (reservoir) and Eclipse (fluid flow), we are testing injection scenarios (one point, several points, bleeding wells) in several intra-formational geological settings. These results will be evaluated relative to the distribution of facies and heterogeneities in the reservoir, considering multiphase flow given the local pressure regime.

  14. Pre-test geological and geochemical evaluation of the Caprock, St. Peter Sandstone and formation fluids, Yakley Field, Pike County, Illinois

    SciTech Connect

    Not Available

    1983-03-01

    The goal of these studies is to ensure long-term stable containment of air in the underground reservoirs used in conjunction with compressed air energy storage (CAES) plants. The specific objective is to develop stability criteria and engineering guidelines for designing CAES reservoirs in each of the three major reservoir types, including aquifers, salt cavities, and mined hard rock caverns. This document characterizes the geologic nature of porous media constituents native to the aquifer field test site near Pittsfield, Illinois. The geologic samples were subjected to geochemical evaluations to determine anticipated responses to cyclic air injection, heating and moisture - conditions typical of an operating CAES reservoir. This report documents the procedures used and results obtained from these analyses.

  15. Method of analysis at the U.S. Geological Survey California Water Science Center, Sacramento Laboratory - determination of haloacetic acid formation potential, method validation, and quality-control practices

    USGS Publications Warehouse

    Zazzi, Barbara C.; Crepeau, Kathryn L.; Fram, Miranda S.; Bergamaschi, Brian A.

    2005-01-01

    An analytical method for the determination of haloacetic acid formation potential of water samples has been developed by the U.S. Geological Survey California Water Science Center Sacramento Laboratory. The haloacetic acid formation potential is measured by dosing water samples with chlorine under specified conditions of pH, temperature, incubation time, darkness, and residual-free chlorine. The haloacetic acids formed are bromochloroacetic acid, bromodichloroacetic acid, dibromochloroacetic acid, dibromoacetic acid, dichloroacetic acid, monobromoacetic acid, monochloroacetic acid, tribromoacetic acid, and trichloroacetic acid. They are extracted, methylated, and then analyzed using a gas chromatograph equipped with an electron capture detector. Method validation experiments were performed to determine the method accuracy, precision, and detection limit for each of the compounds. Method detection limits for these nine haloacetic acids ranged from 0.11 to 0.45 microgram per liter. Quality-control practices include the use of blanks, quality-control samples, calibration verification standards, surrogate recovery, internal standard, matrix spikes, and duplicates.

  16. Soil Formation

    NSDL National Science Digital Library

    Humans use soil for their daily needs but do not sufficiently take account of its slow formation and fast loss. Discover the amazing geology of soil formation and the basic rock and soil types.Although soil seems the end product from weathering rocks, it is merely a stage in the gigantic cycle of mineral recycling by the movement of tectonic plates.

  17. Geology Fieldnotes: Capitol Reef National Park, Utah

    NSDL National Science Digital Library

    This Capitol Reef National Park site contains park geology information, park maps, photographs, visitor information, and a teacher feature (resources for teaching geology with National Park examples). Geologic data includes descriptions of the Waterpocket Fold, a monocline formed in the Laramide Orogeny and made of sedimentary rock. Also covered is erosion, and details about the Cathedral Valley outcrop of gypsum. This formation is Permian to Cretaceous in age (270-80 million years old).

  18. Tour of Park Geology: Shoreline Geology

    NSDL National Science Digital Library

    This National Park Service (NPS) site provides links to shoreline geology fieldnotes for National Parks, Monuments, and Recreation Areas. When appropriate, fieldnotes include visitor information, geology, maps, photographs, multimedia resources, geologic research, and teacher features (lessons for teaching geology with National Park examples). Some of the parks included on this site: Acadia National Park, Everglades National Park, and Padre Island National Seashore.

  19. Geologic nozzles

    NASA Astrophysics Data System (ADS)

    Kieffer, Susan Werner

    Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low characteristic velocities of geologic fluids has not been widely recognized and, as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the geyser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid-flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, supercritical flow occurs where debris discharged from tributary canyons constricts the channel into the shape of a converging-diverging nozzle. The geometry of the channel in these regions can be used to interpret the flood history of the Colorado River over the past 103-105 years. The unity of fluid mechanics in these three natural phenomena is provided by the well-known analogy between gas flow and shallow-water flow in converging-diverging nozzles.

  20. Geologic Nozzles

    NASA Astrophysics Data System (ADS)

    Kieffer, Susan Werner

    1989-02-01

    Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low characteristic velocities of geologic fluids has not been widely recognized, and as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the gyeser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, the channel is constricted into the shape of a converging-diverging nozzle by debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. The transport capacity in the rapids can be so great that the river contours the channel to a characteristic shape. This shape can be used to interpret the flood history of the Colorado River over the past 10³-105 years. The unity of fluid mechanics in these three natural phenomena is provided by the well-known analogy between gas flow and shallow-water flow in converging-diverging nozzles.

  1. WESTERN PALESTINE. PHYSICAL GEOLOGY AND GEOGRAPHY

    E-print Network

    McKay, Brendan

    ' OF MOUNTAINS-SPRINGS- RELATIONS OF FORMER LAND AND SEA PART 11. CHAPTER I. GEOLOGICAL STRUCTURE OF ARABIA PETRl.' '/ SURVEY ()~. .., . / ~:. WESTERN PALESTINE. MEMOIR ON THE PHYSICAL GEOLOGY AND GEOGRAPHY ARABIA PETlUEA, PALESTINE, AND ADJOINING DISTRICTS. WITH SPECIAL REFERENCE TO THE MODE OF FORMATION

  2. Analysis of 3d complex structure and heterogeneity effects on formation and propagation of regional phases in Eurasia. Final report, 15 August 1992-30 September 1994

    SciTech Connect

    Lay, T.; Wu, R.S.

    1994-12-13

    This document is the final report for this grant to develop new three-dimensional wave propagation techniques for high frequency waves in heterogeneous media. The report is divided into four sections, each being a published paper sponsored by this grant. In the first section we formulate a one-way wide-angle elastic wave propagation method for arbitrarily heterogeneous media in both the space and wavenumber domains using elastic Rayleigh integrals and local elastic Born scattering theory. In the second section this complex phase screen method is compared with fourth-order finite differences and exact eigenfunction expansion calculations for two-dimensional inhomogeneous media to assess the accuracy of the one-way propagation algorithm. In the third section, an observational study of continental margin structure influence on Lg propagation is presented, using data from the former Soviet stations for nuclear explosions at Novaya Zemlya. We find that bathymetric features can be correlated with energy levels of Lg, suggesting that waveguide structure influences regional phase energy partitioning. This idea is pursued in the fourth section, using Eurasian earthquake and nuclear explosion data along with information about the crustal structure in Eurasia. We develop empirical relations that reduce the scatter in the P/Lg discriminant at low frequency.

  3. Co2 geological sequestration

    SciTech Connect

    Xu, Tianfu

    2004-11-18

    Human activities are increasingly altering the Earth's climate. A particular concern is that atmospheric concentrations of carbon dioxide (CO{sub 2}) may be rising fast because of increased industrialization. CO{sub 2} is a so-called ''greenhouse gas'' that traps infrared radiation and may contribute to global warming. Scientists project that greenhouse gases such as CO{sub 2} will make the arctic warmer, which would melt glaciers and raise sea levels. Evidence suggests that climate change may already have begun to affect ecosystems and wildlife around the world. Some animal species are moving from one habitat to another to adapt to warmer temperatures. Future warming is likely to exceed the ability of many species to migrate or adjust. Human production of CO{sub 2} from fossil fuels (such as at coal-fired power plants) is not likely to slow down soon. It is urgent to find somewhere besides the atmosphere to put these increased levels of CO{sub 2}. Sequestration in the ocean and in soils and forests are possibilities, but another option, sequestration in geological formations, may also be an important solution. Such formations could include depleted oil and gas reservoirs, unmineable coal seams, and deep saline aquifers. In many cases, injection of CO2 into a geological formation can enhance the recovery of hydrocarbons, providing value-added byproducts that can offset the cost of CO{sub 2} capture and sequestration. Before CO{sub 2} gas can be sequestered from power plants and other point sources, it must be captured. CO{sub 2} is also routinely separated and captured as a by-product from industrial processes such as synthetic ammonia production, H{sub 2} production, and limestone calcination. Then CO{sub 2} must be compressed into liquid form and transported to the geological sequestration site. Many power plants and other large emitters of CO{sub 2} are located near geological formations that are amenable to CO{sub 2} sequestration.

  4. Geologic mapping of Vesta

    NASA Astrophysics Data System (ADS)

    Yingst, R. A.; Mest, S. C.; Berman, D. C.; Garry, W. B.; Williams, D. A.; Buczkowski, D.; Jaumann, R.; Pieters, C. M.; De Sanctis, M. C.; Frigeri, A.; Le Corre, L.; Preusker, F.; Raymond, C. A.; Reddy, V.; Russell, C. T.; Roatsch, T.; Schenk, P. M.

    2014-11-01

    We report on a preliminary global geologic map of Vesta, based on data from the Dawn spacecraft's High-Altitude Mapping Orbit (HAMO) and informed by Low-Altitude Mapping Orbit (LAMO) data. This map is part of an iterative mapping effort; the geologic map has been refined with each improvement in resolution. Vesta has a heavily-cratered surface, with large craters evident in numerous locations. The south pole is dominated by an impact structure identified before Dawn's arrival. Two large impact structures have been resolved: the younger, larger Rheasilvia structure, and the older, more degraded Veneneia structure. The surface is also characterized by a system of deep, globe-girdling equatorial troughs and ridges, as well as an older system of troughs and ridges to the north. Troughs and ridges are also evident cutting across, and spiraling arcuately from, the Rheasilvia central mound. However, no volcanic features have been unequivocally identified. Vesta can be divided very broadly into three terrains: heavily-cratered terrain; ridge-and-trough terrain (equatorial and northern); and terrain associated with the Rheasilvia crater. Localized features include bright and dark material and ejecta (some defined specifically by color); lobate deposits; and mass-wasting materials. No obvious volcanic features are evident. Stratigraphy of Vesta's geologic units suggests a history in which formation of a primary crust was followed by the formation of impact craters, including Veneneia and the associated Saturnalia Fossae unit. Formation of Rheasilvia followed, along with associated structural deformation that shaped the Divalia Fossae ridge-and-trough unit at the equator. Subsequent impacts and mass wasting events subdued impact craters, rims and portions of ridge-and-trough sets, and formed slumps and landslides, especially within crater floors and along crater rims and scarps. Subsequent to the formation of Rheasilvia, discontinuous low-albedo deposits formed or were emplaced; these lie stratigraphically above the equatorial ridges that likely were formed by Rheasilvia. The last features to be formed were craters with bright rays and other surface mantling deposits. Executed progressively throughout data acquisition, the iterative mapping process provided the team with geologic proto-units in a timely manner. However, interpretation of the resulting map was hampered by the necessity to provide the team with a standard nomenclature and symbology early in the process. With regard to mapping and interpreting units, the mapping process was hindered by the lack of calibrated mineralogic information. Topography and shadow played an important role in discriminating features and terrains, especially in the early stages of data acquisition.

  5. Geological implications and controls on the determination of water saturation in shale gas reservoirs

    NASA Astrophysics Data System (ADS)

    Hartigan, David; Lovell, Mike; Davies, Sarah

    2014-05-01

    A significant challenge to the petrophysical evaluation of shale gas systems can be attributed to the conductivity behaviour of clay minerals and entrained clay bound waters. This is compounded by centimetre to sub-millimetre vertical and lateral heterogeneity in formation composition and structure. Where despite significant variation in formation geological and therefore petrophysical properties, we routinely rely on conventional resistivity methods for the determination of water saturation (Sw), and hence the free gas saturation (Sg) in gas bearing mudstones. The application of resistivity based methods is the subject of continuing debate, and there is often significant uncertainty in both how they are applied and the saturation estimates they produce. This is partly a consequence of the view that "the quantification of the behaviour of shale conductivity....has only limited geological significance" (Rider 1986). As a result, there is a separation between our geological understanding of shale gas systems and the petrophysical rational and methods employed to evaluate them. In response to this uncertainty, many petrophysicists are moving away from the use of more complex 'shaly-sand' based evaluation techniques and returning to traditional Archie methods for answers. The Archie equation requires various parameter inputs such as porosity and saturation exponents (m and n), as well as values for connate fluid resistivity (Rw). Many of these parameters are difficult to determine in shale gas systems, where obtaining a water sample, or carrying out laboratory experiments on recovered core is often technically impractical. Here we assess the geological implications and controls on variations in pseudo Archie parameters across two geological formations, using well data spanning multiple basinal settings for a prominent shale gas play in the northern Gulf of Mexico basin. The results, of numerical analysis and systematic modification of parameter values to minimise the error between core derived Sw (Dean Stark analysis) and computed Sw, links sample structure with composition, highlighting some unanticipated impacts of clay minerals on the effective bulk fluid resistivity (Rwe) and thus formation resistivity (Rt). In addition, it highlights simple corrective empirical adaptations that can significantly reduce the error in Sw estimation for some wells. Observed results hint at the possibility of developing a predictive capability in selecting Archie parameter values based on geological facies association and log composition indicators (i.e. V Clay), establishing a link between formation depositional systems and their petrophysical properties in gas bearing mudstones. Rider, M.H., 1986. The Geological Interpretation of Well Logs, Blackie.

  6. A Handbook for Geology Students Why study Geology?.............................................................................................3

    E-print Network

    Thaxton, Christopher S.

    1 A Handbook for Geology Students #12;2 Contents Why study Geology ..................................................................................7 Why Appalachian Geology?................................................................................10 Geology Faculty and Staff

  7. Historical Geology Online Laboratory Manual

    NSDL National Science Digital Library

    Pamela Gore

    1982-01-01

    The laboratories in this manual cover the following topics: rocks and minerals, weathering of rocks and the formation of sediment, sedimentary rocks and structures, depositional sedimentary environments, sand sieve analysis, relative dating, stratigraphy and lithologic correlation, fossils on the Internet, invertebrate macrofossils, microfossils, preservation, biostratigraphy, evolution, vertebrate paleontology, and interpreting geologic history from maps.

  8. Briefing on geological sequestration (Tulsa)

    EPA Science Inventory

    Geological sequestration (GS) is generally recognized as the injection and long-term (e.g., hundreds to thousands of years) trapping of gaseous, liquid or supercritical carbon dioxide (CO2) in subsurface media ? primarily saline formations, depleted or nearly depleted oil and gas...

  9. Geologic nozzles

    USGS Publications Warehouse

    Werner, Kieffer S.

    1989-01-01

    The importance of the low characteristic velocities of geologic fluids has not been widely recognized, and as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the geyser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, the channel is constricted into the shape of a converging-diverging nozzle by the debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. -from Author

  10. Illinois State Geological Survey

    NSDL National Science Digital Library

    The Illinois State Geological Survey (ISGS) homepage provides information on geologic mapping, earthquakes, fossils, groundwater, wetlands, glacial geology, bedrock geology, and Lake Michigan geology. Educational materials include field trip guides, short publications on Illinois geology for students and teachers, online tours, single-page maps, and a geologic column. Other materials include databases and collections of GIS data, well records, drill cores, and mining information; a bibliography of Illinois geology; online maps and data; and information on water and land use, resource development, and geologic hazards.

  11. Geology Fieldnotes: Zion National Park, Utah

    NSDL National Science Digital Library

    Annabelle Foos

    Zion is located on the edge of the Colorado Plateau, and is part of a formation known as the Grand Staircase (Bryce Canyon and the Grand Canyon are also part of this formation). The site discusses the formation of the park, from sedimentation 240 million years ago (Triassic), to lithification, uplift, and erosion. Visible formations include the Navajo sandstone and the Kaibab formation. Additional resources include visitor information, maps, photographs, and a teacher feature (lessons for teaching geology with National Parks as examples).

  12. Method of Analysis by the U.S. Geological Survey California District Sacramento Laboratory?Determination of Trihalomethane Formation Potential, Method Validation, and Quality-Control Practices

    USGS Publications Warehouse

    Crepeau, Kathryn L.; Fram, Miranda S.; Bush, Noel

    2004-01-01

    An analytical method for the determination of the trihalomethane formation potential of water samples has been developed. The trihalomethane formation potential is measured by dosing samples with chlorine under specified conditions of pH, temperature, incubation time, darkness, and residual-free chlorine, and then analyzing the resulting trihalomethanes by purge and trap/gas chromatography equipped with an electron capture detector. Detailed explanations of the method and quality-control practices are provided. Method validation experiments showed that the trihalomethane formation potential varies as a function of time between sample collection and analysis, residual-free chlorine concentration, method of sample dilution, and the concentration of bromide in the sample.

  13. The cost of meeting increased cooling-water demands for CO2 capture and storage utilizing non-traditional waters from geologic saline formations

    NASA Astrophysics Data System (ADS)

    Klise, Geoffrey T.; Roach, Jesse D.; Kobos, Peter H.; Heath, Jason E.; Gutierrez, Karen A.

    2013-05-01

    Deep (> ˜800 m) saline water-bearing formations in the United States have substantial pore volume that is targeted for storage of carbon dioxide (CO2) and the associated saline water can be extracted to increase CO2 storage efficiency, manage pressure build up, and create a new water source that, once treated, can be used for power-plant cooling or other purposes. Extraction, treatment and disposal costs of saline formation water to meet added water demands from CO2 capture and storage (CCS) are discussed. This underutilized water source may be important in meeting new water demand associated with CCS. For a representative natural gas combined-cycle (NGCC) power plant, simultaneous extraction of brine from the storage formation could provide enough water to meet all CCS-related cooling demands for 177 out of the 185 (96 %) saline formations analyzed in this study. Calculated total cost of water extraction, treatment and disposal is less than 4.00 US Dollars (USD) m-3 for 93 % of the 185 formations considered. In 90 % of 185 formations, treated water costs are less than 10.00 USD tonne-1 of CO2 injected. On average, this represents approximately 6 % of the total CO2 capture and injection costs for the NGCC scenario.

  14. The Necessity of Geologic Disposal

    SciTech Connect

    R. Linden

    2004-07-01

    Nuclear wastes are the radioactive byproducts of nuclear power generation, nuclear weapons production, and other uses of nuclear material. Experts from around the world agree that deep geologic disposal of nuclear waste in a mined repository is the most environmentally sound means of removing these potential sources of radiation from interaction with the biosphere. Of the 360 millirem of background radiation received annually by the average American, from both natural and man-made sources, less than 1 millirem results from the nuclear fuel cycle. Spent nuclear fuel and high-level radioactive waste, destined for geologic disposal, are located at 126 sites in 39 states. The proposed repository site at Yucca Mountain, Nevada, is far more isolated from the general population than any sites where these radioactive materials are presently located. Only solid forms of high-level wastes will be transported for disposal in a geologic repository. For more than 50 years, nuclear materials have been safely transported in North America, Europe, and Asia, without a single significant radiation release. Since the 1950s, select panels from the National Academy of Sciences-National Research Council and interagency advisory groups, and international experts selected by the OECD/Nuclear Energy Agency, have examined the environmental, ethical, and intergenerational aspects of nuclear waste disposal, plus alternatives to geologic disposal. All have concluded that deep geologic disposal in a mined repository is clearly the preferred option. The concept of deep geologic disposal is based on the analogy to ore deposits, which are formed deep within the Earth's crust, commonly remain isolated from the biosphere for millions to billions of years, and are, generally, extremely difficult to detect. Before selecting the unsaturated tuffs at Yucca Mountain, DOE evaluated salt formations, basalts, and both crystalline and sedimentary rocks. Other nations generating nuclear power also plan to use deep geologic disposal, and are evaluating sites in granites, argillaceous rocks, and salt formations.

  15. Geological modeling for methane hydrate reservoir characterization in the eastern Nankai Trough, offshore Japan

    NASA Astrophysics Data System (ADS)

    Tamaki, M.; Komatsu, Y.; Suzuki, K.; Takayama, T.; Fujii, T.

    2012-12-01

    The eastern Nankai trough, which is located offshore of central Japan, is considered as an attractive potential resource field of methane hydrates. Japan Oil, Gas and Metals National Corporation is planning to conduct a production test in early 2013 at the AT1 site in the north slope of Daini-Atsumi Knoll in the eastern Nankai Trough. The depositional environment of methane hydrate-bearing sediments around the production test site is a deep submarine-fan turbidite system, and it is considered that the reservoir properties should show lateral as well as vertical heterogeneity. Since the variations in the reservoir heterogeneity have an impact on the methane hydrate dissociation and gas production performance, precise geological models describing reservoir heterogeneity would be required for the evaluation of reservoir potentials. In preparation for the production test, 3 wells; two monitoring boreholes (AT1-MC and AT1-MT1) and a coring well (AT1-C), were newly acquired in 2012. In addition to a geotechnical hole drilling survey in 2011 (AT1-GT), totally log data from 2 wells and core data from 2 wells were obtained around the production test site. In this study, we conducted well correlations between AT1 and A1 wells drilled in 2003 and then, 3D geological models were updated including AT1 well data in order to refine hydrate reservoir characterization around the production test site. The results of the well correlations show that turbidite sand layers are characterized by good lateral continuity, and give significant information for the distribution morphology of sand-rich channel fills. We also reviewed previously conducted 3D geological models which consist of facies distributions and petrophysical properties distributions constructed from integration of 3D seismic data and a well data (A1 site) adopting a geostatistical approach. In order to test the practical validity of the previously generated models, cross-validation was conducted using AT1 well data. The results show that geological modeling including AT1 well data is important to reduce the uncertainty of the reservoir properties around the production test site. The geological models including AT1 well data were constructed taking into account for the lateral continuity of turbidite formations based on the well correlations. The concepts of these models are considered to be much more effective for describing reservoir continuity and heterogeneity and predicting upcoming production tests.

  16. Geology Fieldnotes: Sleeping Bear Dunes National Lakeshore, Michigan

    NSDL National Science Digital Library

    The Sleeping Bear Dunes National Lakeshore site contains park geology information, park maps, photographs, related links, and visitor information. The park geology section discusses the geologic history of the region and formation of Sleeping Bear Dunes through westerly winds from Lake Michigan. The park maps section includes a map of the Sleeping Bear Dunes National Lakeshore and the surrounding area.

  17. Excerpts from selected LANDSAT 1 final reports in geology

    NASA Technical Reports Server (NTRS)

    Short, N. M.; Smith, A.; Baker, R.

    1976-01-01

    The standard formats for the summaries of selected LANDSAT geological data are presented as checklists. These include: (1) value of LANDSAT data to geology, (2) geologic benefits, (3) follow up studies, (4) cost benefits, (5) optimistic working scales, (6) statistical analysis, and (7) enhancement effects.

  18. Unraveling Geological History: Glaciers and Faults at Discovery Park, Seattle

    NSDL National Science Digital Library

    Trileigh Tucker

    This introductory geology field exercise asks students to make individual observations about parts of an outcrop, then combine their observations in larger teams to interpret the overall geological history of the exposure. Content learning includes stratigraphy, faulting, and local geologic history; process learning includes data gathering and recording, hypothesis formation, and outlining helpful evidence that could be gathered in the future.

  19. Geologic Technician New Curriculum

    ERIC Educational Resources Information Center

    Karp, Stanley E.

    1970-01-01

    Describes a developing two-year geologic technician program at Bakersfield College in which a student may major in five areas - geologic drafting, land and legal, geologic assistant, engineering or paleontology. (RR)

  20. Geological Time Scale

    NSDL National Science Digital Library

    This document describes how geologic time is approached in discussions of geologic topics. The uses of relative time and absolute time are compared, and a geologic time scale is provided to represent both concepts. References are provided.

  1. The National Park Service: Park Geology

    NSDL National Science Digital Library

    A National Park Service (NPS) site primarily composed of three main sections corresponding to the following program areas within the Geologic Resources Division (GRD): Disturbed Lands Restoration and Abandoned Mineral Lands (AML), Mineral Management Programs, and Geology and Soils Programs. Of these, the first two consist principally of textual resources pertaining to Park System procedures, policies, and regulations - as well as reports on example restoration projects with a focus on stream corridor restoration, bioengineering, riparian management, and revegetation. Perhaps of most interest to educators will be the third main program area, the Geology and Soils Programs section. Here are included textual resources pertaining to NPS-GRD programs on cave and karst formations, coastal and shoreline geology, paleontology, soils (e.g., soil biology and soil surveying), geological indicators (geoindicators), and stratigraphy. Lastly, a searchable photographic collection and geologic glossary are available.

  2. The Geologic Story of Yosemite Valley

    NSDL National Science Digital Library

    N. Huber

    This website of the United States Geological Survey (USGS) and the National Park Service (NPS) discusses the geology of Yosemite Valley in California, beginning 100 million years ago with the formation of the granite rocks found in this park and continuing with jointing, exfoliation, and erosion through ice and water. Bedrock Geology includes details about the formation, classification, and descriptions of the plutonic bedrock. It also discusses the relationship of landforms to rock composition and structure and their role in shaping the Yosemite valley.

  3. West's Geology Resources

    NSDL National Science Digital Library

    Ian West

    This is one of the world's largest geological web sites, with more than 200 web pages comprised of geological field guides, with hundreds of full screen color photographs of varied geological features, and with associated bibliographies. All of the field guides are for geologic locations in England. Also included is a large directory of internet sites sorted by topic. Topics range from mineral and rock types, to geologic time periods, fossils, plate tectonics, geochronology, mapping, and geologic surveys.

  4. FUNDAMENTAL COMBUSTION RESEARCH APPLIED TO POLLUTION FORMATION. VOLUME 2C. PHYSICS AND CHEMISTRY OF TWO-PHASE SYSTEMS: HETEROGENEOUS NO REDUCTION

    EPA Science Inventory

    The reports included in the three-part volume describe eight studies by various investigators, to better understand the physics and chemistry of two-phase combustion with respect to pollution formation. Volume IIc gives information on the kinetic rates and mechanisms of nitrogen ...

  5. Coal geology of the Paleocene-Eocene Calvert Bluff Formation (Wilcox Group) and the Eocene Manning Formation (Jackson Group) in east-central Texas; field trip guidebook for the Society for Organic Petrology, Twelfth Annual Meeting, The Woodlands, Texas, August 30, 1995

    USGS Publications Warehouse

    Warwick, Peter D.; Crowley, Sharon S.

    1995-01-01

    The Jackson and Wilcox Groups of eastern Texas (fig. 1) are the major lignite producing intervals in the Gulf Region. Within these groups, the major lignite-producing formations are the Paleocene-Eocene Calvert Bluff Formation (Wilcox) and the Eocene Manning Formation (Jackson). According to the Keystone Coal Industry Manual (Maclean Hunter Publishing Company, 1994), the Gulf Coast basin produces about 57 million short tons of lignite annually. The state of Texas ranks number 6 in coal production in the United States. Most of the lignite is used for electric power generation in mine-mouth power plant facilities. In recent years, particular interest has been given to lignite quality and the distribution and concentration of about a dozen trace elements that have been identified as potential hazardous air pollutants (HAPs) by the 1990 Clean Air Act Amendments. As pointed out by Oman and Finkelman (1994), Gulf Coast lignite deposits have elevated concentrations of many of the HAPs elements (Be, Cd, Co, Cr, Hg, Mn, Se, U) on a as-received gm/mmBtu basis when compared to other United States coal deposits used for fuel in thermo-electric power plants. Although regulations have not yet been established for acceptable emissions of the HAPs elements during coal burning, considerable research effort has been given to the characterization of these elements in coal feed stocks. The general purpose of the present field trip and of the accompanying collection of papers is to investigate how various aspects of east Texas lignite geology might collectively influence the quality of the lignite fuel. We hope that this collection of papers will help future researchers understand the complex, multifaceted interrelations of coal geology, petrology, palynology and coal quality, and that this introduction to the geology of the lignite deposits of east Texas might serve as a stimulus for new ideas to be applied to other coal basins in the U.S. and abroad.

  6. The conchostracan subgenus Orthestheria (Migransia) from the Tacuarembó Formation (Late Jurassic-?Early Cretaceous, Uruguay) with notes on its geological age

    NASA Astrophysics Data System (ADS)

    Yanbin, Shen; Gallego, Oscar F.; Martínez, Sergio

    2004-04-01

    Conchostracans from the Tacuarembó Formation s.s. of Uruguay are reassigned to the subgenus Orthestheria (Migransia) Chen and Shen. They show more similarities to genera of Late Jurassic age in the Congo Basin and China than to those of Early Cretaceous age. On the basis of the character of the conchostracans, we suggest that the Tacuarembó Formation is unlikely to be older than Late Jurassic. It is probably Kimmeridgian, but an Early Cretaceous age cannot be excluded. This finding is consistent with isotopic dating of the overlying basalts, as well as the age range of recently described fossil freshwater sharks.

  7. Old Geology and New Geology

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 28 May 2003

    Mangala Vallis one of the large outflow channels that channeled large quantities of water into the northern lowlands, long ago on geological timescales. This valley is one of the few in the southern hemisphere, as well as one of the few west of the Tharsis bulge. A closer look at the channel shows more recent weathering of the old water channel: the walls of the channel show small, dark slope streaks that form in dusty areas; and much of the surrounding terrain has subtle linear markings trending from the upper left to the lower right, which are probably features sculpted and streamlined by the wind. Geology still shapes the surface of Mars today, but its methods over the eons have changed.

    Image information: VIS instrument. Latitude -6, Longitude 209.6 East (150.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  8. Geology of the Lower Cretaceous Travis Peak Formation, East Texas. Depositional history, diagenesis, structure, and reservoir-engineering implications. Topical report, November 1982February 1990

    Microsoft Academic Search

    S. P. Dutton; S. E. Laubach; R. S. Tye; R. W. Baumgardner; K. L. Herrington

    1990-01-01

    The report summarizes stratigraphic, petrographic, and structural studies of the Lower Cretaceous Travis Peak Formation, a low-permeability gas sandstone in East Texas, and presents reservoir engineering implications. Depositional systems in this region were interpreted from logs and cores and include (1) a braided- to meandering-fluvial system that forms the majority of the Travis Peak section; (2) deltaic deposits interbedded with

  9. The geology and geochemistry of the Espungabera Formation of central Mozambique and its tectonic setting on the eastern margin of the Kalahari Craton

    NASA Astrophysics Data System (ADS)

    Moabi, Neo G.; Grantham, Geoffrey H.; Roberts, James; Roux, Petrus le; Matola, Rogerio

    2015-01-01

    Whole rock major and trace element chemistry as well as radiogenic isotope data from the Espungabera Formation of central Mozambique are compared with published data from the Umkondo Formation lavas in SE Zimbabwe and Straumsnutane Formation lavas in western Dronning Maud Land, Antarctica. These formations form part of the ?1100 Ma Umkondo Igneous Province in southern Africa and are now preserved on the Grunehogna (in Antarctica) and Zimbabwe (in Zimbabwe) Cratons. The chemical data indicate that the Espungabera Formation lavas are dominantly tholeiitic and basaltic to basaltic andesitic in composition. The Espungabera lavas are dominated by plagioclase, clinopyroxene and Fe-Ti oxides. Metamorphic mineral assemblages indicate the lavas have been metamorphosed under mid-greenschist facies on a retrograde path to prehnite-pumpellyite facies conditions. The decrease in FeOt with increasing MgO content in the Espungabera lavas and the slight decrease in TiO2 with increasing MgO indicates fractionation of Fe-Ti oxides. The lavas are characterised by negative Nb anomalies; enriched LILE's and high 87Sr/86Sr isotopic ratios. The 87Sr/86Sr data calculated at 1100 Ma suggest contamination by continental crust during the petrogenesis of the lavas. The Espungabera volcanics have negative ?Nd values (-2.83 to -3.49) also suggesting that the magma was contaminated by older crust. Comparison of the chemical data from the Espungabera Formation with data from the Umkondo Group basalts from SE Zimbabwe and the Straumsnutane Formation lavas from Dronning Maud Land, Antarctica shows that they are similar. These similarities, along with similarities in the available geochronological data suggest that these rocks are comagmatic. Both units are also geochemically similar to some rock units that form part of the Umkondo Large Igneous Province (i.e. Zimbabwe basalts that were regarded as Umkondo basalts by Munyanyiwa (1999), Waterberg sills, Umkondo sills and Type III Mutare and Guruve dykes identified by Ward (2002)), and therefore we conclude that the Espungabera lavas in Mozambique also form part of the Umkondo Igneous Province. The craton-based tholeiitic Umkondo Igneous Province is broadly coeval with tonalitic calc-alkaline and granitic gneisses in the Nampula and Maud Terranes in Mozambique and Antarctica respectively, immediately east of the Kalahari Craton in a reconstructed Gondwana. These data can be interpreted to indicate that the Espungabera and Straumsnutane lavas form part of a back-arc complex, west of a volcanic arc/subduction zone along the eastern margin of the Kalahari Craton at ?1100 Ma.

  10. Colorado Geological Survey

    NSDL National Science Digital Library

    The Colorado Geological Survey (CGS) is an agency of state government within the Department of Natural Resources whose mission is to help reduce the impact of geologic hazards on the citizens of Colorado, to promote the responsible economic development of mineral and mineral fuel resources, to provide geologic insight into water resources, and to provide geologic advice and information to a variety of constituencies. This site contains extensive information about Colorado geology such as maps, a geologic time scale for the state, program information, and state field trip information. This site hosts the Avalanche Information Center which contains avalanche forecasting and education center details. Publications report on geologic hazards, land use, environmental geology, mineral resources, oil, gas, coal, geologic mapping and earthquake information for the state. There are online editions of RockTalk, which is a quarterly newsletter published by the Colorado Geological Survey dealing with all aspects of geology throughout the state of Colorado. Links are provided for more resources.

  11. GEOLOGICAL CHARACTERISTICS

    E-print Network

    G. A. Gross; C. F. Gower; D. V. Lefebure; Commodities (byproducts) Ti

    CAPSULE DESCRIPTION: Ilmenite, hemo-ilmenite or titaniferous magnetite accumulations as cross-cutting lenses or dike-like bodies, Ia> ers or disseminations within anorthositiclgabbroicinoritic rocks. These deposits can be subdivided into an ilmenite subtype (anorthosite-hosted titanium-iron) and a titaniferous magnetite subtype (gabbro-anorthosite-hosted iron-titanium). TECTONIC SETTING: Commonly associated with anorthosite-gabbro-norite-monzonite (mangerite)charnockite granite (AMCG) suites that are conventionally interpreted to be anorogenic and/or extensional. Some of the iron-titanium deposits occur at continental margins related to island arc magmatism followed by an episode of erogenic compression. DEPOSITIONAL ENVIRONMENT i GEOLOGICAL SETTING: Deposits occur in intrusive complexes which typically are emplaced at deeper levels in the crust. Progressive differentiation of liquids residual from anorthosite-norite magmas leads to late stage intrusions enriched in Fe and Ti oxides and apatite. AGE OF MINERALIZATION: Mainly Mesoproterozoic (1.65 to 0.90 Ga) for the ihnenite deposits, but this may be a consequence of a particular combination of tectonic circumstances, rather than any a priori temporal control. The Fe-Ti deposits with titaniferous magnetite do not appear to be restricted in time. HOST/ASSOCIATED ROCKS: Hosted by massive, layered or zoned intrusive complexes- anorthosite, norite,

  12. SEISMIC DETERMINATION OF RESERVOIR HETEROGENEITY; APPLICATION TO THE CHARACTERIZATION OF HEAVY OIL RESERVOIRS

    SciTech Connect

    Matthias G. Imhof; James W. Castle

    2003-11-01

    The objective of the project is to examine how seismic and geologic data can be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study is performed at West Coalinga Field in California. We continued our investigation on the nature of seismic reactions from heterogeneous reservoirs. We began testing our algorithm to infer parameters of object-based reservoir models from seismic data. We began integration of seismic and geologic data to determine the deterministic limits of conventional seismic data interpretation. Lastly, we began integration of seismic and geologic heterogeneity using stochastic models conditioned both on wireline and seismic data.

  13. Multiple-point geostatistics for modeling subsurface heterogeneity: A comprehensive review

    NASA Astrophysics Data System (ADS)

    Hu, L. Y.; Chugunova, T.

    2008-11-01

    For more than half a century, geostatistics has been developed and has increasingly been used for modeling subsurface heterogeneity. Traditionally, geostatistical simulations are based on a random function model defined according to the specificities of the geological formation under investigation. Unlike traditional geostatistics, multiple-point (MP) geostatistics avoids the explicit definition of a random function but directly infers the necessary multivariate distributions from training images. This confers on MP geostatistics a potential applicability to any geological environment, provided that there is a training image representative of the geological heterogeneity and that the essential features of this training image can be characterized by statistics defined on a limited point configuration. This paper presents a comprehensive review of MP geostatistics. If the principle of MP geostatistics is straightforward and attractive, its industrial applicability largely depends on the implementation methods. The use of a search tree for storing MP statistics is a great step that made MP geostatistics actually applicable in industry. In the meantime, other methods such as multiple grids and image postprocessing are introduced and allow enhancing the reproduction of patterns observed in training images. Because of the sequential procedure, MP simulations can easily honor local hard data. There are methods available for constraining MP simulations to target global statistics (facies proportions) and also for integrating spatial auxiliary constraints that can tremendously improve the spatial features of MP simulations. Furthermore, both the gradual deformation method and the probability perturbation method are compatible with MP geostatistics and allow integrating hydrodynamic data into MP simulations. More recent developments of MP geostatistics include sequentially simulating patterns instead of points and using different geological scenarios (training images) for dynamic data inversion.

  14. Bedrock Geologic Map of Maine

    NSDL National Science Digital Library

    In this activity students study a map of bedrock geology which describes the types of rocks that exist in a given area. It shows these rock units as well as their known and inferred contacts. Consideration is also given to folding, faulting, unconformities, and similar rock relationships. These features are often included in bedrock geology maps. Students study the legend and scale and become aware of the other information that is included on the map such as the stratigraphic column, list of formations, and inset map of metamorphic grade. Students then locate their city or town and draw a 40-mile diameter circle around it and identify all the symbols inside the circle and the age of the various rocks. Student question sheets are available at this site. Although this activity was written for a map of Maine, it will work in any state where geological maps are available.

  15. Ultra-deep oxidation and exotic copper formation at the late pliocene boyongan and bayugo porphyry copper-gold deposits, surigao, philippines: Geology, mineralogy, paleoaltimetry, and their implications for Geologic, physiographic, and tectonic controls

    USGS Publications Warehouse

    Braxton, D.P.; Cooke, D.R.; Ignacio, A.M.; Rye, R.O.; Waters, P.J.

    2009-01-01

    The Boyongan and Bayugo porphyry copper-gold deposits are part of an emerging belt of intrusion-centered gold-rich deposits in the Surigao district of northeast Mindanao, Philippines. Exhumation and weathering of these Late Pliocene-age deposits has led to the development of the world's deepest known porphyry oxidation profile at Boyongan (600 m), and yet only a modest (30-70 m) oxidation profile at adjacent Bayugo. Debris flows, volcanic rocks, and fluviolacustrine sediments accumulating in the actively extending Mainit graben subsequently covered the deposits and preserved the supergene profiles. At Boyongan and Bayugo, there is a vertical transition from shallower supergene copper oxide minerals (malachite + azurite + cuprite) to deeper sulfide-stable assemblages (chalcocite ?? hypogene sulfides). This transition provides a time-integrated proxy for the position of the water table at the base of the saturated zone during supergene oxidation. Contours of the elevation of the paleopotentiometric surface based on this min- eralogical transition show that the thickest portions of the unsaturated zone coincided with a silt-sand matrix diatreme breccia complex at Boyongan. Within the breccia complex, the thickness of the unsaturated zone approached 600 in, whereas outside the breccia complex (e.g., at Bayugo), the thickness averaged 50 m. Contours of the paleopotentiometric surface suggest that during weathering, groundwater flowed into the breccia complex from the north, south, and east, and exited along a high permeability zone to the west. The high relief (>550 m) on the elevation of the paleopotentiometric surface is consistent with an environment of high topographic relief, and the outflow zone to the west of the breccia complex probably reflects proximity to a steep scarp intersecting the western breccia complex margin. Stable isotope paleoaltimetry has enabled estimation of the elevation of the land surface, which further constrains the physiographic setting during supergene oxidation. Isotopic measurements of oxygen in supergene kaolinite from Boyongan suggest that local paleometeoric water involved in weathering had a ??180 composition of approximately -5.7 per mil. At the latitude of the southern Philippines, this value corresponds to Pleistocene rain water condensing at elevations between 750 and 1,050 m above contemporary sea level, providing a maximum estimate for the surface elevation during weathering of the porphyry systems. Physiographic reconstuctions suggest that the deep oxidation profile at Boyongan formed in an environment of high topographic relief immediately east of a prominent (>550 m) escarpment. The high permeability contrast between the breccia complex and the surrounding wall rocks, coupled with the proximity of the breccia complex to the escarpment, led to a depressed groundwater table and a vertically extensive unsaturated zone in the immediate vicinity of Boyongan. This thick vadose zone and the low hypogene pyrite/copper sulfide ratios (0.6) at Boyongan promoted in situ oxidation of copper sulfides with only modest (<200 m) supergene remobilization of copper. In contrast, higher hypogene pyrite/chalcopyrite ratios (2.3) at Bayugo led to greater acid production during weathering and more complete leaching of copper above the base of oxidation. This process promoted significant (600 m) lateral dispersion of copper down the paleohydraulic gradient into the diatreme breccia comple, ultimately leading to the formation of an exotic copper deposit. ?? 2009 Society of Economices Geologists, Inc.

  16. Three-dimensional, geological representation of Quaternary deposits, Goettingen, Germany

    NASA Astrophysics Data System (ADS)

    Thomas, Katrin; Wagner, Bianca

    2010-05-01

    The Quaternary unconsolidated rock in north-eastern Goettingen was newly interpreted according to current scientific expertise. Especially the deposits of the Lutter River, a tributary to the Leine River, were examined using 253 drillings previously undertaken to create 24 two-dimensional cross-sections and a three-dimensional model of the geologic underground in the study area. The interpretation of the included data (drillings, previous studies, two-dimensional cross-sections) resulted in a stratigraphic sequence with 17 Quaternary model units, which was depicted three-dimensionally. During the investigation period, open pits were limited in the entire working area. Natural outcrops of Quaternary subsurfaces are absent. For the creation of a two-dimensional and three-dimensional representation of the geologic structure, it was necessary to fall back on available information of drillings. The spatial distribution of the drilling information in the scope of work is very heterogeneous. In addition, numerous engineer-geologic surveys were used for the interpretation and interpolation within areas where no other information could be obtained by drilling within this study. The production of a three-dimensional illustration of the unconsolidated rock first required an exact investigation and homogenisation of all available information. The choice of the drillings used in the scope of work were chosen with priority according to their depth with the aid of ArcMap. Two-dimensional cross-sections of the profiles of these drillings were produced with the help of the computer program GeoDin. Using the two-dimensional cross sections, the drillings were correlated with each other and compared and discussed extensively. The sequence of the geologic unities thereby presented itself more clearly and more exactly than in linear consideration. A geologic unity could be assigned to every examined layer of each drilling. Additionally, a top and a base were assigned to each geologic layer as a limitation of the layers, which were documented in Access-Database. The base of a younger layer corresponds directly to the top of the following older layer beneath. The creation of the three-dimensional underground model was undertaken using the licensed software goCad® ("Geological Objects computer Aided Design"). The provided markers of the geologic layer borders were saved in the ASCII-format intersystem within the MS Access data base and were imported in the programme goCad®. Using this information, 17 geologic layers were constructed three-dimensionally. The geologic sequence of the investigation area includes glacial deposits. The loess clays (three sequences) and the three fluvial debris series were emphasised in the results. After detailed examination, the fluvial debris could be divided into Elster, Saale and Weichsel Gilbert-type delta deposits of a glacial lake of the Leine River, respectively. The loess clays are interglacial deposits following the named glacial periods.

  17. Geology Fieldnotes: Wind Cave National Park South Dakota

    NSDL National Science Digital Library

    Wind Cave National Park includes one of the world's longest and most complex caves and 28,295 acres of mixed-grass prairie, ponderosa pine forest, and associated wildlife. The cave is well known for its outstanding display of boxwork, an unusual cave formation composed of thin calcite fins resembling honeycombs. Features include park geology information, maps, photographs of cave formations, related links, and visitor information. The park geology section discusses geologic history, structural geology, cave formations, and history of exploration of the region. The park maps section includes an area map of Wind Cave National Park and a detailed cave map.

  18. Paleosols of the Upper Cretaceous Lower Tertiary Maghra El-Bahari Formation in the northeastern portion of the Eastern Desert, Egypt: Their recognition and geological significance

    Microsoft Academic Search

    H. A. Wanas; M. M. Abu El-Hassan

    2006-01-01

    The Upper Cretaceous\\/Lower Tertiary Maghra El-Bahari Formation at Gabal Ataqa and Gabal Shabrawet in the northeastern portion of the Eastern Desert of Egypt is subdivided into two informal lithostratigraphic parts: lower and upper. The lower part has common features of alluvial floodplain-dominated deposits with occasional occurrences of crevasse splay deposits. The upper part has sediments typical of marginal lacustrine environments.

  19. Paleosols of the Upper Cretaceous–Lower Tertiary Maghra El-Bahari Formation in the northeastern portion of the Eastern Desert, Egypt: Their recognition and geological significance

    Microsoft Academic Search

    H. A. Wanas; M. M. Abu El-Hassan

    2006-01-01

    The Upper Cretaceous\\/Lower Tertiary Maghra El-Bahari Formation at Gabal Ataqa and Gabal Shabrawet in the northeastern portion of the Eastern Desert of Egypt is subdivided into two informal lithostratigraphic parts: lower and upper. The lower part has common features of alluvial floodplain-dominated deposits with occasional occurrences of crevasse splay deposits. The upper part has sediments typical of marginal lacustrine environments.Both

  20. REMOTE SENSING GEOLOGICAL SURVEY

    E-print Network

    REMOTE SENSING IN GEOLOGICAL SURVEY OF BRAZIL August/2010 Mônica Mazzini Perrotta Remote Sensing Division Head #12;SUMMARY The Geological Survey of Brazil mission The Remote Sensing Division Main remote sensing data used in CPRM geologic projects Future perspective: the Spectral Library of Geological Survey

  1. Maryland Geological Survey

    NSDL National Science Digital Library

    The Maryland Geological Survey (MGS) homepage contains information from MGS programs on hydrogeology, hydrology, coastal and estuarine geology, environmental geology and mineral resources; an online guide to Maryland geology; and information on oyster habitat restoration projects. There are also maps, data, information on MGS publications, MGS news, and online educational resources.

  2. History of Geology.

    ERIC Educational Resources Information Center

    Greene, Mott T.

    1985-01-01

    Discusses: (1) geologists and the history of geology; (2) American historians and the history of geology; (3) history of geology in the 1980s; (4) sources for the history of geology (bibliographies, dictionaries, encyclopedias, handbooks, periodicals, public/official histories, compilations, and books); (5) research opportunities; and (6) other…

  3. GEOLOGY (GEOL) Robinson Foundation

    E-print Network

    Dresden, Gregory

    177Geology GEOLOGY (GEOL) Robinson Foundation PROFESSOR HARBOR ASSOCIATE PROFESSORS KNAPP, CONNORS ASSISTANT PROFESSORS GREER, RAHL MAJORS BACHELOR OF SCIENCE A major in geology leading to a Bachelor of Science degree consists of 50 credits as follows: 1. Geology 160, 185, 211, 311, 330, 350

  4. Geologic Maps and Mapping

    NSDL National Science Digital Library

    This portal provides access to resources on geologic mapping, and to sources of geologic maps. There is an introduction to geologic mapping, which summarizes its principles and practices, and a history of United States Geological Survey (USGS) mapping activities from 1879 to the present, as well as links to papers on the values and hazards associated with geologic maps and mapping. Online sources of maps include the USGS Geologic Map Database, other federal map products (FEDMAP), state geological survey products (STATEMAP), and university map products (EDMAP).

  5. Tennessee Division of Geology

    NSDL National Science Digital Library

    This is the homepage of the Geology Division of the Tennessee Department of Environment and Conservation. It provides information on the division's programs, including geologic hazards research, public service, education programs, basic and applied research on geology and mineral resources, publication of geologic information, permitting of oil and gas wells, and regulation of Tennessee's oil and gas industry. Materials include a catalog of publications, maps, geologic bulletins, and the Public Information series of pamphlets; the Geology Division Newsletter; and information on the state's mineral industry. There is also a section on the Gray Fossil Site, an unusual assemblage of fossils and sedimentary geology encountered during road construction near the town of Gray, Tenessee.

  6. The Paleozoic petroleum geology of central Arabia

    Microsoft Academic Search

    J. G. McGillivray; M. I. Husseini

    1991-01-01

    Recent exploratory drilling in central Saudi Arabia indicates that all the geological elements of a major petroleum basin are present in this province. Several Paleozoic siliciclastic sequences which were deposited along the stable Arabian margin of Gondwanaland constitute excellent reservoirs. The identified reservoir targets include the Cambrian-Ordovician Saq Formation, Upper Ordovician-Lower Silurian glaciogenic clastics of the Sarah and Zarqa formations,

  7. Marine geology: A planet earth perspective

    SciTech Connect

    Anderson, R.N.

    1986-01-01

    This text provides coverage of the basic geology of the marine development. It starts with the formation of the oceans using plate tectonics, continues with discussions of the mid-ocean ridges, and concludes with coverage of the formation and deformation of the continents.

  8. Geology Fieldnotes: Acadia National Park, Maine

    NSDL National Science Digital Library

    This National Park Service website highlights the geology of Acadia National Park. The story begins 500 million years ago, and goes through rock cycles, formations (Ellsworth, Bar Harbor, and Cranberry formations), intrusions, the Ice Age, glacial features, and development of shore patterns. There are area and park maps, photos, and links to additional information.

  9. Geology, coal resources, and chemical analyses of coal from the Fruitland Formation, Kimbeto EMRIA study site, San Juan County, New Mexico

    USGS Publications Warehouse

    Schneider, Gary B.; Hildebrand, Rick T.; Affolter, Ronald H.

    1979-01-01

    The Kimbeto EMRIA study site, an area of about 20 square miles (52 km2), is located on the south margin of the San Juan Basin on the gently northward-dipping strata of the Upper Cretaceous Fruitland Formation and the Kirtland Shale. The coal beds are mainly in the lower 150 feet (45 m) of the Fruitland Format ion. Coal resources--measured, indicated, and inferred--with less than 400 feet (120 m) of overburden in the site are 69,085,000 short tons (62,660,100 metric tons), 369,078,000 short tons (334,754,000 metric tons), and 177,803,000 short tons (161,267,000 metric tons) respectively. About 68 percent of these resources are overlain by 200 feet (60 m) or less of overburden. The apparent rank of the coal ranges from subbituminous B to subbituminous A. The average Btu/lb value of 14 core samples from the site on the as-received basis is 8,240 (4580 Kcal/kg), average ash content is 23.4 percent, and average sulfur content is 0.5 percent. Analyses of coal from the Kimbeto EMRIA study site show significantly higher ash content and significantly lower contents of volatile matter, fixed carbon, carbon, and a significantly lower heat of combustion when compared with other coal analyses from the Rocky Mountain province.

  10. Simulation of CO2 Sequestration at Rock Spring Uplift, Wyoming: Heterogeneity and Uncertainties in Storage Capacity, Injectivity and Leakage

    SciTech Connect

    Deng, Hailin [Los Alamos National Laboratory; Dai, Zhenxue [Los Alamos National Laboratory; Jiao, Zunsheng [Wyoming State Geological Survey; Stauffer, Philip H. [Los Alamos National Laboratory; Surdam, Ronald C. [Wyoming State Geological Survey

    2011-01-01

    Many geological, geochemical, geomechanical and hydrogeological factors control CO{sub 2} storage in subsurface. Among them heterogeneity in saline aquifer can seriously influence design of injection wells, CO{sub 2} injection rate, CO{sub 2} plume migration, storage capacity, and potential leakage and risk assessment. This study applies indicator geostatistics, transition probability and Markov chain model at the Rock Springs Uplift, Wyoming generating facies-based heterogeneous fields for porosity and permeability in target saline aquifer (Pennsylvanian Weber sandstone) and surrounding rocks (Phosphoria, Madison and cap-rock Chugwater). A multiphase flow simulator FEHM is then used to model injection of CO{sub 2} into the target saline aquifer involving field-scale heterogeneity. The results reveal that (1) CO{sub 2} injection rates in different injection wells significantly change with local permeability distributions; (2) brine production rates in different pumping wells are also significantly impacted by the spatial heterogeneity in permeability; (3) liquid pressure evolution during and after CO{sub 2} injection in saline aquifer varies greatly for different realizations of random permeability fields, and this has potential important effects on hydraulic fracturing of the reservoir rock, reactivation of pre-existing faults and the integrity of the cap-rock; (4) CO{sub 2} storage capacity estimate for Rock Springs Uplift is 6614 {+-} 256 Mt at 95% confidence interval, which is about 36% of previous estimate based on homogeneous and isotropic storage formation; (5) density profiles show that the density of injected CO{sub 2} below 3 km is close to that of the ambient brine with given geothermal gradient and brine concentration, which indicates CO{sub 2} plume can sink to the deep before reaching thermal equilibrium with brine. Finally, we present uncertainty analysis of CO{sub 2} leakage into overlying formations due to heterogeneity in both the target saline aquifer and surrounding formations. This uncertainty in leakage will be used to feed into risk assessment modeling.

  11. North Dakota geology school receives major gift

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-10-01

    Petroleum geology and related areas of study at the University of North Dakota (UND) received a huge financial boost with the announcement on 24 September of $14 million in private and public partnership funding. The university announced the naming of the Harold Hamm School of Geology and Geological Engineering, formerly a department within the College of Engineering and Mines, in recognition of $10 million provided as a gift by oilman Harold Hamm and Continental Resources, Inc. Hamm is the chair and chief executive officer of Continental, the largest leaseholder in the Bakken Play oil formation in North Dakota and Montana, and he is also an energy policy advisor to Republican presidential candidate Mitt Romney. UND also received $4 million from the Oil and Gas Research Program of the North Dakota Industrial Commission to support geology and geological engineering education and research.

  12. Significant achievements in the Planetary Geology Program. [geologic processes, comparative planetology, and solar system evolution

    NASA Technical Reports Server (NTRS)

    Head, J. W. (editor)

    1978-01-01

    Developments reported at a meeting of principal investigators for NASA's planetology geology program are summarized. Topics covered include: constraints on solar system formation; asteriods, comets, and satellites; constraints on planetary interiors; volatiles and regoliths; instrument development techniques; planetary cartography; geological and geochemical constraints on planetary evolution; fluvial processes and channel formation; volcanic processes; Eolian processes; radar studies of planetary surfaces; cratering as a process, landform, and dating method; and the Tharsis region of Mars. Activities at a planetary geology field conference on Eolian processes are reported and techniques recommended for the presentation and analysis of crater size-frequency data are included.

  13. SIMULATION MODEL ANALYSIS OF THE MOST PROMISING GEOLOGIC SEQUESTRATION FORMATION CANDIDATES IN THE ROCKY MOUNTAIN REGION, USA, WITH FOCUS ON UNCERTAINTY ASSESSMENT

    SciTech Connect

    Lee, Si-Yong; Zaluski, Wade; Will, Robert; Eisinger, Chris; Matthews, Vince; McPherson, Brian

    2013-09-01

    The purpose of this report is to report results of reservoir model simulation analyses for forecasting subsurface CO2 storage capacity estimation for the most promising formations in the Rocky Mountain region of the USA. A particular emphasis of this project was to assess uncertainty of the simulation-based forecasts. Results illustrate how local-scale data, including well information, number of wells, and location of wells, affect storage capacity estimates and what degree of well density (number of wells over a fixed area) may be required to estimate capacity within a specified degree of confidence. A major outcome of this work was development of a new workflow of simulation analysis, accommodating the addition of “random pseudo wells” to represent virtual characterization wells.

  14. Depositional and diagenetic history and petroleum geology of the Jurassic Norphlet Formation of the Alabama coastal waters area and adjacent federal waters area

    USGS Publications Warehouse

    Kugler, R.L.; Mink, R.M.

    1999-01-01

    The discovery of deep (>20,000 ft) gas reservoirs in eolian sandstone of the Upper Jurassic Norphlet Formation in Mobile Bay and offshore Alabama in the late 1970s represents one of the most significant hydrocarbon discoveries in the nation during the past several decades. Estimated original proved gas from Norphlet reservoirs in the Alabama coastal waters and adjacent federal waters is 7.462 trillion ft3 (Tcf) (75% recovery factor). Fifteen fields have been established in the offshore Alabama area. Norphlet sediment was deposited in an arid environment in alluvial fans, alluvial plains, and wadis in updip areas. In downdip areas, the Norphlet was deposited in a broad desert plain, with erg development in some areas. Marine transgression, near the end of Norphlet deposition, resulted in reworking of the upper part of the Norphlet Formation. Norphlet reservoir sandstone is arkose and subarkose, consisting of a simple assemblage of three minerals, quartz, albite, and K-feldspar. The present framework grain assemblage of the Norphlet is dominantly diagenetic, owing to albitization and dissolution of feldspar. Despite the simple framework composition, the diagenetic character of the Norphlet is complex. Important authigenic minerals include carbonate phases (calcite, dolomite, Fe-dolomite, and breunnerite), feldspar (albite and K-feldspar), evaporite minerals (anhydrite and halite), clay minerals (illite and chlorite), quartz, and pyrobitumen. The abundance and distribution of these minerals varies significantly between onshore and offshore regions of Norphlet production. The lack of sufficient internal sources of components for authigenic minerals, combined with unusual chemical compositions of chloride (Mg-rich), breunnerite, and some minor authigenic minerals, suggests that Louann-derived fluids influenced Norphlet diagenesis. In offshore Alabama reservoirs, porosity is dominantly modified primary porosity. Preservation of porosity in deep Norphlet reservoirs is due to a combination of factors, including a lack of sources of cement components and lack of pervasive early cement, so that fluid-flow pathways remained open during burial. Below the dominantly quartz-cemented tight zone near the top of the Norphlet, pyrobitumen is a major contributor to reduction in reservoir quality in offshore Alabama. The highest reservoir quality occurs in those wells where the present gas-water contact is below the paleohydrocarbon-water contact. Thiz zone of highest reservoir quality is between the lowermost occurrence of pyrobitumen and the present gas-water contact.The Upper Jurassic Norphlet Formation sediment was deposited in an arid environment in alluvial fans, alluvial plains, and wadis in undip areas. In downdip areas, the Norphlet was deposited in a broad desert plain, with erg development in some areas. Marine transgression, near the end of Norphlet deposition resulted in reworking of the upper part of the formation. he present framework grain assemblage of the Norphlet is dominantly diagenetic, owing to albitization and dissolution of feldspar. Despite the simple framework composition, the diagenetic character of the Norphlet is complex.

  15. Predictions of long-term behavior of a large-volume pilot test for CO2 geological storage in a saline formation in the Central Valley, California

    SciTech Connect

    Doughty, Christine; Myer, Larry R.; Oldenburg, Curtis M.

    2008-11-01

    The long-term behavior of a CO{sub 2} plume injected into a deep saline formation is investigated, focusing on mechanisms that lead to plume stabilization. Key measures are plume migration distance and the time evolution of CO{sub 2} phase-partitioning, which are examined by developing a numerical model of the subsurface at a proposed power plant with CO{sub 2} capture in the San Joaquin Valley, California, where a large-volume pilot test of CO{sub 2} injection will be conducted. The numerical model simulates a four-year CO{sub 2} injection period and the subsequent evolution of the CO{sub 2} plume until it stabilizes. Sensitivity studies are carried out to investigate the effect of poorly constrained model parameters permeability, permeability anisotropy, and residual gas saturation.

  16. Investigating the effects of target heterogeneity on the cratering process.

    NASA Astrophysics Data System (ADS)

    Barnouin, O. S.

    2012-12-01

    Pre-existing target structures are known to influence the dynamics and morphologies of many terrestrial and planetary impact craters. Good examples include the Chesapeake and Ries craters, which both possess an inverted sombrero structure as a result of a weaker sedimentary surface layer overlying a stronger crystalline basement. But beyond such horizontal layering, closer analyses of the subsurface geology present in these and other planetary craters indicate that vertical heterogeneity in the strength and geochemistry of a target are also often present. These may influence the formation and subsequent modification of terrestrial craters. Evidence indicates that at Meteor crater, for example, pre-existing vertical jointing of the target gives this crater its square appearance, either by confining and re-directing the shock and subsequent rarefraction waves, or by allowing preferential weathering zones of weakness along the joints. In this study, we present a series of laboratory investigations and 2- and 3-dimensional numerical calculations of crater formation in a conceptually simple but physically complex target: a box of randomly distributed quartz spheres of identical size. These investigations provide constraints on how all types of target heterogeneity influence the cratering process. In both the laboratory and numerical studies, we measure the rate of crater growth, the transient crater shape, and in some instances the velocity of individual ejecta. These investigations vary the ratio of the impact shock thickness to target grain size by altering the impact velocity, projectile size, and target grain size. The laboratory data were collected at the NASA Ames vertical gun range, the NASA Johnson Space Center vertical gun range, and the University of Tokyo vertical gun range using non-intrusive diagonistic techniques. The numerical investigations were performed using the CTH hydrocode that solves the equations of motion, while conserving mass, energy, and momentum using a second order multi-material Eulerian methodology. This code possesses an adaptive mesh refinement that allows investigating the effects of fine-scale target heterogeneity on the cratering process, through the use of a simple microscopic model with complex but resolvable heterogeneous geometries, rather than a complex macroscopic model. Both approaches provide insights on how the thickness of the shock front relative to the average dimension of any pre-exiting structure could be a controlling factor during impact cratering.

  17. Performance assessment for the geological disposal of Deep Burn spent fuel using TTBX

    SciTech Connect

    Van den Akker, B.P.; Ahn, J. [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States)

    2013-07-01

    The behavior of Deep Burn Modular High Temperature Reactor Spent Fuel (DBSF) is investigated in the Yucca Mountain geological repository (YMR) with respect to the annual dose (Sv/yr) delivered to the Reasonably Maximally Exposed Individual (RMEI) from the transport of radionuclides released from the graphite waste matrix. Transport calculations are performed with a novel computer code, TTBX which is capable of modeling transport pathways that pass through heterogeneous geological formations. TTBX is a multi-region extension of the existing single region TTB transport code. Overall the peak annual dose received by the RMEI is seen to be four orders of magnitude lower than the regulatory threshold for exposure, even under pessimistic scenarios. A number of factors contribute to the favorable performance of DBSF. A reduction of one order of magnitude in the peak annual dose received by the RMEI is observed for every order of magnitude increase in the waste matrix lifetime, highlighting the importance of the waste matrix durability and suggesting graphite's utility as a potential waste matrix for the disposal of high-level waste. Furthermore, we see that by incorporating a higher fidelity far-field model the peak annual dose calculated to be received by the RMEI is reduced by two orders of magnitude. By accounting for the heterogeneities of the far field we have simultaneously removed unnecessary conservatisms and improved the fidelity of the transport model. (authors)

  18. Seismic Determination of Reservoir Heterogeneity: Application to the Characterization of Heavy Oil Reservoirs

    SciTech Connect

    Imhof, Matthias G.; Castle, James W.

    2003-03-12

    The objective of the project was to examine how seismic and geologic data could be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study was performed at West Coalinga Field in California.

  19. Digital geologic map and GIS database of Venezuela

    USGS Publications Warehouse

    Garrity, Christopher P.; Hackley, Paul C.; Urbani, Franco

    2006-01-01

    The digital geologic map and GIS database of Venezuela captures GIS compatible geologic and hydrologic data from the 'Geologic Shaded Relief Map of Venezuela,' which was released online as U.S. Geological Survey Open-File Report 2005-1038. Digital datasets and corresponding metadata files are stored in ESRI geodatabase format; accessible via ArcGIS 9.X. Feature classes in the geodatabase include geologic unit polygons, open water polygons, coincident geologic unit linework (contacts, faults, etc.) and non-coincident geologic unit linework (folds, drainage networks, etc.). Geologic unit polygon data were attributed for age, name, and lithologic type following the Lexico Estratigrafico de Venezuela. All digital datasets were captured from source data at 1:750,000. Although users may view and analyze data at varying scales, the authors make no guarantee as to the accuracy of the data at scales larger than 1:750,000.

  20. Can heterogeneity of the near-wellbore rock cause extrema of the Darcian fluid inflow rate from the formation (the Polubarinova-Kochina problem revisited)?

    NASA Astrophysics Data System (ADS)

    Obnosov, Yurii; Kasimova, Rouzalia; Al-Maktoumi, Ali; Kacimov, Anvar

    2010-10-01

    Darcian steady 2-D flow to a point sink (vertical well) placed eccentrically with respect to two circles demarcating zones of contrasting permeability is studied by the methods of complex analysis and numerically by MODFLOW package. In the analytical approach, two conjugated Laplace equations for a characteristic flow function are solved by the method of images, i.e. the original sink is mirrored about two circles that generates an infinite system of fictitious sinks and source. The internal circle of the annulus models formation damage (gravel pack) near the well and the ring-shaped zone represents a pristine porous medium. On the external circle the head (pressure) is fixed and on the internal circle streamlines are refracted. The latter is equivalent to continuity of pressure and normal component of specific discharge that is satisfied by the choice of the intensity and loci of fictitious sinks. Flow net and dependence of the well discharge on eccentricity are obtained for different annulus radii and permeability ratios. A non-trivial minimum of the discharge is discovered for the case of the ring domain permeability higher than that of the internal circle. In the numerical solution, a finite difference code is implemented and compared with the analytical results for the two-conductivity zone. Numerical solution is also obtained for an aquifer with a three-conductivity zonation. The case of permeability exponentially varying with one Cartesian coordinate within a circular feeding contour is studied analytically by series expansions of a characteristic function obeying a modified Helmholtz equation with a point singularity located eccentrically inside the feeding contour. The coefficients of the modified Bessel function series are obtained by the Sommerfeld addition theorem. A trivial minimum of the flow rate into a small-radius well signifies the trade-off between permeability variation and short-cutting between the well and feeding contour.

  1. Glossary of Geologic Terms

    NSDL National Science Digital Library

    This page from Iowa State University presents a general glossary of geologic terms. The site would be a good reference for geology coursework. This glossary of geologic terms is based on the glossary in Earth: An Introduction to Geologic Change, by S. Judson and S.M. Richardson (Englewood Cliffs, NJ, Prentice Hall, 1995). Where possible, definitions conform generally, and in some cases specifically, to definitions given in Robert L Bates and Julia A Jackson (editors), Glossary of Geology, 3rd ed., American Geological Institute, Alexandria, Virginia, 1987.

  2. Volcanic geology of Tyrrhena Patera, Mars

    NASA Astrophysics Data System (ADS)

    Greeley, R.; Crown, D. A.

    1990-05-01

    Consideration is given to the geology of Tyrrhena Patera, a large low-relief volcano in the southern cratered highlands of Mars. The general geology of Tyrrhena Patera is outlined and models for the formation of the volcano are described. Models derived from studies of terrestrial pyroclastic flows are applied to deposits at Tyrrhena Patera, showing that the characteristics of the deposits are consistent with an origin by the emplacement of gravity-driven ash flows generated by hydromagmatic or magmatic explosive eruptions.

  3. Geologging in Oil and Gas Exploration

    Microsoft Academic Search

    Bhagwan Sahay

    1986-01-01

    Geologging, which is usually referred to in the oil industry as mud logging, is a continuous monitoring system of various parameters during drilling of exploratory-assessment wells aimed for geological, gas logging, drilling, and overpressure studies. Inasmuch as it is a formation evaluation tool, monitoring of the various parameters must be carried out by geologists, who keep round-the-clock watch and plot

  4. Volcanic geology of Tyrrhena Patera, Mars

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Crown, David, A.

    1990-01-01

    Consideration is given to the geology of Tyrrhena Patera, a large low-relief volcano in the southern cratered highlands of Mars. The general geology of Tyrrhena Patera is outlined and models for the formation of the volcano are described. Models derived from studies of terrestrial pyroclastic flows are applied to deposits at Tyrrhena Patera, showing that the characteristics of the deposits are consistent with an origin by the emplacement of gravity-driven ash flows generated by hydromagmatic or magmatic explosive eruptions.

  5. Bureau of Economic Geology annual report, 1988

    SciTech Connect

    Not Available

    1988-01-01

    Assessment, quantification, and geologic analysis of the state's vast petroleum and natural gas resources were the focus of new and ongoing research programs conducted during 1988. Primary emphasis was placed on investigation of methods to increase production from older mature hydrocarbon reservoirs. For more than 4 years the Bureau has conducted an integrated geologic/engineering study sponsored by the University of Texas system of remaining mobile oil in selected San Andres/Grayburg reservoirs on University Lands located in the Permian Basin. Analysis of subregional facies geometry, depositional environments, rock fabric/petrophysical properties, and production trends has helped to identify the geologic heterogeneity patterns in these carbonate reservoirs. A three-dimensional computer model of permeability applied to a section of the Dune field on University Lands enabled stochastic simulation of fluid flow and, thus, visualization of the complexity of the reservoir architecture.

  6. Geology of Death Valley National Park

    NSDL National Science Digital Library

    This site of the United States Geologic Survey (USGS) and the National Park Service (NPS) highlights the geologic history of Death Valley National Park in Nevada and California. The story begins 1.8 billion years ago with the formation of rocks and continues through uplift, faulting, volcanism, early animals of the area, glaciers, and the making of deserts and dunes. A geologic timescale connects to specific events in the history of Death Valley. There are topographic maps of the area, a field trip of the park, an image gallery, and technical papers available to download.

  7. Geology Fieldnotes: Bryce Canyon National Park, Utah

    NSDL National Science Digital Library

    Annabelle Foos

    Located on the Colorado Plateau in Utah, this canyon is comprised mostly of sedimentary rocks, and continues to be eroded and shaped by the Paria River. Its geologic and human history are outlined on this site, including the formation of the canyon, from the Cretaceous period (144 million years ago) to the present, and geologic features, such as fins, columns, pinnacles, and hoodoos. Visitor information, links to other resources, maps, and a teacher feature (resources for teaching geology with National Park examples) are also available.

  8. AN INTEGRATED VIEW OF GROUNDWATER FLOW CHARACTERIZATION AND MODELING IN FRACTURED GEOLOGIC MEDIA

    EPA Science Inventory

    The particular attributes of fractured geologic media pertaining to groundwater flow characterization and modeling are presented. These cover the issues of fracture network and hydraulic control of fracture geometry parameters, major and minor fractures, heterogeneity, anisotrop...

  9. OneGeology: Making the World’s Geological Map Data Accessible Online

    NASA Astrophysics Data System (ADS)

    Broome, H.; Jackson, I.; Robida, F.; Thorleifson, H.

    2009-12-01

    OneGeology (http://onegeology.org) is a successful international initiative of the geological surveys of the world and the flagship project of the ‘International Year of Planet Earth’. Its aim is to provide dynamic web access to geological map data covering the world, creating a focus for accessing geological information for everyone. Thanks to the enthusiasm and support of participating nations the initiative has progressed rapidly and geological surveys and the many users of their data are excited about this ground-breaking project. Currently 10 international geoscience organizations have endorsed the initiative and more than 109 countries have agreed to participate. OneGeology works with whatever digital format is available in each country. The target scale is 1:1 million, but the project is pragmatic and accepts a range of scales and the best available data. The initiative recognizes that different nations have differing abilities to participate and transfer of know-how to those who need it is a key aspect of the approach. A key contributor to the success of OneGeology has been its utilization of the latest new web technology and an emerging data exchange standard for geological map data called GeoSciML. GeoSciML (GeoScience Markup Language) is a schema written in GML (Geography Markup Language) for geological data. GeoSciML has the ability to represent both the geography (geometries e.g. polygons, lines and points) and geological attribution in a clear and structured format. OneGeology was launched March 2007 at the inaugural workshop in Brighton England. At that workshop the 43 participating nations developed a declaration of a common objective and principles called the “Brighton Accord” (http://onegeology.org/what_is/accord.html) . Work was initiated immediately and the resulting OneGeology Portal was launched at the International Geological Congress in Oslo in August 2008 by Simon Winchester, author of “The Map that Changed the World”. Since the successful launch, OneGeology participants have continued working both to increase national participation and content, and to put in place a more formal governance structure to oversee the long term evolution of the initiative. OneGeology is an example of collaboration in action and is both multilateral and multinational. In 2007, a group of motivated geoscientists and data managers identified an opportunity and took the initiative to engage their peers to work in concert to achieve a shared objective. OneGeology has facilitated collaborative development of an Internet site that provides unprecedented online access to global geological map data.

  10. Paleosols of the Upper Cretaceous Lower Tertiary Maghra El-Bahari Formation in the northeastern portion of the Eastern Desert, Egypt: Their recognition and geological significance

    NASA Astrophysics Data System (ADS)

    Wanas, H. A.; Abu El-Hassan, M. M.

    2006-01-01

    The Upper Cretaceous/Lower Tertiary Maghra El-Bahari Formation at Gabal Ataqa and Gabal Shabrawet in the northeastern portion of the Eastern Desert of Egypt is subdivided into two informal lithostratigraphic parts: lower and upper. The lower part has common features of alluvial floodplain-dominated deposits with occasional occurrences of crevasse splay deposits. The upper part has sediments typical of marginal lacustrine environments. Both the floodplain and marginal lacustrine deposits exhibit pedogenic features comprising various types of paleosols. Among other soil-forming processes, diversity in the paleosols studied is mainly attributed to paleoclimatic and paleohydrologic changes. The paleosol criteria suggest two climatic regimes, a subhumid-semiarid one succeeded by a semiarid-arid one. The continental depositional environments recognized (floodplain and lacustrine) with their associated paleosols helped in the recognition of a marine regression in the area studied. In a regional perspective, comparison of the data presented in this study with paleosol data spanning the same time period in other localities suggests that the proposed paleoclimatic changes may have been of regional extent.

  11. Abstracts of the Annual Meeting of Planetary Geologic Mappers, Flagstaff, AZ, 2008

    NASA Technical Reports Server (NTRS)

    Bleamaster, Leslie F., III (Editor); Tanaka, Kenneth L. (Editor); Kelley, Michael S. (Editor)

    2008-01-01

    Topics discussed include: Merging of the USGS Atlas of Mercury 1:5,000,000 Geologic Series; Geologic Mapping of the V-36 Thetis Regio Quadrangle: 2008 Progress Report; Structural Maps of the V-17 Beta Regio Quadrangle, Venus; Geologic Mapping of Isabella Quadrangle (V-50) and Helen Planitia, Venus; Renewed Mapping of the Nepthys Mons Quadrangle (V-54), Venus; Mapping the Sedna-Lavinia Region of Venus; Geologic Mapping of the Guinevere Planitia Quadrangle of Venus; Geological Mapping of Fortuna Tessera (V-2): Venus and Earth's Archean Process Comparisons; Geological Mapping of the North Polar Region of Venus (V-1 Snegurochka Planitia): Significant Problems and Comparisons to the Earth's Archean; Venus Quadrangle Geological Mapping: Use of Geoscience Data Visualization Systems in Mapping and Training; Geologic Map of the V-1 Snegurochka Planitia Quadrangle: Progress Report; The Fredegonde (V-57) Quadrangle, Venus: Characterization of the Venus Midlands; Formation and Evolution of Lakshmi Planum (V-7), Venus: Assessment of Models using Observations from Geological Mapping; Geologic Map of the Meskhent Tessera Quadrangle (V-3), Venus: Evidence for Early Formation and Preservation of Regional Topography; Geological Mapping of the Lada Terra (V-56) Quadrangle, Venus: A Progress Report; Geology of the Lachesis Tessera Quadrangle (V-18), Venus; Geologic Mapping of the Juno Chasma Quadrangle, Venus: Establishing the Relation Between Rifting and Volcanism; Geologic Mapping of V-19, V-28, and V-53; Lunar Geologic Mapping Program: 2008 Update; Geologic Mapping of the Marius Quadrangle, the Moon; Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars: Introductory Report; New Geologic Map of the Argyre Region of Mars; Geologic Evolution of the Martian Highlands: MTMs -20002, -20007, -25002, and -25007; Mapping Hesperia Planum, Mars; Geologic Mapping of the Meridiani Region, Mars; Geology of Holden Crater and the Holden and Ladon Multi-Ring Impact Basins, Margaritifer Terra, Mars; Geologic Mapping of Athabasca Valles; Geologic Mapping of MTM -30247, -35247 and -40247 Quadrangles, Reull Vallis Region of Mars; Geologic Mapping of the Martian Impact Crater Tooting; Geology of the Southern Utopia Planitia Highland-Lowland Boundary Plain: First Year Results and Second Year Plan; Mars Global Geologic Mapping: Amazonian Results; Recent Geologic Mapping Results for the Polar Regions of Mars; Geologic Mapping of the Medusae Fossae Formation on Mars (MC-8 SE and MC-23 NW) and the Northern Lowlands of Venus (V-16 and V-15); Geologic Mapping of the Zal, Hi'iaka, and Shamshu Regions of Io; Global Geologic Map of Europa; Material Units, Structures/Landforms, and Stratigraphy for the Global Geologic Map of Ganymede (1:15M); and Global Geologic Mapping of Io: Preliminary Results.

  12. Hanford Site Guidelines for Preparation and Presentation of Geologic Information

    SciTech Connect

    Lanigan, David C.; Last, George V.; Bjornstad, Bruce N.; Thorne, Paul D.; Webber, William D.

    2010-04-30

    A complex geology lies beneath the Hanford Site of southeastern Washington State. Within this geology is a challenging large-scale environmental cleanup project. Geologic and contaminant transport information generated by several U.S. Department of Energy contractors must be documented in geologic graphics clearly, consistently, and accurately. These graphics must then be disseminated in formats readily acceptable by general graphics and document producing software applications. The guidelines presented in this document are intended to facilitate consistent, defensible, geologic graphics and digital data/graphics sharing among the various Hanford Site agencies and contractors.

  13. Geological Sciences 330 Fall 2007 Sedimentary Geology

    E-print Network

    : Sediments and Sedimentary Rocks Week 3 17 Sept Sedimentary Textures and Rock Classification 19 Sept Fluid Dynamics (2 & 3) Lab 2: Sedimentary Rock Classification Week 4 24 Sept Sediment Entrainment and DepositionGeological Sciences 330 Fall 2007 Sedimentary Geology This course is intended to provide

  14. Investigation of CO2 plume behavior for a large-scale pilot test of geologic carbon storage in a saline formation

    SciTech Connect

    Doughty, C.

    2009-04-01

    The hydrodynamic behavior of carbon dioxide (CO{sub 2}) injected into a deep saline formation is investigated, focusing on trapping mechanisms that lead to CO{sub 2} plume stabilization. A numerical model of the subsurface at a proposed power plant with CO{sub 2} capture is developed to simulate a planned pilot test, in which 1,000,000 metric tons of CO{sub 2} is injected over a four-year period, and the subsequent evolution of the CO{sub 2} plume for hundreds of years. Key measures are plume migration distance and the time evolution of the partitioning of CO{sub 2} between dissolved, immobile free-phase, and mobile free-phase forms. Model results indicate that the injected CO{sub 2} plume is effectively immobilized at 25 years. At that time, 38% of the CO{sub 2} is in dissolved form, 59% is immobile free phase, and 3% is mobile free phase. The plume footprint is roughly elliptical, and extends much farther up-dip of the injection well than down-dip. The pressure increase extends far beyond the plume footprint, but the pressure response decreases rapidly with distance from the injection well, and decays rapidly in time once injection ceases. Sensitivity studies that were carried out to investigate the effect of poorly constrained model parameters permeability, permeability anisotropy, and residual CO{sub 2} saturation indicate that small changes in properties can have a large impact on plume evolution, causing significant trade-offs between different trapping mechanisms.

  15. Geological evolution and analysis of confirmed or suspected gas hydrate localities: Volume 10, Basin analysis, formation and stability of gas hydrates of the Aleutian Trench and the Bering Sea

    SciTech Connect

    Krason, J.; Ciesnik, M.

    1987-01-01

    Four major areas with inferred gas hydrates are the subject of this study. Two of these areas, the Navarin and the Norton Basins, are located within the Bering Sea shelf, whereas the remaining areas of the Atka Basin in the central Aleutian Trench system and the eastern Aleutian Trench represent a huge region of the Aleutian Trench-Arc system. All four areas are geologically diverse and complex. Particularly the structural features of the accretionary wedge north of the Aleutian Trench still remain the subjects of scientific debates. Prior to this study, suggested presence of the gas hydrates in the four areas was based on seismic evidence, i.e., presence of bottom simulating reflectors (BSRs). Although the disclosure of the BSRs is often difficult, particularly under the structural conditions of the Navarin and Norton basins, it can be concluded that the identified BSRs are mostly represented by relatively weak and discontinuous reflectors. Under thermal and pressure conditions favorable for gas hydrate formation, the relative scarcity of the BSRs can be attributed to insufficient gas supply to the potential gas hydrate zone. Hydrocarbon gas in sediment may have biogenic, thermogenic or mixed origin. In the four studied areas, basin analysis revealed limited biogenic hydrocarbon generation. The migration of the thermogenically derived gases is probably diminished considerably due to the widespread diagenetic processes in diatomaceous strata. The latter processes resulted in the formation of the diagenetic horizons. The identified gas hydrate-related BSRs seem to be located in the areas of increased biogenic methanogenesis and faults acting as the pathways for thermogenic hydrocarbons.

  16. Monocyte and macrophage heterogeneity

    Microsoft Academic Search

    Philip R. Taylor; Siamon Gordon

    2005-01-01

    Heterogeneity of the macrophage lineage has long been recognized and, in part, is a result of the specialization of tissue macrophages in particular microenvironments. Circulating monocytes give rise to mature macrophages and are also heterogeneous themselves, although the physiological relevance of this is not completely understood. However, as we discuss here, recent studies have shown that monocyte heterogeneity is conserved

  17. Geophysics & Geology Inspected.

    ERIC Educational Resources Information Center

    Neale, E. R. W.

    1981-01-01

    Summarizes findings of a recently published report of the Canadian Geoscience Council, which includes the following topics regarding college geology: facilities; teaching; undergraduate enrollments; postgraduate enrollments; geologic research; and integration of Canadian geoscience with other countries. (CS)

  18. Louisiana Geological Survey

    NSDL National Science Digital Library

    The Louisiana Geological Survey, located at Louisiana State University, developed this website to promote its goal to provide geological and environmental data that will allow for environmentally sound natural resource development and economic decisions. Users can find general information about the Survey's mission, staff, plan, and history. The website features the research and publications of the Basin Research, Cartographic, Coastal, Geologic Mapping, and Water and Environmental sections. Researchers can discover stratigraphic charts of Louisiana, information on lignite resources, and other geologic data.

  19. South Carolina Geological Survey

    NSDL National Science Digital Library

    The South Carolina Geological Survey (SCGS) homepage contains information about state mapping, education and outreach programs, and recent news. For educators, there is the Earth Science education series of publications which includes presentations and page-size graphics on such topics as earthquakes, plate tectonics, geologic time, fossils, and others. Other materials include information on mineral resources, links to organizations in and about South Carolina geology, the South Carolina core repository, the Geologic Map of South Carolina, and others.

  20. A theoretical framework for modeling dilution enhancement of non-reactive solutes in heterogeneous porous media.

    PubMed

    de Barros, F P J; Fiori, A; Boso, F; Bellin, A

    2015-01-01

    Spatial heterogeneity of the hydraulic properties of geological porous formations leads to erratically shaped solute clouds, thus increasing the edge area of the solute body and augmenting the dilution rate. In this study, we provide a theoretical framework to quantify dilution of a non-reactive solute within a steady state flow as affected by the spatial variability of the hydraulic conductivity. Embracing the Lagrangian concentration framework, we obtain explicit semi-analytical expressions for the dilution index as a function of the structural parameters of the random hydraulic conductivity field, under the assumptions of uniform-in-the-average flow, small injection source and weak-to-mild heterogeneity. Results show how the dilution enhancement of the solute cloud is strongly dependent on both the statistical anisotropy ratio and the heterogeneity level of the porous medium. The explicit semi-analytical solution also captures the temporal evolution of the dilution rate; for the early- and late-time limits, the proposed solution recovers previous results from the literature, while at intermediate times it reflects the increasing interplay between large-scale advection and local-scale dispersion. The performance of the theoretical framework is verified with high resolution numerical results and successfully tested against the Cape Cod field data. PMID:25795562

  1. Teaching Sedimentary Geology

    NSDL National Science Digital Library

    This site contains a variety of resources for faculty members who teach undergraduate sedimentary geology. You will find links to a growing collection of activities and assignments, internet and computer resources, useful articles, presentations from the summer 2006 workshop on teaching sedimentary geology, and lots of creative ideas for teaching sedimentary geology.

  2. Environmental geology in Australia

    Microsoft Academic Search

    G. M. Philip

    1976-01-01

    In Australia the concept of environmental geology is developing slowly from mainly engineering based activities to resource planning and utilization. This is particularly so with increasing activity in urban geology and in some States environmental geology influences land use and zoning. Since 1972 there have been clearly stated national policies in regard to the planned development of Australia's mineral and

  3. Geological Survey Program

    NSDL National Science Digital Library

    If your research or interests lie in the geology of South Dakota, then the state's Geological Survey Program Web site is for you. Offered are online publications and maps, a geologic reference database, a lithologic logs database, digital base maps, a water quality database, and several other quality information sources worth checking out.

  4. Andrei borisovich vistelius: a dominant figure in 20th century mathematical geology

    USGS Publications Warehouse

    Merriam, D.F.

    2001-01-01

    Andrei Borisovich Vistelius (1915-1995), along with William Christian Krumbein (1902-1979) and John Cedric Griffiths (1912-1992), were dominant figures in the formative and development years of mathematical (or quantitative) geology as a subdiscipline of geology.

  5. Geologic Maps and Structures Name ______________________________ Geology 100 Harbor section

    E-print Network

    Harbor, David

    Geologic Maps and Structures Name ______________________________ Geology 100 ­ Harbor section The objectives of this lab are for you to learn the basic geologic structures in 3-D and to develop some facility in interpreting the nature of geologic structures from geologic maps and geologic cross sections. A big part

  6. Advanced Technologies for Monitoring CO2 Saturation and Pore Pressure in Geologic Formations: Linking the Chemical and Physical Effects to Elastic and Transport Properties

    SciTech Connect

    Mavko, G.; Vanorio, T.; Vialle, S.; Saxena, N.

    2014-03-31

    Ultrasonic P- and S-wave velocities were measured over a range of confining pressures while injecting CO2 and brine into the samples. Pore fluid pressure was also varied and monitored together with porosity during injection. Effective medium models were developed to understand the mechanisms and impact of observed changes and to provide the means for implementation of the interpretation methodologies in the field. Ultrasonic P- and S-wave velocities in carbonate rocks show as much as 20-50% decrease after injection of the reactive CO2-brine mixture; the changes were caused by permanent changes to the rock elastic frame associated with dissolution of mineral. Velocity decreases were observed under both dry and fluid-saturated conditions, and the amount of change was correlated with the initial pore fabrics. Scanning Electron Microscope images of carbonate rock microstructures were taken before and after injection of CO2-rich water. The images reveal enlargement of the pores, dissolution of micrite (micron-scale calcite crystals), and pitting of grain surfaces caused by the fluid- solid chemical reactivity. The magnitude of the changes correlates with the rock microtexture – tight, high surface area samples showed the largest changes in permeability and smallest changes in porosity and elastic stiffness compared to those in rocks with looser texture and larger intergranular pore space. Changes to the pore space also occurred from flow of fine particles with the injected fluid. Carbonates with grain-coating materials, such as residual oil, experienced very little permanent change during injection. In the tight micrite/spar cement component, dissolution is controlled by diffusion: the mass transfer of products and reactants is thus slow and the fluid is expected to be close to thermodynamical equilibrium with the calcite, leading to very little dissolution, or even precipitation. In the microporous rounded micrite and macropores, dissolution is controlled by advection: because of an efficient mass transfer of reactants and products, the fluid remains acidic, far from thermodynamical equilibrium and the dissolution of calcite is important. These conclusions are consistent with the lab observations. Sandstones from the Tuscaloosa formation in Mississippi were also subjected to injection under representative in situ stress and pore pressure conditions. Again, both P- and S-wave velocities decreased with injection. Time-lapse SEM images indicated permanent changes induced in the sandstone microstructure by chamosite dissolution upon injection of CO2-rich brine. After injection, the sandstone showed an overall cleaner microstructure. Two main changes are involved: (a) clay dissolution between grains and at the grain contact and (b) rearrangement of grains due to compaction under pressure Theoretical and empirical models were developed to quantify the elastic changes associated with injection. Permanent changes to the rock frame resulted in seismic velocity-porosity trends that mimic natural diagenetic changes. Hence, when laboratory measurments are not available for a candidate site, these trends can be estimated from depth trends in well logs. New theoretical equations were developed to predict the changes in elastic moduli upon substitution of pore-filling material. These equations reduce to Gassmann’s equations for the case of constant frame properties, low seismic frequencies, and fluid changes in the pore space. The new models also predict the change dissolution or precipitation of mineral, which cannot be described with the conventional Gassmann theory.

  7. Preliminary Geologic Characterization of West Coast States for Geologic Sequestration

    SciTech Connect

    Larry Myer

    2005-09-29

    Characterization of geological sinks for sequestration of CO{sub 2} in California, Nevada, Oregon, and Washington was carried out as part of Phase I of the West Coast Regional Carbon Sequestration Partnership (WESTCARB) project. Results show that there are geologic storage opportunities in the region within each of the following major technology areas: saline formations, oil and gas reservoirs, and coal beds. The work focused on sedimentary basins as the initial most-promising targets for geologic sequestration. Geographical Information System (GIS) layers showing sedimentary basins and oil, gas, and coal fields in those basins were developed. The GIS layers were attributed with information on the subsurface, including sediment thickness, presence and depth of porous and permeable sandstones, and, where available, reservoir properties. California offers outstanding sequestration opportunities because of its large capacity and the potential of value-added benefits from enhanced oil recovery (EOR) and enhanced gas recovery (EGR). The estimate for storage capacity of saline formations in the ten largest basins in California ranges from about 150 to about 500 Gt of CO{sub 2}, depending on assumptions about the fraction of the formations used and the fraction of the pore volume filled with separate-phase CO{sub 2}. Potential CO{sub 2}-EOR storage was estimated to be 3.4 Gt, based on a screening of reservoirs using depth, an API gravity cutoff, and cumulative oil produced. The cumulative production from gas reservoirs (screened by depth) suggests a CO{sub 2} storage capacity of 1.7 Gt. In Oregon and Washington, sedimentary basins along the coast also offer sequestration opportunities. Of particular interest is the Puget Trough Basin, which contains up to 1,130 m (3,700 ft) of unconsolidated sediments overlying up to 3,050 m (10,000 ft) of Tertiary sedimentary rocks. The Puget Trough Basin also contains deep coal formations, which are sequestration targets and may have potential for enhanced coal bed methane recovery (ECBM).

  8. Flow and transport in unsaturated fractured rock: effects of multiscale heterogeneity of hydrogeologic properties

    Microsoft Academic Search

    Quanlin Zhou; Hui-Hai Liu; Gudmundur S Bodvarsson; Curtis M Oldenburg

    2003-01-01

    The heterogeneity of hydrogeologic properties at different scales may have different effects on flow and transport processes in a subsurface system. A model for the unsaturated zone of Yucca Mountain, Nevada, is developed to represent complex heterogeneity at two different scales: (1) layer scale corresponding to geologic layering and (2) local scale. The layer-scale hydrogeologic properties are obtained using inverse

  9. Geological Survey research 1978

    USGS Publications Warehouse

    U.S. Geological Survey

    1978-01-01

    This U.S. Geological Survey activities report includes a summary of 1978 fiscal year scientific and economic results accompanied by a list of geologic and hydrologic investigations in progress and a report on the status of topographic mapping. The summary of results includes: (1) Mineral and water resources, (2) Engineering geology and hydrology, (3) Regional geology, (4) Principles and processes, (5) Laboratory and field methods, (6) Topographic surveys and mapping, (7) Management of resources on public lands, (8) Land information and analysis, and (9) Investigations in other countries. Also included are lists of cooperating agencies and Geological Survey offices. (Woodard-USGS)

  10. Geological Survey research 1976

    USGS Publications Warehouse

    U.S. Geological Survey

    1976-01-01

    This U.S. Geological Survey activities report includes a summary of recent (1976 fiscal year) scientific and economic results accompanied by a list of geologic and hydrologic investigations in progress and a report on the status of topographic mapping. The summary of results includes: (1) Mineral resources, Water resources, (2) Engineering geology and hydrology, (3) Regional geology, (4) Principles and processes, (5) Laboratory and field methods, (6) Topographic surveys and mapping, (7) Management of resources on public lands, (8) Land information and analysis, and (9) Investigations in other countries. Also included are lists of cooperating agencies and Geological Survey offices. (Woodard-USGS)

  11. Virtual-Geology.Info

    NSDL National Science Digital Library

    At virtual-geology.info, Roger Suthren, a professor at Oxford Brookes University, offers educational materials on geologic phenomena throughout the world. Users can take virtual field trips to study the geology of Scotland, Alaska, and France. In the Regional Geology link, visitors can view wonderful pictures of the volcanoes of Germany, Italy, France, and Greece. Educators can find images of sediments and sedimentary rocks which can be used in a variety of classroom exercises. The website supplies descriptions and additional educational links about sedimentology and environmental geology.

  12. Geology of Kentucky

    NSDL National Science Digital Library

    This website contains geologic maps of Kentucky, with a discussion of geologic time in regards to the rocks, minerals, fossils, and economic deposits found there. There are also sections that describe strata and geologic structures beneath the surface (faults, basins, and arches), the structural processes (folding and faulting) that create stratigraphic units, the geomorphology of the state, geologic information by county, a general description of geologic time, fossil, rocks, and minerals of Kentucky, and a virtual field trip through Natural Bridges State Park. Links are provided for further information.

  13. Arkansas Geological Survey

    NSDL National Science Digital Library

    The Arkansas Geological Survey (AGS) homepage aims to develop and provide knowledge of the geology and hydrogeology of the State, and to stimulate development and effective management and utilization of the mineral, fossil-fuel, and water resources of Arkansas while protecting the environment. The AGC collects and disperses geologic data consisting of geologic maps, historical data concerning resources, and various datasets concerning water, fossil-fuel, and mineral resources of Arkansas. The site contains publications that can be ordered, sections about Arkansas geology, a list of mineral producers of Arkansas, and reports on mineral resources.

  14. U.S. Geological Survey Geologic Carbon Sequestration Assessment

    NASA Astrophysics Data System (ADS)

    Warwick, P. D.; Blondes, M. S.; Brennan, S.; Corum, M.; Merrill, M. D.

    2012-12-01

    The Energy Independence and Security Act of 2007 authorized the U.S. Geological Survey (USGS) to conduct a national assessment of potential geological storage resources for carbon dioxide (CO2) in consultation with the U.S. Department of Energy (DOE), the U.S. Environmental Protection Agency (EPA) and State geological surveys. To conduct the assessment, the USGS developed a probability-based assessment methodology that was extensively reviewed by experts from industry, government and university organizations (Brennan et al., 2010, http://pubs.usgs.gov/of/2010/1127). The methodology is intended to be used at regional to sub-basinal scales and it identifies storage assessment units (SAUs) that are based on two depth categories below the surface (1) 3,000 to 13,000 ft (914 to 3,962 m), and (2) 13,000 ft (3,962 m) and greater. In the first category, the 3,000 ft (914 m) minimum depth of the storage reservoir ensures that CO2 is in a supercritical state to minimize the storage volume. The depth of 13,000 ft (3,962 m) represents maximum depths that are accessible with average injection pressures. The second category represents areas where a reservoir formation has potential storage at depths below 13,000 ft (3,962 m), although they are not accessible with average injection pressures; these are assessed as a separate SAU. SAUs are restricted to formation intervals that contain saline waters (total dissolved solids greater than 10,000 parts per million) to prevent contamination of protected ground water. Carbon dioxide sequestration capacity is estimated for buoyant and residual storage traps within the basins. For buoyant traps, CO2 is held in place in porous formations by top and lateral seals. For residual traps, CO2 is contained in porous formations as individual droplets held within pores by capillary forces. Preliminary geologic models have been developed to estimate CO2 storage capacity in approximately 40 major sedimentary basins within the United States. More than 200 SAUs have been identified within these basins. The results of the assessment are estimates of the technically accessible storage resources based on present-day geological and engineering technology related to CO2 injection into geologic formations; therefore the assessment is not of total in-place resources. Summary geologic descriptions of the evaluated basins and SAUs will be prepared, along with the national assessment results. During the coming year, these results will be released as USGS publications available from http://energy.usgs.gov. In support of these assessment activities, CO2 sequestration related research science is being conducted by members of the project. Results of our research will contribute to current and future CO2 storage assessments conducted by the USGS and other organizations. Research topics include: (a) geochemistry of CO2 interactions with subsurface environments; (b) subsurface petrophysical rock properties in relation to CO2 injection; (c) enhanced oil recovery and the potential for CO2 storage; (d) storage of CO2 in unconventional reservoirs (coal, shale, and basalt); (e) statistical aggregation of assessment results; and (f) potential risks of induced seismicity.

  15. Small scale laboratory design investigation of leakage of gaseous CO2 through heterogeneous subsurface system

    NASA Astrophysics Data System (ADS)

    Basirat, F.; Sharma, P.; Niemi, A.; Fagerlund, F.

    2012-04-01

    The technology for geological sequestration of carbon dioxide has been developed to reduce the CO2 emissions into the atmosphere from the use of fossil fuels in power generation and other industries. One of the main concerns associated with the geological storage is the possible leakage of CO2 into the shallow aquifers, for which effective detection methods are needed. The processes related to the spreading and trapping of CO2 in the reservoir formation and in supercritical conditions have received major attention and form the basis of understanding of CO2 trapping processes. Some of the CO2 may, however, also leak to the upper layers of the rock and all the way to land surface through faults and imperfections in the seal. A proper understanding and capability to detect such leaks is essential for a safe performance of any storage operation. This, in turn, involves a proper understanding of the processes related to the transport of gaseous CO2 in the near-surface conditions, a topic that has received considerably less attention. The objective of this study is to analyze the transport and migration of gaseous CO2 in heterogeneous porous media, in controlled laboratory conditions. CO2 may reach the unsaturated zone by different leak mechanisms which may subsequently affect how and where it can be detected by leakage monitoring program. These mechanisms include exsolution from CO2 supersaturated water and continuous bubbling or gas flow along a leakage path. Below the water table, gaseous CO2 can also be trapped under capillary barriers. However, as more CO2 is supplied by leakage from below the water table, the pressure may at some point exceed the entry pressure of the barrier leading to a leak event. Similarly, fluctuations in the water table may also produce leak events of temporarily trapped CO2. In the unsaturated zone, the CO2 is heavier than air and may accumulate below ground surface and move laterally. The presence of heterogeneity influences both the movement and detectability of the CO2. Our laboratory experiment is designed and implemented for measuring CO2 distribution in time and space through the heterogeneous porous material. The CO2 concentrations through the domain are measured by using sensitive gas sensors. To better understand the consequences of CO2 leakage and how it can be detected, this study presents a conceptual model together with the design and setup of an experimental system to understand the transport, trapping and detectability of gaseous CO2 in a heterogeneous shallow geological system.

  16. Predictive uncertainty analysis of plume distribution for geological carbon sequestration using sparse-grid Bayesian method

    NASA Astrophysics Data System (ADS)

    Shi, X.; Zhang, G.

    2013-12-01

    Because of the extensive computational burden, parametric uncertainty analyses are rarely conducted for geological carbon sequestration (GCS) process based multi-phase models. The difficulty of predictive uncertainty analysis for the CO2 plume migration in realistic GCS models is not only due to the spatial distribution of the caprock and reservoir (i.e. heterogeneous model parameters), but also because the GCS optimization estimation problem has multiple local minima due to the complex nonlinear multi-phase (gas and aqueous), and multi-component (water, CO2, salt) transport equations. The geological model built by Doughty and Pruess (2004) for the Frio pilot site (Texas) was selected and assumed to represent the 'true' system, which was composed of seven different facies (geological units) distributed among 10 layers. We chose to calibrate the permeabilities of these facies. Pressure and gas saturation values from this true model were then extracted and used as observations for subsequent model calibration. Random noise was added to the observations to approximate realistic field conditions. Each simulation of the model lasts about 2 hours. In this study, we develop a new approach that improves computational efficiency of Bayesian inference by constructing a surrogate system based on an adaptive sparse-grid stochastic collocation method. This surrogate response surface global optimization algorithm is firstly used to calibrate the model parameters, then prediction uncertainty of the CO2 plume position is quantified due to the propagation from parametric uncertainty in the numerical experiments, which is also compared to the actual plume from the 'true' model. Results prove that the approach is computationally efficient for multi-modal optimization and prediction uncertainty quantification for computationally expensive simulation models. Both our inverse methodology and findings can be broadly applicable to GCS in heterogeneous storage formations.

  17. Geological and production characteristics of strandplain/barrier island reservoirs in the United States

    SciTech Connect

    Cole, E.L.; Fowler, M.; Jackson, S.; Madden, M.P.; Reeves, T.K.; Salamy, S.P.; Young, M.A.

    1994-12-01

    The Department of Energy`s (DOE`s) primary mission in the oil research program is to maximize the economically and environmentally sound recovery of oil from domestic reservoirs and to preserve access to this resource. The Oil Recovery Field Demonstration Program supports DOE`s mission through cost-shared demonstrations of improved Oil Recovery (IOR) processes and reservoir characterization methods. In the past 3 years, the DOE has issued Program Opportunity Notices (PONs) seeking cost-shared proposals for the three highest priority, geologically defined reservoir classes. The classes have been prioritized based on resource size and risk of abandonment. This document defines the geologic, reservoir, and production characteristics of the fourth reservoir class, strandplain/barrier islands. Knowledge of the geological factors and processes that control formation and preservation of reservoir deposits, external and internal reservoir heterogeneities, reservoir characterization methodology, and IOR process application can be used to increase production of the remaining oil-in-place (IOR) in Class 4 reservoirs. Knowledge of heterogeneities that inhibit or block fluid flow is particularly critical. Using the TORIS database of 330 of the largest strandplain/barrier island reservoirs and its predictive and economic models, the recovery potential which could result from future application of IOR technologies to Class 4 reservoirs was estimated to be between 1.0 and 4.3 billion barrels, depending on oil price and the level of technology advancement. The analysis indicated that this potential could be realized through (1) infill drilling alone and in combination with polymer flooding and profile modification, (2) chemical flooding (sufactant), and (3) thermal processes. Most of this future potential is in Texas, Oklahoma, and the Rocky Mountain region. Approximately two-thirds of the potentially recoverable resource is at risk of abandonment by the year 2000.

  18. Kansas Geological Survey

    NSDL National Science Digital Library

    The mission of the Kansas Geological Survey, operated by the University of Kansas in connection with its research and service program, is to conduct geological studies and research and to collect, correlate, preserve, and disseminate information leading to a better understanding of the geology of Kansas, with special emphasis on natural resources of economic value, water quality and quantity, and geologic hazards. The website includes information about the High Plains and Ogallala aquifers, the Upper Arkansas corridor, the Dakota aquifer, county and state geologic maps, an online bibliography of Kansas geology, publications, a photo archive, a digital petroleum atlas, a petroleum primer for the state, gravity and magnetic maps, Hugoton project information, and details about the Hutchinson Kansas natural gas fires. The educational resources section contains a mineral information page for the state, and GeoKansas, which provides information on state geology for schools.

  19. Wave Propagation in Jointed Geologic Media

    SciTech Connect

    Antoun, T

    2009-12-17

    Predictive modeling capabilities for wave propagation in a jointed geologic media remain a modern day scientific frontier. In part this is due to a lack of comprehensive understanding of the complex physical processes associated with the transient response of geologic material, and in part it is due to numerical challenges that prohibit accurate representation of the heterogeneities that influence the material response. Constitutive models whose properties are determined from laboratory experiments on intact samples have been shown to over-predict the free field environment in large scale field experiments. Current methodologies for deriving in situ properties from laboratory measured properties are based on empirical equations derived for static geomechanical applications involving loads of lower intensity and much longer durations than those encountered in applications of interest involving wave propagation. These methodologies are not validated for dynamic applications, and they do not account for anisotropic behavior stemming from direcitonal effects associated with the orientation of joint sets in realistic geologies. Recent advances in modeling capabilities coupled with modern high performance computing platforms enable physics-based simulations of jointed geologic media with unprecedented details, offering a prospect for significant advances in the state of the art. This report provides a brief overview of these modern computational approaches, discusses their advantages and limitations, and attempts to formulate an integrated framework leading to the development of predictive modeling capabilities for wave propagation in jointed and fractured geologic materials.

  20. Inter-well field test to determine in-situ CO2 trapping in a deep saline aquifer: Modelling study of the effects of test design and geological parameters

    NASA Astrophysics Data System (ADS)

    Fagerlund, Fritjof; Niemi, Auli; Bensabat, Jacob; Shtivelman, Vladimir

    2013-04-01

    Trapping of CO2 by capillary effects and dissolution to groundwater is important for the security of geologically stored CO2 at many potential storage sites. Field tests are critical to measure the amount of CO2 which is effectively trapped in-situ and evaluate parameters that influence the trapping over larger scales and under influence of geological heterogeneity. Such well-monitored, small-scale field tests are being designed within the EU-FP7 MUSTANG project at the Heletz site, Israel. In an inter-well test, supercritical CO2 is injected in one well while fluids are produced from a second well. Several measurement techniques, including hydraulic, tracer, thermal and geophysical tests, are used to measure the trapping that occurs as the CO2 migrates through the formation between the two wells. The general outcome and success of the test depend on design options such as the distance between the wells and the injection/withdrawal rates and volumes, and also on site-specific geological parameters such as permeability, trapping parameters and heterogeneity. The objective of this study was to use numerical modelling to investigate how these design options and geological parameters affect the flow and transport processes in the formation and outcome of the test. The feasibility of the test depends e.g. on the amount of dissolution and residual trapping that occur, the pressure build-up in the formation and the time required to achieve complete trapping and perform the tests. Furthermore, the accuracy of the test depends on the ability of the different measurement techniques to quantify the trapping under different conditions. The results illustrate the sensitivity of the test outcome criteria to both the design options and the geological conditions. An efficient test design should take into account site-specific conditions so that design criteria are met and measurement accuracy and robustness are maximized.

  1. Geology of the reading prong

    SciTech Connect

    Schutz, D.

    1987-03-01

    For over a billion years the geological terrain now called New Jersey has been the site of unusually high uranium concentrations. Although the highest of these concentrations occurs in the Reading Prong, the area is itself only part of a larger geologic province extending to the northeast and southwest. The rocks in the Reading Prong are not uniformly radioactive. High uranium concentrations tend to be associated with magnetite deposits - metamorphic equivalents of iron-rich formations - and with pegmatites - rocks formed by precipitation from mineralizing solutions in the late phases of granite emplacement. Because of the way they were formed, the uranium-bearing magnetite and pegmatite bodies tend to be long and narrow, and the resulting patterns of radon occurrence can be expected to be the same. This may explain why, in some places, adjacent houses have very different radon concentrations.

  2. Modeling Fractures in Thermal Systems: Thermal-Mechanical Feedback and Vein Formation

    NSDL National Science Digital Library

    Barb Dutrow, Department of Geology & Geophysics, Louisiana State University Topic: Mineralogy, Petrology, fracture formation Course type: Upper level undergraduate course Description In many geologic systems, ...

  3. Generating Reproducible Heterogeneity for Laboratory Flow and Transport Experiments

    NASA Astrophysics Data System (ADS)

    Griffith, B. C.; Holt, R. M.; Glass, R. J.

    2003-12-01

    To understand the impact of heterogeneity on unsaturated flow and transport processes, many researchers have begun to conduct flow and transport experiments in laboratory analogues to heterogeneous geologic materials. Most of these experiments are conducted in macroheterogeneous media where homogeneous units are arranged to represent large-scale heterogeneity. However, most sedimentary media displays heterogeneity at a hierarchy of scales, the smallest of which is a stratum that is graded. Such stratification can lead to complicated wetted-phase structures that influence moisture retention, unsaturated hydraulic conductivity, access to surface area for reaction, and non-ideal transport. Because of the difficulty in reproducing "geologically realistic" microheterogeneity, the impact of small-scale stratification on flow and transport is difficult to evaluate using current laboratory constructed analogues. We have developed and evaluated a new approach for constructing reproducible, "geologically realistic" heterogeneity for laboratory flow and transport experiments. Using an apparatus with a computer-controlled arm, mixtures of sand are deposited in an experimental chamber through a tube. Mechanical grading processes within the tube and the chamber lead to stratification that mimics that produced by sedimentary processes. By varying the arm speed, stratum thickness and angle can be controlled. By using different sand mixtures, the grain size at the top and bottom of a stratum can be varied. Through the use of carefully designed computer programs, a variety of reproducible micro/macroheterogeneous structures can be produced.

  4. Regional Geologic History of the Polar Regions of Mars

    NASA Astrophysics Data System (ADS)

    Tanaka, K. L.; Kolb, E. J.

    2000-08-01

    Geologic mapping and topical studies of the martian polar regions based on Mariner 9 and Viking data have identified major geologic units and structures and their formational sequence. However, several fundamental questions remain poorly answered, such as: (1) What has been the history of ice and dust deposits at the poles and their subsequent modification over geologic time? (2) Is their a signature of melting and discharge from any polar deposits? (3) Can long-term or sporadic climatic and geologic changes of global significance be detected in the polar geologic records? (4) How have volcanism, tectonism, and impacts been involved in the geologic evolution of the polar regions? Here we discuss how these questions are currently being re-examined with Mars Global Surveyor data and new geologic mapping of the polar regions. Additional information is contained in the original extended abstract.

  5. Stochastic models of solute transport in highly heterogeneous geologic media

    SciTech Connect

    Semenov, V.N.; Korotkin, I.A.; Pruess, K.; Goloviznin, V.M.; Sorokovikova, O.S.

    2009-09-15

    A stochastic model of anomalous diffusion was developed in which transport occurs by random motion of Brownian particles, described by distribution functions of random displacements with heavy (power-law) tails. One variant of an effective algorithm for random function generation with a power-law asymptotic and arbitrary factor of asymmetry is proposed that is based on the Gnedenko-Levy limit theorem and makes it possible to reproduce all known Levy {alpha}-stable fractal processes. A two-dimensional stochastic random walk algorithm has been developed that approximates anomalous diffusion with streamline-dependent and space-dependent parameters. The motivation for introducing such a type of dispersion model is the observed fact that tracers in natural aquifers spread at different super-Fickian rates in different directions. For this and other important cases, stochastic random walk models are the only known way to solve the so-called multiscaling fractional order diffusion equation with space-dependent parameters. Some comparisons of model results and field experiments are presented.

  6. The Geological Society of America Special Paper 430

    E-print Network

    Garnero, Ed

    , Santa Cruz, California 95064, USA Allen McNamara School of Earth and Space Exploration, Bateman PhysicalThe Geological Society of America Special Paper 430 2007 Implications of lower-mantle structural heterogeneity for existence and nature of whole-mantle plumes Edward J. Garnero School of Earth and Space

  7. Geology Fieldnotes: White Sands National Monument, New Mexico

    NSDL National Science Digital Library

    The White Sands National Monument site contains park geology information, maps, related links, and visitor information. The park geology section discusses the park's geologic history, the formation of the gypsum sand dunes, and the four types of dunes found at the White Sands National Monument: dome, barchan, transverse, and parabolic. The park maps section includes a map of the White Sands National Monument and the surrounding area, showing the location of each type of dune.

  8. A LONG, LONG time ago: geologic timescales

    NSDL National Science Digital Library

    Elizabeth Johnson

    Each student randomly picks a card with a geologic event (written description and an image) on it. A timeline has 11 events, not including the formation of the Earth and today. Students attach their event where they think it should go on a 45.5' timeline (in the hallway) made out of paper adding tape and mark the location on the timeline. They return to the classroom and receive a list of age dates for each event. Each group figures out the scale (1 foot = 100 million years) and then moves their events to the correct locations. Students are asked how the position of the events changed, and answer other questions that reinforce the difference between human timescales and geologic timescales. The powerpoint file below contains a template for making geologic event labels for the index cards. Instructors can tailor the geologic event list to fit their course.

  9. Fractal heterogeneous media.

    PubMed

    Türk, Christian; Carbone, Anna; Chiaia, Bernardino M

    2010-02-01

    A method is presented for generating compact fractal disordered media by generalizing the random midpoint displacement algorithm. The obtained structures are invasive stochastic fractals, with the Hurst exponent varying as a continuous parameter, as opposed to lacunar deterministic fractals, such as the Menger sponge. By employing the detrending moving average algorithm [A. Carbone, Phys. Rev. E 76, 056703 (2007)], the Hurst exponent of the generated structure can be subsequently checked. The fractality of such a structure is referred to a property defined over a three-dimensional topology rather than to the topology itself. Consequently, in this framework, the Hurst exponent should be intended as an estimator of compactness rather than of roughness. Applications can be envisaged for simulating and quantifying complex systems characterized by self-similar heterogeneity across space. For example, exploitation areas range from the design and control of multifunctional self-assembled artificial nanostructures and microstructures to the analysis and modeling of complex pattern formation in biology, environmental sciences, geomorphological sciences, etc. PMID:20365674

  10. Dealing with spatial heterogeneity

    NASA Astrophysics Data System (ADS)

    Marsily, Gh.; Delay, F.; Gonçalvès, J.; Renard, Ph.; Teles, V.; Violette, S.

    2005-03-01

    Heterogeneity can be dealt with by defining homogeneous equivalent properties, known as averaging, or by trying to describe the spatial variability of the rock properties from geologic observations and local measurements. The techniques available for these descriptions are mostly continuous Geostatistical models, or discontinuous facies models such as the Boolean, Indicator or Gaussian-Threshold models and the Markov chain model. These facies models are better suited to treating issues of rock strata connectivity, e.g. buried high permeability channels or low permeability barriers, which greatly affect flow and, above all, transport in aquifers. Genetic models provide new ways to incorporate more geology into the facies description, an approach that has been well developed in the oil industry, but not enough in hydrogeology. The conclusion is that future work should be focused on improving the facies models, comparing them, and designing new in situ testing procedures (including geophysics) that would help identify the facies geometry and properties. A world-wide catalog of aquifer facies geometry and properties, which could combine site genesis and description with methods used to assess the system, would be of great value for practical applications. On peut aborder le problème de l'hétérogénéité en s'efforçant de définir une perméabilité équivalente homogène, par prise de moyenne, ou au contraire en décrivant la variation dans l'espace des propriétés des roches à partir des observations géologiques et des mesures locales. Les techniques disponibles pour une telle description sont soit continues, comme l'approche Géostatistique, soit discontinues, comme les modèles de faciès, Booléens, ou bien par Indicatrices ou Gaussiennes Seuillées, ou enfin Markoviens. Ces modèles de faciès sont mieux capables de prendre en compte la connectivité des strates géologiques, telles que les chenaux enfouis à forte perméabilité, ou au contraire les faciès fins de barrières de perméabilité, qui ont une influence importante sur les écoulement, et, plus encore, sur le transport. Les modè les génétiques récemment apparus ont la capacité de mieux incorporer dans les modèles de faciès les observations géologiques, chose courante dans l'industrie pétrolière, mais insuffisamment développée en hydrogéologie. On conclut que les travaux de recherche ultérieurs devraient s'attacher à développer les modèles de faciès, à les comparer entre eux, et à mettre au point de nouvelles méthodes d'essais in situ, comprenant les méthodes géophysiques, capables de reconnaître la géométrie et les propriétés des faciès. La constitution d'un catalogue mondial de la géométrie et des propriétés des faciès aquifères, ainsi que des méthodes de reconnaissance utilisées pour arriver à la détermination de ces systèmes, serait d'une grande importance pratique pour les applications. La heterogeneidad se puede manejar por medio de la definición de características homogéneas equivalentes, conocidas como promediar o tratando de describir la variabilidad espacial de las características de las rocas a partir de observaciones geológicas y medidas locales. Las técnicas disponibles para estas descripciones son generalmente modelos geoestadísticos continuos o modelos de facies discontinuos como los modelos Boolean, de Indicador o de umbral de Gaussian y el modelo de cadena de Markow. Estos modelos de facies son mas adecuados para tratar la conectvidad de estratos geológicos (por ejemplo canales de alta permeabilidad enterrados o barreras de baja permeabilidad que tienen efectos importantes sobre el flujo y especialmente sobre el transporte en los acuíferos. Los modelos genéticos ofrecen nuevas formas de incorporar más geología en las descripciones de facies, un enfoque que está bien desarollado en la industria petrolera, pero insuficientemente en la hidrogeología. Se concluye que los trabajos futuros deberían estar más enfocados en mejorar los modelos de facies, en establecer comparaciones y en

  11. The Geologically Recent Giant Impact Basins at Vesta’s South Pole

    NASA Astrophysics Data System (ADS)

    Schenk, Paul; O'Brien, David P.; Marchi, Simone; Gaskell, Robert; Preusker, Frank; Roatsch, Thomas; Jaumann, Ralf; Buczkowski, Debra; McCord, Thomas; McSween, Harry Y.; Williams, David; Yingst, Aileen; Raymond, Carol; Russell, Chris

    2012-05-01

    Dawn’s global mapping of Vesta reveals that its observed south polar depression is composed of two overlapping giant impact features. These large basins provide exceptional windows into impact processes at planetary scales. The youngest, Rheasilvia, is 500 kilometers wide and 19 kilometers deep and finds its nearest morphologic analog among large basins on low-gravity icy satellites. Extensive ejecta deposits occur, but impact melt volume is low, exposing an unusual spiral fracture pattern that is likely related to faulting during uplift and convergence of the basin floor. Rheasilvia obliterated half of another 400-kilometer-wide impact basin, Veneneia. Both basins are unexpectedly young, roughly 1 to 2 billion years, and their formation substantially reset Vestan geology and excavated sufficient volumes of older compositionally heterogeneous crustal material to have created the Vestoids and howardite-eucrite-diogenite meteorites.

  12. Physical and geological processes of delta formation

    E-print Network

    Bates, Charles Carpenter

    1953-01-01

    Tsrs-is1 6MT 0gs F2T0 F529s 1 -4 8.FF59-4y 8.T6 -46MTu20-M 4 0M 0gs S.FTsus Gs21?.2T0sT8f P55-s 1 IUFs1-0-M42T9 lMTrs 6MT 0gs NMTu2419 -4i28-M 4, nFM 4 os-4y 1-8v rg2Tys1 28 2 D2F02-4 -4 e24.2T9 t(J3f hT, R20s 8 6-T80 8 sTis1 28 SFsr-25 P88-80240 0M 0gs...-o5 s I66sr0 M 6 S0Ts88 M 6 OTsi2-5-4y G-41 M 4 P89uus0T-r HsFM 8-0-M425 O200sT4 20 L.05s08 M 6 h-88-88-FF- C-isT, t;; cc, PFF5-r20-M 4 M 6 0gs Y4 sT0-25 D-Tr5 s DM4rsF0 0M 0gs Hs65sr0-M 4 M 6 l 5 sW 6TMu C-isT hM.0g8, t;3 c), Lo8 sTis1 l 5MW O200sT4 DMuF2Ts1 W-0...

  13. Geology Fieldnotes: Bighorn Canyon National Recreation Area, Montana/Wyoming

    NSDL National Science Digital Library

    This site contains Bighorn Canyon National Recreation Area information, including geology, maps, photographs, visitor information, and links for additional facts about this area of Wyoming and Montana. Included are details about the geologic history of the area, formations, the Pryar and Bighorn Mountains, and the exploration history of the land.

  14. SUBSURFACE PROPERTY RIGHTS: IMPLICATIONS FOR GEOLOGIC CO2 STORAGE

    EPA Science Inventory

    The paper discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of the...

  15. SUBSURFACE PROPERTY RIGHTS: IMPLICATIONS FOR GEOLOGIC CO2 SEQUESTRATION (PRESENTATION)

    EPA Science Inventory

    The paper discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of the...

  16. SUBSURFACE PROPERTY RIGHTS: IMPLICATIONS FOR GEOLOGIC CO2 SEQUESTRATION

    EPA Science Inventory

    The chapter discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of t...

  17. The geology of the Great Lakes ice cover

    Microsoft Academic Search

    E. W. Marshall

    1977-01-01

    Geological processes and features of the Great Lakes coastal zone during winter and spring were examined in detail and extensively illustrated by ground and aerial photographs. There were 39 geological, ice-forming regions identified on the Great Lakes and in the connecting lakes, straits and rivers. The patterns of ice land formation on the Great Lakes in mild, normal, and severe

  18. The Geological Society of London

    NSDL National Science Digital Library

    The Geological Society of London promotes "the geosciences and the professional interests of UK geoscientists." The website offers media, geological, and society news. Researchers can find out about upcoming conferences covering a variety of geological topics as well as information on a series of journals. Everyone interested in geology can find materials on geological careers, including required education, qualifications, and funding. The website provides teaching resources on volcanoes, geologic hazards, and other geological phenomena.

  19. Louisiana Geological Survey

    NSDL National Science Digital Library

    This is the homepage of the Louisiana Geological Survey (LGS). The site includes general information about LGS and its various offices, as well as an overview of the Basin Research Energy Section, the oil, gas, and coal research section of LGS. The publications and data page features a catalog and ordering information for documents on mineral resources, fossils, water resources, geological bulletins and maps, and many others, as well as a selection of downloadable maps, including 30 x 60 minute geologic quadrangles, a generalized geologic map of the state with accompanying text, and an online map viewer of the state with selectable layers (geology, water bodies, cultural features, and Landsat imagery). There is also an online listing of well logs, grouped by parish, online listings of core samples, grouped by state, and downloadable public information documents on a variety of geologic topics.

  20. Heterogeneous Catalysis: On Bathroom Mirrors and Boiling Stones

    ERIC Educational Resources Information Center

    Philipse, Albert P.

    2011-01-01

    Though heterogeneous nucleation of liquid droplets on a smooth surface (such as a bathroom mirror) is a classical topic in nucleation theory, it is not well-known that this topic is actually a pedagogical example of heterogeneous catalysis: the one and only effect of the surface is to lower the activation Gibbs energy of droplet formation. In…

  1. Geology Before Pluto: Pre-encounter Considerations

    NASA Technical Reports Server (NTRS)

    Moore, Jeffrey M.

    2014-01-01

    Pluto, its large satellite Charon, and its four known satellites represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula, and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Modeling of the interior suggests that geologic activity may have been to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. However, the putative indicators of Pluto's geologic history are inconclusive and unspecific. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observations. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system's geologic history. The cameras of New Horizons will provide robust data sets that should be immanently amenable to geological analysis of the Pluto System's landscapes. In this talk, we begin with a brief discussion of the planned observations by New Horizons' cameras that will bear most directly on geological interpretability. Then I will broadly review major geological processes that could potentially operate of the surfaces of Pluto and its moons. I will first survey exogenic processes (i.e., those for which energy for surface modification is supplied externally to the planetary surface): impact cratering, sedimentary processes (including volatile migration) and the work of wind. I will conclude with an assessment of prospects for endogenic activity in the form of tectonics and cryo-volcanism.

  2. Geologic Time : Online Edition

    NSDL National Science Digital Library

    1997-01-01

    Offered by the United States Geological Survey (USGS) as a general interest publication, this site is an online edition of a text by the same name, offering a concise overview of the concepts associated with the age of the Earth. The online edition was revised in October of 1997 to reflect current thinking on this topic. Section headers are Geologic Time, Relative Time Scale, Major Divisions of Geologic Time, Index Fossils, Radiometric Time Scale, and Age of the Earth.

  3. The Geology of Virginia

    NSDL National Science Digital Library

    From the College of William of Mary Department of Geology comes the Geology of Virginia Web site. From the Appalachian Plateau to the coastal plain, visitors can explore the geology and physical characteristics of the diverse landscape of the commonwealth of Virginia through simple descriptions and well designed graphics. Even if you don't live in the area, the site does a good job of capturing the interest of anyone looking for quality material on the presented subjects.

  4. North Carolina Geological Survey

    NSDL National Science Digital Library

    The North Carolina Geological Survey (NCGS) examines, describes, and maps the state's geology and mineral resources and publishes reports and maps. The site contains lists of publications, maps, aerial photographs, frequently asked questions about North Carolina geology, and mineral and professional information. Project Earth Science is designed to provide relevant and accurate earth science education information for the state's high school students and earth/environmental science teachers.

  5. Pennsylvania Geological Survey

    NSDL National Science Digital Library

    This is the homepage of the Pennsylvania Geological Survey. Users can access digital maps, data, and Geographic Information Systems (GIS), information on economic resources, and information on field mapping in the state. Classroom resources include a set of lesson plans on Pennsylvania geology; 'Rock Boxes', a set of rock samples which can be ordered; information on mineral collecting; and a series of educational publications, page-sized maps, and the 'Trail of Geology' park guide.

  6. Icelandic Geology Resources

    NSDL National Science Digital Library

    Douglas, Georg R.

    The main feature of this site from Hamrahlio College of Reykjavik, Iceland is an interactive geological map of Iceland showing lava flows and glaciers. Other highlights include links to related Icelandic geology pages (e.g., The Effect of Diatom Mining, Iceland's Ministry of the Environment), news sources and journals, and Icelandic geological societies (not all are in English). A recommended resource for glaciologists, volcanologists, and educators in earth science.

  7. Geologic Maps and Structures Name ______________________________ Geology 100 Harbor section

    E-print Network

    Harbor, David

    Geologic Maps and Structures Name ______________________________ Geology 100 ­ Harbor section Read Ch. 7 before you begin. The objectives of this lab are for you to learn the basic geologic structures in 3-D and to develop some facility in interpreting the nature of geologic structures from geologic

  8. Environmental Geology Major www.geology.pitt.edu/uprogs.html

    E-print Network

    Jiang, Huiqiang

    Environmental Geology Major www.geology.pitt.edu/uprogs.html Revised: 04/2004 Environmental geology in environmental geology provides the diverse skills required to work in many different employment settings issues. Within the field of geology, environmental and geotechnical jobs exist for people with BS degrees

  9. Department of Geology and Geological Engineering University of Mississippi Announces

    E-print Network

    Elsherbeni, Atef Z.

    Department of Geology and Geological Engineering University of Mississippi Announces Krista Pursuing a degree within the Geology & Geological Engineering department Record of financial need the University of Mississippi with a Bachelor of Science degree in geological engineering in 1982. After earning

  10. Optical lattice with heterogeneous atomic density

    NASA Astrophysics Data System (ADS)

    Yukalov, V. I.; Yukalova, E. P.

    2015-03-01

    The possibility is considered for the formation in optical lattices of a heterogeneous state characterized by a spontaneous mesoscopic separation of a system into spatial regions with different atomic densities. It is shown that such states can arise if there are repulsive interactions between atoms in different lattice sites and the filling factor is less than one-half.

  11. Phenotypically heterogeneous populations in spatially heterogeneous environments

    NASA Astrophysics Data System (ADS)

    Patra, Pintu; Klumpp, Stefan

    2014-03-01

    The spatial expansion of a population in a nonuniform environment may benefit from phenotypic heterogeneity with interconverting subpopulations using different survival strategies. We analyze the crossing of an antibiotic-containing environment by a bacterial population consisting of rapidly growing normal cells and slow-growing, but antibiotic-tolerant persister cells. The dynamics of crossing is characterized by mean first arrival times and is found to be surprisingly complex. It displays three distinct regimes with different scaling behavior that can be understood based on an analytical approximation. Our results suggest that a phenotypically heterogeneous population has a fitness advantage in nonuniform environments and can spread more rapidly than a homogeneous population.

  12. Geological Survey research 1981

    USGS Publications Warehouse

    U.S. Geological Survey

    1982-01-01

    This U.S. Geological Survey activities report includes a summary of 1981 fiscal year scientific and economic results accompanied by a list of geologic, hydrologic, and cartographic investigations in progress. The summary of results includes: (1) Mineral, (2) Water resources, (3) Engineering geology and hydrology, (4) Regional geology, (5) Principles and processes, (6) Laboratory and field methods, (7) Topographic surveys and mapping, (8) Management of resources on public lands, (9) Land information and analysis, and (10) Investigations in other countries. Also included are lists of investigations in progress. (USGS)

  13. Structural Geology 'Research' Conference

    NSDL National Science Digital Library

    Julie Willis

    In this assignment students read and discuss a peer-reviewed journal article and prepare for and attend our class 'research' conference. In the conference they present on an area of current research as discussed in the journal article they read, and they practice formulating questions about other's research. Outcomes: 1. Read and discuss a structural geology peer-reviewed journal article. 2. Prepare a presentation that demonstrates your understanding of a current research topic in structural geology. 3. View and understand several diverse areas within geology and geophysics that use structural geology in research. 4. Ask questions relevant to a research presentation.

  14. Understanding Geologic Maps

    NSDL National Science Digital Library

    Cara Burberry

    This is an exercise in which students are reintroduced to geologic maps and encouraged to "deconstruct" the map into constituent elements in order to understand the geologic history of the area. The preceding lectures in the course have recapitulated material that the students have covered in Introduction to Physical Geology. During class, the students work through the maps that were part of lab exercises in the Intro level course, so that basic concepts are recalled (superposition, cross-cutting relationships, basic faults and folds). The final product is a geologic history of this map area.

  15. Geologic Mapping Exercise

    NSDL National Science Digital Library

    Andrew Smith

    This exercise is designed to simulate how a basic geological investigation of a site takes place. A basic geological investigation includes familiarizing yourself with the unconsolidated sediments, rocks, structural geology, and groundwater present at your site. As part of this exercise you will have to properly identify a variety of rock types and sediments, create maps that represent data you collected at each location, and complete a basic report of your findings (optional). Once completed, this exercise should give students a basic understanding of how the various concepts used throughout the semester are applied in the real world in the form of a geological investigation.

  16. Geology Fieldnotes: Arches National Park, Utah

    NSDL National Science Digital Library

    Annabelle Foos

    This park is located on the Colorado Plateau near Moab, Utah, and contains many arches and sculpted sedimentary rocks. The visible rock formations in the park are the Entrada and Navajo sandstones. Covered topics include the formation of arches in stages, different types of arches, as well as sizes and names (Delicate Arch being the most famous). The site also provides visitor information, photos, maps, additional links, and a teacher feature (tools for teaching geology with National Park examples).

  17. Geology: The Science of our World

    NSDL National Science Digital Library

    David Leveson

    2002-02-05

    This online course provides interactive laboratory exercises and information on mineralogy, map reading, and topography of New York City. There are also sections on rock formation and origins, geologic time, and Earth history. The course also features 'The Drowning of New York', an interactive study of the effects of climate change, sea level rise, and storm surges on the city.

  18. Geology Fieldnotes: Buffalo National River, Arkansas

    NSDL National Science Digital Library

    This site contains information on the Buffalo National River in Arkansas, including geology, park maps, and visitor information. It discusses landscape formations, the course of the river, and prehistoric sites along the river, which is situated in the Ozarks of Arkansas.

  19. 4th Grade Geology Lesson Plans

    NSDL National Science Digital Library

    This site has a lesson plan for a class activity on mountain building and graben and horst formation. This particular lesson is number 14, at the top of the page. There are a few other geology lesson plans also listed on this site.

  20. Geological myths and reality

    NASA Astrophysics Data System (ADS)

    Ostrihansky, Lubor

    2014-05-01

    Myths are the result of man's attempts to explain noteworthy features of his environment stemming from unfounded imagination. It is unbelievable that in 21st century the explanation of evident lithospheric plates movements and origin of forces causing this movement is still bound to myths, They are the myth about mantle convection, myth about Earth's expansion, myth about mantle heterogeneities causing the movement of plates and myth about mantle plumes. From 1971 to 1978 I performed extensive study (Ost?ihanský 1980) about the terrestrial heat flow and radioactive heat production of batholiths in the Bohemian Massive (Czech Republic). The result, gained by extrapolation of the heat flow and heat production relationship, revealed the very low heat flow from the mantle 17.7mW m-2 close to the site of the Quarterly volcano active only 115,000 - 15,000 years ago and its last outbreak happened during Holocene that is less than 10,000 years ago. This volcano Komorní H?rka (Kammerbühls) was known by J. W. Goethe investigation and the digging of 300 m long gallery in the first half of XIX century to reach the basaltic plug and to confirm the Stromboli type volcano. In this way the 19th century myth of neptunists that basalt was a sedimentary deposit was disproved in spite that famous poet and scientist J.W.Goethe inclined to neptunists. For me the result of very low heat flow and the vicinity of almost recent volcanoes in the Bohemian Massive meant that I refused the hypothesis of mantle convection and I focused my investigation to external forces of tides and solar heat, which evoke volcanic effects, earthquakes and the plate movement. To disclose reality it is necessary to present calculation of acting forces using correct mechanism of their action taking into account tectonic characteristics of geologic unites as the wrench tectonics and the tectonic of planets and satellites of the solar system, realizing an exceptional behavior of the Earth as quickly rotating body exposed to strong tidal action of Moon and Sun. Ostrihansky, L.: The structure of the earth's crust and the heat-flow--heat-generation relationship in the Bohemian Massif. Tectonophysics, 68(3-4), 325-337, doi:10.1016/0040-1951(80)90182-1 1980.

  1. Neurobiological heterogeneity in ADHD

    Microsoft Academic Search

    P. de Zeeuw

    2011-01-01

    Attention-Deficit\\/Hyperactivity Disorder (ADHD) is a highly heterogeneous disorder clinically. Symptoms take many forms, from subtle but pervasive attention problems or dreaminess up to disruptive and unpredictable behavior. Interestingly, early neuroscientific work on ADHD assumed either a homogeneous neurobiological substrate or one that somehow mimicked clinical heterogeneity. Recent work however, has started to emphasize multiple neurobiological pathways towards ADHD, regardless of

  2. Geology explorer: virtual geologic mapping and interpretation

    NASA Astrophysics Data System (ADS)

    Saini-Eidukat, Bernhardt; Schwert, Donald P.; Slator, Brian M.

    2002-12-01

    We are developing internet-based freeware for virtual mapping and geologic interpretation. This takes the form of a synthetic, virtual world, Planet Oit, where students are given the means and the equipment to carry out geologic investigation and interpretation as a geologist would in the field. The environment is designed to give students an authentic experience that includes elements of: (1) exploration of a spatially oriented, virtual, world; (2) practical, field oriented, expedition planning and decision-making; and (3) scientific problem solving (i.e. a "hands on" approach to mapping, geologic investigation, data acquisition, and interpretation). The game-like environment is networked, multi-player, and simulation-based. Planet Oit can be visited on the Internet at http://oit.cs.ndsu.nodak.edu/

  3. Scale dependent solute dispersion with linear isotherm in heterogeneous medium

    NASA Astrophysics Data System (ADS)

    Singh, Mritunjay Kumar; Das, Pintu

    2015-01-01

    This study presents an analytical solution for one-dimensional scale dependent solute dispersion with linear isotherm in semi-infinite heterogeneous medium. The governing advection-dispersion equation includes the terms such as advection, dispersion, zero order production and linear adsorption with respect to the liquid and solid phases. Initially, the medium is assumed to be polluted as the linear combination of source concentration and zero order production term with distance. Time dependent exponentially decreasing input source is assumed at one end of the domain in which initial source concentration is also included i.e., at the origin. The concentration gradient at the other end of the aquifer is assumed zero as there is no mass flux exists at that end. The analytical solution is derived by using the Laplace integral transform technique. Special cases are presented with respect to the different forms of velocity expression which are very much relevant in solute transport analysis. Result shows an excellent agreement between the analytical solutions with the different geological formations and velocity patterns. The impacts of non-dimensional parameters such as Peclet and Courant numbers have also been discussed. The results of analytical solution are compared with numerical solution obtained by explicit finite difference method. The stability condition has also been discussed. The accuracy of the result has been verified with root mean square error analysis. The CPU time has also been calculated for execution of Matlab program.

  4. Geology of Earth's Moon

    NSDL National Science Digital Library

    First, researchers at the University of California, San Diego discuss the importance of studying earthquakes on the moon, also known as moonquakes, and the Apollo Lunar Seismic Experiment (1). Users can discover the problems scientists must deal with when collecting the moon's seismic data. The students at Case Western Reserve University created the second website to address three missions the Institute of Space and Astronautical Science (ISAS) has planned between now and 2010, including a mission to the moon (2). Visitors can learn about the Lunar-A probe that will be used to photograph the surface of the moon, "monitor moonquakes, measure temperature, and study the internal structure." Next, the Planetary Data Service (PDS) at the USGS offers users four datasets that they can use to create an image of a chosen area of the moon (3). Each dataset can be viewed as a basic clickable map; a clickable map where users can specify size, resolution, and projection; or an advanced version where visitors can select areas by center latitude and longitude. The fourth site, produced by Robert Wickman at the University of North Dakota, presents a map of the volcanoes on the moon and compares their characteristics with those on earth (4). Students can learn how the gravitational forces on the Moon affect the lava flows. Next, Professor Jeff Ryan at the University of South Florida at Tampa supplies fantastic images and descriptive text of the lunar rocks obtained by the Apollo missions (5). Visitors can find links to images of meteorites, terrestrial rocks, and Apollo landings as well. At the Science Channel website, students and educators can find a video clip discussing the geologic studies on the moon along with videos about planets (6). Users can learn about how studying moon rocks help scientists better understand the formation of the earth. Next, the Smithsonian National Air and Space Museum presents its research of "lunar topography, cratering and impacts basins, tectonics, lava flows, and regolith properties" (7). Visitors can find summaries of the characteristics of the moon and the main findings since the 1950s. Lastly, the USGS Astrogeology Research Program provides archived lunar images and data collected between 1965 and 1992 by Apollo, Lunar Orbiter, Galileo, and Zond 8 missions (8). While the data is a little old, students and educators can still find valuable materials about the moon's topography, chemical composition, and geology.

  5. Abstracts of the Annual Meeting of Planetary Geologic Mappers, San Antonio, TX, 2009

    NASA Technical Reports Server (NTRS)

    Bleamaster, Leslie F., III (Editor); Tanaka, Kenneth L.; Kelley, Michael S.

    2009-01-01

    Topics covered include: Geologic Mapping of the Beta-Atla-Themis (BAT) Region of Venus: A Progress Report; Geologic Map of the Snegurochka Planitia Quadrangle (V-1): Implications for Tectonic and Volcanic History of the North Polar Region of Venus; Preliminary Geological Map of the Fortuna Tessera (V-2) Quadrangle, Venus; Geological Map of the Fredegonde (V-57) Quadrangle, Venus; Geological Mapping of the Lada Terra (V-56) Quadrangle, Venus; Geologic Mapping of V-19; Lunar Geologic Mapping: A Preliminary Map of a Portion of the LQ-10 ("Marius") Quadrangle; Geologic Mapping of the Lunar South Pole, Quadrangle LQ-30: Volcanic History and Stratigraphy of Schr dinger Basin; Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars; Geologic Mapping Investigations of the Northwest Rim of Hellas Basin, Mars; Geologic Mapping of the Meridiani Region of Mars; Geology of a Portion of the Martian Highlands: MTMs -20002, -20007, -25002 and -25007; Geologic Mapping of Holden Crater and the Uzboi-Ladon-Morava Outflow System; Mapping Tyrrhena Patera and Hesperia Planum, Mars; Geologic Mapping of Athabaca Valles; Geologic Mapping of MTM -30247, -35247 and -40247 Quadrangles, Reull Vallis Region, Mars Topography of the Martian Impact Crater Tooting; Mars Structural and Stratigraphic Mapping along the Coprates Rise; Geology of Libya Montes and the Interbasin Plains of Northern Tyrrhena Terra, Mars: Project Introduction and First Year Work Plan; Geology of the Southern Utopia Planitia Highland-Lowland Boundary Plain: Second Year Results and Third Year Plan; Mars Global Geologic Mapping: About Half Way Done; New Geologic Map of the Scandia Region of Mars; Geologic Mapping of the Medusae Fossae Formation on Mars and the Northern Lowland Plains of Venus; Volcanism on Io: Insights from Global Geologic Mapping; and Planetary Geologic Mapping Handbook - 2009.

  6. Urgent problems of geological substantiation of geomechanical calculations

    SciTech Connect

    Varga, A.A.

    1987-08-01

    This article reviews current problems in the approach to and analysis of geomechanical data for hydroelectric power plant and dam siting studies. These problems include the classification of rock masses from an engineering geology standpoint, the approach to geological modeling and microregionalization of formations and structures, data acquisition inconsistencies in geophysical survey methods, and the estimation of the internal stress states of rock formations. Recommendations are outlined in each of these problem fields.

  7. Investigating the impact of microbial interactions with geologic media on geophysical properties

    NASA Astrophysics Data System (ADS)

    Davis, Caroline Ann

    The goals of this study were to investigate the effect of: (1) microbial metabolic byproducts, microbial growth, and biofilm formation on the low frequency electrical properties of porous media, (2) biofilm formation on acoustic wave properties, and (3) the natural electrical (self-potential) signatures associated with an in-situ biological permeable reactive barrier (PRB). The results suggest: (1) increases in electrolytic conductivity are consistent with increased concentrations of organic acids and biosurfactants; (2) mineral weathering promoted by organic acids causes increases in electrolytic conductivity, concomitant with increases in major cation concentrations; (3) interfacial conductivity generally parallels microbial cell concentrations and biofilm formation; (4) variations in microbial growth and biofilms causes spatiotemporal heterogeneity in the elastic properties of porous media; (5) SP signatures associated with the injection of groundwater into an in-situ biological PRB are dominated by diffusion potentials induced by the injections. The results suggest that electrolytic conductivity may be useful as an indicator of metabolism, while interfacial conductivity may be used as proxy indicator for microbial growth and biofilm formation in porous media. In addition, acoustic measurements may provide diagnostic spatiotemporal data for the validation of bioclogging models/simulations. Collectively, this study provides further evidence that geophysical measurements are sensitive to microbial-induced changes to geologic media, and may be useful for the detection and monitoring of subsurface mi