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Faculty Publications

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Articles 271 - 300 of 383

Full-Text Articles in Earth Sciences

Structural And Stratigraphic Control On The Migration Of A Contaminant Plume At The P Reactor Area, Savannah River Site, South Carolina, Antonio E. Cameron González, Camelia C. Knapp, Michael G. Waddell, Adrian Addison, John M. Shafer Jun 2010

Structural And Stratigraphic Control On The Migration Of A Contaminant Plume At The P Reactor Area, Savannah River Site, South Carolina, Antonio E. Cameron González, Camelia C. Knapp, Michael G. Waddell, Adrian Addison, John M. Shafer

Faculty Publications

Geophysical methods, including a shallow seismic reflection (SSR) survey, surface and borehole ground-penetrating radar (GPR) data, and electrical resistivity imaging (ERI), were conducted at the Savannah River site (SRS), South Carolina, to investigate the shallow stratigraphy, hydrogeophysical zonation, and the applicability and performance of these geophysical techniques for hydrogeological characterization in contaminant areas. The study site is the P Reactor area located within the upper Atlantic coastal plain, with clastic sediments ranging from Late Cretaceous to Miocene in age. The target of this research was the delineation and prediction of migration pathways of a trichloroethylene (TCE) contaminant plume that originates …

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The Holocene Depositional History Of Thousand Acre Marsh (Georgetown County, Sc, Usa) From Correlation Of Ground Penetrating Radar With Subsurface Stratigraphy, A L. Springer, Camelia C. Knapp, Paul T. Gayes, Leonard R. Gardiner May 2010

The Holocene Depositional History Of Thousand Acre Marsh (Georgetown County, Sc, Usa) From Correlation Of Ground Penetrating Radar With Subsurface Stratigraphy, A L. Springer, Camelia C. Knapp, Paul T. Gayes, Leonard R. Gardiner

Faculty Publications

No abstract provided.

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Slab Window Migration And Terrane Accretion Preserved By Low‐Temperature Thermochronology Of A Magmatic Arc, Northern Antarctic Peninsula, William R. Guenthner, David L. Barbeau Jr, Peter W. Reiners, Stuart N. Thomson Mar 2010

Slab Window Migration And Terrane Accretion Preserved By Low‐Temperature Thermochronology Of A Magmatic Arc, Northern Antarctic Peninsula, William R. Guenthner, David L. Barbeau Jr, Peter W. Reiners, Stuart N. Thomson

Faculty Publications

Existing paleogeographic reconstructions indicate that the northern Antarctic Peninsula was central to several Mesozoic and Cenozoic tectonic events that have implications for ocean circulation and continental margin evolution. To evaluate the exhumational record of these processes, we collected new samples and measured fission track and (U‐Th)/He cooling ages of apatite and zircon from 13 Jurassic and Cretaceous granitoids in western Graham Land between the northern tip of the peninsula and the Antarctic Circle. Apatite He data reveal distinct ages and systematic age patterns north and south of Anvers Island, near the midpoint of the study area: To the south, apatite …

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Analysis Of Fluvial Suspended Sediment Load Contribution Through Anthropocene History To The South Atlantic Bight Coastal Zone, U.S.A., K Mccarney-Castle, George Voulgaris, A J. Kettner Jan 2010

Analysis Of Fluvial Suspended Sediment Load Contribution Through Anthropocene History To The South Atlantic Bight Coastal Zone, U.S.A., K Mccarney-Castle, George Voulgaris, A J. Kettner

Faculty Publications

Discerning the effects of anthropogenic activities (i.e., reservoir construction, land use change), as opposed to those of natural processes (i.e., climate variability), on suspended sediment flux has become an increasingly difficult challenge. This contribution presents water and suspended sediment flux from five major watersheds that discharge into the southeastern U.S. Atlantic, a region that is currently considered sediment starved. Three periods of Anthropocenetime were defined and evaluated: (1) “pre-European conditions” (1680–1700), (2) “pre-dam conditions" (1905-1925), and (3) "post-dam conditions" (1985-2005). Physical and hydrologic watershed data were used to run a climate-driven hydrological transport numerical model (HydroTrend) to estimate …

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Application Of Foreland Basin Detrital-Zircon Geochronology To The Reconstruction Of The Southern And Central Appalachian Orogen, Hyunmee Park, David L. Barbeau Jr, Alan Rickenbaker, Denise Bachmann-Krug, George E. Gehrels Jan 2010

Application Of Foreland Basin Detrital-Zircon Geochronology To The Reconstruction Of The Southern And Central Appalachian Orogen, Hyunmee Park, David L. Barbeau Jr, Alan Rickenbaker, Denise Bachmann-Krug, George E. Gehrels

Faculty Publications

We report the U-Pb age distribution of detrital zircons collected from central and southern Appalachian foreland basin strata, which record changes of sediment provenance in response to the different phases of the Appalachian orogeny. Taconic clastic wedges have predominantly ca. 1080–1180 and ca. 1300–1500 Ma zircons, whereas Acadian clastic wedges contain abundant Paleozoic zircons and minor populations of 550–700 and 1900–2200 Ma zircons consistent with a Gondwanan affinity. Alleghanian clastic wedges contain large populations of ca. 980–1080 Ma and ca. 2700 Ma and older Archean zircons and fewer Paleozoic zircons than occur in the Acadian clastic wedges. The abundance of …

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Empirical Mode Decomposition Operator For Dewowing Gpr Data, Bradley M. Battista, Adrian Addison, Camelia C. Knapp Dec 2009

Empirical Mode Decomposition Operator For Dewowing Gpr Data, Bradley M. Battista, Adrian Addison, Camelia C. Knapp

Faculty Publications

Signal processing tools available to ground penetrating radar data used for shallow subsurface imaging and hydrogeophysical parameter estimation are significantly handled using the same tools available to seismic reflection data. Overall, the same tools produce interpretable images from both data types, but particular noise (wow noise) in electromagnetic data must be removed before stable and accurate quantitative results can be produced. Wow noise is an inherent, nonlinear electromagnetic interference and a significant component of GPR data. Further, the nonlinear and non-stationary nature of wow noise provides a strong argument for preprocessing radar traces with time-domain operators. Time-domain operators designed for …

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Improved Hydrogeophysical Parameter Estimation From Empirical Mode Decomposition Processed Ground Penetrating Radar Data, Adrian Addison, Bradley M. Battista, Camelia C. Knapp Dec 2009

Improved Hydrogeophysical Parameter Estimation From Empirical Mode Decomposition Processed Ground Penetrating Radar Data, Adrian Addison, Bradley M. Battista, Camelia C. Knapp

Faculty Publications

Various techniques have been designed to maximize the use of ground penetrating radar (GPR) as an exploration tool. Improvements in signal processing are expected to further facilitate the accuracy of parameters derived from using GPR in certain geologic environments. Common-offset GPR data were collected at the Marine Corps Air Station (MCAS) in Beaufort, South Carolina, and dielectric constants were calculated following the application of the empirical mode decomposition (EMD) for dewowing GPR traces. Conventional signal processing is applied to the GPR traces to provide hydrogeophysical parameter estimates such as volumetric water content, porosity, and hydraulic conductivity. The results are validated …

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Root Production And Methane Dynamics: Impact Of Wetland Functional Group Diversity And Composition, Rachel Schultz, Virginie Bouchard, Serita D. Frey Aug 2009

Root Production And Methane Dynamics: Impact Of Wetland Functional Group Diversity And Composition, Rachel Schultz, Virginie Bouchard, Serita D. Frey

Faculty Publications

Background/Question/Methods: The loss of biodiversity worldwide has prompted a close investigation of the link between diversity and ecosystem functions. Most experimental studies have looked at the relationship between grassland plant diversity and aboveground productivity. Less is known about other ecosystems or how diversity affects belowground processes. Our objective was to investigate the link between plant community (diversity and composition) and key belowground processes such as root biomass production and CH4 dynamics in wetland ecosystems. We hypothesized that 1) root biomass would increase with functional group diversity due to complementarity and 2) the sediment pool of CH4 would decrease with diversity …

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Revised Crustal Architecture Of The Southeastern Carpathian Foreland From Active And Passive Seismic Data, Dana M. Enciu, Camelia C. Knapp, James H. Knapp Aug 2009

Revised Crustal Architecture Of The Southeastern Carpathian Foreland From Active And Passive Seismic Data, Dana M. Enciu, Camelia C. Knapp, James H. Knapp

Faculty Publications

Integration of active and passive source seismic data is employed in order to study the nature of the relationships between crustal seismicity and geologic structures in the southeastern (SE) Carpathian foreland of Romania and the possible connection with the Vrancea Seismogenic Zone (VSZ) of intermediatedepth seismicity, one of the most active earthquakeprone areas in Europe. Crustal epicenters and focal mechanisms are correlated with four deep industry seismic profiles, the reprocessed Danube and Carpathian Integrated Action on Process in the Lithosphere and Neotectonics (DACIA PLAN) profile and the Deep Reflection Acquisition Constraining Unusual Lithospheric Activity II and III (DRACULA) profiles in …

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Developing A Robust Geologic Conceptual Model Using Pseudo 3-D P-Wave Seismic Reflection Data, Adrian Addison, Michael G. Waddell, Camelia C. Knapp, Duke T. Brantley, John M. Shafer Mar 2009

Developing A Robust Geologic Conceptual Model Using Pseudo 3-D P-Wave Seismic Reflection Data, Adrian Addison, Michael G. Waddell, Camelia C. Knapp, Duke T. Brantley, John M. Shafer

Faculty Publications

As part of a multiscale hydrogeophysical and modeling study, a pseudo three-dimensional (3-D) seismic surveywas conducted over a contaminant plume at P area, Savannah River site (South Carolina), to enhance the existing geologicmodel by resolving uncertainties in the lithostratigraphic sequence. The geometry of the dissolved phase trichloroethylene plume, based on initial site characterization, appears to be confined to a narrow corridor within the Eocene sand overlying a clay unit approximately 25m(82 ft) below land surface. Processing the seismic data as a 3-D data volume instead of a series of closely spaced two-dimensional lines allowed for better interpretation of the target …

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The Pecos River Hypogene Speleogenetic Province: A Basin-Scale Karst Paradigm For Eastern New Mexico And West Texas, Usa, Kevin W. Stafford, Alexander Klimchouk, Lewis Land, Marcus O. Gary Jan 2009

The Pecos River Hypogene Speleogenetic Province: A Basin-Scale Karst Paradigm For Eastern New Mexico And West Texas, Usa, Kevin W. Stafford, Alexander Klimchouk, Lewis Land, Marcus O. Gary

Faculty Publications

Since the mid-Tertiary, lateral migration and entrenchment of the Pecos River Valley in eastern New Mexico and west Texas, USA, has significantly influenced regional groundwater flow paths, providing a focus for ascending flow in multi-storey artesian systems and a powerful potentiometric driving force for hypogene speleogenesis. Individual occurrences of hypogene karst phenomena associated with the central Pecos River Valley are widespread throughout the greater Delaware Basin region, including development in a wide range of Permian carbonate and evaporate fades. Hypogene occurrences are well-documented as far north as Santa Rosa, New Mexico and as far south as Lake Amistad, Texas. Throughout …

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Detrital-Zircon Geochronology Of The Metasedimentary Rocks Of North-Western Graham Land, David L. Barbeau Jr, Justin T. Davis, Kendra E. Murray, Victor Valencia, George E. Gehrels, Khandaker M. Zahid, David J. Gombosi Jan 2009

Detrital-Zircon Geochronology Of The Metasedimentary Rocks Of North-Western Graham Land, David L. Barbeau Jr, Justin T. Davis, Kendra E. Murray, Victor Valencia, George E. Gehrels, Khandaker M. Zahid, David J. Gombosi

Faculty Publications

Metasedimentary rocks constitute an important but comparatively poorly understood part of the Antarctic Peninsula. Herein we report single-grain U-Pb detrital-zircon ages from samples of the Trinity Peninsula and Botany Bay Groups of north-western Graham Land. All studied samples are dominated by a large and narrowly defined population of late Palaeozoic zircons. Significant early–middle Palaeozoic and minor Neoproterozoic and Mesoproterozoic sub-populations constitute the majority of pre-Carboniferous grains. These detrital-zircon age populations are consistent with sediment derivation entirely from western Gondwana sources. Despite the clear Gondwana signatures, our data suggest that the Trinity Peninsula Group province was either a parautochthonous peri-Gondwanan terrane …

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Petromode, Eric H. Christiansen Jan 2009

Petromode, Eric H. Christiansen

Faculty Publications

PetroMode is an Excel spreadsheet that can be used to (1) calculate the modal composition of a rock given the elemental composition of the rock and (2) calculate the major element mass balance to test the derivation of a daughter liquid by removal of minerals from a parent liquid (fractional crystallization).

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Global Distribution Of Atmospheric Phosphorus Sources, Concentrations And Deposition Rates, And Anthropogenic Impacts, Natalie Mahowald, Timothy D. Jickells, Alex R. Baker, Paulo Artaxo, Claudia R. Benitez-Nelson, Gilles Bergametti, Tami C. Bond, Ying Chen, David D. Cohen, Barak Herut, Nilgun Kubilay, Remi Losno, Chao Luo, Willy Maenhaut, Kenneth A. Mcgee, Gregory S. Okin, Ronald L. Siefert, Seigen Tsukuda Dec 2008

Global Distribution Of Atmospheric Phosphorus Sources, Concentrations And Deposition Rates, And Anthropogenic Impacts, Natalie Mahowald, Timothy D. Jickells, Alex R. Baker, Paulo Artaxo, Claudia R. Benitez-Nelson, Gilles Bergametti, Tami C. Bond, Ying Chen, David D. Cohen, Barak Herut, Nilgun Kubilay, Remi Losno, Chao Luo, Willy Maenhaut, Kenneth A. Mcgee, Gregory S. Okin, Ronald L. Siefert, Seigen Tsukuda

Faculty Publications

[1] A worldwide compilation of atmospheric total phosphorus (TP) and phosphate (PO4) concentration and deposition flux observations are combined with transport model simulations to derive the global distribution of concentrations and deposition fluxes of TP and PO4. Our results suggest that mineral aerosols are the dominant source of TP on a global scale (82%), with primary biogenic particles (12%) and combustion sources (5%) important in nondusty regions. Globally averaged anthropogenic inputs are estimated to be ∼5 and 15% for TP and PO4, respectively, and may contribute as much as 50% to the deposition over the oligotrophic ocean where productivity may …

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Forcing And Dynamics Of Seafloor-Water Column Exchange On A Broad Continental Shelf, William B. Savidge, Ann Gargett, Richard A. Jahnke, James R. Nelson, Dana K. Savidge, R Timothy Short, George Voulgaris Dec 2008

Forcing And Dynamics Of Seafloor-Water Column Exchange On A Broad Continental Shelf, William B. Savidge, Ann Gargett, Richard A. Jahnke, James R. Nelson, Dana K. Savidge, R Timothy Short, George Voulgaris

Faculty Publications

Relict sediments of elevated permeability characterize the majority of continental shelves globally (Emery, 1968). In these settings, interactions between benthic boundary layer (BBL) flows and seabed topography generate pressure fluctuations that drive advective and dispersive porewater transport, dramatically increasing the magnitude and variability of porewater solute and particulate exchange across the sediment-water interface (Huettel et al., 1996; Huettel and Rusch, 2000). On broad shallow shelves with a relatively large area-to-volume ratio, the seafloor’s role is magnified. Energetic events may reorganize bedforms across a significant fraction of the shelf, leading to altered exchange dynamics that may persist long after the organizing …

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Si Cycle In The Cariaco Basin, Venezuela: Seasonal Variability In Silicate Availability And The Si:C:N Composition Of Sinking Particles, Robert Thunell, Claudia R. Benitez-Nelson, Frank Muller-Karger, Laura Lorenzoni, Kent Fanning, Mary Scranton, Ramon Varela, Yrene Astor Oct 2008

Si Cycle In The Cariaco Basin, Venezuela: Seasonal Variability In Silicate Availability And The Si:C:N Composition Of Sinking Particles, Robert Thunell, Claudia R. Benitez-Nelson, Frank Muller-Karger, Laura Lorenzoni, Kent Fanning, Mary Scranton, Ramon Varela, Yrene Astor

Faculty Publications

[1] A 9‐year time series of water column and sediment trap measurements was used to examine silicon cycling within the anoxic Cariaco Basin. The dynamic hydrographic regime within Cariaco Basin results in strong seasonal changes in nutrient availability and the Si:C:N of sinking particles. Upwelling in early winter injects silicic acid (Si(OH)4= ) and nitrate (NO3−) rich waters into the photic zone which stimulates primary production and results in opal fluxes in excess of 4 mmol Si m−2 d−1. However, even during upwelling, surface waters tend to be depleted (μM) in both Si(OH)4= and NO3− as a result …

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High-Resolution Surveys Along The Hot Spot–Affected Galapagos Spreading Center: 1. Distribution Of Hydrothermal Activity, Edward T. Baker, Rachel M. Haymon, Joseph A. Resing, Scott M. White, Sharon L. Walker, Ken C. Macdonald, Ko-Ichi Nakamura Sep 2008

High-Resolution Surveys Along The Hot Spot–Affected Galapagos Spreading Center: 1. Distribution Of Hydrothermal Activity, Edward T. Baker, Rachel M. Haymon, Joseph A. Resing, Scott M. White, Sharon L. Walker, Ken C. Macdonald, Ko-Ichi Nakamura

Faculty Publications

The spatial density of hydrothermal activity along most mid-ocean ridges is a robust linear function of spreading rate (or magmatic budget), but extreme crustal properties may alter this relationship. In 2005–2006 we tested the effect of thickened crust on hydrothermal activity using high-resolution mapping of plumes overlying the hot spot–affected Galapagos Spreading Center from 95o to 89o42'W (~560 km of ridge crest). Plume mapping discovered only two active, high-temperature vent fields, subsequently confirmed by camera tows, though strong plume evidence indicated minor venting from at least six other locations. Total plume incidence (ph), the fraction of ridge …

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Lateral Circulation And Suspended Sediment Transport In A Curved Estuarine Channel: Winyah Bay, Sc, Usa, Yong Hoon Kim, George Voulgaris Sep 2008

Lateral Circulation And Suspended Sediment Transport In A Curved Estuarine Channel: Winyah Bay, Sc, Usa, Yong Hoon Kim, George Voulgaris

Faculty Publications

Shipborne vertical profiles of flow and suspended sediment concentration collected on a transect, across a curved, nonsymmetrical estuarine channel are presented. Analysis of the transient cross-channel momentum balance equation shows that the lateral circulation pattern is controlled by the interaction between centrifugal and lateral baroclinic forcings although those two might not be necessarily in balance as suggested earlier by Seim and Gregg (1997). Instead, differential along-channel advection and local acceleration appear to influence greatly lateral circulation dynamics. During ebb when the water column is highly stratified, the interaction between centrifugal acceleration and opposite-directed lateral baroclinic forcing results in weak lateral …

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Epigene And Hypogene Karst Manifestations Of The Castile Formation: Eddy County, New Mexico And Culberson County, Texas, Usa, Kevin W. Stafford, Raymond Nance, Laura Rosales-Lagarde, Penelope J. Boston Jul 2008

Epigene And Hypogene Karst Manifestations Of The Castile Formation: Eddy County, New Mexico And Culberson County, Texas, Usa, Kevin W. Stafford, Raymond Nance, Laura Rosales-Lagarde, Penelope J. Boston

Faculty Publications

Permian evaporites of the Castile Formation crop out over ~1,800 km2 in the western Delaware Basin (Eddy County, New Mexico and Culberson County, Texas, USA) with abundant and diverse karst manifestations. Epigene karst occurs as well-developed karren on exposed bedrock, while sinkholes dominate the erosional landscape, including both solutional and collapse forms. Sinkhole analyses suggest that more than half of all sinks are the result of upward stoping of subsurface voids, while many solutional sinks are commonly the result of overprinting of collapsed forms. Epigene caves are laterally limited with rapid aperture decreases away from insurgence, with passages developed along …

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Characterizing Subpixel Variability Of Low Resolution Radiometer Derived Soil Moisture Using High Resolution Radar Data, Ujjwal Narayan, Venkataraman Lakshmi Jun 2008

Characterizing Subpixel Variability Of Low Resolution Radiometer Derived Soil Moisture Using High Resolution Radar Data, Ujjwal Narayan, Venkataraman Lakshmi

Faculty Publications

Soil moisture estimates obtained using passive remote sensing from satellite platforms often suffer from the drawback of coarse spatial resolution. In this current work, low resolution soil moisture estimates from passive remote sensing are fused with high resolution radar backscatter data to produce soil moisture change estimates at the spatial resolution of radar. More specifically, soil moisture estimated from AMSR-E and TMI (separate cases) for a single 50 km × 50 km pixel has been fused with TRMM-PR backscatter data at 5 km resolution to produce soil moisture change estimates at 5 km resolution. A brief sensitivity analysis has been …

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W(H)Ither Fossils? Studying Morphological Character Evolution In The Age Of Molecular Sequences, Elizabeth J. Hermsen, Jonathan R. Hendricks Apr 2008

W(H)Ither Fossils? Studying Morphological Character Evolution In The Age Of Molecular Sequences, Elizabeth J. Hermsen, Jonathan R. Hendricks

Faculty Publications

A major challenge in the post-genomics era will be to integrate molecular sequence data from extant organisms with morphological data from fossil and extant taxa into a single, coherent picture of phylogenetic relationships; only then will these phylogenetic hypotheses be effectively applied to the study of morphological character evolution. At least two analytical approaches to solving this problem have been utilized: (1) simultaneous analysis of molecular sequence and morphological data with fossil taxa included as terminals in the analysis, and (2) the molecular scaffold approach, in which morphological data are analyzed over a molecular backbone (with constraints that force extant …

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Hypogenic Speleogenesis Within Seven Rivers Evaporites: Coffee Cave, Eddy County, New Mexico, Kevin W. Stafford, Lewis Land, Alexander Klimchouk Apr 2008

Hypogenic Speleogenesis Within Seven Rivers Evaporites: Coffee Cave, Eddy County, New Mexico, Kevin W. Stafford, Lewis Land, Alexander Klimchouk

Faculty Publications

Coffee Cave, located in the lower Pecos region of southeastern New Mexico, illustrates processes of hypogenic speleogenesis in the middle Permian Seven Rivers Formation. Coffee Cave is a rectilinear gypsum maze cave with at least four stratigraphically-distinct horizons of development. Morphological features throughout the cave provide unequivocal evidence of hypogenic ascending speleogenesis in a confined aquifer system driven by mixed (forced and free) convection. Morphologic features in individual cave levels include a complete suite that defines original rising flow paths, ranging from inlets for hypogenic fluids (feeders) through transitional forms (rising wall channels) to ceiling half-tube flow features and fluid …

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Oligocene Deep Water Export From The North Atlantic And The Development Of The Antarctic Circumpolar Current Examined With Neodymium Isotopes, Howie Scher, Ellen E. Martin Jan 2008

Oligocene Deep Water Export From The North Atlantic And The Development Of The Antarctic Circumpolar Current Examined With Neodymium Isotopes, Howie Scher, Ellen E. Martin

Faculty Publications

Neodymium (Nd) isotopes were measured on 181 samples of fossil fish teeth recovered from Oligocene toMiocene sections at Ocean Drilling Program Site 1090 (3700 m water depth) on Agulhas Ridge in the Atlanticsector of the Southern Ocean. A long-term decreasing trend toward less radiogenic Nd isotope compositionsdominates the record. This trend is interrupted by shifts toward more radiogenic compositions near the early/lateOligocene boundary and the Oligocene/Miocene boundary. Overall, eNd values at Agulhas Ridge are moreradiogenic than at other Atlantic locations, and are similar to those at Indian Ocean locations. The pattern ofvariability is remarkably similar to Nd isotope results from …

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Hypogene Calcitization: Evaporite Diagenesis In The Western Delaware Basin, Kevin W. Stafford, Dana Ulmer-Scholle, Laura Rosales-Lagarde Jan 2008

Hypogene Calcitization: Evaporite Diagenesis In The Western Delaware Basin, Kevin W. Stafford, Dana Ulmer-Scholle, Laura Rosales-Lagarde

Faculty Publications

Evaporite calcitization within the Castile Formation of the Delaware Basin is more widespread and diverse than originally recognized. Coupled field and GIS studies have identified more than 1000 individual occurrences of calcitization within the Castile Formation outcrop area, which includes both calcitized masses (limestone buttes) and laterally extensive calcitized horizons (limestone sheets). Both limestone buttes and sheets commonly contain a central brecciated zone that we attribute to hypogene dissolution. Lithologic fabric of calcitized zones ranges from little alteration of original varved laminae to fabrics showing extensive laminae distortion as well as extensive vuggy and open cavernous porosity. Calcitization is most …

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Hypogene Speleogenesis Within The Central Basin Platform: Karst Porosity In The Yates Field, Pecos County, Texas, U.S.A., Kevin W. Stafford, Fred H. Behnken, Jesse G. White Jan 2008

Hypogene Speleogenesis Within The Central Basin Platform: Karst Porosity In The Yates Field, Pecos County, Texas, U.S.A., Kevin W. Stafford, Fred H. Behnken, Jesse G. White

Faculty Publications

The Yates Unit Oil Field is located on the southeastern tip of the Central Basin Platform in eastern Pecos County, Texas. It produces from Middle Permian strata, primarily the upper San Andres Formation. Locally, the productive upper San Andres Formation is comprised of successively vertically stacked progradational shelf carbonates. Stratigraphically overlying the Yates Field reservoir, the Toborg Field produces from the uppermost Triassic and Cretaceous units. Both fields are bounded on the north and east sides by the Pecos River, which has remained entrenched in its current location since the early Tertiary. As mapped, the top of the San Andres …

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Castile Evaporite Karst Potential Map Of The Gypsum Plain, Eddy County, New Mexico And Culberson County, Texas: A Gis Methodological Comparison, Kevin W. Stafford, Laura Rosales-Lagarde, Penelope J. Boston Jan 2008

Castile Evaporite Karst Potential Map Of The Gypsum Plain, Eddy County, New Mexico And Culberson County, Texas: A Gis Methodological Comparison, Kevin W. Stafford, Laura Rosales-Lagarde, Penelope J. Boston

Faculty Publications

Castile Formation gypsum crops out over ,1,800 km2 in the western Delaware Basin where it forms the majority of the Gypsum Plain. Karst development is well recognized in the Gypsum Plain (i.e., filled and open sinkholes with associated caves); however, the spatial occurrence has been poorly known. In order to evaluate the extent and distribution of karst development within the Castile portion of the Gypsum Plain, combined field and Geographic Information System (GIS) studies were conducted, which enable a first approximation of regional speleogenesis and delineate karst-related natural resources for management. Field studies included physical mapping of 50, 1-km2 sites, …

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Tidal Asymmetry And Residual Circulation Over Linear Sandbanks And Their Implication On Sediment Transport: A Process-Oriented Numerical Study, Rosario Sanay, George Voulgaris, John C. Warner Dec 2007

Tidal Asymmetry And Residual Circulation Over Linear Sandbanks And Their Implication On Sediment Transport: A Process-Oriented Numerical Study, Rosario Sanay, George Voulgaris, John C. Warner

Faculty Publications

A series of process-oriented numerical simulations is carried out in order to evaluate the relative role of locally generated residual flow and overtides on net sediment transport over linear sandbanks. The idealized bathymetry and forcing are similar to those present in the Norfolk Sandbanks, North Sea. The importance of bottom drag parameterization and bank orientation with respect to the ambient flow is examined in terms of residual flow and overtide generation, and subsequent sediment transport implications are discussed. The results show that although the magnitudes of residual flow and overtides are sensitive to bottom roughness parameterization and bank orientation, the …

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Hunting For Hydrothermal Vents Along The Galápagos Spreading Center, Rachel M. Haymon, Edward T. Baker, Joseph A. Resing, Scott M. White, Ken C. Macdonald Dec 2007

Hunting For Hydrothermal Vents Along The Galápagos Spreading Center, Rachel M. Haymon, Edward T. Baker, Joseph A. Resing, Scott M. White, Ken C. Macdonald

Faculty Publications

No abstract provided.

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Relationship Between Vegetation Biophysical Properties And Surface Temperature Using Multisensor Satellite Data, Seungbum Hong, Venkataraman Lakshmi, Eric Small Nov 2007

Relationship Between Vegetation Biophysical Properties And Surface Temperature Using Multisensor Satellite Data, Seungbum Hong, Venkataraman Lakshmi, Eric Small

Faculty Publications

Vegetation is an important factor in global climatic variability and plays a key role in the complexinteractions between the land surface and the atmosphere. This study focuses on the spatial and temporalvariability of vegetation and its relationship with land–atmosphere interactions. The authors have analyzedthe vegetation water content (VegWC) from the Advanced Microwave Scanning Radiometer for EOS(AMSR-E), the leaf area index (LAI), the normalized difference vegetation index (NDVI), the land surfacetemperature (Ts), and the Moderate Resolution Imaging Spectroradiometer (MODIS). Three regions,which have climatically differing characteristics, have been selected: the North America Monsoon System(NAMS) region, the Southern Great Plains (SGP) region, and …

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Exceptionally Preserved Jellyfishes From The Middle Cambrian, Paulyn Cartwright, Susan L. Halgedahl, Jonathan R. Hendricks, Richard D. Jarrard, Antonio C. Marques, Allen G. Collins, Bruce S. Lieberman Oct 2007

Exceptionally Preserved Jellyfishes From The Middle Cambrian, Paulyn Cartwright, Susan L. Halgedahl, Jonathan R. Hendricks, Richard D. Jarrard, Antonio C. Marques, Allen G. Collins, Bruce S. Lieberman

Faculty Publications

Cnidarians represent an early diverging animal group and thus insight into their origin and diversification is key to understanding metazoan evolution. Further, cnidarian jellyfish comprise an important component of modern marine planktonic ecosystems. Here we report on exceptionally preserved cnidarian jellyfish fossils from the Middle Cambrian (~505 million years old) Marjum Formation of Utah. These are the first described Cambrian jellyfish fossils to display exquisite preservation of soft part anatomy including detailed features of structures interpreted as trailing tentacles and subumbrellar and exumbrellar surfaces. If the interpretation of these preserved characters is correct, their presence is diagnostic of modern jellyfish …

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