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2004

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Articles 31 - 60 of 155

Full-Text Articles in Geology

An Unusually Large Aulocopella Winnipegensis And Associated Demosponges From The Upper Ordovician Beaverfoot Formation, Southeastern British Columbia, J. Keith Rigby, Paul A. Johnston Aug 2004

An Unusually Large Aulocopella Winnipegensis And Associated Demosponges From The Upper Ordovician Beaverfoot Formation, Southeastern British Columbia, J. Keith Rigby, Paul A. Johnston

Faculty Publications

An unusually large specimen of the rare digitate to bladed Aulocopella winnipegensis Rauff and three relatively normal sized specimens of ashtray-shaped Hudsonospongia? sp. constitute the first record of demosponges from the Upper Ordovician Beaverfoot Formation in southeastern British Columbia and the first record of these taxa from western Canada. Gross form and canal structure are well preserved, but dolomitization and (or) coarse microsphaeroidal silicification have obliterated spicules and other structural details. We interpret these sponges as epifaunal recliners, without means of attachment to the substrate, a life mode rarely encountered in the modern sponge biota.


Classifying Mollisol Soils Using Hyperspectral Remote Sensing Data, Adil M. Wadia Aug 2004

Classifying Mollisol Soils Using Hyperspectral Remote Sensing Data, Adil M. Wadia

All-Inclusive List of Electronic Theses and Dissertations

Soil classification is a complex task that involves several factors. Soil classifications that have been published usually need to be updated as soil series definitions and boundaries change over time. Most existing soil classification surveys in the United States, although often very good, lack the required accuracy for selected applications such as precision agriculture. 111 Hyperspectral remote sensing data, with its 100+ bands and very high spectral resolution can help facilitate soil classification detail not achieved through traditional remote sensing methods. The study area selected for research was Wolf Field, near Homer, Champaign County, Illinois, which is a very agriculturally …


Experimental Investigation Of Time Dependent Behavior Of Welded Topopah Spring Tuff, Lumin Ma Aug 2004

Experimental Investigation Of Time Dependent Behavior Of Welded Topopah Spring Tuff, Lumin Ma

Publications (YM)

Four types of laboratory tests have been performed. Specimens were attained from four lithophysal zones of the welded Topopah Spring Tuff unit at Yucca Mountain, Nevada: upper lithophysal, middle nonlithophysal, lower lithophysal and lower nonlithophysal zones. Two types of tests are conducted to study time-dependent behavior: constant strain rate and creep tests. Sixty five specimens from the middle nonlithophysal zone were tested at six strain rates: 10 , 10 , 10 , 10 , 10 , and 10 . Test durations range from 2 seconds to 7 days. Fourteen specimens from middle nonlithophysal, lower lithophysal and lower nonlithophysal zones are …


Volatile Light Hydrocarbons In Geothermal Gas Emissions From Yellowstone National Park, Usa, And Comparisons To El Salvador And Honduras, Bethany Burnett Jul 2004

Volatile Light Hydrocarbons In Geothermal Gas Emissions From Yellowstone National Park, Usa, And Comparisons To El Salvador And Honduras, Bethany Burnett

Earth and Planetary Sciences ETDs

Twenty-six samples from hot springs and fumaroles in Yellowstone National Park (YNP) and 11 in Central America were analyzed for inorganic gases (CO2, SO2, H2S, HCl, Ar, N2, CO, H2, He, 02), methane, and trace volatile light hydrocarbons. Stable isotope analyses of carbon and nitrogen were used in conjunction with the gas geochemistry to determine potential sources of hydrocarbons.

δ13C-CH4 values ranged between -37.6 and-18.2‰ for YNP, from -31.9 to -30.2‰ for El Salvador, and from -38.8 to -23.9‰ for Honduras. δ13C-CO2 …


Lewis And Clark State Park Signs, Robert F. Diffendal Jr., Les Howard Jul 2004

Lewis And Clark State Park Signs, Robert F. Diffendal Jr., Les Howard

School of Natural Resources: Faculty Publications

Bob Diffendal wrote text and Les Howard created maps for new Lewis and Clark signs at Ponca State Park on the Missouri River.

The Corps of Discovery led by Meriwether Lewis and William Clark reached what is now southeastern Nebraska on July 10, 1804. It arrived at the point on the Missouri River adjacent to what is now Ponca State Park on August 22, 1804; and entered fully into South Dakota on September 8, 1804. Over this span of nearly two months members of the expedition saw and described many geologic features. The locations of some of the more prominent …


Sediments, Facies Tracts, And Variations In Sedimentation Rates Of Holocene Platform Carbonate Sediments And Associated Deposits, Northern Belize -- Implications For "Representative" Sedimentation Rates, Wan Yang, Salvatore J. Mazzullo, Chellie S. Teal Jul 2004

Sediments, Facies Tracts, And Variations In Sedimentation Rates Of Holocene Platform Carbonate Sediments And Associated Deposits, Northern Belize -- Implications For "Representative" Sedimentation Rates, Wan Yang, Salvatore J. Mazzullo, Chellie S. Teal

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In stratigraphic analysis and simulation, sedimentation rates are typically assumed to be constant for meter-scale sedimentation units of similar lithology. The rates of Holocene, shallow-marine carbonate and associated sediments within an 820 km2 area of Chetumal Bay in northern Belize were evaluated to test this assumption. Rates were determined from thickness data from 363 locations, durations derived from 14C age dates of mangrove peat on Pleistocene bedrock limestone and of overlying cerithid gravels, and reference to a sea-level curve for this area. The rate of entire Holocene sections (basal transgressive mangrove peat, shelly gravel, and overlying carbonate) varies …


Anthropogenic Lead Deposition And Four National Parks In Poland As Determined By Lead Isotope Ratios, Shannon Simcoe Jul 2004

Anthropogenic Lead Deposition And Four National Parks In Poland As Determined By Lead Isotope Ratios, Shannon Simcoe

OES Theses and Dissertations

Polluted soils are recognized by having high concentrations of heavy metals, including Pb. Partitioning of metals in geochemical fractions, by sequential chemical extractions, may indicate whether a metal has been recently deposited in the soil. While concentration levels alone cannot distinguish between natural and anthropogenic Pb, studies have demonstrated that anthropogenic pollution is accurately recorded by specific Pb isotope signatures, which differ from natural Pb isotopes. The objective of this project was to use 206Pb/207Pb and 206Pb/204Pb isotope ratios to differentiate between the anthropogenic Pb input and the naturally occurring Pb in four national …


Platinum Group Element Mineralization In "Ballrooms" Of The J-M Reef Of The Stillwater Complex, Montana, Matthew P. Harper Jun 2004

Platinum Group Element Mineralization In "Ballrooms" Of The J-M Reef Of The Stillwater Complex, Montana, Matthew P. Harper

Theses and Dissertations

The J-M Reef of the Stillwater Complex, Montana (a large layered mafic intrusion), is one of the highest grade platinum group element (PGE) deposits known in the world, producing primarily palladium and platinum in a 3.4:1 ratio. "Ballrooms" of the Stillwater Complex are anomalously wide areas within or stratigraphically below the J-M Reef that host platinum group element mineralization. Ballrooms have two typical morphologies (type 1 and type 2); the first is an abrupt thickening of the mineralization that extends below the Reef Package and the second is a gentle widening of the Reef Package and associated reef mineralization to …


Karst Of Western Cuba: Observations, Geomorphology, And Diagenesis, Larry D. Seale, Limaris R. Soto, Lee J. Florea, Beth Fratesi Jun 2004

Karst Of Western Cuba: Observations, Geomorphology, And Diagenesis, Larry D. Seale, Limaris R. Soto, Lee J. Florea, Beth Fratesi

Earth, Environmental, and Atmospheric Sciences Faculty Publications

In Cuba, we observed many karst features in a variety of hydrogeologic settings. These hy-drogeologic settings occur in close proximity only because of the complex tectonic history of the is-land. We observed caves within rocks ranging from Pleistocene to Jurassic, and representing a range of diagenetic ages from eogenetic to teloge-netic. Our observations are from the western one-third of the island of Cuba; however, we believe they are representative of hydrogeologic settings found throughout the island.


Effects Of Microbial Processes On Electrolytic And Interfacial Electrical Properties Of Unconsolidated Sediments, Gamal Z. Abdal Aal, Estella A. Atekwana, Lee D. Slater, Eliot A. Atekwana Jun 2004

Effects Of Microbial Processes On Electrolytic And Interfacial Electrical Properties Of Unconsolidated Sediments, Gamal Z. Abdal Aal, Estella A. Atekwana, Lee D. Slater, Eliot A. Atekwana

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The effect of microbial processes on electrical properties of unconsolidated sediments was investigated in a laboratory experiment consisting of biotic and abiotic sand columns. The biotic column (nutrient, diesel and bacteria) showed (a) temporal increase in the real, imaginary, and surface conductivity, and (b) temporal decrease in the formation factor. The abiotic columns (nutrient; and nutrient and diesel) showed no significant changes. Increase in microbial population numbers, decrease in organic carbon source, nitrate, and sulfate and increase in dissolved inorganic carbon and fluid conductivity were indicative of microbial activity in the biotic column. We also measure relative increase in the …


Point Load Strength Testing Of Irregular Rock Fragments Of Welded Tuff, Jaak J.K. Daemen, George Danko, Amy J. Smiecinski Jun 2004

Point Load Strength Testing Of Irregular Rock Fragments Of Welded Tuff, Jaak J.K. Daemen, George Danko, Amy J. Smiecinski

Publications (YM)

Yucca Mountain is composed of a thick sequence of variably welded and nonwelded ashflow tuffs (Rautman and Engstrom, 1996). The understanding of the rock mechanical properties is useful for characterizing the mechanical stability of the potential repository and for estimating the amount of ground support needed in underground construction (Sweetkind et al, 2003). According to Brook (1993), knowledge of lump point load strength is helpful because it can help in estimating the compressive strength. Lump point load testing is one basic mechanical characterization test to support the study of long term drift stability at the potential High Level Waste repository …


Marine Anthropogenic Debris Surveys On Hanna Bay And East Beaches, San Salvador Island, Bahamas, 1998–2004, Virginia White, H. Allen Curran Jun 2004

Marine Anthropogenic Debris Surveys On Hanna Bay And East Beaches, San Salvador Island, Bahamas, 1998–2004, Virginia White, H. Allen Curran

Geosciences: Faculty Publications

Reprinted from: R.L. Davis & D. Gamble, eds., Proceedings of the 12th Symposium on the Geology of the Bahamas and Other Carbonate Regions, San Salvador, Gerace Research Center


Particles In The Great Pinatubo Volcanic Cloud Of June 1991:The Role Of Ice, Song Guo, William I. Rose, Gregg J. S. Bluth, M. I. Watson May 2004

Particles In The Great Pinatubo Volcanic Cloud Of June 1991:The Role Of Ice, Song Guo, William I. Rose, Gregg J. S. Bluth, M. I. Watson

Department of Geological and Mining Engineering and Sciences Publications

Pinatubo's 15 June 1991 eruption was Earth's largest of the last 25 years, and it formed a substantial volcanic cloud. We present results of analysis of satellite-based infrared remote sensing using Advanced Very High Resolution Radiometer (AVHRR) and TIROS Operational Vertical Sounder/High Resolution Infrared Radiation Sounder/2 (TOVS/HIRS/2) sensors, during the first few days of atmospheric residence of the Pinatubo volcanic cloud, as it drifted from the Philippines toward Africa. An SO2-rich upper (25 km) portion drifted westward slightly faster than an ash-rich lower (22 km) part, though uncertainty exists due to difficulty in precisely locating the ash cloud. …


Defining Archaeological Stratigraphy: Evaluating Microartifact Sampling, David N. Holycross May 2004

Defining Archaeological Stratigraphy: Evaluating Microartifact Sampling, David N. Holycross

All-Inclusive List of Electronic Theses and Dissertations

A variety of subsurface methods have been used to discover and evaluate buried archaeological occupations. Researchers such as Stafford (1993,1995) have proposed that micro artifacts are an effective means of defining the archaeological stratigraphy of deposits, but only limited evaluation of this approach has been undertaken. This study tested the utility of microartifacts within a range of sample size and site density characteristics at three Ohio Valley archaeological sites buried within early and late Holocene age landforms. Occupations were typically detected in unit-to-core comparisons, within acceptable margins of error, and microartifacts often revealed a more complex stratigraphy than reflected by …


Sulfide Sulfur Concentration And Sulfur Isotopic Composition Of Methane Seep Sediments, V. Lynn Means, Walter S. Borowski May 2004

Sulfide Sulfur Concentration And Sulfur Isotopic Composition Of Methane Seep Sediments, V. Lynn Means, Walter S. Borowski

EKU Faculty and Staff Scholarship

No abstract provided.


Hydraulic Testing Of The Big Hole Fault, Northern San Rafael Swell, Utah, William M. Schieb May 2004

Hydraulic Testing Of The Big Hole Fault, Northern San Rafael Swell, Utah, William M. Schieb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Six cross-hole packer tests were conducted at the Big Hole fault, a dip-slip normal fault in the northern San Rafael Swell of east-central Utah. Three tests were conducted at each of two locations along the fault, each location having a different total displacement. Water was injected in the footwall, hanging wall, and fault core and pressure changes were monitored in isolated intervals in the adjoining wells. Response curves were analyzed using the type curves developed by Hsieh and Neuman, and Theis, in order to evaluate the hydraulic properties of the fault and its associated damage zone.

The tests were not …


Geochemistry Of Ground Water - Surface Water Interactions And Metals Loading Rates In The North Fork Of The American Fork River, Utah, From An Abandoned Silver/Lead Mine, Neil I. Burk May 2004

Geochemistry Of Ground Water - Surface Water Interactions And Metals Loading Rates In The North Fork Of The American Fork River, Utah, From An Abandoned Silver/Lead Mine, Neil I. Burk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The aqueous geochemistry and hydrology of the North Fork of the American Fork River, its tributaries, and the ground water in the vicinity of the Pacific Mine site were investigated in order to determine what impact ground water entering the North Fork has on toxic metal loads in the river. Toxic metal contamination in the North Fork is great enough that brown and cutthroat trout have absorbed lead, cadmium, and arsenic in their tissues at concentrations that are hazardous to human health if consumed. Ground water that flows through the mine site flows directly through the mine tailings before entering …


Structural Analysis Of Co2 Leakage Through The Salt Wash And Little Grand Wash Faults From Natural Reservoirs In The Colorado Plateau, Southeastern Utah, Anthony P. Williams May 2004

Structural Analysis Of Co2 Leakage Through The Salt Wash And Little Grand Wash Faults From Natural Reservoirs In The Colorado Plateau, Southeastern Utah, Anthony P. Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Little Grand Wash fault and the Salt Wash Graben in the Colorado Plateau of southeastern Utah emit CO2 gas from abandoned drillholes, springs, and a hydrocarbon seep. Similar CO2-charged water has also been emitted in the past, as shown by large localized travertine deposits and veins along and near the fault traces. The faults cut natural CO2 reservoirs and provide an excellent analog for geologic CO2 sequestration. The faults cut a north-plunging anticline of rocks consisting of siltstones, shales, and sandstones from the Permian Cutler Formation through the Cretaceous Mancos Shale. The Little Grand …


Geologic Context Of Geodetic Data Across A Basin And Range Normal Fault, Crescent Valley, Nevada, A. M. Friedrich, Jeffrey Lee, B. P. Wernicke, K. Sieh Apr 2004

Geologic Context Of Geodetic Data Across A Basin And Range Normal Fault, Crescent Valley, Nevada, A. M. Friedrich, Jeffrey Lee, B. P. Wernicke, K. Sieh

All Faculty Scholarship for the College of the Sciences

Geodetic strain and late Quaternary faulting in the Basin and Range province is distributed over a region much wider than historic seismicity, which is localized near the margins of the province. In the relatively aseismic interior, both the magnitude and direction of geodetic strain may be inconsistent with the Holocene faulting record. We document the best example of such a disagreement across the NE striking, ∼55° NW dipping Crescent normal fault, where a NW oriented, 70 km geodetic baseline records contemporary shortening of ∼2 mm/yr orthogonal to the fault trace. In contrast, our geomorphic, paleoseismic, and geochronologic analyses of the …


Re-Evaluation Of So2 Release Of The 15 June 1991 Pinatubo Eruption Using Ultraviolet And Infrared Satellite Sensors, Song Guo, Gregg J. S. Bluth, William I. Rose, M. I. Watson, A. J. Prata Apr 2004

Re-Evaluation Of So2 Release Of The 15 June 1991 Pinatubo Eruption Using Ultraviolet And Infrared Satellite Sensors, Song Guo, Gregg J. S. Bluth, William I. Rose, M. I. Watson, A. J. Prata

Department of Geological and Mining Engineering and Sciences Publications

In this study, ultraviolet TOMS (Total Ozone Mapping Spectrometer) satellite data for SO2 are re-evaluated for the first 15 days following the 15 June 1991 Pinatubo eruption to reflect new data retrieval and reduction methods. Infrared satellite SO2 data from the TOVS/HIRS/2 (TIROS (Television Infrared Observation Satellite) Optical Vertical Sounder/High Resolution Infrared Radiation Sounder/2) sensor, whose data sets have a higher temporal resolution, are also analyzed for the first time for Pinatubo. Extrapolation of SO2 masses calculated from TOMS and TOVS satellite measurements 19–118 hours after the eruption suggest initial SO2 releases of 15 ± 3 …


Keith County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 51, Robert F. Diffendal Jr., James W. Goeke Apr 2004

Keith County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 51, Robert F. Diffendal Jr., James W. Goeke

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the U.S. Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test holes drilled in the county under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies.

The maps in this report show the locations of all test holes drilled in the county since 1934.

Present techniques of …


A North Dakota Geology Field Trip Primer, Joseph H. Hartman Apr 2004

A North Dakota Geology Field Trip Primer, Joseph H. Hartman

Geology and Geological Engineering Faculty Publications

The rocks containing vertebrate fossils in North Dakota represent an important archive of biological and geological events that took place from around 80 million years ago to the present (Figure 1). Although the record is not complete through this interval of time, significant exposures provide important sections of Earth’s geologic history (Figure 2). We continue to understand better how seas moved back and forth across North Dakota and the life that persisted in these seas and adjacent estuaries. The terrestrial habitats and river drainages that are recorded in nonmarine strata contain important insights into the patterns of dinosaur diversity up …


Chemical And Isotopic Investigation Of Groundwater In Eastern United Arab Emirates (Uae), Ahmed Ali Abdalla Murad Apr 2004

Chemical And Isotopic Investigation Of Groundwater In Eastern United Arab Emirates (Uae), Ahmed Ali Abdalla Murad

Dissertations

UAE is located at the southeast of Arabian Peninsula. Two main aquifers occupy the study area: the Eastern Gravel Plain and Ophiolite aquifer. Increasing salinity of groundwater and depletion of aquifers are a major concern in the UAE. Previous studies suggest that groundwater, particularly in the Eastern Gravel Plain aquifer, is affected by seawater intrusion and evaporation. Isotopes of oxygen, hydrogen, carbon and chlorine, and chemical analyses were used to investigate this problem in detail. Samples of groundwater from the Eastern Gravel Plain aquifer have R36Cl values in the range of 13.3 to 17.4 x10-15 while those …


Isotopic Concentration Of Sulfide Sulfur And Delta-34s From Methane Seeps On The Blake Ridge Diapir And Monterey Canyon, V. Lynn Means, Walter S. Borowski Apr 2004

Isotopic Concentration Of Sulfide Sulfur And Delta-34s From Methane Seeps On The Blake Ridge Diapir And Monterey Canyon, V. Lynn Means, Walter S. Borowski

EKU Faculty and Staff Scholarship

Marine sediments contain pore water with dissolved sulfate. Pore-water sulfate is depleted by two anaerobic chemical reactions tat involves microbes: 1) oxidation of sedimentary organic matter; and 2) anaerobic methane oxidation (AMO; CH4 + SO4 → HCO3- + HS- + H2O). Both sulfate depletion pathways produce dissolved hydrogen sulfide (∑HS-), which is scavenged by dissolved iron to produce authigenic sulfide minerals. These minerals crystallize in pore spaces or on grain surfaces. Seafloor seeps are where methane moves upward in the sediments to escape into overlying waters. Additional methane supply should fuel …


Explosion Dynamics Of Pyroclastic Eruptions At Santiaguito Volcano, Jeffrey B. Johnson, Andrew J. L. Harris, Steve T. M. Sahetapy-Engel, Rudiger Wolf, William I. Rose Mar 2004

Explosion Dynamics Of Pyroclastic Eruptions At Santiaguito Volcano, Jeffrey B. Johnson, Andrew J. L. Harris, Steve T. M. Sahetapy-Engel, Rudiger Wolf, William I. Rose

Department of Geological and Mining Engineering and Sciences Publications

In Jan. 2003 we monitored explosions at Santiaguito Volcano (Guatemala) with thermal, infrasonic, and seismic sensors. Thermal data from 2 infrared thermometers allowed computation of plume rise speeds, which ranged from 8 to 20 m/s. Rise rates correlated with cumulative thermal radiance, indicating that faster rising plumes correspond to explosions with greater thermal flux. The relationship between rise speeds and elastic energy is less clear. Seismic radiation may not scale well with thermal output and/or rise speed because some of the thermal component may be associated with passive degassing, which does not induce significant seismicity. But non-impulsive gas release is …


Drift Scale Test: Analyze And Report, George Danko, Davood Bahrami, Amy J. Smiecinski Mar 2004

Drift Scale Test: Analyze And Report, George Danko, Davood Bahrami, Amy J. Smiecinski

Publications (YM)

This report summarizes the results of the in situ thermophysical properties measurements as part of the Drift Scale Test (DST) measurement program at Yucca Mountain, Nevada. Thermophysical measurements have been performed with three built-in thermal probes since November 13, 1997 and were expected to continue for three more years until the end of the DST cooling period. The Department of Energy (DOE), under Cooperative Agreement, Number DEFC28- 98NV12081, has funded a research project at the University of Nevada, Reno since November, 1999 titled: "Continuing site characterization and performance verification applications with the REKA method at Yucca Mountain, Task 13." This …


Stress Corrosion Cracking Studies, K. S. Raja, S. Namjoshi, Amy J. Smiecinski Mar 2004

Stress Corrosion Cracking Studies, K. S. Raja, S. Namjoshi, Amy J. Smiecinski

Publications (YM)

This document reports on the activities for Task 17 of the U.S. DOE/UCCSN Cooperative Agreement Number DE-FC28-98NV12081. There are three subtasks in this Task, the experimental results, discussions, and conclusions of which are presented in the following sections. Data Sources and Electronic Data Control The Data Identification numbers for the data, graphs, and tables in this report, as submitted to the Data Management Database, are tabulated below. The table also includes the source files for the said data as well as the corresponding scientific notebooks where the data can be found. All data in the Q section of the report …


Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii Mar 2004

Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Patterns of sulfide sulfur concentration and sulfur isotopic composition (d34 S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the effect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern United States) by extracting total sedimentary sulfide using chromium reduction. We use …


Geomorphic And Environmental Change Around A Large, Aging Reservoir: Lake C. W. Mcconaughy, Western Nebraska, Usa, R. Matthew Joeckel, Robert F. Diffendal Jr. Feb 2004

Geomorphic And Environmental Change Around A Large, Aging Reservoir: Lake C. W. Mcconaughy, Western Nebraska, Usa, R. Matthew Joeckel, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Lake C. W. McConaughy, a 63-year-old manmade reservoir in the North Platte Valley of western Nebraska, is the largest standing body of water in the state. From the time that Kingsley Dam was completed in 1941 until the present day (2004), many geomorphic and environmental changes have occurred along the shores and within the North Platte Valley. Erosion on the southeastern shoreline of the lake had been perceived as a problem for landowners and managers for at least three decades, but the full scale of erosion was revealed only after a cumulative 18-m drawdown in lake level: bedrock platforms, extending …


Dense Nonaqueous Phase Liquid (Dnapl) Source Zone Characterization: Influence Of Hydraulic Property Correlation On Predictions Of Dnapl Infiltration And Entrapment, Lawrence D. Lemke, Linda M. Abriola, Pierre Goovaerts Jan 2004

Dense Nonaqueous Phase Liquid (Dnapl) Source Zone Characterization: Influence Of Hydraulic Property Correlation On Predictions Of Dnapl Infiltration And Entrapment, Lawrence D. Lemke, Linda M. Abriola, Pierre Goovaerts

Environmental Science and Geology Faculty Research Publications

The influence of aquifer property correlation on multiphase fluid migration and entrapment was explored through the use of correlated and uncorrelated porosity, permeability, and capillary pressure-saturation (Pc-Sat) parameter fields in a crosssectional numerical multiphase flow model. Data collected from core samples in a nonuniform sandy aquifer were used to generate three-dimensional aquifer parameter fields. Porosity was assumed to be uniform or simulated using sequential Gaussian simulation (SGS). Permeability (k) was modeled independently of porosity using SGS as well as simulated geostatistical indicator classes derived from measured grain size distribution curves. Retention characteristics were assigned employing Leverett …