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Articles 1381 - 1410 of 1536
Full-Text Articles in Geochemistry
Application Of Environmental Organic Petrology And Geochemistry To Fingerprint Organic Pollutants In The Recent Sediments Of Lake Ontario, Prasanta K. Mukhopadhyay, Michael A. Kruge, C.F. Michael Lewis
Application Of Environmental Organic Petrology And Geochemistry To Fingerprint Organic Pollutants In The Recent Sediments Of Lake Ontario, Prasanta K. Mukhopadhyay, Michael A. Kruge, C.F. Michael Lewis
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Selected surface sediment samples (sediment depth 0-10 cm) collected in the Niagara basin (western Lake Ontario) were chosen for organic matter characterization using organic petrological and geochemical techniques normally reserved for the study of coal, petroleum source rock and crude oil. The study was performed to assess the effectiveness of these techniques in discriminating between natural and anthropogenic organic matter and to determine the extent of organic pollution of the lake sediments. The organic carbon contents of the samples vary from 1.5 to 3.5%, with upper layer (0-5 cm) samples have higher TOC values than those from the lower layer …
Comparison Of Source Rock Geochemistry Of Selected Rocks From The Schei Point Group And Ringnes Formation, Sverdrup Basin, Arctic Canada, P. K. Mukhopadhyay, F. Goodarzi, Michael A. Kruge, M. H. Alimi
Comparison Of Source Rock Geochemistry Of Selected Rocks From The Schei Point Group And Ringnes Formation, Sverdrup Basin, Arctic Canada, P. K. Mukhopadhyay, F. Goodarzi, Michael A. Kruge, M. H. Alimi
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Organic-rich from the Schei Point group (middle to late Triassic in age) and the Ringnes formation (late Jurassic) from the Sverdrup basin of the Canadian arctic archipelago have been geochemically evaluated for source rock characterization. Most samples from the Schei Point group are organic-rich (> 2% TOC) and are considered as immature to mature oil-prone source rocks [kerogen types I, I-II (IIA) and II (IIA)]. These kerogen types contain abundant AOM1, AOM2 and alginite (Tasmanales, Nostocopsis, Leiosphaeridia, acritarch and dinoflagellate) with variable amounts of vitrinite, inertinite and exinite. Samples from the Ringnes formation contain dominant vitrinite and inertinite …
Separation And Artificial Maturation Of Macerals From Type Ii Kerogen, Michael A. Kruge, Patrick Landais, David F. Bensley, B Artur Stankiewicz, Marcel Elie, Olivier Ruau
Separation And Artificial Maturation Of Macerals From Type Ii Kerogen, Michael A. Kruge, Patrick Landais, David F. Bensley, B Artur Stankiewicz, Marcel Elie, Olivier Ruau
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Immature Type II kerogen (HI= 660 mg/g) from the Lower Toarcian of the Paris Basin was separated into an alginite concentrate (HI = 952 mg/g) and an amorphous organic matter (AOM) concentrate (HI = 573 mg/g) by density centrifugation. The flash pyrolyzate of the alginite is characterized by high relative concentrations of several series of n-alkanones and n-alkenones (including mid-chain alkyl ketones), in addition to n-alkanes, n-alk-1-enes and n-alkadienes. To our knowledge, this Toarcian alginite is the oldest example of marine organic matter whose pyrolyzate contains mid-chain alkanones in such high relative concentrations. In sharp …
The Petrogenesis Of Andesites Produced During Regional Extension: Examples From The Northern Mccullough Range, Nv And Xitle Volcano, Mexico, Kelly Ann Boland
The Petrogenesis Of Andesites Produced During Regional Extension: Examples From The Northern Mccullough Range, Nv And Xitle Volcano, Mexico, Kelly Ann Boland
UNLV Theses, Dissertations, Professional Papers, and Capstones
Andesite dominated volcanic systems produced during regional crustal extension remain a relatively unexplored aspect of andesite petrogenesis. In the southern Basin and Range province, thick sections of andesite and basaltic andesite have been documented in areas including the Piute Range, California, the Eldorado Range, Nevada, and the McCullough Range, Nevada. The northern McCullough Range, located 20 miles south-southeast of Las Vegas, is an ideal place to study the petrogenesis of an andesite dominated system. This area contains a mid-Miocene stratocone composed mainly of a 1200 m thick section of andesite flows that formed synchronous with regional extension.
The northern McCullough …
Prolonged History Of Silicic Peralkaline Volcanism In The Eastern Pacific Ocean, Wendy A. Bohrson, Mary R. Reid, Anita L. Grunder, Matthew Heizler, T. Mark Harrison, Jeffrey Lee
Prolonged History Of Silicic Peralkaline Volcanism In The Eastern Pacific Ocean, Wendy A. Bohrson, Mary R. Reid, Anita L. Grunder, Matthew Heizler, T. Mark Harrison, Jeffrey Lee
All Faculty Scholarship for the College of the Sciences
Socorro Island, Mexico, is an alkaline and peralkaline volcanic island located in the eastern Pacific Ocean on a mid-ocean ridge spreading center that was abandoned at ∼3.5 Ma. Silicic peralkaline rocks comprise up to 80% of the surface of the island, rendering Socorro virtually unique in the Pacific Ocean. Precise, replicate 40Ar/39Ar ages of 21 peralkaline trachytes and rhyolites reveal a history of episodic volcanic activity from ∼540 to 370 ka that may have culminated with caldera formation; repose periods between these episodes may have had maximum duration of ∼30 kyr. After up to 200 kyr of …
Residence Time Of Groundwater Issuing From The South Rim Aquifer In The Eastern Grand Canyon, Jim Fitzgerald
Residence Time Of Groundwater Issuing From The South Rim Aquifer In The Eastern Grand Canyon, Jim Fitzgerald
UNLV Theses, Dissertations, Professional Papers, and Capstones
In the eastern Grand Canyon, secondary porosity created by north trending faults, folds, and breccia pipes, facilitates groundwater flow through the South Rim carbonate aquifer. Springs associated with the South Rim Aquifer have low 3H concentrations, [Ca2+]/[Mg2+] rations close to unity, and variable uranium concentrations. For a geochemical comparison, springs are subcategorized on the basis of geology and discharge. Type I springs are associated with high-angle normal faults and have high discharge rates. These springs discharge Ca2+ - Mg2+, HCO3- waters, have 3H concentrations <2 TR, and 234U/238U activity …2>
Study Of Volcanic Sediments By Microbeam-Pixe Technique, Nazrul I. Khandaker, M. Ahmed, M. A. Garwan
Study Of Volcanic Sediments By Microbeam-Pixe Technique, Nazrul I. Khandaker, M. Ahmed, M. A. Garwan
Publications and Research
Single mineral grains in a suite of Cretaceous (85–90 Ma) volcanic sedimentary rocks were analyzed using the microbeam-PIXE technique to understand fundamental geological processes responsible for micro-scale variation in elemental composition across mineral zones, twinning, cleavage planes, fractures and grain boundaries. Distributions of major and trace elements show distinct geochemical features indicative of a specific geological setting and a subsequent diagenetic process in these volcanic sediments. Examples of mineral zoning, microstructures of variable chemistry and post-depositional fluid flow are discussed using the data on feldspar group of minerals.
Artificial Maturation Of Alginite And Organic Groundmass Separated From Torbanites, Michael A. Kruge, Patrick Landais, David F. Bensley
Artificial Maturation Of Alginite And Organic Groundmass Separated From Torbanites, Michael A. Kruge, Patrick Landais, David F. Bensley
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The two principal organic constituents — Botryococcus-related alginite and organic groundmass — were isolated by density separation from two torbanite samples (from the Stellarton Fm., Nova Scotia, Canada and the King Cannel, Utah, USA). The groundmass consisted of degraded algal, bacterial and terrestrial plant debris. Aliquots of alginite and groundmass were separately heated in gold tubes for 24 hr. with 70 MPa confining pressure, at fixed temperatures ranging between 250 and 375°C. The 250, 300 and 325°C experiments run on the alginite produced very low yields of CHCl3-extractable organic matter (EOM), indicating that very little of the generation potential …
Organic Geochemistry And Petrology Of Oil Source Rocks, Carpathian Overthrust Region, Southeastern Poland — Implications For Petroleum Generation, Michael A. Kruge, Maria Mastalerz, Andrzej Solecki, B Artur Stankiewicz
Organic Geochemistry And Petrology Of Oil Source Rocks, Carpathian Overthrust Region, Southeastern Poland — Implications For Petroleum Generation, Michael A. Kruge, Maria Mastalerz, Andrzej Solecki, B Artur Stankiewicz
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The organic matter rich Oligocene Menilite black shales and mudstones are widely distributed in the Carpathian Overthrust region of southeastern Poland and have excellent hydrocarbon generation potential, according to TOC, Rock-Eval, and petrographic data. Extractable organic matter was characterized by an equable distribution of steranes by carbon number, by varying amounts of 28,30-dinor-hopane, 18α(H)-oleanane and by a distinctive group of C24 ring-A degraded triterpanes. The Menilite samples ranged in maturity from pre-generative to mid-oil window levels, with the most mature in the southeastern portion of the study area. Carpathian petroleum samples from Campanian-Oligocene sandstone reservoirs were similar …
Flash Pyrolysis Of Anthropogenic And Natural Organic Matter In Polluted Sediments, Sami T. Abdel Bagi, Michael A. Kruge, Gary L. Salmon
Flash Pyrolysis Of Anthropogenic And Natural Organic Matter In Polluted Sediments, Sami T. Abdel Bagi, Michael A. Kruge, Gary L. Salmon
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
INTRODUCTION - Combustion products along with spilled petroleum and industrial chemicals contribute to environmental degradation by contaminating soils and sediments. Such anthropogenic organic matter (OM), if preserved in sediments, can serve an archival function, documenting the local, history of industrial pollution. Christensen and Zhang (1993) determined the sources of polycyclic aromatic hydrocarbons (P AH) to Lake Michigan from sedimentary records, finding that coal combustion was a major source for PAHs in these sediments. Bodzek and Luks-Betlej (1993) reported that atmospheric deposition is the main source of PAH in soils of the heavily industrialized Upper Silesia region of Poland. Smith and …
Hydrogeology, Hydrogeochemistry, And Spoil Settlement At A Large Mine-Spoil Area In Eastern Kentucky: Star Fire Tract, David R. Wunsch, James S. Dinger, Page B. Taylor, Daniel I. Carey, C. Douglas R. Graham
Hydrogeology, Hydrogeochemistry, And Spoil Settlement At A Large Mine-Spoil Area In Eastern Kentucky: Star Fire Tract, David R. Wunsch, James S. Dinger, Page B. Taylor, Daniel I. Carey, C. Douglas R. Graham
Report of Investigations--KGS
An applied research program at the Star Fire surface mine in eastern Kentucky, owned and operated by Cypress-AMAX Coal Co., defined spoil characteristics to develop and monitor water resources, which will help identify a reliable water supply for future property development. Water stored in the mine spoil may provide a usable ground-water supply, and the spoil could also be engineered to provide base flow to surfacewater reservoirs.
Ground-water recharge enters the spoil by way of sinking streams, ground-water flow from bedrock in contact with the mine spoil, and a specially designed infiltration basin. Ground water discharges predominantly from springs and …
The Implications Of Turbidite-Driven Redox Changes In Sediments Of The Iberia Abyssal Plain, Timothy J. Shaw, P. A. Meyers
The Implications Of Turbidite-Driven Redox Changes In Sediments Of The Iberia Abyssal Plain, Timothy J. Shaw, P. A. Meyers
Faculty Publications
No abstract provided.
Organic Matter Accumulation, Sulfate Reduction, And Methanogenesis In Pliocene–Pleistocene Turbidites On The Iberia Abyssal Plain, P. A. Meyers, Timothy J. Shaw
Organic Matter Accumulation, Sulfate Reduction, And Methanogenesis In Pliocene–Pleistocene Turbidites On The Iberia Abyssal Plain, P. A. Meyers, Timothy J. Shaw
Faculty Publications
No abstract provided.
Geology And Geochemistry Of Tertiary Volcanic Rocks In The Northern Reveille And Southern Pancake Ranges, Nye County, Nevada, Kelly Brian Rash
Geology And Geochemistry Of Tertiary Volcanic Rocks In The Northern Reveille And Southern Pancake Ranges, Nye County, Nevada, Kelly Brian Rash
UNLV Theses, Dissertations, Professional Papers, and Capstones
The northern Reveille and southern Pancake Ranges, located in the south-central Great Basin, experienced a prolonged history of Tertiary volcanism. Volcanic activity in this area began with the eruption of large-volumes of ash-flow tuffs from calderas of the central Nevada caldera complex. The Reveille Range and the southernmost portion of the Pancake Range are the site of two calderas that are the sources for the tuff of Goblin Knobs and tuff of northern Reveille Range. The tuff of Goblin Knobs (70.4-75.3 wt.% SiO2) erupted from the caldera of Goblin Knobs (25.6 Ma) and is the thickest (~1700 m) …
Geochemical Evolution Of A Mid-Miocene Synextensional Volcanic Complex: The Dolan Springs Volcanic Field, Northwestern Arizona, Scott Michael Mcdaniel
Geochemical Evolution Of A Mid-Miocene Synextensional Volcanic Complex: The Dolan Springs Volcanic Field, Northwestern Arizona, Scott Michael Mcdaniel
UNLV Theses, Dissertations, Professional Papers, and Capstones
The Dolan Springs volcanic field (DSV), of northwestern Arizona, is dominated by andesite and basaltic-andesite flows and breccias, with minor amounts of basalt, rhyolite, and ash-flow tuff. Geochemistry is used here as a tool to evaluate the roles and contributions of the lithospheric and asthenospheric mantles to magmatism related to Miocene extension in the Colorado River extension corridor (CREC). The majority of synextensional volcanic rocks in the DSV are geochemically similar to regional trends, but rare tholeiitic basalts erupted near the end of extension. The tholeiites have trace element signatures similar to ocean island basalt (OIB), but have isotopic values …
A Petrographic And Fluid Inclusion Study Of The Purple Vein And Post/Betze Orebodies, Carlin, Nevada, Jan B. Lamb
A Petrographic And Fluid Inclusion Study Of The Purple Vein And Post/Betze Orebodies, Carlin, Nevada, Jan B. Lamb
UNLV Theses, Dissertations, Professional Papers, and Capstones
The Purple Vein (Meikle Mine) and Post/Betze orebodies, two Carlin-type, gold deposits, display important differences in size, alteration, silicification, pyritization, and gold grade. A core hole was examined from each deposit to gather petrographic and microthermometric data to determine the mineral paragenesis, to determine fluid pressure, temperature, and composition to compare of the two orebodies, and to determine depths of formation.
The parageneses determined were divided into three stages. (1) The Early Mineralization Stage contains quartz, pyrobitumen, barite, sphalerite, sulfosalts, quartz, and pyrite in the Purple Vein deposit and consists of calcite in the Post/Betze deposit. High salinity basinal brines, …
Hydrogeochemical Delineation Of A Groundwater Flow System, Berrien County, Michigan, Patrick J. Bartnik
Hydrogeochemical Delineation Of A Groundwater Flow System, Berrien County, Michigan, Patrick J. Bartnik
Masters Theses
The objective of this study was to examine the possibility of determining groundwater flow directions from natural variations in groundwater chemistry. Groundwater samples were analyzed for major cation and anion concentrations. These data were to have been contoured and then compared with groundwater flow maps generated by conventional methods. The purpose was to determine whether a correlation could be drawn between the two methods. However, the results of the study did not allow for this comparison.
The plotted major cation and anion data did not lend themselves to contouring, which suggests that greater control may be required during the selection …
Organic Facies And Maturation Of Jurassic/Cretaceous Rocks, And Possible Oil-Source Rock Correlation Based On Pyrolysis Of Asphaltenes, Scotian Basin, Canada, Prasanta K. Mukhopadhyay, John A. Wade, Michael A. Kruge
Organic Facies And Maturation Of Jurassic/Cretaceous Rocks, And Possible Oil-Source Rock Correlation Based On Pyrolysis Of Asphaltenes, Scotian Basin, Canada, Prasanta K. Mukhopadhyay, John A. Wade, Michael A. Kruge
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
This paper establishes source rock characterization and oil-oil and oil-source rock correlations of selected organic-rich shale source rocks and selected light oils and condensates from Jurassic and Cretaceous formations of the Scotian Basin. Multiple source rocks of Kerogen Types IIA (oil-prone), IIA-IIB (oil- and condensate-prone), IIB (condensate and gas prone), III (gas-prone), and IV (nonsource) are identified in various stratigraphic horizons. Vitrinite reflectance and Tmax data indicate variable maturation histories, in different parts of the basin, which are related to differences in lithology-related heat conductivity and the presence of older sediments closer to areas of rifting. Multiple linear regression …
Exposure Of A Food Crop To Trichloroethylene From A Contaminated Aquifer, Richard G. Baringer
Exposure Of A Food Crop To Trichloroethylene From A Contaminated Aquifer, Richard G. Baringer
Theses and Dissertations
This research developed a methodology for assessment of the exposure of a mature corn crop to trichloroethylene from a contaminated aquifer. The methodology was then applied to the case of Hill AFB to determine the ability of the methodology to provide information about a specific exposure. Current procedures sample for food contamination but do not attempt to predict exposure problems. A review of the potential exposure pathways from the aquifer to the crop was conducted. Based on this review, the exposures due to soil gas and irrigation were modeled. Empirical estimated were used to approximate the expected flux of soil …
Hydrogeology And Hydrogeochemistry Of Government Marsh, North St. Joseph County, Michigan, Michael C. Kasenow
Hydrogeology And Hydrogeochemistry Of Government Marsh, North St. Joseph County, Michigan, Michael C. Kasenow
Dissertations
A hydrogeologic and hydrogeochemical investigation was conducted at Government Marsh located in St. Joseph County, Michigan from May, 1988, to November, 1993. Information on glacial geology, topography, drainage patterns, hydraulic conductivity, vegetation, water chemistry, and static water table elevations has been collected and analyzed. Data were collected in order to determine directions of ground water flow and areas of recharge and discharge. Bail-down tests, grain-size analysis, and permeameters were used to determine hydraulic conductivity adjacent to and within the wetland. Water table elevations and chemistry were analyzed from wells adjacent to the wetland perimeter and within the boundaries of the …
The Speciation Of Dissolved Uranium In Marine Waters, Darrin Kent Mann
The Speciation Of Dissolved Uranium In Marine Waters, Darrin Kent Mann
OES Theses and Dissertations
Uranium has been used extensively for quantifying geochemical processes in the marine environment. Due to its low concentration, about 3.3 μg/1, some form of preconcentration is required for analysis. The two most widely used pre-concentration schemes are co-precipitation with iron hydroxide, and chelating ion exchange chromatography. These methods were developed by following the behavior of inorganic uranium isotopes and seemed to give identical results. However, when used for trace metal analysis, these methods have been shown to extract different fractions from the same sample. Chelex-100 resin removes only inorganic or weakly bound trace metals from a solution, while the precipitates …
Speciation Of Heteroatoms In Coal By Sulfur- And Nitrogen-Selective Techniquestrogen-Selective Techniques, Stephen R. Palmer, Michael A. Kruge, Edwin J. Hippo, John C. Crelling
Speciation Of Heteroatoms In Coal By Sulfur- And Nitrogen-Selective Techniquestrogen-Selective Techniques, Stephen R. Palmer, Michael A. Kruge, Edwin J. Hippo, John C. Crelling
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The peroxyacetic acid oxidation products from a series of coals of organic sulfur content 0.5-9.8 wt% were examined. The distributions of organic S and N compounds were determined by gas chromatography with sulfur-selective flame photometric and nitrogen-selective thermionic specific detection respectively. A selected sample was also examined in greater detail using low-voltage high-resolution mass spectrometry. The distribution of organic sulfur compounds in the oxidation products was remarkably similar for all the coals. The number of sulfur compounds detected was small compared with that of organic nitrogen compounds detected. This suggests that the sulfur chemistry of coal is considerably simpler than …
Fossil Charcoal In Cretaceous-Tertiary Boundary Strata: Evidence For Catastrophic Firestorm And Megawave, Michael A. Kruge
Fossil Charcoal In Cretaceous-Tertiary Boundary Strata: Evidence For Catastrophic Firestorm And Megawave, Michael A. Kruge
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Organic matter separated from calcareous sandstone from the upper portion of a deep-water tsunami deposit at Arroyo el Mimbral, Taumalipas (Mexico), which marks the biostratigraphically-defined Cretaceous-Tertiary boundary, consists primarily of fossil charcoal, including semifusinite and pyrofusinite. Analytical pyrolysis-gas chromatography-mass spectrometry revealed the highly aromatic and polyaromatic character of the organic matter assemblage, typical of the products of partial combustion. The organic matter probably originated as terrestrial vegetation that was caught in a firestorm and subsequently transported far offshore in the backwash of a megawave. These data are consistent with the hypothesis of combustion of large masses of vegetation triggered by …
Flash Pyrolysis-Gas Chromatography/Mass Spectrometry Of Lower Kittanning Vitrinites: Changes In The Distributions Of Polyaromatic Hydrocarbons As A Function Of Coal Rank, Michael A. Kruge, David F. Bensley
Flash Pyrolysis-Gas Chromatography/Mass Spectrometry Of Lower Kittanning Vitrinites: Changes In The Distributions Of Polyaromatic Hydrocarbons As A Function Of Coal Rank, Michael A. Kruge, David F. Bensley
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Chemical analyses restricted to a single coal maceral permit a focus on rank effects without concern for variations in organic matter type. Vitrinite concentrates of high purity were isolated from coal samples of the Lower Kittanning seam by multi-step density gradient centrifugation, with reflectances ranging from 0.66 to 1.39% Rmax. In addition to the previously recognized losses of phenolic compounds, the vitrinite pyrolyzates exhibit marked increases in relative concentrations of tri- and tetraaromatic hydrocarbons (especially benzo[a]fluorene, methyl-phenanthrenes, methylfluorenes and methylchrysenes) above 0.9% Rmax, i.e., beyond the "second coalification jump" of Teichmüller. Thus, petrographically-recognizable physical transformations are shown …
Further Evidence Of Lead Contamination Of Omaha Skeletons, A. Mohamad Ghazi, Karl J. Reinhard, Mary Anne Holmes, Eric M. Durrance
Further Evidence Of Lead Contamination Of Omaha Skeletons, A. Mohamad Ghazi, Karl J. Reinhard, Mary Anne Holmes, Eric M. Durrance
Department of Earth and Atmospheric Sciences: Faculty Publications
A previous analysis of Omaha skeletons dating between A.D. 1780 and 1820 revealed the presence of lead in all skeletons with high concentrations in children and adult males (Reinhard and Ghazi [1992] Am. J. Phys. Anthropol. 89: 183-195). Two likely explanations for the high lead levels were presented: 1) metabolic absorption of lead and 2) diagenetic uptake of lead by the bones from postmortem application of pigments to the corpse. Two types of lead were available to the Omaha tribe: 1) Mississippi Valley type, and 2) non-Mississippi Valley type. It has been suggested that red-lead pigment mixed with mercury sulfide …
Field Test Of A Calcite Dissolution Rate Law: Fort’S Funnel Cave, Mammoth Cave National Park, J. Scott Slunder
Field Test Of A Calcite Dissolution Rate Law: Fort’S Funnel Cave, Mammoth Cave National Park, J. Scott Slunder
Masters Theses & Specialist Projects
The laboratory-derived calcite dissolution rate law of Plummer et al. (1978) is the most widely used and mechanistically detailed expression currently available for predicting dissolution rates as a function of water chemistry. Such rate expressions are of great use in understanding timescales associated with limestone karst development. Little work has gone into the field testing of the rate law under natural conditions.
This work compared measured dissolution rates measured by a crystal weight loss experiment in Buffalo Creek within Fort’s Funnel Cave, which lies within a pristine, forested catchment of Mammoth Cave National Park. Continuous water chemistry sampling over the …
The Geology Of The Tuff Of Bridge Spring: Southern Nevada And Northwestern Arizona, Shirley Ann Morikawa
The Geology Of The Tuff Of Bridge Spring: Southern Nevada And Northwestern Arizona, Shirley Ann Morikawa
UNLV Theses, Dissertations, Professional Papers, and Capstones
The Tuff of Bridge Spring (TBS) is a regionally-widespread, andesite to rhyolite (59.50 to 74.91 wt. %) ash-flow tuff of mid-Miocene age (ca. 15.2 Ma) that is exposed in the northern Colorado River extensional corridor of southern Nevada and northwestern Arizona. Determination of the areal distribution, geochronology, lithology, geochemistry, and internal stratigraphy of the TBS is important for its establishment as a reliable stratigraphic reference horizon for tectonic reconstructions of the extensional corridor during the middle Miocene. Based on reoccurring patterns of major and trace element variation, the TBS is divided into constant Cr/variable SiO2 and variable Cr/variable SiO …
Anomalous Mesozoic Thermal Regime, Central Appalachian Piedmont: Evidence From Sphene And Zircon Fission-Track Dating, B. P. Kohn, M. E. Wagner, Tim M. Lutz, G. Organist
Anomalous Mesozoic Thermal Regime, Central Appalachian Piedmont: Evidence From Sphene And Zircon Fission-Track Dating, B. P. Kohn, M. E. Wagner, Tim M. Lutz, G. Organist
Earth & Space Sciences Faculty Publications
No abstract provided.
Identification And Quantitation Of Volatile Amines In Chesapeake Bay Sediments, Neeraja Y. Krishna
Identification And Quantitation Of Volatile Amines In Chesapeake Bay Sediments, Neeraja Y. Krishna
Chemistry & Biochemistry Theses & Dissertations
Sediments from different parts of the Chesapeake Bay were analyzed to determine the presence of volatile amines. A HF-HCl extraction method was used to extract both exchangeable and fixed amines from the sediments and a purge-and-trap technique was used to concentrate the amines. Following derivatization with heptafluorobutyric anhydride (HFBA), the HFBA-amines were analyzed by gas chromatography with electron capture detection and with mass spectrometric detection. One primary amine, i-amylamine with a concentration ranging from 0. 78 nmoles/g dry weight to < 0.05 nmoles/g dry weight was found in a total of twenty seven samples collected on three different dates in 1993. Another primary amine, 2-methylbutylamine with a concentration ranging from 0.18 nmoles/g dry weight to < 0.05 nmoles/g dry weight was found in a total of twenty three samples collected on three different dates in 1993. A secondary amine, diethylamine was detected but could not be quantified in a total of seven samples collected in September 1993. The concentrations of these amines varied with location in the Bay, depth in the sediment, and time of year the sediments were collected. The origin of i-amylamine and 2-methylbutylamine might be from the biological decarboxylation of amino acids leucine and isoleucine, respectively. The origin of diethylamine is unknown.
Epa's Map Of Radon Zones, Nebraska, Sharon W. White, Lisa Ratcliff, Kirk Maconaughey, R. Thomas Peake, Dave Rowson, Steve Page, Linda C. S. Gundersen, R. Randall Schumann, James K. Otton, Doug Owen, Russell Dubiel, Kendell Dickinson, Sandra L. Szarzi
Epa's Map Of Radon Zones, Nebraska, Sharon W. White, Lisa Ratcliff, Kirk Maconaughey, R. Thomas Peake, Dave Rowson, Steve Page, Linda C. S. Gundersen, R. Randall Schumann, James K. Otton, Doug Owen, Russell Dubiel, Kendell Dickinson, Sandra L. Szarzi
United States Environmental Protection Agency: Publications
Sections 307 and 309 of the 1988 Indoor Radon Abatement Act (IRAA) direct EPA to identify areas of the United States that have the potential to produce elevated levels of radon. EPA, the U.S. Geological Survey (USGS), and the Association of, American State Geologists (AASG) have worked closely over the past several years to produce a series of maps and documents which address these directives. The EPA Map of Radon Zones is a compilation of that work and fulfills the requirements of sections 307 and 309 of IRAA. The Map of Radon Zones identifies, on a county-by-county basis, areas of …