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Geochemistry

2013

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Full-Text Articles in Earth Sciences

Hydrochemical Investigation Of A Transient Parafluvial Zone Under Drought Conditions, Platte River, Nebraska, Audrey R. Boerner Dec 2013

Hydrochemical Investigation Of A Transient Parafluvial Zone Under Drought Conditions, Platte River, Nebraska, Audrey R. Boerner

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Shallow groundwater (0.5 m -1.2 m deep) beneath a vegetated and non-vegetated fluvial island was observed in the lower Platte River, Nebraska, USA during exceptional summer drought. Over the course of three months, sub-hourly measurements of hydraulic head, and weekly measurements of redox indicators, δ2H, δ18O, and dissolved gases were analyzed together with nitrogen and carbon species from an array of shallow piezometers in the river bed and islands. These data were compared with the same parameters collected from a 15 m-deep riparian borehole. Vertical hydraulic gradients in the island piezometers indicated the vertical component to …


Organic Geochemical And Petrographic Properties Of Hazro Dadaş (Di̇yarbakir) Coals, Orhan Kavak, Selami Toprak Dec 2013

Organic Geochemical And Petrographic Properties Of Hazro Dadaş (Di̇yarbakir) Coals, Orhan Kavak, Selami Toprak

Bulletin of the Mineral Research and Exploration

This study was carried out in Hazro-Dadaş (Diyarbakır) region which owns the only coal basin in the area. Chemical, petrographic analysis and organic geochemical evaluations of the Permian aged coals were taken into consideration. Coal quality investigation along with proximate (moisture, volatile matter, fixed carbon, ash) and elemental analyses (C, H, O, and S, N) were performed and revealed. The huminite reflectance of organically abundant matter and coal levels were found to be between 0.458 and 1.141 %. This parameter complies with fluorescence colors, calorific value (average original 3165 – 3432 Kcal/kg) and average Tmax (418 oC). Hasbro coals show …


Deformation And Fluid Interactions In The Mineral Fork Diamictites, Antelope Island, Utah, Kimberly Rose Johnson Dec 2013

Deformation And Fluid Interactions In The Mineral Fork Diamictites, Antelope Island, Utah, Kimberly Rose Johnson

Theses and Dissertations

ABSTRACT

DEFORMATION AND FLUID INTERACTIONS IN THE MINERAL FORK DIAMICTITES,

ANTELOPE ISLAND, UTAH

by

Kimberly R. Johnson

The University of Wisconsin-Milwaukee, 2013

Under the Supervision of Professor Dyanna Czeck

Diamictite from the Mineral Fork Formation on Antelope Island, Utah was deformed to various degrees on the footwall of the Willard Thrust Fault during the Sevier Orogeny. The diamictite contains clasts of differing strength resulting in quartzite clasts deformed the least, pink granitic clasts deformed to a greater degree, and softer green gneissic clasts deformed the most. The pink granitic and green gneissic clasts have similar compositions, but deform differently. This …


Isotopes Of Carbon In A Karst Aquifer Of The Cumberland Platea Of Kentucky , Usa, Lee J. Florea Dec 2013

Isotopes Of Carbon In A Karst Aquifer Of The Cumberland Platea Of Kentucky , Usa, Lee J. Florea

Lee J Florea, PhD, P.G.

In this study, the concentration and isotopic composition of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) are measured in the karst groundwater of the Otter Creek watershed of the Cumberland Plateau of Kentucky, USA. Comparisons among these data and with the geochemistry of carbonate and gypsum equilibrium reactions reveal that DOC concentration is inversely related to discharge, multiple reaction pathways provide DIC with isotopic enrichment that may be directly related to mineral saturation, and oxidation of reduced sulfur is possible for dissolution. DOC is derived from C3 vegetation with an average δ13CDOC of ‒27‰. DIC in groundwater is …


Sources Of Co2 Controlling The Carbonate Chemistry Of The Logsdon River, Mammoth Cave, Kentucky, Bruce Elliott Hatcher Dec 2013

Sources Of Co2 Controlling The Carbonate Chemistry Of The Logsdon River, Mammoth Cave, Kentucky, Bruce Elliott Hatcher

Masters Theses & Specialist Projects

Logsdon River is a major, base-level stream within the Turnhole Bend Drainage basin of the Mammoth Cave System. The Logsdon River system has provided a unique opportunity to examine the geochemical evolution of a stream flowing through a major karst conduit that can be traversed for 10 km. This study examines CO2 inputs at the upstream portion of the river, which provide major control for the river’s hydrochemistry. Samples were collected from the upstream portion of Logsdon River at what is referred to as the S-188 sump and also nearby at Crowbar Dome over the course of 44 weeks …


Hydrogeology And Chemical Characterization Of Hydrocarbon In Domestic Water Wells, Rancho Villa Subdivision, Rogers, Arkansas, Janelle Renee Sherman Dec 2013

Hydrogeology And Chemical Characterization Of Hydrocarbon In Domestic Water Wells, Rancho Villa Subdivision, Rogers, Arkansas, Janelle Renee Sherman

Graduate Theses and Dissertations

This project is centered on the Rancho Villa community in Rogers, Arkansas where several residents have had hydrocarbon contamination in their domestic water wells. The goal of this project was to understand the hydrogeology in the study area, characterize the contaminant chemically, and determine the source of the contaminant. The hydrogeology of the area was determined from previous theses. Seventeen samples were taken from the wells in the Rancho Villa community; each sample was analyzed for geochemical parameters and by Gas Chromatography/Mass Spectrometry (GC/MS) for organic compounds analysis. Four of the 17 samples had a visible non-aqueous layer of hydrocarbon …


Hydrogeology Of The Little River Animal Agriculture Environmental Research Unit And Impacts Of Dairy Operations On Groundwater, Robert Wesley Hunter Dec 2013

Hydrogeology Of The Little River Animal Agriculture Environmental Research Unit And Impacts Of Dairy Operations On Groundwater, Robert Wesley Hunter

Masters Theses

This thesis describes the development of an integrated hydrogeologic/hydrologic site assessment and groundwater/surface water quality monitoring program at the University of Tennessee – Little River Dairy Farm, located near Townsend, TN. Hydrologic/hydrogeologic investigations of streams and groundwater at the site have been underway for more than 5 years, and these are expected to provide background data for assessing impacts of dairy wastes. The lower half of the ~180 ha site consists of low-relief fields used for row crops, which are underlain by 4 – 9 m of alluvial deposits on top of black shale or limestone that include sinkhole features. …


Elemental Analysis And Forensic Comparison Of Soils By Laser-Induced Breakdown Spectroscopy (Libs) And Laser Ablation Inductively Coupled Plasma Mass Spectrometry (La-Icp-Ms), Sarah C. Jantzi Nov 2013

Elemental Analysis And Forensic Comparison Of Soils By Laser-Induced Breakdown Spectroscopy (Libs) And Laser Ablation Inductively Coupled Plasma Mass Spectrometry (La-Icp-Ms), Sarah C. Jantzi

FIU Electronic Theses and Dissertations

The elemental analysis of soil is useful in forensic and environmental sciences. Methods were developed and optimized for two laser-based multi-element analysis techniques: laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS). This work represents the first use of a 266 nm laser for forensic soil analysis by LIBS.

Sample preparation methods were developed and optimized for a variety of sample types, including pellets for large bulk soil specimens (470 mg) and sediment-laden filters (47 mg), and tape-mounting for small transfer evidence specimens (10 mg). Analytical performance for sediment filter pellets and tape-mounted soils was similar …


Preliminary Summary Of Water Resource Investigations During 2012 At Timpanogos Cave National Monument, Utah, Lee J. Florea, Chelsie R. Dugan, Camille Mckinney Nov 2013

Preliminary Summary Of Water Resource Investigations During 2012 At Timpanogos Cave National Monument, Utah, Lee J. Florea, Chelsie R. Dugan, Camille Mckinney

Lee J Florea, PhD, P.G.

This manuscript considers the hydrology and geochemistry of water resources within Timpanogos Cave National Monument in American Fork, Utah. In particular, data are presented for five cave pools within the Monument and the American Fork River that flows through the Monument. Two independent dye trace attempts in this study have not established a connection between the surface near the canyon rim at the south border of the Monument and the cave pools or the river. Ion chemistry of the pools reveals elevated sulfate concentrations. Analysis of sulfate and other reaction products suggests the possibility of combined carbonic and sulfuric acids …


A Precambrian History Of Cratonic North American Crust Beneath The Snake River Plain, Idaho, Emerald Kirke Shirley Oct 2013

A Precambrian History Of Cratonic North American Crust Beneath The Snake River Plain, Idaho, Emerald Kirke Shirley

Boise State University Theses and Dissertations

Granulite xenoliths erupted in Neogene basalts, and a rare outcrop of Precambrian basement along the northern margin of the Snake River Plain (SRP), can be used as windows into the origin and stabilization of the lower crust of southern Idaho. Previous work to determine the nature of the lower crust beneath the Snake River Plain was conducted on a suite of xenoliths exposed in Southern Idaho at Square Mountain (SM), Craters of the Moon National Monument and Preserve (CRMO), and the Spencer-Kilgore (SK) area (Leeman, 1979; Leeman et al., 1985; Matty, 1984; Wolf et al., 2005), as well as on …


Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas John Ward Oct 2013

Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas John Ward

Dr Nicholas J Ward

This thesis examines sulfide oxidation in 4 physically and mineralogically diverse acid sulfate soil (ASS) materials collected from coastal floodplain sites in north-eastern New South Wales. The aim of this study is to gain further understanding of the process of sulfide oxidation in ASS materials, which will allow improved and more effective management strategies to be applied to these materials. The process of sulfide oxidation was examined using laboratory incubation experiments. The oxidation of pyrite was the primary cause of initial acidification of the ASS materials studied. Although the acid volatile sulfur fraction increased in concentration by an order of …


A Detailed Seabed Signature From Hurricane Sandy Revealed In Bedforms And Scour, Arthur Trembanis, Carter Duval, Jonathan Beaudoin, Val E. Schmidt, Doug Miller, Larry A. Mayer Oct 2013

A Detailed Seabed Signature From Hurricane Sandy Revealed In Bedforms And Scour, Arthur Trembanis, Carter Duval, Jonathan Beaudoin, Val E. Schmidt, Doug Miller, Larry A. Mayer

Center for Coastal and Ocean Mapping

On 30 October 2012, Hurricane Sandy made landfall near Brigantine New Jersey bringing widespread erosion and damage to the coastline. We have obtained a unique set of high-resolution before and after storm measurements of seabed morphology and in situhydrodynamic conditions (waves and currents) capturing the impact of the storm at an inner continental shelf field site known as the “Redbird reef”. Understanding the signature of this storm event is important for identifying the impacts of such events and for understanding the role that such events have in the transport of sediment and marine debris on the inner continental shelf. …


Geogram 2013, David J. Keeling Editor, Wku Department Of Geography And Geology Oct 2013

Geogram 2013, David J. Keeling Editor, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.


The Mechanism And Timescales Of Soil Formation In The Hyper-Arid Atacama Desert, Chile, Fan Wang Oct 2013

The Mechanism And Timescales Of Soil Formation In The Hyper-Arid Atacama Desert, Chile, Fan Wang

Open Access Dissertations

The planetary surfaces that evolve in the near absence of water are strikingly different from surfaces where water is abundant, but their formation is poorly documented. This research is an in-depth exemplary work in the Atacama Desert in northern Chile to understand the soil formation in hyper-arid environments, as an analog for planetary surfaces such as the Mars. In detail, the basic mechanism regarding the source material, timescale, paleo-climatic settings and the role of crypto-biotic crusts have been investigated to constrain the Atacama soil development.

The geochemical, isotopic and mineralogical composition of atmospheric dust deposited along a West-East transect in …


Molecular Characteristics Of The Water Soluable Organic Matter In Size Resolved Aerosols Collected Over The North Atlantic Ocean, Sarah Catherine Gurganus Oct 2013

Molecular Characteristics Of The Water Soluable Organic Matter In Size Resolved Aerosols Collected Over The North Atlantic Ocean, Sarah Catherine Gurganus

Chemistry & Biochemistry Theses & Dissertations

Aerosol particulate matter is acknowledged to have effects on health and the environment and further investigation into the molecular characteristics of aerosols is necessary in order to fully understand the potential links between the molecular characteristics and the impacts that these particles have on health and the environment. Aerosols are often discussed with reference to their size because particles of different sizes can often be associated with different primary sources. This study presents a molecular-level chemical characterization of the water soluble organic matter fraction of 17 aerosol impactor samples representing 3 air mass influences (North American, North African, and marine) …


Unusual Polygenetic Void And Cave Development In Dolomitized Miocene Chalks On Barbados, West Indies, Jonathan B. Sumrall, John E. Mylroie, Hans G. Machel Sep 2013

Unusual Polygenetic Void And Cave Development In Dolomitized Miocene Chalks On Barbados, West Indies, Jonathan B. Sumrall, John E. Mylroie, Hans G. Machel

International Journal of Speleology

Barbados provides an unusual case of polygenetic cave development within dolomitized chalks and marls of the Miocene Oceanics Group. These diagenetic processes are driven by a succession and interplay of tectonic uplift, fracturing, hypogene fluid injection, overprinting by mixing zone diagenesis, and mechanical and biological erosion in the current littoral zone. The significance of the voids and caves within the chalks on Barbados are: 1) these appear to be the first dissolution caves documented in dolomitized chalk, and 2) these features show a polygenetic origin documenting the diagenetic changes in lithology that allowed the development and preservation of these cave …


Origin And Provenance Of Spherules And Magnetic Grains At The Younger Dryas Boundary, Yingzhe Wu, Mukul Sharma, Malcom A. Lecompte, Mark N. Demitroff, Joshua D. Landis Sep 2013

Origin And Provenance Of Spherules And Magnetic Grains At The Younger Dryas Boundary, Yingzhe Wu, Mukul Sharma, Malcom A. Lecompte, Mark N. Demitroff, Joshua D. Landis

Dartmouth Scholarship

One or more bolide impacts are hypothesized to have triggered the Younger Dryas cooling at ∼12.9 ka. In support of this hypothesis, varying peak abundances of magnetic grains with iridium and magnetic microspherules have been reported at the Younger Dryas boundary (YDB). We show that bulk sediment and/or magnetic grains/microspherules collected from the YDB sites in Arizona, Michigan, New Mexico, New Jersey, and Ohio have (187)Os/(188)Os ratios ≥1.0, similar to average upper continental crust (= 1.3), indicating a terrestrial origin of osmium (Os) in these samples. In contrast, bulk sediments from YDB sites in Belgium and Pennsylvania exhibit (187)Os/(188)Os ratios <<1.0 and at face value suggest mixing with extraterrestrial Os with (187)Os/(188)Os of ∼0.13. However, the Os concentration in bulk sample and magnetic grains from Belgium is 2.8 pg/g and 15 pg/g, respectively, much lower than that in average upper continental crust (=31 pg/g), indicating no meteoritic contribution. The YDB site in Pennsylvania is remarkable in yielding 2- to 5-mm diameter spherules containing minerals such as suessite (Fe-Ni silicide) that form at temperatures in excess of 2000 °C. Gross texture, mineralogy, and age of the spherules appear consistent with their formation as ejecta from an impact 12.9 ka ago. The (187)Os/(188)Os ratios of the spherules and their leachates are often low, but Os in these objects is likely terrestrially derived. The rare earth element patterns and Sr and Nd isotopes of the spherules indicate that their source lies in 1.5-Ga Quebecia terrain in the Grenville Province of northeastern North America.


Geochemistry And Inorganic Carbon Transport Of A Glacial Till Drumlin At A Road Salt Facility, Houbao Li Sep 2013

Geochemistry And Inorganic Carbon Transport Of A Glacial Till Drumlin At A Road Salt Facility, Houbao Li

Open Access Dissertations

Investigations were conducted at a salt/premix storage facility lying on top of a glacial drumlin near the coastline in eastern Massachusetts, to characterize salt contaminated groundwater. Groundwater hydrogeochemical variations at different depths were determined based on ten years of monthly or quarterly water quality data from 54 monitoring wells. Groundwater was grouped in three water categories – shallow, middle and deep. Hydrogeochemical characterization indicates that the dominant water types are Na-Cl, Na-Ca-Cl and Ca-HCO3 from the shallow to deep water group. Rock weathering is the dominant hydrogeochemical process for deep water group, whereas salt water percolation and cation exchange control …


Assessing The Reliability Of Stable Isotopes In Fossil Bone: A Unique Case Study Of Prehistoric Lung Pathology., Kathleen Bundy, Samuel D. Matson Aug 2013

Assessing The Reliability Of Stable Isotopes In Fossil Bone: A Unique Case Study Of Prehistoric Lung Pathology., Kathleen Bundy, Samuel D. Matson

Student Research Initiative

Mammals at Ashfall Fossil Beds State Historical Park (NE Nebraska) offer a unique opportunity to test for the preservation of primary isotopic signatures in fossilized materials. At this site, large herbivores such as rhinoceroses, horses and camels are buried in volcanic ash sourced from an eruption of the Bruneau-Jarbridge caldera (Idaho/Nevada) ca. 11.8 million years ago. Most fossils from Ashfall display pathologic bone symptomatic of a lung disease (hypertrophic osteopathy or HPOA) likely related to inhalation of volcanic ash. In this study, we compare the stable oxygen isotopic composition (δ18O) of pathologic bone with that of normal cortical …


Stratigraphic And Geochemical Investigation Of The Mesoproterozoic Atar And El Mreiti Groups, Mauritania: Insights Into Carbon Cycling And Ocean Redox Stratification In A Low Oxygen World, Geoffrey J. Gilleaudeau Aug 2013

Stratigraphic And Geochemical Investigation Of The Mesoproterozoic Atar And El Mreiti Groups, Mauritania: Insights Into Carbon Cycling And Ocean Redox Stratification In A Low Oxygen World, Geoffrey J. Gilleaudeau

Doctoral Dissertations

The protracted oxygenation of Earth’s surface environments played a critical role in biospheric evolution during the Proterozoic eon. Initial oxygenation began ~2.3 Ga during the Great Oxidation Event, yet Earth’s oceans did not become fully oxygenated until at least the end of the Neoproterozoic—coincident with the first appearance of metazoans in the fossil record. Patterns of environmental change and evolutionary innovation are more complex and less certain, however, in the prolonged period between these two oxygenation thresholds. The late Mesoproterozoic (1.3 to 1.0 Ga) was marked by increasing biospheric oxygen—evidenced by increased carbon isotopic variability and an increase in marine …


Genetic Analysis Of Bacterial Gene Variations In Sulfidic Springs And The Influence On Geochemistry, Brendan Joseph Headd Aug 2013

Genetic Analysis Of Bacterial Gene Variations In Sulfidic Springs And The Influence On Geochemistry, Brendan Joseph Headd

Doctoral Dissertations

Culture-independent methods have revolutionized environmental microbiology and geomicrobiology studies and next-generation sequencing and metagenomics techniques continue to reveal the vast genetic diversity of microorganisms. But, these approaches provide comparatively little quantitative information about the roles that naturally occurring microbial gene variations play in local biogeochemical cycling. The goal of this study was to identify how the physical distribution and genetic diversity of microbial genes within a habitat impact environmental geochemistry by examining the biogeography of 16S rRNA genes and bacterial sulfur oxidation (Sox) genes in terrestrial sulfidic springs. 16S rRNA gene pyrosequences were obtained from microbial mats inhabiting eight sulfidic …


Spectroscopic Study Of Uranium (Vi) Reduction By Plant Biomass, Margaret C. Murphy, John Bargar, Noémie Janot Aug 2013

Spectroscopic Study Of Uranium (Vi) Reduction By Plant Biomass, Margaret C. Murphy, John Bargar, Noémie Janot

STAR Program Research Presentations

Uranium is a common and problematic groundwater contaminant at Department of Energy legacy sites. At the former uranium ore processing plant at Rifle, Colorado, sediments rich in decayed plant biomass contain large concentrations of uranium that are slowly being released back to the aquifer. To simulate the reaction that occurs in organic rich sediments of the Rifle aquifer, biomass was incubated in U (VI) bearing groundwater. Carbon X-ray absorption spectroscopy (XAS) was then used to measure if uranium was bound to the biomass. When uranium binds to biomass the peaks in the C XAS spectra will change shape. Uranium L …


Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova Aug 2013

Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova

Boise State University Theses and Dissertations

The continuous Pennsylvanian shallow-marine, paralic, siliciclastic succession in the Donets Basin is pivotal for correlation of marine and continental strata in northern Pangaea with coeval shallow-marine mainly carbonate strata in the Moscow Basin, a historical type area of Moscovian Horizons. The details of the history of establishment, lithostratigraphy and current biostratigraphy of Podolskian and Myachkovian Horizons in the Moscow Basin that are not readily available in Western literature are reviewed.

A model of cyclic recurrence (~0.6 —1myr) of three main fusulinid assemblages in the Pennsylvanian siliciclastic-carbonate succession in the Donets Basin is proposed. A Hemifusulina-association (A) indicates the onset …


Activated Carbon Preconditioning To Reduce Contaminant Leaching In Cement-Based Stabilization Of Soils, Renee Elizabeth Crane Aug 2013

Activated Carbon Preconditioning To Reduce Contaminant Leaching In Cement-Based Stabilization Of Soils, Renee Elizabeth Crane

Masters Theses

Powdered activated carbon (PAC) is often added with cement to enhance the stabilization and solidification (S/S) of materials contaminated with organic compounds. Adsorption of organic contaminants onto PAC can reduce leaching of organic contaminants. Simultaneous addition of PAC and cement reduces soil handling costs, but cement hydration reactions coat PAC with Ca(OH)2 before contaminants can be adsorbed onto PAC. Laboratory studies were done on four aged, contaminated soils from manufactured gas plant sites to compare the performance of S/S treatment with simultaneous addition of PAC and cement vs. cement addition after preconditioning with PAC to enhance contaminant adsorption. Performance was …


Surface Complexation Modeling Of Cr(Vi) Absorption On Mineral Assemblages, Ann M. Gilchrist Aug 2013

Surface Complexation Modeling Of Cr(Vi) Absorption On Mineral Assemblages, Ann M. Gilchrist

Masters Theses

Hexavalent chromium (Cr(VI)) is a waste product of many anthropogenic processes. Because it is highly mobile, the improper disposal of Cr(VI) has caused widespread contamination. Because reduction and adsorption reactions may reduce the bioavailability and mobility of Cr(VI) in environmental systems, a better understanding of Cr(VI) adsorption behavior will improve remediation efforts.

Subsurfaces and soils are heterogeneous, however most studies focus on single sorbate/sorbent interactions to develop surface complexation models (SCM) for prediction of heavy metal adsorption. Theoretically, combining the SCMsdeveloped for single sorbate/sorbent systems should yield accurate predictions of adsorption in more complex systems (i.e., the component additivity approach …


Applying Geochemistry To Investigate The Occurrence Of Riverbank Inducement Into A Shallow Aquifer In Southeastern Wisconsin, Anna Maria Thorp Aug 2013

Applying Geochemistry To Investigate The Occurrence Of Riverbank Inducement Into A Shallow Aquifer In Southeastern Wisconsin, Anna Maria Thorp

Theses and Dissertations

Increased urbanization in southeastern Wisconsin has led to significant drawdown in both the shallow and deep aquifer. In Waukesha County combined radium activity levels exceeding the limit set forth by the USEPA have been detected within the deep aquifer. This has prompted the community to consider alternative, long term, drinking water supply solutions.

One possible solution is riverbank inducement (RBI), in which river water is induced into the adjacent aquifer as recharge. This would make the shallow aquifer an effective addendum to growing water supply demands, and reduce the effects of excessive pumping. Using basic geochemical analyses, this study examines …


Late Holocene Paleoenvironmental Reconstruction In Barbados, Gilman Reno Ouellette Aug 2013

Late Holocene Paleoenvironmental Reconstruction In Barbados, Gilman Reno Ouellette

Masters Theses & Specialist Projects

Barbados is the easternmost island in the Caribbean region, and is uniquely situated between the Atlantic Ocean and Caribbean Sea. Being an isolated island with a karstified aquifer providing the majority of the nation’s water resources, Barbados has found itself in water scarce situations in recent years. In order to better understand natural shifts in groundwater recharge (which is determined by shifts in precipitation), longer records of precipitation are needed than are available from modern measurements. This study presents a paleoclimate reconstruction for the late Holocene on Barbados using stable and radiogenic isotope ratios in speleothem lamina as proxies. In …


Assessment And Conceptualization Of Groundwater Flow In The Edwards Aquifer Through The Knippa Gap In Uvalde County, Texas, Jennifer Raye Adkins Aug 2013

Assessment And Conceptualization Of Groundwater Flow In The Edwards Aquifer Through The Knippa Gap In Uvalde County, Texas, Jennifer Raye Adkins

Graduate Theses and Dissertations

The Edwards aquifer is one of the major regional karst aquifers in the United States, with an average withdrawal of 950 million liters per day (L/d). This investigation focuses on the connection between the Uvalde pool and the San Antonio pool of the Edwards aquifer, known as the Knippa Gap, west of the San Antonio metropolitan area in Uvalde County. This is a major zone of recharge to the Edwards aquifer and is approximately 6.4 km wide. The Knippa Gap is bounded by northeast trending faults of the Balcones Fault Zone (BFZ) on the north (specifically the Cooks and Trio …


Tectonosedimentologic Significance Of The Upper Cretaceous Foreland Basin Siliciclastics: Western Interior, Usa, Nazrul I. Khandaker Aug 2013

Tectonosedimentologic Significance Of The Upper Cretaceous Foreland Basin Siliciclastics: Western Interior, Usa, Nazrul I. Khandaker

Publications and Research

The Upper Cretaceous Frontier Formation exposed along the western margin of the western interior foreland basin is composed of clastic sediments that were deposited during the initial late Cretaceous transgressive-regressive phases of the Western Interior Seaway across Wyoming (Figure 1). Current study is aimed at providing attendees with the best practices associated with tectonic, lithofacies and sedimentologic interpretation of foreland basin sequences and emphasizing the need for utilizing field, structural, geochemical, and compositional data for reconstructing a viable scenario connected with foreland basin sedimentary packages. An attempt will be made to compare documented sedimentological findings with foreland basins located in …


Water Track Modification Of Soil Ecosystems In The Lake Hoare Basin, Taylor Valley, Antarctica, Joseph S. Levy, Andrew G. Fountain, Michael N. Gooseff, John E. Barrett, Robert Vantreese, Kathleen A. Welch, W. Berry Lyons, Uffe N. Nielsen, Diana H. Wall Jul 2013

Water Track Modification Of Soil Ecosystems In The Lake Hoare Basin, Taylor Valley, Antarctica, Joseph S. Levy, Andrew G. Fountain, Michael N. Gooseff, John E. Barrett, Robert Vantreese, Kathleen A. Welch, W. Berry Lyons, Uffe N. Nielsen, Diana H. Wall

Geology Faculty Publications and Presentations

Water tracks are zones of high soil moisture that route shallow groundwater down-slope, through the active layer and above the ice table. A water track in Taylor Valley, McMurdo Dry Valleys, was analysed for surface hydrogeological, geochemical, and biological characteristics in order to test the hypothesis that water tracks provide spatial structure to Antarctic soil ecosystems by changing the physical conditions in the soil environment within the water tracks from those outside the water tracks. The presence of the water track significantly affected the distribution of biotic and abiotic ecosystem parameters: increasing soil moisture, soil salinity, and soil organic matter …