Geochemistry Commons^™

Contact Zone Mineralogy And Geochemistry Of The Mt. Mica Pegmatite, Oxford County, Maine, Kimberly T. Clark

LSU New Orleans Theses and Dissertations

This study focuses on exocontact mineral assemblages to determine composition, thermal signatures, and the extent of exomorphism that occurred between the Mt. Mica pegmatite and the migmatite host rock at the contact. Biotite-garnet thermometry of country rock samples resulted in an average temperature estimate of 630 °C. Measured biotite Fe/(Fe+Mg) ratios were used to calculate an fO2 of -18. The results indicate that the country rock and pegmatite formed under similar oxidizing conditions near the quartz-fayalite-magnetite (QFM) equilibria buffer. Whole rock (REE) analysis indicates an interaction trend between the country rock and pegmatite. Exomorphism does not appear to have …

Geochemistry, Mineralogy And Evolution Of Mica And Feldspar From Within The Mount Mica Pegmatite, Maine, Usa, Karen L. Marchal

LSU New Orleans Theses and Dissertations

Mount Mica is a poorly zoned sodic LCT-type pegmatite consisting dominantly of quartz, albite and muscovite in the outer portions. Potassium feldspar and lepidolite are restricted to the core zone. Micas in the wall zone are chemically homogeneous, but abruptly evolve into higher Cs + Rb bearing lithian muscovites and lepidolites in the core zone. The abrupt increase of the Cs, Rb in K-feldspar, and Cs, Rb and F in muscovite, and lepidolite combined with the occurrence of highly evolved species lepidolite, pollucite, elbaite, beryl and spodumene in the core zone suggests that incompatible elements were retained in residual …

Mineralogy And Geochemistry Of The Erongo Granite And Interior Quartz-Tourmaline Orbicules And Nyf-Type Miarolitic Pegmatites, Namibia, Andrew P. Boudreaux

LSU New Orleans Theses and Dissertations

The early Cretaceous anorogenic Erongo Granite of Namibia is known to host abundant boron mineralization in rounded, quartz-tourmaline clusters and in NYF-type miarolitic, pegmatitic cavities. Rock and mineral samples were taken from the bulk granite, tourmaline nests, and miarolitic cavities and analyzed using a variety of modern analytical techniques. Geochemical and mineralogical data suggest substantial input from the metasedimentary rocks of the Damara orogen was important in the genesis of the Erongo Granite magma. The geochemical signature of the Damara orogen is most evident in the tourmaline clusters and miarolitic cavities, where fractional crystallization accumulated volatile and incompatible elements enough …

Impacts Of Carbonate Mineral Weathering On Hydrochemistry Of The Upper Green River Basin, Kentucky, Laura Leigh Osterhoudt

Masters Theses & Specialist Projects

Kentucky’s Upper Green River Basin has received significant attention due to the area’s high biodiversity and spectacular karst development. While carbonate bedrock is present throughout the watershed, it is more extensive and homogenous along the river between Greensburg and Munfordville than upstream from Greensburg where the geology is more heterogeneous. This research quantitatively evaluated how lithological differences between the two catchment areas impact hydrochemistry and inorganic carbon cycling. This first required correcting catchment boundaries on previous US Geological Survey Hydrologic Unit Maps to account for areas where the boundaries cross sinkhole plains. Basin boundaries using existing Kentucky Division of Water …

Geologic Factors Affecting Hydrocarbon Occurrence In Paleovalleys Of The Mississippian-Pennsylvanian Unconformity In The Illinois Basin, Jeremy Taylor London

Masters Theses & Specialist Projects

Paleovalleys associated with the Mississippian-Pennsylvanian unconformity have been identified as potential targets for hydrocarbon exploration in the Illinois Basin. Though there is little literature addressing the geologic factors controlling hydrocarbon accumulation in sub-Pennsylvanian paleovalleys basin-wide, much work has been done to identify the Mississippian-Pennsylvanian unconformity, characterize the Chesterian and basal Pennsylvanian lithology, map the sub-Pennsylvanian paleogeology and delineate the pre-Pennsylvanian paleovalleys in the Illinois Basin. This study uses Geographic Information Systems (GIS) to determine the geologic factors controlling the distribution of hydrocarbon-bearing sub-Pennsylvanian paleovalley fill in the Illinois Basin. A methodology was developed to identify densely-drilled areas without associated petroleum …

Investigating Telogenetic Karst Aquifer Processes And Evolution In South-Central Kentucky, U.S., Using High-Resolution Storm Hydrology And Geochemistry Monitoring, Nicholas Lawhon

Masters Theses & Specialist Projects

Recent studies have investigated the hydrological and geochemical characteristics of karst aquifers in different settings; however, telogenetic karst aquifer processes remain poorly understood. In south-central Kentucky, the iconic Lost River Cave and Valley represents a large, complex telogenetic karst drainage basin with a series of discharge points along a collapsed section of the cave. Two Campbell Scientific® CR1000 automated dataloggers were installed at Blue Hole Four, a primary discharge point of the Lost River Karst Aquifer (LRKA). These dataloggers recorded spring discharge, water temperature, specific conductance (SpC), and pH at ten-minute intervals from January to November, 2013. During the year, …

Pore Water Extraction For Unsaturated Zone Isotope Research: An Investigation Using An Immiscible Displacement Fluid And A Centrifuge, Caitlin Burnett Weaver

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

Accurate and reliable pore water extraction techniques are important to an array of scientific fields including, but not limited to, hydrogeology, soil science, and paleoenvironmental research. The aim of the current project is to test the applicability of an immiscible displacement extraction technique for stable isotopes of water under a range of textural, hydrologic, and chemical conditions. In this study, laboratory experiments were conducted to establish the extent to which the proposed method 1) achieves sufficient yield for laboratory isotopic analyses, 2) results in isotopic exchange between water and the displacement fluid, 3) conserves initial isotopic compositions of spike test …

The Effect Of Single Crystal Elastic And Plastic Anisotropy On Stress And Strain Heterogeneity: Comparison Of Olivine To Other Common Minerals, Christopher Joseph Cline Ii

UNLV Theses, Dissertations, Professional Papers, and Capstones

In order to investigate the influence of single crystal elastic anisotropy on the heterogeneity of stress distributions during polycrystalline deformation multiple deformed crystalline materials were analyzed using electron backscatter diffraction (EBSD). Deformation experiments were conducted on samples of Solnhofen limestone using a modified Griggs piston cylinder apparatus at UNLV, and also on San Carlos olivine using the D-DIA multi-anvil press at the National Synchrotron Light Source beamline X17B2. Analysis of the mechanical twins in deformed calcite and kink bands in olivine help elucidate deviations in local stress directions away from that of the applied macroscopic stress. Combined calculated compression directions …

Modern To Late Pleistocene Stable Isotope Climatology Of Alaska, Alison Sloat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Understanding modern controls on climate is necessary to interpret past climatic conditions. This project investigated the modern controls on δ18O and δD values in Alaskan surface waters to interpret the controls on Late Pleistocene climate variability. ArcGIS was used to develop an isoscape of modern δ18O and δD values of over 400 surface water samples collected across Alaska and the Yukon. It was found that winter temperature and precipitation have the greatest controls on δ18O and δD values in Alaska, resulting in high δ18O values along the coast of the Gulf of Alaska and low values inland toward Central Alaska. …

Linking Mineral Deposits To Speleogenetic Processes In Cova Des Pas De Vallgornera (Mallorca, Spain), Bogdan P. Onac, Joan J. Fornós, Antoni Merino, Joaquín Ginés, Jacqueline Diehl

International Journal of Speleology

Cova des Pas de Vallgornera (CPV) is the premier cave of the Balearic Archipelago. Over 74 km of passages develop within two carbonate lithofacies (reef front and back reef), which ultimately control the patterns of the cave and to some degree its mineral infilling. The diversity of speleothem-forming minerals is four times greater around or within hypogene-related features (vents, rims, cupolas), compared to any other vadose passages in the cave. The mineralogy of speleothems (crusts, nodules, crystals, earthy masses) associated with hypogene features in the seaward upper maze of Sector F is characterized by the presence of aragonite, ankerite, huntite, …

Groundwater Geochemistry Observations In Littoral Caves Of Mallorca (Western Mediterranean): Implications For Deposition Of Phreatic Overgrowths On Speleothems, Liana M. Boop, Bogdan P. Onac, Jonathan G. Wynn, Joan J. Fornós, Marta Rodríguez-Homar, Antoni Merino

International Journal of Speleology

Phreatic overgrowths on speleothems (POS) precipitate at the air-water interface in the littoral caves of Mallorca, Spain. Mainly composed of calcite, aragonite POS are also observed in specific locations. To characterize the geochemical environment of the brackish upper water column, water samples and salinity values were collected from water profiles (0-2.9 m) in April 2012 and March 2013 near aragonite POS in Cova des Pas de Vallgornera and calcite POS in Coves del Drac (hereafter, Vallgornera and Drac). Degassing of CO₂ from the water was evidenced by the existence of lower dissolved inorganic carbon (DIC) concentration and enriched δ …

Response Of Benthic Foraminifera To Ocean Acidification And Impact On Florida's Carbonate Sediment Production, Paul O. Knorr

USF Tampa Graduate Theses and Dissertations

Increasing concentrations of atmospheric CO2 are in dynamic equilibrium with the oceans. The absorption of CO2 by seawater causes a decrease in seawater pH and calcite saturation state (SS). This process, termed ocean acidification, exerts deleterious effects on marine calcifiers. Studies of symbiont-bearing large benthic foraminifera (LBF) have reported a generally unfavorable response to increased concentrations of carbon dioxide ([CO2]).

Experiments and analyses were undertaken to examine the effect of increased [CO2] on the growth rate, ultrastructure, stable isotopes of carbon and oxygen, as well as Mg/Ca of the high-Mg miliolid Archaias angulatus and the low-Mg rotalid Amphistegina gibbosa. A …

Are You Getting What You Paid For? A Case Study In Forensic Geochemistry, Abdelmawgoud Mohammed, R. V . Krishnamurthy

Research and Creative Activities Poster Day

Introduction

Isotopes are atoms of the same element that differ in atomic mass due to different number of neutrons in the nucleus. Some isotopes are stable isotopes and others are unstable, or radioactive, isotopes. Stable isotopes maintain constant concentrations in the environment over time. Unstable isotopes continue to decay into daughter elements. Stable isotopes of oxygen, hydrogen, carbon, sulfur, and nitrogen are the most commonly used in environmental and ecological research.

Forensic geochemistry is a relatively new discipline that uses chemical and isotopic markers to solve problems of forensic interest. These include fingerprinting oil spills, food adulteration and forgery in …

Growth And Nitrogen Uptake Kinetics In Cultured Procentrum Donghaiense, Zhangxi Hu, Shunshan Duan, Margaret R. Mulholland

OES Faculty Publications

We compared growth kinetics of Prorocentrum donghaiense cultures on different nitrogen (N) compounds including nitrate, ammonium urea, glutamic acid, dialanine, and cynate. P. donghaiense exhibited standard Monod-type growth kinetics over a range of nitrogen concentrations for all N. Compounds tested. Cultures grown on glu and urea had the highest maximum growth rates. However, cultures grown on cyanate had lower half saturation constants. Nitrogen uptake kinetics were measured in nitrate-deplete and replete batch cultures of P. donghaiense. In nitrate-deplete batch cultures, P. donghaiense exhibited Michaelis-Menten type uptake kinetics for nitrate, ammonium, urea and algal amino acids; uptake was saturated at …

Cosmogenic Beryllium Cycling In A Natural Forest Setting, Grace Conyers

Open Access Theses

10 Bemet , or cosmogenic beryllium, has a long half-life of 1.4 million years and quick adsorption on soil particles, which may make it ideal for dating soil erosion in historical context. However, there are questions on about the fundamental assumptions of the retentivity of 10 Bemet . This manuscript explores these assumptions and the context of nutrient cycling in a natural forest setting.

To see if 10 Bemet was being cycled through the trees, and at what rate, we looked at the[10 Bemet ] in the soil, 4 species of trees, and their leaves. The isotopic ratio 10 Be/9 …

Connecting Aerial Gamma Ray Surveys And Geochemical Data, Kara Marsac, Pamela Burnley, Elisabeth Hausrath, Russell Malchow, Daniel Haber

NSTec UNLV Symposium

• Radiation in the Environment
• Aerial Gamma Ray Surveys
• Radiation and Geology
• Collecting Existing Geochemical Data
• Rock Unit Geochemistry
• Model Creation and Comparison

Predictive Modeling Of Radiological Background Using Geochemistry, Daniel Haber, Pamela C. Burnley, Kara Marsac, Russell Malchow, Elisabeth Hausrath, Christopher Adcock

NSTec UNLV Symposium

• Introduction & Background
• Methods
• Models
• Results and Discussion
• Future Work

Slides: Thoughts On Regulatory Mechanisms For Natural Resource Development: Alternatives To Command And Control, Including A Look At Open Source Approaches, Stanley Dempsey

Natural Resource Industries and the Sustainability Challenge (Martz Winter Symposium, February 27-28)

Presenter: Stanley Dempsey, Chairman, Royal Gold

17 slides

Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker

School of Natural Resources: Faculty Publications

The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale eddy covariance flux observations from towers to the continental scale by integrating flux observations, meteorology, stand age,aboveground biomass, and a proxy for canopy nitrogen concentrations from AmeriFlux and Fluxnet-Canada Research Network as well as a variety of satellite data streams from the MODIS sensors. …

Linking Instrumental Neutron Activation Analysis (Inaa) With Geology In The Ancestral Caddo Region, Robert Z. Selden Jr.

CRHR: Archaeology

This poster illustrates the success of a novel method of INAA that was employed to reveal geochemical signatures in Caddo ceramic vessel sherds that correlate with local surficial geology. The geochemical data from the sherd assemblage were used within an exploration of potential ceramic provenance, which was successful at demarcating sherds from ceramic vessels made from clays in either the Claiborne or Wilcox Groups. Further geochemical segregation was also apparent between the Recklaw Formation in the Claiborne Group, and the Weches Formation in the Wilcox Group. These results point to a high degree of geochemical variability within the East Texas …

At The Confluence Of Gis And Geochemistry: Identifying Geochemical Correlates Of Ripley Engraved Caddo Ceramics, Robert Z. Selden Jr., Timothy K. Perttula

CRHR: Archaeology

In this poster, we discuss a new approach to the identification and definition of spatial trends in archeologically-recovered ceramics associated with geochemical results produced using instrumental neutron activation analysis (INAA). Using all of the Ripley Engraved INAA samples, we posit that clays in the Claiborne and Wilcox Groups can be successfully demarcated by sodium (Na), cerium (Ce), and zinc (Zn). Using a subset of those data from the Big Cypress Creek basin, we find that ceramics manufactured in three different Caddo political communities can be successfully demarcated based upon differential concentrations of arsenic (As), iron (Fe), and vanadium (V) found …

Interpreting The Paleozoogeography And Sea Level History Of Thermally Anomalous Marine Terrace Faunas: A Case Study From The Last Interglacial Complex Of San Clemente Island, California, Daniel R. Muhs, Lindsey T. Groves, R. Randall Schumann

United States Geological Survey: Publications

Marine invertebrate faunas with mixtures of extralimital southern and extralimital northern faunal elements, called thermally anomalous faunas, have been recognized for more than a century in the Quaternary marine terrace record of the Pacific Coast of North America. Although many mechanisms have been proposed to explain this phenomenon, no single explanation seems to be applicable to all localities where thermally anomalous faunas have been observed. Here, we describe one such thermally anomalous fossil fauna that was studied on the second emergent marine terrace at Eel Point on San Clemente Island. The Eel Point terrace complex is a composite feature, consisting …

Identifying Sources Of Aeolian Mineral Dust: Present And Past, Daniel R. Muhs, Joseph M. Prospero, Matthew C. Baddock, Thomas E. Gill

United States Geological Survey: Publications

Aeolian mineral dust is an important component of the Earth’s environmental systems, playing roles in the planetary radiation balance, as a source of fertilizer for biota in both terrestrial and marine realms and as an archive for understanding atmospheric circulation and paleoclimate in the geologic past. Crucial to understanding all of these roles of dust is the identification of dust sources. Here we review the methods used to identify dust sources active at present and in the past. Contemporary dust sources, produced by both glaciogenic and non-glaciogenic processes, can be readily identified by the use of Earth-orbiting satellites. These data …

Molecular Characterization And Photochemical Transformation Of Dissolved Organic Matter From Land To Ocean, Hongmei Chen

Chemistry & Biochemistry Theses & Dissertations

Molecular characterization and photochemical transformation of dissolved organic matter (DOM) in both rivers and the ocean is the main research focus of this dissertation. Chemical characterization of DOM is hampered by the limited application of advanced techniques to desalt, concentrate, isolate and then molecularly characterize DOM. An affordable, commercially available mini-electrodialysis (mini-ED) system has been evaluated and recommended for the efficient desalting of small volume samples of seawater prior to analysis by electrospray Fourier transform ion cyclotron resonance mass spectrometry (ESI FTICR-MS).

A high-recovery technique of DOM isolation – reverse osmosis coupled with electrodialysis (RO/ED) – was used to isolate …

Spectroscopic Characterization Of Dissolved Organic Matter: Insights Into The Linkage Between Sources And Chemical Composition, Xiaoyan Cao

Chemistry & Biochemistry Theses & Dissertations

This dissertation investigated the chemical structure of DOM by advanced solid-state nuclear magnetic resonance (NMR) spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) techniques, as well as isotopic measurements and UV-visible spectroscopy, to shed light on the linkages between DOM sources and DOM composition. Unique and extensive sets of DOM samples studied here were isolated from various aquatic systems, covering end-member environments in which DOM is considered either microbially derived or terrestrially derived, and areas in which DOM has characteristics intermediate between the two end members. Important insights into specific site-related questions were also gained such as …

Temporal And Spatial Characterization Of Macondo 252 Signatures In Gulf Of Mexico Shelf And Slope Sediments, Olivia P. Woodruff

Theses and Dissertations--Earth and Environmental Sciences

The long-term fate of hydrocarbons in the Gulf of Mexico (GOMx) following the 2010 Deepwater Horizon oil spill has yet to be fully characterized. Elemental (% C and % N), stable isotopes (δ¹³C_organic), and polycyclic aromatic hydrocarbon (PAH) molecular signatures were investigated in shelf and slope sediments collected in October 2010 and 2011 to gain insight into processes affecting the distribution and fate of spilled Macondo oil. Particulate organic carbon (POC) ranged between 1.55 and 2.22 wt. % in 2010 and 0.55 and 2.06 % in 2011 while the corresponding δ¹³C_organic ranges were …

Geochemical Studies Of Backfill Aggregates, Lake Sediment Cores And The Hueco Bolson Aquifer, Anita Thapalia

Open Access Theses & Dissertations

This Dissertation comprises of three different researches that focuses on the application of geochemistry from aggregates, lake sediment cores and Hueco Bolson Aquifer. Each study is independent and presented in the publication format. The first chapter is already published and the second chapter is in revision phase. Overall, three studies measure the large scale (field) as well as bench scale (lab) water-rock interactions influenced by the climatic and anthropogenic factors spans from the field of environmental geology to civil engineering.

The first chapter of this Dissertation addresses the chemical evaluation of coarse aggregates from six different quarries in Texas. The …

Zn(Ii) And Cu(Ii) Adsorption And Retention Onto Iron Oxyhydroxide Nanoparticles: Effects Of Particle Aggregation And Salinity, Rebecca B. Chesne, Christopher S. Kim

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Iron oxyhydroxides are commonly found in natural aqueous systems as nanoscale particles, where they can act as effective sorbents for dissolved metals due to their natural surface reactivity, small size and high surface area. These properties make nanoscale iron oxyhydroxides a relevant option for the remediation of water supplies contaminated with dissolved metals. However, natural geochemical processes, such as changes in ionic strength, pH, and temperature, can cause these particles to aggregate, thus affecting their sorption capabilities and remediation potential. Other environmental parameters such as increasing salinity may also impact metal retention, e. g. when particles are transported …

A Coupled Geochemical And Biogeochemical Approach To Characterize The Bioreactivity Of Dissolved Organic Matter From A Headwater Stream, Rachel L. Sleighter, Rose M. Cory, Louis A. Kaplan, Hussain A.N. Abdulla, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The bioreactivity or susceptibility of dissolved organic matter (DOM) to microbial degradation in streams and rivers is of critical importance to global change studies, but a comprehensive understanding of DOM bioreactivity has been elusive due, in part, to the stunningly diverse assemblages of organic molecules within DOM. We approach this problem by employing a range of techniques to characterize DOM as it flows through biofilm reactors: dissolved organic carbon (DOC) concentrations, excitation emission matrix spectroscopy (EEMs), and ultrahigh resolution mass spectrometry. The EEMs and mass spectral data were analyzed using a combination of multivariate statistical approaches. We found that 45% …

Exploring The Hydrogeologic Controls On Brackish Water And Its Suitability For Use In Hydraulic Fracturing: The Dockum Aquifer, Midland Basin Texas, Francisco Ruben Reyes

Open Access Theses & Dissertations

Water scarcity in arid regions can limit or impede certain hydrocarbon production activities, such as hydraulic fracturing and well drilling. The Midland Basin, a major oil-producing area in semi-arid far west Texas and the eastern sub-basin of the Permian Basin, is already impacted by limited freshwater availability. A typical tight oil well in the Midland Basin requires ~3.8-11.4 x 103 m3 of water per fracture treatment (Nicot et al., 2012). Despite draught conditions and limited resources, data for 2011 indicate freshwater comprises ~70% of the water used in hydraulic fracturing in the Midland basin. Thus, the Midland Basin represents an …