Geochemistry Commons^™

Magnesium Isotopic Compositions Of The Moon And Achondrites: Implications For Their Origin And Evolution, Fatemeh Sedaghatpour

Graduate Theses and Dissertations

The main objectives of this thesis are to estimate Mg isotopic compositions of the Moon and achondrites, to understand the behavior of Mg isotopes during magmatic differentiation processes in different planetary bodies, and to evaluate the extent of Mg isotopic heterogeneity in the solar system. In order to achieve these goals, Mg isotopes have been measured for 47 well-characterized lunar samples and 22 differentiated meteorites by MC-ICPMS. The limited Mg isotopic variations among mare and highland regolith, mare breccias, and highland impact-melt rocks reflect negligible Mg isotope fractionation during lunar surface processes (e.g. solar wind, cosmic rays, micrometeorite bombardments, meteorite …

Dissolution Rates Of Amorphous Al- And Fe-Phosphates And Their Relevance To Phosphate Mobility On Mars, Valerie Tu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Phosphate is an essential element for life on Earth, and therefore if life exists or ever existed on Mars it may have required phosphate. Amorphous Al- and Fe-phosphates rapidly precipitate from acidic solutions and amorphous Al-phosphates likely control phosphate concentrations in some natural waters on Earth. Amorphous phases may be even more important on Mars than on Earth, and amorphous phosphates are therefore likely important in the phosphate cycle on Mars. Despite this importance, however, few dissolution rates exist for amorphous Al- and Fe- phosphates. In this study, dissolution rates of amorphous Al- and Fe-phosphates were measured in flow-through reactors …

Paleoecology Of Nebraska’S Ungulates During The Eocene–Oligocene Climate Transition, Grant S. Boardman

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

The White River Group (WRG) preserves the Eocene-Oligocene climate transition (EOCT), an interval of global cooling and drying during the onset of Antarctic glaciation. In the Great Plains, a shift from forested conditions to drier woodland-savanna biomes is hypothesized to have occurred at this time. I test this hypothesis through the analyses of several paleoenvironmental proxies on the teeth of 12 WRG ungulate species: stable carbon and oxygen isotopes from tooth enamel, and mesowear and microwear texture. The EOCT shift toward more open habitats and lower vegetation density under drying climates should have resulted in an increase in mean carbon …

Adsorption Of Hexavalent Chromium On Hydrous Manganese Oxide, Andrew K. Macleod

Masters Theses

Hexavalent chromium is a very common contaminant most often associated with industrial processes, it is quite mobile in the subsurface and a better understanding of its mobility and interactions with soil constituents will help ongoing remediation efforts.

Hydrous manganese oxides (HMO) are a very common soil constituent and thus would be likely to interact with Cr(VI) in contaminated shallow subsurface environments. The goal of this study is to develop a working model that can improve predictions of Cr(VI) mobility in natural systems. A diffuse double layer surface complexation model (DLM) was developed by deriving reaction stoichiometries and stability constants for …

Epistemology And Synthesis: Instrumental Neutron Activation Analysis And The Caddo Tradition, Robert Z. Selden Jr.

CRHR: Archaeology

The statistical groupings illustrated herein represent the current iteration of Caddo INAA compositional groups based upon the chemical composition of archaeologically-recovered ceramics. For some time, a number of Caddo archaeologists have thought these results to be lacking. This poster symbolizes the first step toward a new interpretation of chemical composition groups, and the initial instancce within which GIS has been employed as an analytical tool.

Consilience: Radiocarbon, Instrumental Neutron Activation Analysis, And Litigation In The Ancestral Caddo Region, Robert Z. Selden Jr.

CRHR: Archaeology

Through the creation and analysis of databases for radiocarbon, instrumental neutron activation analysis (INAA), and law, macro-level trends are exposed that form the framework of a broader research program aimed at advancing ideas of craft specialization and archaeological theory in the ancestral Caddo region of Southwest Arkansas, Northwest Louisiana, Northeast Texas, and Southeast Oklahoma. The findings of this investigation illustrate the research potential that remains buried within the context of cultural resource management (CRM) reports and legal databases (Westlaw and LexisNexis) that is awaiting consumption within regional research designs aimed at exploring the nuances and trends that appear through synthetic …

Stable Isotope Record Of Archean And Cambrian Serpentinizing Fluid Composition From Stichtite (Mg-Cr Carbonate Hydroxide), Amanda Lopez

Theses Digitization Project

This study will focus on stichtite from two locations that contain the most abundant deposits of stichtite. The first location in Tasmania, Australia includes the Stichtite Hill locality (the type locality for stichtite) and the Tunnel Hill locality. The second location is at the New Amianthus Mine, Barberton District, South Africa. The broad geographical distribution of stichtite in deposits ranging from the Archean tho the early Cambrian, provides a window into the history and chemistry of serpentinizing environments on Earth through time.

Assessment Of Coal Geology, Resources, And Reserve Base In The Powder River Basin, Wyoming And Montana, James A. Luppens, David C. Scott, Lee M. Osmonson, Jon E. Haacke, Paul E. Pierce

United States Geological Survey: Publications

Using a geology-based assessment methodology, the U.S. Geological Survey estimated in-place resources of 1.07 trillion short tons of coal in the Powder River Basin, Wyoming and Montana. Of that total, with a maximum stripping ratio of 10:1, recoverable coal was 162 billion tons. The estimate of economically recoverable resources was 25 billion tons.

Five Year Carbon Storage Analysis In The Gordon Natural Area, Joy Fritschle, Chad Hudson, Catherine Spahr, Andy Tamez

Forest Carbon Storage Study Documents

The Gordon Natural Area (GNA) serves as a natural laboratory for a range of class research projects. In a Geography Field Methods course led by Dr. Fritschle, students established five permanent carbon-study plots in 2008. Since then, students have returned to these plots to measure the carbon stock of standing trees in five plots located along a topographic gradient: floodplain, ridge-top, lower mid-slope, mid-slope and upper mid-slope. Using U.S. Forest Service established guidelines, all trees greater than 5 cm and up to 73 cm in diameter at breast height (DBH) were measured and identified within each 40 m circular plot. …

Oil Pollution In Water Bodies Of Restricted Circulation, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Coastal lagoons and embayments near urban centers around the world share many common characteristics and problems. Physical impediments to free water circulation (spits, barrier islands, internal islands, tombolos, submerged sills) often lead to water stagnation and, in the presence of excess nutrients, eutrophication. Urban and industrial activities provoke (usually accidental) spills of hazardous materials into these confined water bodies, such as crude petroleum and refined petroleum products, leading to difficulties for resident biota and potential hazards for human health. The sluggish turnover of these water bodies (or low-energy zones within them) may retard the natural attenuation of the spilled contaminants. …

Chemostratigraphy Of The Early Pliocene Diatomite Interval From Mis And-1b Core (Antarctica): Paleoenvironment Implications, Giovanna Scopelliti, Adriana Bellanca, Donata Monien, Gerhard Kuhn

ANDRILL Research and Publications

The AND-1B drill core (1285 m-long) was recovered, inside the ANDRILL (ANtarctic geological DRILLing) Program, during the austral summer of 2006/07 from beneath the floating McMurdo Ice Shelf. Drilling recovered a stratigraphic succession of alternating diamictites, diatomites and volcaniclastic sediments spanning about the last 14 Ma. A core portion between 350 and 480 mbsf, including a 80 m-thick diatomite interval recording the early Pliocene warming event, was investigated in term of opal biogenic content and element geochemistry. Across the diatomite interval, in spite of the lithological uniformity, a fluctuating biogenic opal profile mirrors the δ18O record, testifying a decrease in …

Geo402/585: Field Methods; Labs 4-5 Gordon Natural Area Carbon Stock Pilot Study, Joy Fritschle

Gordon Natural Area-related Curricula Documents

No abstract provided.

Water Column Variability In A Coastal Tourist Cave In Mallorca, Spain, Liana M. Boop, Bogdan P. Onac, Jonathan G. Wynn, Joan J. Fornós, Marta Rodríguez-Homar

National Cave and Karst Management Symposium 2013

Coves del Drac is visited by more than 1 million tourists annually and has been a tourist destination in the western Mediterranean for over 100 years. All areas of the cave are developed with historic or current tour route infrastructure, including walkways, handrails, and electric lighting. This study compares one vertical water profile collected along the current tour path with two other profiles from historic tour route locations. Differences in freshwater and organic inputs, as well as direct anthropogenic impacts, are clearly observed in the aquatic parameters and stable isotopes collected in the profiles. Anthropogenically-driven undersaturation in the cave pools, …

Modeling Of Co2-Water-Rock Interactions In A Mississippian Sandstone Reservoir Of Kentucky, Anne M. Schumacher

Theses and Dissertations--Earth and Environmental Sciences

This study examined CO₂-water-rock interactions occurring during a carbon sequestration pilot test into a Mississippian oil reservoir in western Kentucky. New samples (n=62) and archived data, both collected from oil wells, were used to characterize the chemistry of formation waters from the Sugar Creek field in Hopkins County. In addition, core and cuttings samples (n=17) from the reservoir and overlying cap-rocks in, or near, the field were analyzed for bulk and clay mineralogy using X-ray diffraction. Electric logs were used to select sample intervals within the overlying cap-rocks and the center of the producing zones in the Jackson …

Effects Of Chiloquin Dam On Spawning Distribution And Larval Emigration Of Lost River, Shortnose, And Klamath Largescale Suckers In The Williamson And Sprague Rivers, Oregon, Barbara A. Martin, David A. Hewitt, Craig M. Ellsworth

United States Geological Survey: Publications

Chiloquin Dam was constructed in 1914 on the Sprague River near the town of Chiloquin, Oregon. The dam was identified as a barrier that potentially inhibited or prevented the upstream spawning migrations and other movements of endangered Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers, as well as other fish species. In 2002, the Bureau of Reclamation led a working group that examined several alternatives to improve fish passage at Chiloquin Dam. Ultimately it was decided that dam removal was the best alternative and the dam was removed in the summer of 2008. The U.S. …

The Mineral Industry Of Nebraska

United States Geological Survey: Publications

In 2013, the value of the nonfuel mineral production1 in the State of Nebraska was $166 million,2 0.2% of the total U.S. nonfuel mineral production, ranking it 39th in the country. In 2012, the corresponding value was $160 million,2 0.2% of the Nation’s total nonfuel mineral production, ranking it 36th among the 50 States. In 2013, on a per capita basis, nonfuel mineral production in Nebraska in 2013 had a value of $89 compared with the national average of $238. In 2012, the per capita value was $86 compared with the national average of $241. The value of nonfuel mineral …

Lithogeochemical And Stable Isotope Characteristics Of Bristol And Northern Thorneloe Townships And Its Correlation With Gold Mineralization, Zachary Grant Stevison

Wayne State University Theses

The Porcupine Mining Camp located in the southwestend of the Abitibi Greenstone Belt has been mined extensively for its prolific precious and base metal enrichment. This study targeted Bristol and Northern Thorneloe, fifteen kilometers southwest of Timmins, ON, an area that is of economic interest for its gold mineralization. Rock samples were collected (drill- core and outcrop) throughout both townships and analyzed for their major and trace element composition, These were used to determine hydrothermal alteration signatures as well as specific elemental enrichment that relate to gold mineralization in Bristol-Thorneloe Township. Quartz-carbonate and quartz-carbonate-tourmaline vein samples were also collected near …

The Relative Contribution Of Methanotrophs To Microbial Communities And Carbon Cycling In Soil Overlying A Coal-Bed Methane Seep, Christopher T. Mills, Gregpry F. Slater, Robert F. Dias, Stephanie A. Carr, Christopher M. Reddy, Raleigh Schmidt, Kevin W. Mandernack

Chemistry & Biochemistry Faculty Publications

Seepage of coal-bed methane (CBM) through soils is a potential source of atmospheric CH₄ and also a likely source of ancient (i.e. ¹⁴C-dead) carbon to soil microbial communities. Natural abundance ¹³C and ¹⁴C compositions of bacterial membrane phospholipid fatty acids (PLFAs) and soil gas CO₂ and CH₄ were used to assess the incorporation of CBM-derived carbon into methanotrophs and other members of the soil microbial community. Concentrations of type I and type II methanotroph PLFA biomarkers (16:1ω8c and 18:1ω8c, respectively) were elevated in CBM-impacted soils compared with a control site. Comparison …

Distribution And Impacts Of Petroleum Hydrocarbons In Louisiana Tidal Marsh Sediments Following The Deepwater Horizon Oil Spill, Rachel S. Hatch

Theses and Dissertations--Earth and Environmental Sciences

Following the 2010 Deepwater Horizon (DWH) spill, sediment cores were analyzed from marshes at various levels of oiling to determine how deeply oil penetrated sediment in these marsh environments, and if at these sites it had quantifiably affected benthic ecosystems. Minimum mixing depths were determined from penetration of the lithogenic radionuclide ²³⁴Th, which ranged from 0.25 to 4.5 cm. Sediment accumulation rates were determined using ²¹⁰Pb, with verification from ¹³⁷Cs in selected cores. Lead-210 profiles revealed long-term (decadal) mixing. Bay Jimmy, Louisiana was significantly affected by the DWH oil spill, as indicated by total polycyclic aromatic hydrocarbon …

Modeling Potential Chemical Environments: Implications For Astrobiology, Brian Craig Szenay

USF Tampa Graduate Theses and Dissertations

Modeling chemical environments is an important step to understanding the diversity of prebiotic systems that may have formed on the early earth or potentially can occur on other worlds. By using the modern Earth as a test case, these models predict scenarios with systems more conducive to the formation of the organic molecules that are important to life. Here we use the equilibrium thermodynamic modeling program HSC Chem to investigate prebiotic environments. This program uses the raw material that the user inputs into the system in order to calculate the change in amounts of chemical species forming as a function …