Geochemistry Commons^™

Stable Isotope Geochemistry Of Bioapatite, Amanda E. Drewicz

Boise State University Theses and Dissertations

The Cenozoic Era was a time period where dynamic shifts in climate created for both warm-wet greenhouse environments of the mid-Miocene Climatic Optimum (MMCO), and cool-dry, glacial periods of the late Pleistocene. The Cenozoic is close to our own time period, and although past climate reconstructions cannot be used as direct analogs for future climate change, understanding previous environmental responses can help inform policy surrounding future climate change. Presented here are climate reconstructions of the interior western United States, from two different geologic time periods. Each had a different climate, that differed greatly from modern day environments. The use of …

Evaluating Stable Isotope And Geochronologic Techniques For Paleoclimate Reconstruction: Case Study Of The Santa Cruz Formation, Argentina, Robin B. Trayler

Boise State University Theses and Dissertations

Stable isotope analysis has become the method of choice for many studies investigating the paleoecology and paleoclimate of fossil mammal faunas. While organic tissues (collagen, keratins, proteins) persist for < 10⁵ years highly mineralized tooth enamel is resistant to alteration and degradation and faithfully preserves its isotopic composition for millions (> 10⁶) years. Reconstructing past climates from these records relies on both understanding both micro-scale mechanisms of isotope incorporation into individual teeth, and macro-scale changes in isotope compositions over hundreds of thousands or millions of years. In this dissertation I address three questions.

First, how does the geometry and …

Compositional And Thermodynamic Variability In A Stratified Magma Chamber: Evidence From The Green Tuff Ignimbrite (Pantelleria, Italy)., Katarzyna M. Liszewska, John C. White, Ray Macdonald, Bogusław Bagiński

EKU Faculty and Staff Scholarship

The Green Tuff Ignimbrite, Pantelleria, is compositionally zoned from pantellerite at the base to comenditic trachyte at the top, the variation apparently representing an inverted vertical zonation in the pre-eruptive reservoir. The main phenocryst assemblages are alkali feldspar + olivine + clinopyroxene + ilmenite + apatite in the trachytes and alkali feldspar + aenigmatite + clinopyroxene + quartz in the rhyolites. Thermodynamic modelling indicates that the temperature range was ~900–700°C, fO2 FMQ –1.5 to FMQ –0.5 (where FMQ is fayalite–magnetite–quartz buffer) and aSiO2 (relative to quartz saturation) 0.74–1.00. Melt water contents ranged from ~1wt % in the trachytes to ~4wt …

Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles

Electronic Theses and Dissertations

The eastern peninsula of Fort Hood Military Installation is underlain by a complex karst spring network. These springs are a primary water source in a protected habitat for endangered songbirds, which has only recently begun to be fully investigated. These Fredericksburg Group springs express both epigenetic and hypogenetic karst signatures. The study area is part of a paleo reef trend, a hydraulically disconnected segment of the northern section of the Edwards Aquifer. This study utilized standard ion index values, repeated measures, and principal component analyses on the chemical profiles of six perennial springs to classify spring water sources and their …

High-Precision Lead Isotope Analysis On Modern Populations To Determine Geolocation Reliability, Gennifer M. Goad

USF Tampa Graduate Theses and Dissertations

Forensic anthropologists increasingly use chemical isotope analysis in the investigation of unidentified human remains, as biochemical georeferencing continually improves with the development of modern reference data of known origins. Isotope variations in trace elements such as strontium (Sr) and lead (Pb) in human teeth are some of the most useful indicators of past domicile in archaeological research and thus have high potential for modern, forensic applications. In this study, high-precision lead isotope analysis was conducted on 63 modern human teeth, which were previously analyzed for strontium isotopes. The results present new lead isotope data for the following countries: United States …

Relating Cyanobacteria And Physicochemical Water-Quality Properties In Willow Creek Lake, Nebraska, 2012–14, David L. Rus, Brent M. Hall, Steven A. Thomas

United States Geological Survey: Water Reports and Publications

Document abstract

Cyanobacteria (also referred to as blue-green algae) are naturally present members of phytoplankton assemblages that may detract from beneficial uses of water because some strains produce cyanotoxins that pose health hazards to people and animals. Cyanobacteria populations observed in Willow Creek Lake during 2012 through 2014 were compared to external nutrient loading from the Willow Creek drainage basin and several other physicochemical properties within the lake, including internal nutrient loading. This report is part of a cooperative study between the United States Geological Survey, the Lower Elkhorn Natural Resources District, the Nebraska Department of Environmental Quality, the Nebraska …

Evolution Of Noble Gas And Water Isotopes Along The Regional Groundwater Flow Path Of The Konya Closed Basin, Turkey, N. Nur Ozyurt, C. Serdar Bayari

International Journal of Speleology

Noble gas and water isotope compositions of regional groundwater were investigated along two transects in the Konya Closed Basin (KCB) of central Turkey. According to the ³He/⁴He versus Ne/He plot of samples, crust (up to 86%) and mantle (up to 26%) appear to be the primary and secondary sources of dissolved He in groundwater, respectively. After the beginning of both transects where the flow domain is confined, both ³He and ⁴He accumulate steadily in groundwater. Thereafter, the intermediate recharge from the surface in the unconfined part of regional flow system disrupts the steady accumulation trend …

Interpreting The Origin And Evolution Of ‘Karst’ Features From A Siliceous Hydrothermal Terrane: A Case Study From The Upper Geyser Basin In Yellowstone National Park, Usa, Kevin W. Blackwood, Lainee A. Sanders, Stacy I. Gantt-Blackwood

International Journal of Speleology

The Upper Geyser Basin in Yellowstone National Park occurs over a siliceous hydrothermal terrane containing numerous hot springs and geysers. The pool and vent-conduit geometries of these hydrothermal features share a resemblance to conventional karst features known from other rock types, suggesting karst processes could be responsible for their origin and/or evolution. Hypogene speleogenesis is a cave-forming process in which the formation of caves is decoupled from and occurs independently of surface recharge. The geologic setting for hypogene speleogenesis typically occurs at the distal end of regional groundwater systems wherein the hydrogeology is manifested by ascending fluids and/or by geochemical …

Mantle-To-Surface Neotectonic Connections In The San Juan Mountains Documented By 3he/4he, Co2 Flux Meaurements, And Hydrochemical Analysis Of The Geothermal System Near Rico, Colorado, Benjamin D. Holt

Earth and Planetary Sciences ETDs

This project investigates the controls on geothermal fluids and their conduit systems which may account for high mantle helium components of geothermal fluids in intracratonic continental regions. The field laboratory is the western San Juan Mountains of southwestern Colorado where the structural setting and hydrochemistry of carbonic springs suggest potential connections among surface hot springs, fault networks, CO2 degassing, significant geothermal potential, young volcanic and plutonic rocks (< 7 Ma), and low-velocity upper mantle. The Rico Hot Springs have the highest mantle volatile component of any spring in Colorado with air-corrected values of 3He/4He = 5.88 RA indicating 73% mantle helium component. This near-MORB mantle helium value at Rico indicates that volatiles degassing from the mantle must be rapidly transmitted into the groundwater system along deep-seated faults such that accumulation of 4He from radiogenic crust has not swamped mantle-derived primordial 3He. Geologic features that are important for volatile transport and spring chemistry controls include a complex conduit system and fault network involving the Precambrian-cored Rico Dome, ~4 Ma intrusive rocks at Calico Peak and Priest Gulch, and a low-velocity upper mantle. Therefore, Rico and the surrounding region is a natural laboratory for studying geothermal fluid and mantle volatile pathways. Additional noble gas analyses and hydrochemistry data were gathered from regional springs and modeled via chemical geothermometers. New noble gas measurements from this study, paired with literature values, reveal highest air corrected 3He/4He at Rico (4.09-5.88 RA), Dunton (3.11-4.54 RA), Geyser Warm Spring (3.39 RA), and Paradise Warm Spring (2.72 RA). Water volume is dominated by meteoric fluids as shown by stable isotope data but hydrochemistry indicates high TDS, high CO2, and high He come from a geothermal fluid endmember. Variable mixing and water-rock interactions are processes that can explain chemistry variations between spatially proximal springs. CO2 flux measurements (up to 36.2 g/m2/hr) vary across structural features and demonstrate that the faults act as pathways for CO2 flux suggesting ongoing degassing. Overall, we find that local high mantle helium signature is localized directly above regions of lowest upper mantle velocity in the San Juan mantle anomaly and is derived from neotectonic mantle melts in those regions.

Use Of Sodium Dithionite For Groundwater Restoration Following Uranium In-Situ Recovery Mining At The Smith Ranch-Highalnd Site In Wyoming, Rose J. Harris

Earth and Planetary Sciences ETDs

Uranium in-situ recovery (ISR) is a subsurface aqueous mining technique used to extract uranium from sandstone roll-front deposits. After ISR mining, groundwater restoration is conducted to decrease concentrations of residual U(VI) and other contaminants leftover in the groundwater. Sodium dithionite, a strong chemical reductant, is being tested for use in groundwater restoration following uranium ISR at the Smith Ranch-Highland site in Wyoming. Sodium dithionite has been used to remediate chromium plumes by creating an in-situ permeable reactive barrier, but there has been no work using sodium dithionite for groundwater restoration following uranium ISR mining.

Laboratory batch and column experiments, and …

Are The Oxygen Isotope Values Of The Late Cretaceous Western Interior Seaway Different From The Open Ocean?, Camille H. Dwyer, Corinne Myers, Viorel Atudorei

Shared Knowledge Conference

The Western Interior Seaway (WIS) was a North American epicontinental sea that was connected to the open ocean through the passage of the northern Boreal Sea and the southern Tethys Sea from the early Albian (~113 million years ago) to the early Paleogene (~65 million years ago). The WIS began to recced and lost its connection to the southern Tethys Sea in the late Campanian (~72 million years ago). In the early Paleogene, the WIS dried up completely. The oxygen isotopic composition (δ18O) of benthic bivalves was measured from the upper Campanian and lower Maastrichtian (75 million years ago to …

Natural Trace Element Salinization Of The Jemez River, New Mexico By Geothermal Springs And Major Tributaries, Jon K. Golla, Laura J. Crossey, Abdul-Mehdi S. Ali, Karl E. Karlstrom

Shared Knowledge Conference

The Jemez River (JR), a tributary of the Rio Grande, is in north-central New Mexico within the Jemez Mountains, which houses the active, high-temperature (≤ 300 oC), liquid-dominated Valles Caldera geothermal system (VC). This work focuses on the northern portion of the JR, spanning a reach from the East Fork JR to the town of San Ysidro. Previous decadal work during low-flow or baseflow conditions (~10-20 cfs) has identified and characterized significant major-solute contributions from two outflow expressions of the VC, Soda Dam Springs and Jemez Hot Springs, and two major tributaries, Rio San Antonio and Rio Guadalupe. There is …

Longitudinal Study Of Water Quality In Jennings Creek, Bowling Green, Kentucky: Urbanization Impacts On Karst Groundwater, Lea Mitchell, Jason S. Polk, Rachel Kaiser, Ethan Givan, Kegan Mcclanahan

Posters-at-the-Capitol

Karst groundwater systems, which occur in areas where caves, sinkholes, and underground rivers dominate the landscape, are vulnerable to pollution from surface contaminants. In urban areas, like Bowling Green, Kentucky, which is home to extensive caves and groundwater supplies, the immediate transport of heavy metals, organic waste, chemicals, and other pollutants from surface activities into groundwater poses a serious threat. This research project was done to examine the water quality of urban karst sites in Bowling Green, Kentucky at Jennings Creek, which is a local river primarily fed from springs; the water quality of Jennings Creek was never tested before …

Elevated Black Carbon Concentrations And Atmospheric Pollution Around Singrauli Coal-Fired Thermal Power Plants (India) Using Ground And Satellite Data, Ramesh Singh, Sarvan Kumar, Abhay K. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

The tropospheric NO₂ concentration from OMI AURA always shows high concentrations of NO₂ at a few locations in India, one of the high concentrations of NO2 hotspots is associated with the locations of seven coal-fired Thermal Power plants (TPPs) in Singrauli. Emissions from TPPs are among the major sources of black carbon (BC) soot in the atmosphere. Knowledge of BC emissions from TPPs is important in characterizing regional carbonaceous particulate emissions, understanding the fog/haze/smog formation, evaluating regional climate forcing, modeling aerosol optical parameters and concentrations of black carbon, and evaluating human health. Furthermore, elevated BC concentrations, over the …

Groundwater Contamination At Coal Ash Deposit Sites In Kentucky, Brandon Rose

Scholars Week

No abstract provided.

Ice And Guano Deposits In El Malpais Lava Tubes: Potential Paleoclimate Archives For The Southwest United States, Dylan S. Parmenter

USF Tampa Graduate Theses and Dissertations

Three ice cores and one guano core were obtained from lava tubes in El Malpais National Monument, New Mexico, in the Southwest United States. A large hiatus in the Bat Cave guano record, resulting from mining activities in the early 1900's, left us with only ~50 years of data (from AD 1955-2006) to use in analysis. 13C values in guano (-18 to -11.6‰) primarily fall within the range of C4 plants, and likely indicate a tendency of Tadarida brasiliensis to feed on insects over grasslands to the North or South of the park. Variations in 13C values for this period …

Crustal Seismic Anisotropy Of The Ruby Mountains Core Complex And Surrounding Northern Basin And Range, Justin T. Wilgus

Earth and Planetary Sciences ETDs

Metamorphic core complexes (MCC) are distinctive uplifts that expose deeply exhumed and deformed crustal rocks due to localized extensional deformation. Consequently, their detailed structure provide a window into deep crustal mechanics. The North American Cordillera contains numerous MCC, one of which is the Ruby Mountains core complex (RMCC) located in the highly extended northern Basin and Range. To constrain the extent to which anisotropy below the RMCC deviates from the regional Basin and Range average and test the depth dependence of crustal anisotropy we conduct a radial anisotropy investigation below the RMCC and surrounding northern Basin and Range. Data from …

The Sedimentology And Origins Of A Giant Mass Transport Complex: The Nataraja Slide, Arabian Sea, Sarah Dailey

LSU Master's Theses

A giant mass transport complex (MTC) was recently discovered in the eastern Arabian Sea exceeding in volume all but one other known complex on passive margins worldwide. The complex, named the Nataraja Slide, was drilled by IODP Expedition 355 in two locations where it is ~300 m (Site U1456) and ~200 m thick (Site U1457). The top is defined by the presence of both reworked microfossil assemblages and deformation structures, such as folding and faulting. The deposit consists of two main phases of mass wasting, each which consists of smaller pulses, with generally fining upward cycles, all emplaced just prior …

Theory On Thermodynamic Constraints To Biogeochemical And Metabolic Diversity, Jordan Okie, Everett Shock

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

On Biospeleothems From A Venezuelan Tepui Cave: U-Th Dating, Growth Rates, And Morphology, Joyce Lundberg, Charles Brewer-Carías, Donald A. Mcfarlane

International Journal of Speleology

Seven silica biospeleothems from Cueva Charles Brewer, Chimantá Plateau, Venezuela have been successfully U-Th dated despite very low U and high detrital Th concentrations. Growth rates are low, between ~100 to ~800 µm/ka, and are greater closer to water level. Dates in unaltered material are in good stratigraphic order, but secondary silicification may compromise the U-Th system, yielding unreliable sequences of ages. Detritally-enriched layers correlate with global climate cycles of the Late Quaternary, in particular the cooler, drier phases of MIS 5d, 5a, and 4. SEM studies indicate that the peloidal material is made up of silica nano-particles assembled to …