Geochemistry Commons^™

Advancement Of Full-Vector Variable-Temperature Magnetometry For Rock-Magnetic And Paleointensity Applications, Leonid Surovitskii

Dissertations, Master's Theses and Master's Reports

Data on the variation of the direction and strength of Earth’s ancient magnetic field (absolute paleointensity) provide crucial information into the mechanisms of the geodynamo and the Earth’s thermal history. However, the use of conventional methods and instrumentation for absolute paleointensity determination has been hampered by physicochemical alteration of the samples caused by multiple high-temperature cycles and long experiment durations. The reliability and efficiency of the measurement process can be improved by the measurement of the full remanent magnetization vector simultaneously with the temperature cycling of a sample. Such as approach can also substantially expand the scope of materials available …

Petrogenesis And Tectonic Implications Of Cordierite-Orthoamphibole Gneisses (Cog) In The Nw Wyoming Province, Brianna K. Crenshaw Ms

Graduate Student Theses, Dissertations, & Professional Papers

Studying cordierite orthoamphibole gneisses (COG) from five different mountain ranges across the Montana Metasedimentary Terrane (MMT) of the Wyoming Province offers a unique opportunity to elucidate the enigmatic origins and petrogenesis of the lithology in addition to gaining a further understanding of Precambrian crustal assembly processes. Geochemical analyses suggest that COG originates from a basalt that underwent metasomatic alteration, likely via seawater, prior to metamorphism. Moreover, COG is considered to represent oceanic crust that was part of the epicontinental sea adjacent to the Wyoming Province before collision with the Medicine Hat Block. Field observations of associated lithologies such as marbles, …

Organic-Input Impacts On Soil Carbon Flux, Storage, And Budget In Conservation Agricultural Soils, Central Washington, Usa, Jessica Hartman

All Master's Theses

The increase in global atmospheric CO₂ over the last 200 years has generated an urgent need for strategies for sequestering carbon (C). Soil C, which has been depleted by land use change and agricultural practices, is a prime target for C storage. Land management practices, including no-till, cover cropping and crop rotation, and the application of C amendments such as compost and biochar, are suggested to increase C in the soil. Spoon Full Farm, near Thorp, WA, was a conventional hay farm until 2016, when management practices changed to implement some of these C sequestration strategies. A prior CWU …

Variations In Produced Water Chemistry And Relation To Regional Geology And Production In The Marcellus Shale, Northcentral West Virginia, Jonathan M. Brady

Graduate Theses, Dissertations, and Problem Reports (ETD)

An investigation of 74 Marcellus Shale wells across northcentral West Virginia indicates changes in produced water chemistry and quantity can be related to geologic conditions based on well logs and core data. These changes are determined by reviewing multiple produced water analyses for individual wells for periods up to ten years. Results show variations among the areas in this study. From west to east across central Harrison County to central Taylor County, then north into Monongalia County, gamma-ray logs show increasing intensity, especially in the middle and lower Marcellus. XRD mineralogy from core data shows increasing clay content from west …

Analysis Of Water Concentration Formed Within Deformed Synthetic Quartz Crystals, Andrew Steward

Williams Honors College, Honors Research Projects

Analyzing the strength of synthetic quartz is essential to understanding the strength of natural milky quartz, which likely controls the strength of Earth’s continental crust. Synthetic quartz is sometimes used for deformation experiments because it has a homogenous water distribution unlike natural milky quartz. The purpose of this study is to determine if annealing synthetic quartz at T = 600°C will convert the water in synthetic quartz to free water, like milky quartz, but with little water loss. Following two annealing experiments at Texas A&M University, I performed four annealing experiments to measure the water content of five synthetic quartz …

Genesis Of Trondhjemite By Low-Pressure Fraction Anatexis Of Hornblende-Gabbro At Alvand Plutonic Complex (Hamedan, Nw Iran): Insights From Geochemical Modelling., Federico Lucci, Adel Saki, Mirmohammad Miri, Ahmad Rabiee, John C. White

EKU Faculty and Staff Scholarship

Amphibole-dominated dehydration melting of gabbro is the primary process responsible for the genesis of adakites, low-K tonalites, modern trondhjemites, and plagiogranites aswell as Archean tonalite-trondhjemite-granodiorite suites that represent the earliest examples of continental crust. Previous literature has mostly focused on the role of Al-rich amphibole during anatexis of a mafic source and many of these studies have investigated this process through experimental melting runs. However, due to experimental boundary conditions, little is known about partial melting of amphibole-bearing mafic rock at temperatures < 800°C for upper crustal conditions (pressure < 500 MPa). Classic and forward thermobarometric modelling suggests that in situ trondhjemite leucosomes, hosted by Cheshmeh-Ghasaban mafic metatexites (Alvand Plutonic Complex, Hamedan, NW Iran), represent a rare natural case study of a low-temperature incipient amphibole-dominated anatectic event of a mafic source with a primary assemblage (Pl+Hbl+Cpx+Bt+Opx) typical of a hornblende-bearing gabbroic rock.

Alteration Reactions In A Hornblende-Biotite-Anthophyllite-Fluid System: Implications For Cu-Au Ore Deposits, James Mitchell Lightner

Graduate Research Theses & Dissertations

High-grade porphyry Cu-Au ore deposits are typically contained in the potassic alteration zone, which forms through the alteration of preexisting country rock by a magmatic volatile phase (MVP) exsolved from an igneous intrusion. The MVP is a H2O dominant phase that contains high concentrations of NaCl, KCl, FeCl2, HCl, sulfur (as H2S or SO2) and minor concentrations of metals. The minerals in the potassic alteration zone are predominantly K-feldspar and biotite with a shreddy texture. Shreddy biotite forms from the replacement of prismatic-tabular shaped hornblende crystals, resulting in a characteristic shreddy texture. The alteration of hornblende to biotite can neutralize …

Quantifying Bedrock Recharge In Two Paired Mountainous Watersheds, Kimberly Bolhuis

Graduate Student Theses, Dissertations, & Professional Papers

This study focuses on 1) estimating the magnitude of bedrock recharge and 2) mean transit time as a function of bedrock permeability in two paired catchments underlain by different lithology. Networks of bedrock wells and stream gauges were installed in two adjacent catchments of approximately the same size in west central Montana. Fracture network properties for both lithologies were characterized from borehole core logging and scan lines on exposed outcrop. Recharge was evaluated using the Water Table Fluctuation (WTF) method on bedrock well hydrographs installed in both catchments. Stable water isotope samples, collected approximately monthly, from precipitation and stream water …

Trondhjemite Leucosomes Generated By Partial Melting Of A Hornblende-Gabbro (Alvand Plutonic Complex, Hamedan, Nw Iran), Adel Saki, Federico Lucci, Mirmohammad Miri, John C. White

EKU Faculty and Staff Scholarship

This work describes the petrogenesis of in situ and in-source trondhjemite leucosomes generated by low-degree partial melting of the Jurassic Cheshmeh-Ghasaban hornblende-gabbros in the northern Alvand batholith (Hamedan, NW Iran). These leucosomes occur in a metatexite migmatite as patches, net-structures, veinlets, and dikes at scales ranging from a few millimetres to a few metres. They have high SiO2 (mean ≈ 78 wt%) and Na2O (4–5 wt%) with low Al2O3 (wt%), K2 O (

The Potential For Remote Sensing Measurement Of Dissolved Organic Carbon As A Tool For Metal Risk Assessments, Mickey Nielsen

Theses and Dissertations (Comprehensive)

The biotic ligand model (BLM) is a tool used to quantitatively evaluate how receiving water chemistry affects the bioavailability of metals. Sensitivity testing can be used to understand how the model outputs vary in response to systematic changes in water chemistry inputs. This will allow users of such models to understand how accurate their input parameters must be for a specified level of confidence in the output. Our focus was on dissolved organic carbon (DOC), which is often the most limiting data for application of BLM approaches to metals risk management. To potentially address DOC data limitations remote sensing can …

Creating Synthetic Analogs Of Fluorescent Speleothems In Wind Cave As An Astrobiological Model Cave, Teresa Feldman

Honors Program Theses

The wind cave system represents a unique environment on Earth where the direct interplay of organic chemistry on the surface can possibly be traced to extremophiles living hundreds of meters below the surface. In many cases, minerals and organics from the surface become trapped in calcite formations creating fluorescent minerals. To understand the environment giving rise to the fluorescent minerals in Wind Cave, laboratory analogs of the calcite crystals found within the Wind Cave National Park cavern were synthesized and analyzed using SEM and fluorescence spectroscopy. This data was compared to the fluorescence and XRF data collected from speleothems in …

Relationships Among Mineralogy, Geochemistry, And Oil And Gas Production In The Tuscaloosa Marine Shale, Hayley Roxana Beitel

Masters Theses

"The Tuscaloosa Marine Shale (TMS) is an unconventional shale reservoir located in southeast Louisiana and southwest Mississippi. Limited mineralogical and geochemical data for the TMS have been published. The data that do exist indicate that the formation is heterogeneous. Consequently, previous investigators and oil and gas companies have not managed to effectively link mineralogical and chemical changes to oil and gas production in the TMS. These linkages are critical to establish for future exploration efforts. In this study, we attempt to establish these relationships by gathering all existing mineralogical and chemical data in the TMS, including newly acquired data from …

Multiple Generations Of Phlogopite In An Alnöite Diatreme: Insights Into The Petrogenesis Of The Avon Alkaline Igneous Province, Missouri, Nathan Gregory Limbaugh

Masters Theses

“Alkaline Ultramafic Carbonatite (AUC) complexes, although rare, are valued for diamonds and REEs, and as windows into subcontinental and mantle processes as recorded by rock fabrics, mineral spatial relationships, and mineral compositions. We report specifically on olivine and phlogopite petrographic relationships and compositions from the Devonian alnoite diatreme-facies of the Avon Alkaline Igneous Province, Missouri. The diatreme alnoite is a mixture of domains of olivine magmaclasts (OM) set in a crystal-rich melilite matrix. OM are highly fractured, serpentinized olivine pseudomorphs with variable amounts of pristine olivine fragments. Larger olivine domains typically exhibit clear crystal faces and irregular “channels” indicative of …

The 3H/3He Groundwater Age-Dating Method And Applications, Troy E. Gilmore, Mikaela L. Cherry, Didier Gastmans, Douglas Kip Solomon, Eric Christopher Humphrey

School of Natural Resources: Faculty Publications

Groundwater age-dating is an important tool for quantifying and managing water resources. Groundwater age is the elapsed time between recharge (at the land surface or water table) and the time when groundwater is sampled. If groundwater is sampled at the point of discharge from an aquifer, then the age represents the groundwater transit time. Groundwater that has recharged in recent decades is considered young groundwater. In many areas, the quality and quantity of young groundwater has been impacted by human activities and groundwater age-dating is useful for quantifying current and historical water and contaminant fluxes into and through aquifers. This …

Mexican Obsidian On Maui: Hawaiian Connection, Harmonic Convergence, Or Hokum?, Matthew Boulanger

Anthropology Research

In 2014, the television show America Unearthed (A & E Networks) featured an episode discussing evidence for pre-Columbian contact between Polynesia and continental North and South America. Included in this “evidence” was a large spearpoint, allegedly found on the island of Maui. The show’s host argues that the spearpoint is made on obsidian from central Mexico, and therefore represents evidence for direct contact between Polynesian and Maya peoples prior to the sixteenth century CE. A detailed analysis of the spearpoint, including geochemical sourcing, reveals that it is indeed made of so-called Pachuca obsidian from central Mexico; however, the size, shape, …

Interpretation Of Hydrogeologic Data To Support Groundwater Management, Bazile Groundwater Management Area, Northeast Nebraska, 2019—A Case Demonstration Of The Nebraska Geocloud, Christopher M. Hobza, Gregory V. Steele

United States Geological Survey: Publications

Nitrate, age tracer, and continuous groundwater-level data were interpreted in conjunction with airborne electromagnetic (AEM) survey data to understand the movement of nitrate within the Bazile Groundwater Management Area (BGMA) in northeastern Nebraska. Previously published age tracer data and nitrate data indicated vertical stratification of groundwater quality. Younger groundwater sampled within shallow parts of the aquifer had higher concentrations of nitrate, with 70 percent exceeding the U.S. Environmental Protection Agency maximum contaminant level of 10 milligrams per liter. In contrast, groundwater sampled from deeper parts of the aquifer indicated that nitrate concentrations were less than 2 milligrams per liter and …

Raman Spectroscopic Investigation Of The Speciation Of Uranyl (Vi) And Thorium (Iv) Ions In Chloride-Bearing Aqueous Solutions Under Hydrothermal Conditions, Nadib Akram

Graduate Theses/Dissertations

Raman spectra were acquired for a uranyl chloride aqueous solution at temperatures ranging from 25°C to 500°C at the chloride concentration of 6M and uranium (vi) concentration of 0.05M. The measurements were taken by sealing the sample in a hydrothermal diamond anvil cell (HDAC) which enabled spectra acquisition at non-ambient conditions. The pressure inside the cell was measured by estimating the liquid-vapor homogenization temperature (T_H) and using the isochoric equation of state diagram of water. The acquired spectra were then fitted to determine the speciation distribution of the various uranyl chloride species for the mentioned concentration. The developed …

The Persistence Of Acid Mine Drainage At An East Texas Coal Mine, Sarah Zagurski

Electronic Theses and Dissertations

The objective of this study was to estimate the time it will take for acid forming materials (pyrite) to be weathered to a state of equilibrium and thus cease to produce acid in ground and surface waters within Oak Hill Mine. This was accomplished using an ex-situ kinetic leaching study incorporating a humidity cell in a controlled laboratory setting. Leaching was conducted on soil cores obtained from the vadose zone at Oak Hill Mine and the humidity cell was used to accelerate oxidation of the pyrite within the cores.

An in-situ field study was also conducted that monitored groundwater conditions …

Microbe-Mineral Interactions During Exceptional Fossil Preservation, Stromatolite Formation, And Desert Varnish Growth, Michael Strange

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Ediacaran to Cambrian Deep Spring Formation consists of mixed carbonate-siliciclastic strata which contain an increasingly complex and biogeographically important biota. Past investigations of the Deep Spring Formation at Mt. Dunfee, Nevada, explored the highly diverse microbialite reefs consisting of a wide range of stromatolite morphologies which exerted significant control on local sedimentation and topography. Early investigations also documented the biomineralizing metazoan Cloudina (an Ediacaran index fossil). However, recent exploration of the area has resulted in the discovery of several new metazoan fossil communities consisting of a diverse assemblage of Ediacaran soft-tissue tubicolous vermiforms (tube fossils) similar to Cloudina. The …

Sodium-Calcium Ratios In The Planktic Foraminifera Trilobatus Sacculifer As A Proxy For Sea Surface Salinity, Colton Steele Watkins

OES Theses and Dissertations

Recent culture and field studies have found a significant positive correlation between seawater salinity and the incorporation of sodium into foraminiferal calcite, suggesting a potential new proxy for reconstructing past changes in sea surface salinity (SSS) (Mezger et al., 2016 and Bertlich et al., 2018). In order to test the applicability of this new proxy in an open-ocean setting, Na/Ca ratios in the planktic foraminifera Trilobatus sacculifer (T. sacculifer Na/Ca) were measured from a suite of sediment core tops spanning a natural salinity gradient from the North Atlantic subtropical gyre to the South Atlantic subtropical gyre. Initial results from …