Geochemistry Commons^™

A Mineralogical And Geochemical Characterization Of The Amo Meteorite, Karinn Johnson '27, Kenneth Brown, Chad Byers, Thomas Grier

Annual Student Research Poster Session

Meteorites provide a wealth of information about solar system evolution, planetary formation and differentiation, and provide clues to the origins of water and life on Earth. On December 10th, 2024 (4:04 EST), a meteor fall was observed approximately 50 km west of Indianapolis, over the small town of Amo, Indiana (Hendricks County). Several pieces of the meteor ranging from about 1g to >60kg were recovered. A local Greencastle, IN resident collected a 1451.3g sample, of which a 7.5g piece was donated to DePauw University for detailed textural, mineralogical, and geochemical characterization using stereomicroscopy, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), …

The Effects Of A Microplate On Plume-Ridge Interactions: Constraints From Comparing Easter And Juan Fernandez Microplates In The Eastern Pacific Ocean, Katherine Ames, Jennifer Georgen

OES Faculty Publications

This study investigates the nature of plume-ridge interactions near a tectonic microplate using mantle Bouguer anomaly (MBA) gravity calculations. The focus of this investigation is a comparison of the Easter and Juan Fernandez microplates, which are located in the eastern Pacific Ocean along the Pacific, Nazca, and Antarctic plate boundaries. The microplates have several similar characteristics, including general size, time of formation, and clockwise rotation within the larger bounding mid-ocean ridge systems. Unlike the Juan Fernandez microplate, however, the Easter microplate is located near a mantle plume (Easter/Salas y Gomez). Previously published geochemical data suggest that material from this plume …

Deep Crustal Boundaries As Fluid Conduits: A Geochemical Investigation Of Mvt Mineralization In Kentucky And Beyond, Dairian Boddy M. Boddy

Theses and Dissertations--Earth and Environmental Sciences

Critical minerals are vital to the United States economy and national security, yet their supply chains are at risk. Common minerals in Mississippi Valley-type (MVT) deposits, such as sphalerite, galena, fluorite, and barite, host critical metals such as barium, gallium, germanium, and zinc, which are essential for energy technologies. An investigation of three MVT mineral districts in Kentucky elucidated previously unrecognized systematics, genetic relationships, and sources of ore components using stable and radiogenic isotope geochemistry, particularly from galena, sphalerite, barite, and gangue minerals (e.g., carbonates). The localization and dominant type of mineralization in each district are potentially influenced by deep …

Sedimentological And Geochemical Investigation Of The Origin Of Upper Pennsylvanian Black Shales, East-Central Appalachian Basin, Tyler Hickey

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the east-central Allegheny foreland basin, laminated black shales overlying Upper Pennsylvanian Glenshaw Fm. coal seams record paleoenvironmental conditions associated with the termination of peat swamp deposition before, during, and after the Carboniferous Coal Forest Collapse (CCFC), a major paleobotanical evolutionary event during the Late Paleozoic Ice Age (LPIA) that contributed to extinction of lepidodendrons near the Desmoinesian-Missourian boundary (~306 Ma). Previous investigations of the CCFC commonly implicate an episode of aridification during intensification of LPIA glaciation that stressed the lepidodendrons beyond their ecological tipping point; however, the cause of this aridification is unclear. An investigation of Glenshaw Fm. black …

Major, Trace And Rare Earth Element Concentrations In Nist Standard Reference Material® 1646a Analyzed By Als Global Using Method Me-Ms61r, Jane L. Alexander

Publications and Research

This technical note compares analytical results obtained from ALS Global Method ME-MS61r with the certified and previously published results for NIST Standard Reference Material® 1646a, Estuarine Sediment. The results are grouped into major, trace and rare earth elements, and focus on elements used by sedimentary geochemists, for example in studies of sediment provenance. The results from ALS Global Method ME-MS61r are internally consistent and generally robust when compared with published analyses. However, acid digestion may not completely dissolve resistant minerals, leading to under-reporting of some elements such as Ti, Cr, Zr, heavy REE and Y.

Collaborative Research: Bocp-Implementation: Us-China: Multi-Scale, Multi- Proxy, Integrative Investigation Of Functional Biodiversity On A Changing Proterozoic Planet, Carol Dehler

Funded Research Records

No abstract provided.

Characterization Of Residual Mineral Content Of Bauxite Stockpiles In Saline County, Arkansas: An Xrd Analysis Approach, Andrew Kaze Sezibera

Electronic Theses and Dissertations

The Saline Mining District of central Arkansas once led U.S. alumina production and hosts extensive bauxite and nepheline syenite deposits. With the depletion of highgrade ore, renewed interest in bauxite stockpiles has focused on critical mineral potential. Previous X-ray Fluorescence studies have identified critical elements in significant concentrations, including uranium (U), thorium (Th), gallium (Ga), molybdenum (Mo), and lanthanides (Ln). This study examines five stockpiles (SP1, Clay, SP2, SP3, and SP4) in Section 20 of the Aluminum Company of America (ALCOA) Saline County bauxite mine, using Xray Diffraction (XRD) on 25 samples to characterize mineral phases and compare them with …

Rectifying The Tephrostratigraphic Record Of The Pacific Northwest, Casey J. Crawford

Boise State University Theses and Dissertations

The Mid-Miocene Climatic Optimum (~17-14Ma) marks the last time that Earth’s atmospheric CO₂ concentrations were as high as modern levels, correlating to a peak of significant warming during an otherwise cooling trend through the Cenozoic. To understand how modern ecological systems may respond to CO₂ -induced climate change, paleontologists are studying how plant type and diversity changed with the rise and fall of CO₂ concentrations over the ~3Ma interval, and utilize intercalated tephras amenable to radioisotope geochronology to bracket fossiliferous horizons in time. The legacy model for tephrostratigraphy in the Pacific Northwest utilized Fe and Ca concentrations …

A Mineralogical And Geochemical Investigation Of The Influence Of Tectonic Setting On Accessory Mineral Assemblages In Serpentinites Along The Western North American Margins, Bryan H.T. Seymour

Electronic Theses, Projects, and Dissertations

Serpentinites are metamorphic rocks typically produced by hydrating mantle peridotites to form assemblages containing one or more serpentine minerals. They occur in various tectonic and geologic settings, such as submarine hydrothermal systems, ophiolite sequences, and the forearc mantle. Serpentinites are associated with highly reduced conditions, as indicated by low oxygen fugacity (ƒO₂) values. Previous investigations suggest that oxygen fugacity varies with tectonic setting due to differences in environmental conditions. To test this hypothesis, we analyzed serpentinites from a wide variety of tectonic settings in western North America: The New Idria forearc diapir (CA), Canyon Mountain Island arc complex (OR), Josephine …

Geochemical And Sedimentological Signals Of Bottom Water Oxygen Dynamics From Lake Tanganyika (Zambia), Njahi Mwangala

Theses and Dissertations--Earth and Environmental Sciences

Lake Tanganyika is a large, ancient freshwater body with exceptional biodiversity that is located in the East African Rift System. Lake Tanganyika’s size and longevity make its sedimentary record useful for understanding environmental changes that cross spatial and temporal boundaries. Lake Tanganyika is known to be susceptible to global warming given its tropical location. Over 12 million people living within Lake Tanganyika’s watershed rely on fishing for their income and nutrition. Changes to limnological function driven by climate could therefore have serious implications for human health and biodiversity conservation. This study focuses on using geochemical properties of modern lake bottom …

Late Holocene Paleolimnology Of Lake Tanganyika (East Africa), Leandro Domingos Luz

Theses and Dissertations--Earth and Environmental Sciences

Understanding the long-term responses of ecosystems to climate variability is crucial for predicting and mitigating future changes in the Afrotropics, a region where a significant portion of the population is highly vulnerable to extreme climatic events. Lake Tanganyika, the largest rift lake in East Africa, offers a unique sedimentary archive that can be used to investigate the limnological changes, hydroclimatic shifts, and vegetation dynamics across various timescales. A multi-proxy approach was employed to assess the landscape responses to hydroclimatic fluctuations in the Late Holocene, integrating paleoenvironmental records from radiocarbon-dated sediment cores. This approach involved sedimentology, mineralogy, geochemistry, phytolith analysis, and …

Origins And Mechanisms Of Mobility Of Geogenic Arsenic Contamination In Toutle And Silver Lake, Wa, Usa, William A. Hays

All Master's Theses

Arsenic (As), a common contaminant in groundwater, is toxic to human health and has a maximum contaminant level of 10 ppb set by both the World Health Organization and the U.S. Environmental Protection Agency (ATSDR, 2007). In Toutle, WA, USA (30 km west of Mount Saint Helens), a private well, labelled TOU1, was previously identified with ~670 ppb of As and was the impetus of this study. This study targeted private wells in the vicinity of TOU1 to identify the extent of the arsenic contamination, identify the aquifer(s) of concern, and identify the mechanism(s) of mobility.

The wells were screened …

Zircon Age And Oxidation State Estimates For Plutons Spatially Associated With Mineral Deposits Along The Kettle Detachment Fault In The Orient Quadrangle, Northeastern Washington, Karla Ortega

All Master's Theses

Critical minerals are essential to national security, economic stability, and the transition to clean energy, making them a priority in geologic research and exploration. To better understand the magmatic conditions associated with critical mineral concentration, zircon, a recorder of magmatic history, was analyzed using U-Pb geochronology and trace element geochemistry. The analyses were conducted via LASS-ICP-MS on ten plutonic samples from the Orient quadrangle in northeastern Washington and one sample from the Adams Mountain and Hunter (AMH) quadrangles to constrain the geological processes leading to ore deposit formation, including tungsten (W). This region, cut by the Kettle Detachment fault, is …

Oil-Oil Correlation Across Sedimentary Basins In Kansas Using Molecular Geochemistry And Fourier Transform Infrared Spectroscopy, Oluwaseun V. Omoyemi

Master's Theses or Doctor of Nursing Practice

Hydrocarbons are produced from different subbasins and stratigraphic intervals in Kansas. However, the geochemical characteristics and sources of these hydrocarbons are still poorly understood. While reservoir rocks, seals, and traps that are essential for petroleum systems are well defined within the state, the possible source rocks are often considered thermally immature, raising questions about their ability to generate the volume of hydrocarbons currently being produced. This research project tries to evaluate the geochemical characteristics of hydrocarbons produced in the state of Kansas and determine if the hydrocarbons from the different subbasins and stratigraphic units are genetically related. Thirty-seven crude oil …

Antarctic Atmosphere-Ocean-Ice Interactions During Past Warm Climates: An Ice-Proximal Perspective, Imogen Mireille Browne

USF Tampa Graduate Theses and Dissertations

Antarctica’s ice sheets contain 58 m of sea level equivalent ice and thus exert a fundamental control on global sea level on decadal to million-year timescales. Interactions between Antarctica’s ice sheets, regional atmospheric circulation, and the Southern Ocean influence ice sheet mass balance, sea ice formation, and deep water production, which regulate Earth’s climate. At present, Antarctica’s fringing ice shelves and outlet glaciers, particularly in West Antarctica, are losing mass as warm ocean waters move landward across the continental shelves, melting the underside of ice shelves and eroding glacial grounding lines. In East Antarctica, net ice mass gain is occurring …

Investigation Of Residual Mineral Content Of Bauxite Stockpiles, Saline Mining District, Arkansas, U.S.A., Melanie L. Ertons

Electronic Theses and Dissertations

The former mining town of Bauxite is in the Saline County Mining District, in central Arkansas. Bauxite is located approximately 40 km (25 mi) southwest of Little Rock just east of Benton, Arkansas. This area contains extensive deposits of bauxite ore and nepheline syenite previously mined by Aluminum Company of America using open pit and subsurface mining techniques. This study incorporates five bauxite stockpiles (SP1, Clay, SP2, SP3, SP4) with varying amounts of alumina content situated on approximately 10 acres of land within an area of the former mine recognized as Section 20. Over the past several years, there has …

Introduction To Nuclear Magnetic Resonance Spectroscopy In A Geochemical Setting, Evan Mack

University Honors College

Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical tool that is heavily employed in organic chemistry, but lacks use in geochemistry. The technique is most useful for characterization and structural analysis of analytes, but also sees use in kinetics analysis, speciation, and detection. This work aims to answer these questions regarding NMR spectroscopy’s use in geochemical settings: Which nuclei are studied? For what purposes is each nucleus studied? What affects the scope of the technique and has caused it to not be widely used? How often is NMR spectroscopy used? What trends are there in the technique’s use? The …

Geochemical Analysis Of Basement Rock As A Potential Metal Source In Mississippi Valley-Type Ores, Southern Midcontinent U.S.A., Mackenzie Moorhead

Graduate Theses and Dissertations

Mississippi Valley-Type (MVT) ores are epigenetic, sedimentary hydrothermal base metal deposits that exist worldwide with type localities in the midcontinent United States. These Permian-aged sulfide ores represent an extraordinary concentration of economic metals, Pb and Zn. Ore deposits occur in vast districts that have a rich mining history. The Pb and Zn from these deposits account for 24% of worldwide reserves. The geologic processes responsible for MVT ore genesis are not fully understood, especially the sourcing of ore constituents. In the midcontinent, the Ouachita Orogeny expelled saline hydrothermal brines in response to high rates of subsidence. These fluids migrated through …

Petrologic And Geochemical Constraints On The Pre-Eruptive Storage Conditions Of Magmas Erupted During The ~12.5 Ka Flare Up Of Medicine Lake Volcano, Ca, Regina M. Khoury

Cal Poly Humboldt theses and projects

The Medicine Lake Volcano (MLV) system in the California Cascades is composed of a large shield volcano with numerous basaltic to rhyolitic vents on and around the flanks, many of which are aligned with N-S trending normal faults. A significant portion of the post-glacial volcanic activity at MLV is comprised of the ~12.5 ka “flare up” eruptions of basalt and basaltic andesite magmas from seven discrete flank vents. Prior work documented surface areas (0.02-198 km²), volumes (0.0001-4.35 km³), and eruption styles (Hawaiian to Strombolian; Donnelly-Nolan, 2010) of the ~12.5 ka deposits. This study uses new geologic …

Global Subterranean Estuaries Modify Groundwater Nutrient Loading To The Ocean, Stephanie J. Wilson, Amy Moody, Tristan Mckenzie, M. Bayani Cardenas, Elco Luijendijk, Audrey H. Sawyer, Alicia Wilson, Holly A. Michael, Bochao Xu, Karen L. Knee, Hyung-Mi Cho, Yishai Weinstein, Adina Paytan, Nils Moosdorf, Chen-Tung Aurthur Chen, Melanie Beck, Cody Lopez, Dorina Murgulet, Guebuem Kim, Mathew A. Charette, Hannelore Waska, J. Severino P. Ibánhez, Gwénaëlle Chaillou, Till Oehler, Shin-Ichi Onodera, Mitsuyo Saito, Valenti Rodellas, Natasha Dimova, Daniel Montiel, Henrietta Dulai, Christina Richardson, Jinzhou Du, Eric Petermann, Xiaogang Chen, Kay L. Davis, Sebastien Lamontagne, Ryo Sugimoto, Guizhi Wang, Hailong Li, Américo I. Torres, Cansu Demir, Emily Bristol, Craig T. Connolly, James W. Mcclelland, Brenno J. Silva, Douglas Tait, Bsk Kumar, R. Viswanadham, Vvss Sarma, Emmanoel Silva-Filho, Alan Shiller, Alanna Lecher, Joseph Tamborski, Henry Bokuniewicz, Carlos Rocha, Anja Reckhardt, Michael Ernst Böttcher, Shan Jiang, Laura M. Hernández-Terrones, Suresh Babu, Beata Szmczycha, Mahmood Sadat-Noori, Felipe Niencheski, Kimberly Null, Craig Tobias, Bongkeun Song, Iris C. Anderson, Isaac R. Santos

OES Faculty Publications

Terrestrial groundwater travels through subterranean estuaries before reaching the sea. Groundwater-derived nutrients drive coastal water quality, primary production, and eutrophication. We determined how dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and dissolved organic nitrogen (DON) are transformed within subterranean estuaries and estimated submarine groundwater discharge (SGD) nutrient loads compiling > 10,000 groundwater samples from 216 sites worldwide. Nutrients exhibited complex, nonconservative behavior in subterranean estuaries. Fresh groundwater DIN and DIP are usually produced, and DON is consumed during transport. Median total SGD (saline and fresh) fluxes globally were 5.4, 2.6, and 0.18 Tmol yr⁻¹ for DIN, DON, and DIP, …

Submarine Groundwater Discharge As A Major Nutrient Source In River-Fed Vs. Tidally Dominated Estuaries, Stephanie J. Wilson, Joseph J. Tamborski, Bongkeun Song, Peter Bernhardt, Margaret R. Mulholland

OES Faculty Publications

The tidal tributaries of the lower Chesapeake Bay experience seasonally recurring harmful algal blooms and the significance of submarine groundwater discharge (SGD) as a nutrient vector is largely unknown. Here, we determined seasonal SGD nutrient loads in two tributaries with contrasting hydrodynamic conditions, river-fed (York River) vs. tidally dominated (Lafayette River). Radon surveys were performed in each river to quantify SGD at the embayment-scale during spring and fall 2021. Total SGD was determined from a ²²²Rn mass balance and Monte Carlo simulations. Submarine groundwater discharge rates differed by a factor of two during spring (Lafayette = 11 ± 17 cm …

Geographically Dependent Thermodynamic And Geochemical Evolution In The Post-Batholith Upper Mantle Beneath The Sierra Nevada: Analysis Of The Blue Knob Xenoliths, Eleanor Ruos

Scripps Senior Theses

Xenoliths entrained in recent (Miocene) volcanics from the Sierra Nevada provide insights into a continuously evolving upper mantle during post-batholith generation periods (early Cenozoic–present). Hypothesized mantle refertilization followed by subsequent delamination of the lithospheric root beneath the Sierra provides a contextual framework for analyzing how the upper mantle responds to such events. This study contributes new geochemical data from the ultramafic xenoliths of Blue Knob, including bulk-rock major and trace element data, thin-section petrography, mineral chemistry and thermobarometry, and oxygen isotopes (delta¹⁸O). Blue knob (Eastern Sierra) data are compared to previous works on xenoliths from Chinese Peak and …

Million-Year Melt-Presence In Mogollon-Datil Volcanic Field Rhyolites: Constraining The Histories Of The Bursum Caldera Resurgent Domes, Ethan Wagner

Graduate Theses/Dissertations

The Mogollon-Datil volcanic field which is located in southwestern New Mexico, is the result of punctuated volcanism and the transition between arc and rift magmatism. The resurgent domes within the 28 Ma Bursum caldera records the transition from rhyolitic to basaltic andesite volcanism that occurred between 27-26 Ma. Using a combination of new zircon U-Pb ages using chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) with zircon U-Pb geochronology and trace element contents by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and whole rock and mineral trace element contents and isotope geochemistry this study investigates the temporal and …

Re-Evaluating Missouri’S Strategic Element Potential: A Geochemical Study Of The Mesoproterozoic Fe-Cu-Co-Ree Deposits In Southeast Missouri, Usa, Brandon James Sullivan

Doctoral Dissertations

"Iron-oxide-copper-gold (IOCG) deposits are poorly understood mineral systems. For example, we do not know why Cu- and Co-rich IOCG deposits typically occur proximal to Fe ore deposits that are notably Cu and Co-poor, such as Iron Oxide Apatite (IOA) deposits. To better understand the formation of IOA and IOCG deposits in Missouri, USA, this PhD thesis examines the genesis of the Kratz Spring IOA and the Boss Central Dome IOCG deposits. This study presents the first constraints on formation conditions and fluid sources in the studied deposits using integrated petrographic, mineral composition, and Fe isotope analyses of oxide minerals. Observations …

Environmental Fate Of Sulfur In Sulphur Creek, Valles Caldera, Nm: Implications For Metal Transport And Water Quality, Daniel Lavery

Earth and Planetary Sciences ETDs

The 1.2 Ma Valles Caldera in north-central New Mexico hosts a young igneous volcanic hydrothermal system after the model proposed in Goff and Janik (2000). The Sulphur Springs area within Valles Caldera is an acid-sulfate area typical of this model, discharging acidic waters (pH 1.5-3) formed by oxidation of magmatic H₂S at the surface. We report on samples obtained from springs and streams collected between October 2021 and May 2023 in the Sulphur Creek and Alamo watersheds. Sulphur Creek receives input from Sulphur Springs and exhibits low pH (2-4) and high concentrations of Al (≤110 mg/L), Fe (≤60 …

Landscape/Atmosphere Interactions And Carbon-Dioxide Dynamics In The Great Onyx Groundwater Basin, Mammoth Cave National Park, Kentucky, Meghan Raines

Masters Theses & Specialist Projects

An increase in atmospheric CO2 since the Industrial Revolution has altered rates of global climate change and has motivated a need to better quantify the flux of carbon between Earth’s reservoirs. Attempts to quantify the exchange of atmospheric carbon between sources and sinks have led to an increasing interest in the terrestrial landscape, including the continental carbon sink associated with carbonate-mineral dissolution. This research sought to better inform an understanding of karst landscapes and their relationship with global climate change through carbon cycling. The study utilized high-resolution data collection of pH, temperature, and specific conductance of waters in the Cascade …

Investigating Mobility In The Northern Balkans During The Fifth Millenium Bc Through Strontium Analysis Of Human Tooth Enamel, Aurélien Tafani

USF Tampa Graduate Theses and Dissertations

This research investigates how individual mobility among ancient populations in Romania during the Eneolithic, between 5000 and 4000 BC, may be related to the spread of the material culture known as Kodjadermen-Gumelniţa-Karonovo VI (KGK VI) that extended over most of southern Romania and Bulgaria. This work seeks to combine results on individual mobility with other lines of archaeological evidence to provide a better understanding of the social context and kinship relationships that were in place when these events took place.

Strontium isotopic analyses were performed on 130 individuals from two sites located in the southern Romania: 49 from Sultana and …

Hydrothermal Carbonization Of Biomass Wastes: Sustainability And Geochemistry, Michael A. Kruge, Teresa A. Centeno, Alvaro Amado-Fierro, José Manuel González-Lafuente, Ruben Forjan-Castro, José Luis Gallego

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Introduction. To reduce the stream of solid waste going to landfills, innovative means for beneficial use are essential. The diversity and volume of organic wastes pose singular problems and opportunities for recovery and circularity. Common processes for organics include conversion to biofuels and carbonization to biochar, typically done by torrefaction (dry pyrolysis). Research on biochar explores its potential as pollutant adsorbent, agricultural or polluted soil amendment, biofuel (directly or as feedstock), and for carbon sequestration (Ighalo et al., 2022; Cavali et al., 2023). Recently, other processes at lower temperatures such as hydrothermal carbonization (HTC) offer new possibilities (Seshadri et al., …

Trace Metal Analysis Of Pond Sediments To Measure Deposition From A Coal-Fired Power Plant In Ackerman Mississippi, Charles Bills

Theses and Dissertations

Trace element sediment pollution due to coal power plants have been reported in many countries. In this study, pond sediment samples collected from locations around a coal fired power plant in Ackerman, MS, were evaluated for their trace element concentration and pollution status. The samples were collected at two depths to study changes in element accumulation over time. The samples were digested and the elements, As, Cd, Cr, Cu, Pb, Hg, and Zn were analyzed using ICP-MS. Results were then compared to known background concentrations as well as sediment quality guidelines and pollution thresholds. The sample locations downwind of the …

Understanding The Connection Between Gypsum Blooms And Human Health At The Salton Sea, Isabel Ichiyama

Undergraduate Honors Theses

The Salton Sea is a closed hypersaline lake in Southern California that has been receiving little input over the past few decades, leading to desiccation that is rapidly increasing every year. This large-scale evaporation of the sea has led to increased dissolved solutes, high salinity, and gypsum blooms. Gypsum blooms, the precipitation of gypsum (CaSO42H2O) in the sea, have been a prominent facet of the sea and their distribution is well known. However, much of their chemistry and potential health hazards are still undetermined. Potential health effects from gypsum salt, an atmospheric dust particle present at the sea, have known …