Geochemistry Commons^™

Late Holocene Terrestrial Hydroclimate Reconstructions From Central And South American Sites, Brittany N. Price

Graduate Research Theses & Dissertations

Terrestrial records of hydroclimate variability from Central and South America were developed to better constrain previously unknown regional responses to a range of hydroclimate drivers in the recent past. Developing these late Holocene terrestrial hydroclimate records improves our understanding of past hydroclimate variability by increasing temporal resolution and allows us to further understand complexities in spatial dynamics of the climate system. From South-Central Chile, a geomorphic analysis of landforms emplaced in a glacial valley indicated a positive glacial mass balance in the recent past. A high-precision chlorine-36 chronology was developed from basaltic boulders, with additional minimum constraining ages from Araucaria …

Petrological And Geochemical Evaluation Of Rare-Earth Element Potential In The Sparta Granite Complex, Max J. Eshbaugh

Honors College Theses

Rare earth elements (REEs) are important resources with applications in the electronics, renewable energy, and automotive industries. REEs may be concentrated in the residual weathered portion of igneous parent rocks, typically granites. These residual deposits are mined in southeast Asia, but analogous climatic and geologic conditions suggest the existence of economically viable REE residual deposits in the southeastern United States (U.S.). The Sparta Granite Complex in east-central Georgia is a granitoid complex emplaced at the end of the Alleghanian orogeny, forming a suture between the Savannah River and Milledgeville terranes. Petrologic and geochemical assessments of the Sparta Granite and overlying …

Phosphorus Release And Recovery From Simulated Ferric Wastewater Sludge, Aseel Alnimer

Theses and Dissertations (Comprehensive)

Phosphorus (P) is a fundamental element necessary for all life forms and a key component in the fertilizer industry. Meanwhile, the excessive load of P to water bodies due to human activities has the potential to promote eutrophication. Wastewater treatment plants remove P either biologically or chemically and produce P rich sludge which could be a potential renewable source for P. At present, commercial technologies exist for P recovery from biological wastewater sludge. However, P recovery from chemical sludge particularly iron(III)-phosphate (Fe-P) sludge generated in chemical P removal plants that use iron(III) salts remains a challenge.

This study explored, in …

Silting Dynamics And Metal Contaminants In The Georgetown Inner Harbor, Ezekiel Wil Meyers

Electronic Theses and Dissertations

The Georgetown inner harbor is an abandoned oxbow-like river loop and a vital historic site with a wealth of traditional businesses and heavy local industry located within Winyah Bay. Since the modification of the Sampit River in 1949, chronic rapid silting has plagued the inner harbor. With these substantial amounts of fine-grained material accumulating inside the inner harbor, business operations along the waterfront, navigational and maritime operations, and contamination within the harbor are of major concern. The goals of this study were to (a) understand the silting dynamics inside the inner harbor, (b) identify heavy metals which might be of …

Phosphate Mineralogy And Paragenesis Of The Fletcher Pegmatite, North Groton, New Hampshire, Susanna T. Kreinik

LSU New Orleans Theses and Dissertations

Investigation of phosphate assemblages selectively collected at the Fletcher Mine pegmatite, North Groton, New Hampshire, yielded eighteen discrete secondary phosphate species. Secondary phases were formed via metasomatic (high temperature) and hydrothermal (low temperature) alteration of primary triphylite and fluorapatite. Mineral associations bear proximal phases known to occur under contrasting conditions, both oxidizing and reducing, suggesting the formation of microenvironments during concomitant mineral generation. Late-stage hydrothermal fluids provide ions taken up in low temperature secondary phases with calcium and magnesium most prevalent in these suites. High iron to manganese ratios in analyzed specimens establish the relative evolution of the pegmatite host. …

Ligand-Promoted Dissolution Of Uranyl Phosphate Across Scales, Brennan Ferguson

All Dissertations

The formation of uranyl phosphate precipitate is a remediation strategy because the low solubility of uranyl phosphate minerals, like chernikovite, limits the mobility of uranium in contaminated soils. However, organic ligands can complex with aqueous metal cations to form more soluble species. For example, citrate is a commonly occurring organic ligand produced by plants and microbes that increases the solubility of uranium and therefore the dissolution of uranyl phosphate minerals in the uranyl phosphate-citrate system. This effect is an important control on the mobility of uranium in organic-rich, and near-surface vegetated environments. Nevertheless, key aspects of the citrate-uranyl phosphate system …

Computational And Experimental Investigations Of Alkali Cation Interactions At The Rutile – Water Interface, Isaac Johnston

All Dissertations

Overall, the objective of this dissertation was to investigate the degree of sorption for the alkali cations on rutile to ascertain the impact of different cation properties, such as ion size and charge density, on sorption mechanics as well as probe how the ion may alter the surface – aqueous interface. Initial molecular dynamic simulations and batch experiments showed minimal surface sorption for any alkali cation at relatively low concentrations while simultaneously suggesting the enthalpy of deprotonation shifts slightly in the presence of the alkali cations at different ionic strengths. The cations are likely causing small reorientations of the near-surface …

Paleoenvironmental Changes Across The Devonian-Carboniferous Transition, Audrey M. Warren

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Devonian-Carboniferous (D-C) transition was a critical interval in earth history, witnessing profound environmental changes associated with plant and animal evolution and extinction. Two first-order mass extinctions occurred leading up to the D-C boundary: the Kellwasser Event at the Frasnian-Famennian (F-F) boundary (~371 Ma) and the D-C boundary Hangenberg Event (~359 Ma). Both events were associated with significant sea level changes and major carbon cycle perturbations, evidenced by widespread deposition of black shale and positive carbon isotope (δ13C) excursions, all of which have been used to correlate these events across the globe. Because preservation of black shale requires anoxic conditions, …

Trace Element Behaviors During Igneous Evolution And Hydrothermal Alteration Of An Evolved Rhyolite, The Blawn Formation, Wah Wah Mountains, Utah: Implications For Critical Metal Abundances In Highly Evolved Rhyolites, Drew William Barkoff

UNLV Theses, Dissertations, Professional Papers, and Capstones

A-type rhyolites and granites often contain elevated concentrations of the rare earth elements (REE) and many other critical trace elements relative to I- and S-type rhyolites and granites. Their trace element-enriched nature makes them potentially prospective bulk tonnage, low-grade resources of the REE and many other critical trace elements, including Li, Be, Mo, Sn, and W, but little work has been performed to delineate their economic potential. The 22.1 Ma Red Beryl Rhyolite (RBR) and the 18.3 Ma Tetons Rhyolite (TR) units of the Blawn Formation represent two A-type rhyolite domes located in the southern Wah Wah Mountains of Utah. …

Snapshots Of Coastal Ecology During Glacial And Deglacial Intervals: A Multiproxy Assessment Of Northern Gulf Of Mexico Sediment Cores, Kendall Emilie Brome

LSU Master's Theses

Terrestrial ecosystems along exposed continental shelves during times of relatively low sea level and glaciation are rarely preserved due to the mechanically erosive nature of marine transgression and regression. In this study, I investigate the geochemical and palynological characteristics of two well-preserved sites in the northern Gulf of Mexico (NGOM) to determine the ecologic settings and subsequent mechanisms of preservation in this region. Both sites contain preserved terrigenous sediments of previously exposed coastal margins; the first is located at the Alabama Underwater Forest (~13 km south of Gulf Shores, AL, at ~15 mbsl), and optically stimulated luminescence dates to 72–56 …

A Rapid High-Precision Analytical Method For Triple Oxygen Isotope Analysis Of Co2 Gas Using Tunable Infrared Laser Direct Absorption Spectroscopy, Nathan Perdue, Zachary Sharp, David Nelson Jr., Rick Wehr, Christoph Dyroff

Earth and Planetary Sciences ETDs

Rationale

The simultaneous analysis of the three stable isotopes of oxygen – triple oxygen isotope analysis – has become an important analytical technique in natural sciences. Determination of the abundance of the rare ¹⁷O isotope in CO₂ gas using magnetic sector isotope ratio mass spectrometry is complicated by the isobaric interference of ¹⁷O by ­¹³C (¹³C¹⁶O¹⁶O and ¹²C¹⁶O¹⁷O both have mass 45 amu). A number of analytical techniques have been used to measure the ¹⁷O/¹⁶O ratio of CO₂ gas. They …

Preliminary Geochemical And Mineralogical Assessment Of The Beach Sand, Vieques, Puerto Rico, Nazrul I. Khandaker

Publications and Research

PRELIMINARY GEOCHEMICAL AND MINERALOGICAL ASSESSMENT OF THE BEACH SAND, VIEQUES, PUERTO RICO

ROBBINS, Kathy H., KHANDAKER, Nazrul, SINGH, Andrew, and MUNRO, Toralv, Geological Society of America Abstracts with Programs, Vol 54, No. 5, https://doi.org/10.1130/abs/2022AM-379886

ROBBINS, Kathy H., Bronx Early College Academy for Teaching and Learning, 250E 164 STREET, Bronx, NY 10456, KHANDAKER, Nazrul, Geology Discipline, York College of CUNY, 9420 Guy R Brewer Blvd, AC-2F09, Jamaica, NY 11451-0001, SINGH, Andrew, Earth and Physical Sciences, York College of CUNY, 9420 Guy R Brewer Blvd, AC-2F09, Jamaica, NY 11451-0001 and MUNRO, Toralv, 10911 164th St Apt 1, Jamaica, NY 11433-2921 …

Sulfur Behavior In The 1257 Ce Samalas Magma (Lombok, Indonesia) As Revealed By Volcanic Apatite, Yasmin Jackson

Earth Sciences Theses and Dissertations

Explosive volcanic eruptions can inject massive amounts of volatiles, including SO₂ and H₂S, into the stratosphere, inducing drastic tropospheric cooling via sulfate aerosols. Greenland and Antarctic ice cores record evidence of these substantial releases of SO₂ and H₂S, including the massive release during the ultraplinian 1257 CE Samalas eruption. The 1257 CE Samalas eruption is estimated to have released ~158 Tg of SO₂, making it the largest volcanogenic release of SO₂ within the last 2000 years. Vidal et al. (2016) propose that most of this sulfur (S) was hosted in a …

Evaluating The Impact Of Submarine Groundwater Discharge On Nutrients And Trace Elements In Coastal Systems: The Examples Of The Tuckean Swamp (Australia) And The Mississippi Sound (Usa), Amy Moody

Dissertations

Submarine groundwater discharge (SGD) is the advective flow of both fresh terrestrial groundwater and recirculating seawater through aquifer sediments, which is released into the coastal ocean. In this dissertation, I evaluated the impact of SGD on the distributions and input of trace metals and nutrients. In the Tuckean Swamp, an estuary in Australia dominated by coastal acid sulfate soils, I determined the impact of groundwater on Ba and U during the flood season, when the local aquifer is flushed out after a rapid increase in water table elevation. For Ba and U, groundwater contributed up to 18 and 66 % …

Combining Freestanding Ferroelectric Perovskite Oxides With Two-Dimensional Semiconductors For High Performance Transistors, Sergio Puebla, Thomas Pucher, Victor Rouco, Gabriel Sanchez-Santolino, Yong Xie, Victor Zamora, Fabian A. Cuellar, Federico J. Mompean, Carlos Leon, Carlos O. Island, Mar Garcia-Hernandez, Jacobo Santamaria, Carmen Munuera, Andres Castellanos-Gomez

Physics & Astronomy Faculty Research

We demonstrate the fabrication of field-effect transistors based on single-layer MoS2 and a thin layer of BaTiO3 (BTO) dielectric, isolated from its parent epitaxial template substrate. Thin BTO provides an ultrahigh-κ gate dielectric effectively screening Coulomb scattering centers. These devices show mobilities substantially larger than those obtained with standard SiO2 dielectrics and comparable with values obtained with hexagonal boron nitride, a dielectric employed for fabrication of high-performance two-dimensional (2D) based devices. Moreover, the ferroelectric character of BTO induces a robust hysteresis of the current vs gate voltage characteristics, attributed to its polarization switching. This hysteresis is strongly suppressed when the …

Geomorphic And Paleoclimatic Implications Of Glacial Extent Records In The Sierra Nevada Del Cocuy, Colombia During Termination 1, Jordan Nickerson Herbert

Dartmouth College Master’s Theses

Reconstructions of past glacial extents using geomorphic mapping and cosmogenic dating provide an opportunity to infer past climates. A record of the past extents of tropical mountain glaciers is particularly useful because there are few other means to reconstruct past temperatures in high-altitude, low-latitude locations. The tropics play an outsized role in mediating global climate, yet there is a lack of understanding of how the tropics may have influenced past climate changes such as the most recent deglaciation (Termination 1, ~18–11.7 ka). Improving reconstructions of tropical mountain glaciers will aid in understanding the role of the tropics in the global …

Acid Mine Drainage In The Shamokin Creek Watershed: A Spatial Analysis Of Economic And Environmental Consequences Of Coal Mining, Ben Shimer

Student Project Reports

No abstract provided.

Revisiting 228Th As A Tool For Determining Sedimentation And Mass Accumulation Rates, Joseph J. Tamborski, Pinghe Cai, Meagan Eagle, Paul Henderson, Matthew A. Charette

OES Faculty Publications

The use of ²²⁸Th has seen limited application for determining sedimentation and mass accumulation rates in coastal and marine environments. Recent analytical advances have enabled rapid, precise measurements of particle-bound ²²⁸Th using a radium delayed coincidence counting system (RaDeCC). Herein we review the ²²⁸Th cycle in the marine environment and revisit the historical use of ²²⁸Th as a tracer for determining sediment vertical accretion and mass accumulation rates in light of new measurement techniques. Case studies comparing accumulation rates from ²²⁸Th and ²¹⁰Pb are presented for a micro-tidal salt marsh and a marginal sea …

Fate Of Metals In Presence Of Minerals And Mineral-Organic Assemblages, Neha Sharma

McKelvey School of Engineering Graduate Student Theses & Dissertations

Metals can enter aquatic systems from natural and anthropogenic processes associated with weathering, sediment re-suspension, industrial activities, and atmospheric deposition. Metals pose health and environmental risks at high concentrations due to their potential toxicity and bioaccumulation, but many trace metals also serve as essential micronutrients for biogeochemical processes in natural aquatic systems. Biogeochemical processes such as methanogenesis, denitrification, and mercury methylation require transition metals such as nickel (Ni), cobalt (Co), copper (Cu), and molybdenum (Mo) for completion. These biogeochemical processes can be substantial contributors of greenhouse gases, such as methane (CH4) and nitrous oxide (N2O), into the atmosphere. The behavior, …

Grand Canyon National Park's Water Corridor: Water Supply, Water Quality, And Recharge Along The Bright Angel Fault, Brionna O'Connor

Earth and Planetary Sciences ETDs

Grand Canyon’s ‘water corridor’ includes the Transcanyon Pipeline that conveys water from Roaring Springs near the North Rim to Grand Canyon Village on the South Rim to provide water for the park’s 6.5 million annual visitors. Roaring Springs water has been used at the park and reclaimed at the South Rim Water Reclamation Plant since the 1970s. Our hypothesis is that the pipeline water infiltrates through faults and intermingles with the South Rim groundwater system. We use geochemical tracers to develop mixing models for these waters. Tracers considered are major ions, water isotopologues, radiogenic strontium, and pharmaceuticals. This study has …

Nanoscale Interfacial Control Of Ion Behaviors And Caco3 Formation In Environmental Systems, Yaguang Zhu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Interfaces in environmental systems can change the distribution of pollutants and nutrients, determine the fate and transport of nanoparticles, and affect the efficiency of engineering projects. Complex interactions, including electrostatic interactions, Van der Waals interactions, chemical interactions, and ion-surface specific interactions, can all contribute to different ion, ion-pair, and nanoparticle formations near interfaces. Although environmental interfaces play critical roles, only a limited number of studies have considered the nanoscale picture of how they control ions and nanoparticles. Thus, this dissertation addresses three research questions: (1) How does sulfate chemically interact with calcium carbonate (CaCO3) during its heterogeneous formation on quartz …

Investigation Of Basal Imnaha Basalt Flows And Their Relationship To The Picture Gorge Basalt Of The Columbia River Basalt Group, Luke James Fredenberg

Dissertations and Theses

The lower American Bar flows (AB 1 and 2) of the Imnaha Basalt have previously been observed as being chemically similar to those of the Picture Gorge Basalt (PGB). Previous age data separate eruption of the Imnaha and Picture Gorge Basalts by approximately 1.5 Ma, precluding the possibility of a genetic link between the two basalt units. New age data for the Picture Gorge Basalt has expanded the eruptive timeframe and the earliest flows coincide with the eruption of the Imnaha Basalt, making it possible that the lower American Bar flows of the Imnaha Basalt and the Picture Gorge Basalt …

Rock-Fluid Interaction And The Incorporation Of Cations Into Calcite During Recrystallization In Multiple Hydrothermal Systems., Van Anh Nguyen

Theses and Dissertations

Fluid-rock interaction causes an exchange of isotopes or elements through various reactions. The rate of these reactions strongly depends on temperature. The interaction involves dissolution precipitation, chemical exchange reactions, redox reactions, diffusion, and their combinations. The goal of studying fluid-rock interaction is to understand the change in mineral chemistry of the rock materials when in contact with an aqueous solution. These processes occur in all regions of the Earth where aqueous solutions are found. This work is comprised of three independent studies which provide an understanding about crystallization processes under multiple hydrothermal conditions with geological and environmental applications.

In the …

Determining The Effects Of Elevated Carbon Dioxide On Soil Acidification, Cation Depletion, And Soil Inorganic Carbon And Mapping Soil Carbons Using Artificial Intelligence, Jannatul Ferdush

Theses and Dissertations

Soil carbon is the largest sink and source of the global carbon cycle and is disturbed by several natural, anthropogenic, and environmental factors. The global increase of atmospheric CO₂ affects soil carbon cycling through varied biogeochemical processes. The first chapter is a compilation of current information on potential factors triggering soil acidification and weathering mechanisms under elevated CO₂ and their consequences on soil inorganic carbon (SIC) pool and quality. Soil water content and precipitation were critical factors influencing elevated CO₂ effects on the SIC pool. The second chapter examines a detailed column experiment in which six soils …

Immobilization Of Uranium And Iodine By Calcium Phosphate Minerals, Angel L. Jimenez-Arroyo

Theses and Dissertations

This dissertation is comprised of three independent but interconnected studies with the scope of further understanding uranium and iodine partitioning between apatite and fluid. The studies herein presented investigated: 1) brushite to apatite crystallization method; 2) the degree of uranium incorporation into apatite; 3) the degree of iodine incorporation into apatite. The importance of this work is assessing the role of apatite in immobilizing these elements, where uranium is a major component of spent nuclear fuel and iodine is a chemical analog of its radioactive isotope (¹²⁹I). Once we understand the incorporation mechanisms, we will provide data that …

Geochemical Characterization Of The Louann Salt, Puma Field, Green Canyon, Gulf Of Mexico Basin – Using Xrf And Xrd, Brian Lesh

Electronic Theses and Dissertations

The Jurassic-aged Louann Salt is an evaporite sequence deposited in the Gulf of Mexico Basin (GOMB). It is an important component of the GOMB petroleum system and influences the facies pattern in overlying strata and the distribution of petroleum stratigraphic traps. The Louann Salt is composed primarily of halite with intercalated anhydrites and silty or sandy-halite intervals, with overall thicknesses in excess of four kilometers (~13,000 feet). Suture zones occur intermittently within the Louann Salt, formed by the collision of allochthonous evaporite layers. The mineralogy and geochemistry of the suture zones are currently understudied and can be hazardous during drilling …

Geochemical Characterization Of The Bone Spring Formation, Delaware Basin, Using Chemostratigraphy And Integrated Petrophysics, David Tonner

Electronic Theses and Dissertations

The Delaware Basin forms part of West Texas's and New Mexico’s famous petroleum-generating Permian Basin. The Bone Spring Formation is a prolific hydrocarbon producer within this basin, creating one of the world’s richest oil shales. This formation has lithological sequences that are characterized by repeating carbonate and siliciclastic intervals of a third-order cycle which can largely be correlated to highstand and lowstand systems tracts, respectively. Lithological complexity and facies change are manifested by debris flows, turbidites, and slumps. In addition to glacio-eustasy, both tectonism and broader Milankovitch cycles have influenced the depositional history. Previous investigations have utilized cores and wireline …

Temporal Lidar Scanning In Quantifying Cumulative Rockfall Volume And Hazard Assessment: A Case Study At Southwestern Saudi Arabia, Abdullah A. Alotaibi, Norbert H. Maerz, Kenneth J. Boyko, Ahmed M. Youssef, Biswajeet Pradhan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Rockfalls and unstable slopes pose a serious threat to people and property along roads/highways in the southwestern mountainous regions of Saudi Arabia. In this study, the application of terrestrial light detection and ranging (LiDAR) technology was applied aiming to propose a strategy to analyze and accurately depict the detection of rockfall changes, calculation of rockfall volume, and evaluate rockfall hazards along the Habs Road, Jazan Region, Saudi Arabia. A series of temporal LiDAR scans were acquired at three selected sites. Our results show that these three sites have different degrees of hazard due to their geological differences. The mean volume …

Petrochronology And Statistical Analysis To Integrate Different Types Of Data To Solve Complex Earth Systems Problems, Claire Ostwald Harrigan

Boise State University Theses and Dissertations

Complex Earth systems problems, like reconstructing orogens and calibrating the geologic time scale, require investigations that link time to geologic processes. To use time as a means of organizing geologic evidence, geochronometric dates must be contextualized by integrating with different data types. This is the work of petrochronology—linking mineral ages to geochemical, textural, or other geologic information. The U-Pb isotopic system as preserved in the minerals zircon (ZrSiO₄) and titanite (CaTiSiO₅) can be used in a petrochronological context to date geologic events including the age of granitoid pluton emplacement, the age of rock fabric formation in …

Evaluation Of Carbon Isotopic Chemostratigraphy Of The Cedar Mountain Formation Of Utah, Clayton Forster

Graduate Theses and Dissertations

The Lower Cretaceous rocks of Utah preserve the origin of a multitude of dinosaur taxa, spread of angiosperms on the North American continent, and evolution of marsupial and eutherian mammals. However, the timing of deposition of these rocks is not well understood and must be determined to understand climatic controls on these biological events. Estimates of the age of the Cedar Mountain Formation and its constituent members range from Late Jurassic to early Late Cretaceous. Understanding the timing of deposition of the Cedar Mountain Formation is critical to dinosaurian and associated taxa studies as well as paleoclimate reconstructions from within …