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Articles 91 - 120 of 1536

Full-Text Articles in Geochemistry

Applying Multi-Method P-T Estimation Techniques To Constrain Deep Crustal Tectonic Processes: An Example From Hp Granulites North Qaidam Terrane, China, James A. Anderson Jan 2025

Applying Multi-Method P-T Estimation Techniques To Constrain Deep Crustal Tectonic Processes: An Example From Hp Granulites North Qaidam Terrane, China, James A. Anderson

All Master's Theses

High pressure (HP) granulites form within collisional and subduction zone tectonic environments. Due to high temperature and presence of melt, it is difficult to recover their pressure and temperature (P-T) history by conventional methods. An integration of multi-method P-T estimations provides insight on these deep crustal processes.

We apply petrographic analysis, Zr-in-Rt thermometry, phase equilibria modeling, and conventional thermobarometric calculations to constrain metamorphic conditions of Early Paleozoic HP granulite samples formed during late stage continental subduction/collision from the North Qaidam terrane.

HP granulites contain the mineral assemblage Grt + Pl ± Cpx + Qtz + Ky + Rt ± Czo. …


Oil-Oil Correlation Across Sedimentary Basins In Kansas Using Molecular Geochemistry And Fourier Transform Infrared Spectroscopy, Oluwaseun V. Omoyemi Jan 2025

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 …


Molecular Characterization Of Humic And Fulvic Acids On Watterlogged And Well-Drained Amazonian Podzols, Amanda M. Tadini, Aleksandar I. Goranov, Stéphane Mounier, Débora M.B.P. Milori, Célia R. Montes, Patrick G. Hatcher Jan 2025

Molecular Characterization Of Humic And Fulvic Acids On Watterlogged And Well-Drained Amazonian Podzols, Amanda M. Tadini, Aleksandar I. Goranov, Stéphane Mounier, Débora M.B.P. Milori, Célia R. Montes, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The Amazon rainforest is the largest tropical rainforest in the world. Amazonian Podzol soils, characteristic of this region, are known to store substantial amounts of organic carbon in both their surface and deep horizons. Despite decades of research, the molecular-level composition of these soils remains uncharacterized. This study addresses this knowledge gap by employing ultrahigh resolution mass spectrometry, namely, Fourier transform–ion cyclotron resonance–mass spectrometry (FT-ICR-MS), to determine the molecular composition of humic acid (HA) and fulvic acid (FA) fractions from two Amazonian Podzol profiles of varying levels of groundwater exposure (waterlogged vs well-drained). In the waterlogged soil compounds containing nitrogen, …


Oxidation Camouflages Terrestrial Organic Matter To Appear Marine-Like, Aleksandar I. Goranov, Susan J. Carter, Ann Pearson, Patrick G. Hatcher Jan 2025

Oxidation Camouflages Terrestrial Organic Matter To Appear Marine-Like, Aleksandar I. Goranov, Susan J. Carter, Ann Pearson, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The export of terrestrial organic matter (TOM) to the ocean has been traditionally viewed to be minimal or only of significance in near-coastal continental margins. The broadly accepted explanation for the widespread loss of terrestrial lignin biomarkers and apparent disappearance of the <-25‰ stable carbon isotopic signature (δ¹³C) of TOM is that TOM is almost fully degraded before reaching the open ocean. Oceanic carbon (δ¹³C value ≥ -22‰) is therefore thought to be derived primarily from algae. However, an alternative explanation for the different molecular and δ¹³C signatures in terrestrial and marine environments may be that oxidative processing transforms TOM to appear marine-like. To test this hypothesis, we subjected eight TOM samples to a strong oxidation gradient. At carbon losses typical of TOM degradation during transport and sedimentation (above 60%), the differentiators of provenance disappeared, leaving a residue that was marine-like both chemically (aliphatic- and nitrogen-rich) and isotopically (δ¹³C enrichment of 4 to 9‰). This challenges the validity of conventional two-endmember mixing models, suggesting that a much larger fraction than previously estimated of the organic matter found in the ocean may originate from terrestrial sources, impacting global models of carbon cycling and sequestration.


Cropsync: Ai-Powered Sustainable Crop Management, Ziad Doughan, Ibrahim Mneimneh, Zouheir Nakouzi, Noor Al Khaib, Samer Damaj, Jamal Chaaban, Hamza Mrad, Sari Itani Dec 2024

Cropsync: Ai-Powered Sustainable Crop Management, Ziad Doughan, Ibrahim Mneimneh, Zouheir Nakouzi, Noor Al Khaib, Samer Damaj, Jamal Chaaban, Hamza Mrad, Sari Itani

BAU Journal - Science and Technology

CropSync is a smart agriculture system that uses AI and IoT technologies to enable sustain- able crop management and precision farming. The system aims to address the challenges faced by the agriculture sector, such as increasing food production to meet global population demands while minimizing environmental impact. CropSync integrates sensors, cameras, and cloud-based analytics to provide farmers with real-time insights and recommendations for optimizing crop cul- tivation. The system upholds engineering professional and ethical standards, considering broader social, environmental, and economic implications. From a social perspective, CropSync improves food security and enhances farmers’ livelihoods through increased productivity and efficient re- …


Evaluating The Usefulness Of Geochronometers In The Packsaddle Domain For Refining The Timing Of Metamorphism Via High-Resolution Petrography, Enchanted Rock State Natural Area, Llano Uplift, Texas, Haylee Vike Dec 2024

Evaluating The Usefulness Of Geochronometers In The Packsaddle Domain For Refining The Timing Of Metamorphism Via High-Resolution Petrography, Enchanted Rock State Natural Area, Llano Uplift, Texas, Haylee Vike

Electronic Theses and Dissertations

The Llano uplift, central Texas, exhumes Mesoproterozoic rocks with a complex history of metamorphism, deformation, and magmatism. There are three recognized metamorphic events related to the Grenville orogeny (~1.3-0.9 Ga). The timing of these metamorphic events is not well resolved due to past methods, technology, and lack of published geologic context for many of the current dates. These current time constraints on metamorphic timing could be further refined through modern geochronologic and petrochronologic methods.

A majority of U-Pb zircon dates from the Valley Spring (~1366-1232 Ma), Coal Creek (~1326-1275 Ma), and Packsaddle (~1257-1215 Ma) domains are interpreted as crystallization ages …


Are There Neurological Impacts Of Exposure To A Burned Wildfire Site As It Recovers?, Rubye Strickland Dec 2024

Are There Neurological Impacts Of Exposure To A Burned Wildfire Site As It Recovers?, Rubye Strickland

Undergraduate Honors Theses

Wildfires are increasing with climate change, making the human health implications of exposure to burned soils an essential area of research. Metals associated with fire-impacted soils can be inhaled or accidentally ingested by surrounding communities, causing health risks. Several studies have evaluated the health impact of wildfires, but few have done so from a neurological perspective. This study explores metal changes in burned soils over time as a site naturally recovers from wildfire and how these changes may impact human neurological health. Soil samples were collected from the burned area 0, 3, 6, 9, and 12 months after the fire. …


Biogeochemical Controls Of Cesium-137 Migration In Surface Waters And Near Surface Sediments At The Usdoe Savannah River Site, Reid Williams Dec 2024

Biogeochemical Controls Of Cesium-137 Migration In Surface Waters And Near Surface Sediments At The Usdoe Savannah River Site, Reid Williams

All Dissertations

Considerable concentrations of cesium-137 (137Cs) and other anthropogenic radionuclides have been released into the environment at the Savannah River Site (SRS). Additionally, cesium-containing radioactive waste will be stored onsite for the foreseeable future. Therefore, the goal of this work was to identify mechanisms controlling cesium transport in surface waters and near surface sediments at SRS to further the understanding of 137Cs migration in the vadose zone and reservoirs. It was hypothesized that a multitude of factors impact the mobility of 137Cs at the SRS, but that the clay sediment fraction provides an important contribution in limiting …


Evidence For Subsidence Rate Variation In The Newark Basin And Its Influence On The Deposition Of Fluvial Sediments Of The Stockton Formation, Jane L. Alexander, Sean T. Thatcher, Jay Tobon, Victoria Rivelli Nov 2024

Evidence For Subsidence Rate Variation In The Newark Basin And Its Influence On The Deposition Of Fluvial Sediments Of The Stockton Formation, Jane L. Alexander, Sean T. Thatcher, Jay Tobon, Victoria Rivelli

Publications and Research

The Stockton Formation of the Newark Basin represents an exciting time in Earth history during the early stages of rifting of the North Atlantic, with rapid subsidence and sediment deposition. Much of the previous work on this formation has been done using drill cores, with development limiting surface exposure. While this allows us to build a full stratigraphic sequence of deposition, it has the potential to miss smaller-scale variability and sedimentary structures. It is also difficult to understand the three-dimensional geometries, architecture and relationships between the depositional elements from drill core alone. An outcrop in North Bergen, NJ that was …


Comparison Of Soil Organic Matter Fractions In Non-Grazed And Prescribed Sheep-Grazed Managed Land In Southwest Michigan, Julia M. Shreve, Katelyn Smith, Lauren Burns Nov 2024

Comparison Of Soil Organic Matter Fractions In Non-Grazed And Prescribed Sheep-Grazed Managed Land In Southwest Michigan, Julia M. Shreve, Katelyn Smith, Lauren Burns

Student Summer Scholars Manuscripts

The impact of prescribed sheep grazing on soil organic carbon (SOC) was investigated by comparing a 2-acre grazed and a 2-acre non-grazed (control) portion of redeveloped land previously seeded with pasture mix in Southwest Michigan. This study aimed to measure changes in SOC resulting from prescribed sheep grazing by examining two key soil organic matter (SOM) fractions: particulate organic matter (POM) and mineral-associated organic matter (MAOM) along with soil physical and chemical properties (e.g., bulk density, infiltration rate, moisture content, pH, conductivity). Soil cores were collected from 5 locations within each of the 2-acre plots using a diagonal random sampling …


Manifestations Of Sulfuric Acid Speleogenesis In The Mulapampa Travertine, Central Andes Of Peru: Evidence From The Gruta Con Lago, Andrzej Tyc, Krzysztof Gaidzik, Justyna Ciesielczuk, Katarzyna Wątor Oct 2024

Manifestations Of Sulfuric Acid Speleogenesis In The Mulapampa Travertine, Central Andes Of Peru: Evidence From The Gruta Con Lago, Andrzej Tyc, Krzysztof Gaidzik, Justyna Ciesielczuk, Katarzyna Wątor

International Journal of Speleology

Sulfuric acid speleogenesis (SAS) is a form of hypogene speleogenesis characterized by the formation of caves in carbonate rocks due to the presence of sulfuric acid. This study focuses on the Gruta con Lago, one of three caves identified in the Mulapampa travertine, located in the central Andes of Peru. These caves are accessed through collapse sinkholes, and much of their morphology results from roof breakdown. The bottom of the studied cave is situated at the current water table. Despite the absence of typical solutional features associated with SAS caves, mineralogical and geochemical evidence of speleogenesis involving H2SO …


Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller Sep 2024

Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller

Master's Theses

An extensive laboratory test program was conducted to analyze and compare the cation exchange processes in three different varieties of sodium bentonite (Na-B) geosynthetic clay liners (GCLs) over increased conditioning durations up to 32 days and investigate the effects of temperature, solution strength, and applied stress. The goal of this test program was to establish whether the variables of temperature, solution strength, and applied stress improved or degraded the engineering properties of GCLs in laboratory testing and municipal solid waste (MSW) landfill applications. The GCLs were conditioned in liquids of increasing ionic strength, using deionized water and 2, 50, and …


Hypogenic Caves Of Syracuse Area, Sicily (Italy): Geomorphological Evidence Of Co2 Degassing, Fresh-Salt Water Mixing, And Late Condensation Corrosion, Philippe Audra, Jean-Yves Bigot, Didier Cailhol, Pierre Camps, Ilenia M. D'Angeli, Hai Cheng, R. Lawrence Edwards, Fernando Gàzquez-Sanchez, Gabriella Koltai, Giuliana Madonia, Jean-Claude Nobécourt, Marjan Temovski, Marco Vattano, Jo De Waele Aug 2024

Hypogenic Caves Of Syracuse Area, Sicily (Italy): Geomorphological Evidence Of Co2 Degassing, Fresh-Salt Water Mixing, And Late Condensation Corrosion, Philippe Audra, Jean-Yves Bigot, Didier Cailhol, Pierre Camps, Ilenia M. D'Angeli, Hai Cheng, R. Lawrence Edwards, Fernando Gàzquez-Sanchez, Gabriella Koltai, Giuliana Madonia, Jean-Claude Nobécourt, Marjan Temovski, Marco Vattano, Jo De Waele

International Journal of Speleology

Many caves in Sicily have been shown to have a sulfuric acid or other hypogenic origin. We studied three caves (Palombara, Scrivilleri, Monello) near Syracuse (eastern Sicily), in an area that was strongly uplifted and faulted, creating multiple Pleistocene marine terraces. Mineralogy, stable isotopes and dating methods (paleomagnetism, U/Th) were used to characterize cave sediments, some of which were related to the initial hypogenic phase (Fe and Mn oxides, calcite spar), others were introduced by surface runoff later. Many other sediments are the result of in situ weathering, such as lime sands produced by condensation-corrosion processes on the calcarenite walls. …


Hypogene Speleogenesis In Carbonates By Cooling Hydrothermal Flow: The Case Of Mt. Berenike Caves, Israel, Roi Roded, Boaz Langford, Einat Aharonov, Piotr Szymczak, Micka Ullman, Shemesh Yaaran, Boaz Lazar, Amos Frumkin Aug 2024

Hypogene Speleogenesis In Carbonates By Cooling Hydrothermal Flow: The Case Of Mt. Berenike Caves, Israel, Roi Roded, Boaz Langford, Einat Aharonov, Piotr Szymczak, Micka Ullman, Shemesh Yaaran, Boaz Lazar, Amos Frumkin

International Journal of Speleology

The Berenike hypogenic cave system near Lake Kinneret, Israel, provides a valuable case study for investigating the recently proposed Confined-Cooling-Flow (CCF) speleogenesis model. Field and speleological surveys, along with existing research, are used to provide a thorough analysis. The CCF model relies on a simple thermo-hydro-chemical scenario, involving the rise of CO2-rich hydrothermal fluids discharging into a confined layer. The cooling of these CO2-rich fluids turns them into aggressive solutions due to the inverse relation between temperature and solubility of carbonates (retrograde solubility). Previous geochemical and numerical analyses of the CCF model predict localized and persistent dissolution and speleogenesis on …


Diatom-Inferred Hydroclimate Variability In Marl Lake, Wi Over The Past ~2050 Years, Christian E. Sizemore Aug 2024

Diatom-Inferred Hydroclimate Variability In Marl Lake, Wi Over The Past ~2050 Years, Christian E. Sizemore

All-Inclusive List of Electronic Theses and Dissertations

Hydroclimate variability in the Midwest has increased over the past few decades, as as evidenced by increases in average precipitation and frequency of extreme hydroclimate events. Understanding natural climate variability in this region will help communities in the Midwest to better prepare and mitigate the risks associated with extreme hydroclimate variability in the future. Natural lakes in the Midwest are often effective archives of hydroclimate; many have been shown to respond directly to changes in climate both locally and regionally. We extracted a 4.5-meter sediment core, representing approximately 2050 years of sediment accumulation, from the deepest part of Marl Lake …


Zebra Limestone From The Gypsum Valley Salt Diapir, Colorado, Rebecca Navarrette Aug 2024

Zebra Limestone From The Gypsum Valley Salt Diapir, Colorado, Rebecca Navarrette

Open Access Theses & Dissertations

Zebra rocks displaying alternating light and dark-colored millimeter to centimeter thick bands of crystals have been found at the Gypsum Valley salt diapir, Colorado in the Paradox Basin where they are associated with gypsic diapiric caprock. Elucidating their origin may provide crucial information about intermittent fluid flow at the margin of salt diapirs and about Zebra rock formation, which often is associated with carbonate-hosted lead-zinc mineralization (Mississippi Valley Type, MVT) and hydrothermal dolomite -hosted hydrocarbon reservoirs.

The Gypsum Valley Zebra rocks consist of calcite, i.e., it is a Zebra limestone. It shows a finely crystalline light banding and coarsely crystalline …


Method Development For The Quantification Of Critically Valuable Elements In Permian Basin Produced Waters, Carley Oliver Aug 2024

Method Development For The Quantification Of Critically Valuable Elements In Permian Basin Produced Waters, Carley Oliver

Open Access Theses & Dissertations

Produced waters (PW) are a major byproduct of the oil and gas industrial hydraulic fracturing processes that create a major waste disposal issue with a need for disposal, treatment, and reuse method developments. The current primary disposal method is subsurface injection, which can lead to high pressures in the subsurface. PWs are often highly saline from mineral leaching due to long residence in subsurface reservoirs. According to the USGS National Minerals Information Center, bromine, calcium chloride, iodine, lithium, magnesium, and sodium chloride have been found in and extracted from these domestic subsurface brines, suggesting that there may be other economically …


Analyzing Fe/Mg-Silicate Chemical Gardens As Analogs To Silicate-Rich Hydrothermal Chimneys On Early Earth And Mars, Nancy Alejandra Carman Aug 2024

Analyzing Fe/Mg-Silicate Chemical Gardens As Analogs To Silicate-Rich Hydrothermal Chimneys On Early Earth And Mars, Nancy Alejandra Carman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrothermal systems have been proposed as environments for prebiotic chemistry on early Earth. Ancient Mars was an ocean world and could also have had hydrothermal vents supporting biological or prebiotic processes. The Strytan Hydrothermal Field (SHF) in Iceland is a basalt-hosted alkaline vent that forms massive hydrothermal Mg-saponite chimneys and is a potential analog to basalt-hosted alkaline vents that may have existed at the Eridania basin on Mars, where saponite deposits are thought to have formed from ancient hydrothermal activity. Chemical garden experiments have previously been used to simulate aspects of hydrothermal chimney growth for other types of vent systems; …


Constraining The Evolutionary Stages Of A Hypogene Karst System By Combining Morphological, Geochemical And Geochronological Data - The Example Of Carbonate Breccia-Hosted Melnička Peštera, Marjan Temovski, Zsófia Ruszkiczay-Rüdiger, Kata Molnár, László Rinyu, Alexander Wieser, Oscar Marchhart, László Palcsu Jul 2024

Constraining The Evolutionary Stages Of A Hypogene Karst System By Combining Morphological, Geochemical And Geochronological Data - The Example Of Carbonate Breccia-Hosted Melnička Peštera, Marjan Temovski, Zsófia Ruszkiczay-Rüdiger, Kata Molnár, László Rinyu, Alexander Wieser, Oscar Marchhart, László Palcsu

International Journal of Speleology

A combination of morphological observations, geochemical data from calcite minerals and geochronology by burial age dating and U-series is used to constrain the geological and geomorphological setting and the evolutionary stages of a hypogene karst system. This methodological suit is applied to Melnička Peštera, a horizontal cave developed in carbonate breccia overlying dolomite marble in Melnica locality (N. Macedonia), where hydrothermal karst development occurred in both dolomite and calcite marble. The passage morphology of the cave, having a reverse triangle, Laughöhle cross-sections, suggests development near the water table by slowly moving waters. Calcite crusts are found throughout the cave, and …


Revealing The Ongoing Speleogenetic Processes In An Underwater Cave Through The Application Of Natural Radionuclides And Stable Isotopes: Case Study From The Hypogene Buda Thermal Karst, Anita Erőss, Katalin Hegedűs-Csondo, Petra Kovács-Bodor, Dénes Szieberth, Ákos Horváth, György Czuppon, Andrea Mindszenty Dr, Szabolcs Leél-Őssy, Judit Mádl-Szőnyi Jul 2024

Revealing The Ongoing Speleogenetic Processes In An Underwater Cave Through The Application Of Natural Radionuclides And Stable Isotopes: Case Study From The Hypogene Buda Thermal Karst, Anita Erőss, Katalin Hegedűs-Csondo, Petra Kovács-Bodor, Dénes Szieberth, Ákos Horváth, György Czuppon, Andrea Mindszenty Dr, Szabolcs Leél-Őssy, Judit Mádl-Szőnyi

International Journal of Speleology

The underwater Molnár János Cave in the hypogene Buda Thermal Karst system (Budapest, Hungary) provides a unique site to study the effects of flowing groundwater and the interplay of fluids of different origin. The aim of the present study is to characterize the groundwater in different parts of the cave with temporal resolution, hence describe the recent speleogenetic processes within the cave. This study uses natural radioisotopes (uranium, radium, and radon) besides stable isotope ratios of oxygen and hydrogen to identify the different fluid components. The results show that the majority of the cave is situated in the flow path …


Chemical And Morphological Characterization Of Airborne Particulate Matter At The Jackpile-Paguate Mine, Pueblo Of Laguna, New Mexico: Implications For Potential Metals Exposure, Andreanna C. Roros Jul 2024

Chemical And Morphological Characterization Of Airborne Particulate Matter At The Jackpile-Paguate Mine, Pueblo Of Laguna, New Mexico: Implications For Potential Metals Exposure, Andreanna C. Roros

Earth and Planetary Sciences ETDs

The inhalation of windblown particulate matter (PM) derived from abandoned uranium mines (AUMs) is a potential environmental health risk to Native American communities that live in proximity to these sites. However, the aeolian transport of metal-bearing PM from AUMs, as a potential exposure pathway, has not been investigated in any detail. In this study, we sampled airborne particulate matter within the Jackpile Mine located on the lands of the Pueblo of Laguna, New Mexico using passive sampling methods to understand the characteristics of dust within the mine site. The objective was to determine the elemental concentrations, mineralogy, and morphology of …


Carbonate And Organic Proxies And The Impacts Of Climate On Lake Systems: Paleoclimate Interpretations From Lake Chalco, Mexico, Aria Holmes Jul 2024

Carbonate And Organic Proxies And The Impacts Of Climate On Lake Systems: Paleoclimate Interpretations From Lake Chalco, Mexico, Aria Holmes

Earth and Planetary Sciences ETDs

This project incorporates several lines of evidence to better understand the climate at Lake Chalco. Chapter 1 utilizes oxygen isotopes from carbonates and show that the Inter Tropical Convergence Zone varies on primarily glacial and millennial timescales; precession is not observed. These data indicate glacials periods were shallower and interglacials were wetter periods at Lake Chalco. Chapter 2 studies carbon, nitrogen, C/N, and TOC proxies and finds that the lake conditions during the glacials and interglacials are primarily a mixed algal-macrophyte-terrestrial organic matter. Deviations show that the lake during the interglacials had more algal organic matter- reflecting influxes of nutrients …


Resolving Antarctic Margin Paleoceanography For Two Different Timescales And Archives, Theresa M. King Jun 2024

Resolving Antarctic Margin Paleoceanography For Two Different Timescales And Archives, Theresa M. King

USF Tampa Graduate Theses and Dissertations

Recent decades have seen increased rates of ice mass loss from Antarctic ice sheets, through thinning of many ice shelves around the periphery of the continent. The most vulnerable are the glacial systems that are marine-terminating and grounded below sea level, a characteristic that exposes these systems to sea level rise and warming oceans. Enhanced basal melting under the influence of warm ocean water masses can lead to thinning and retreat of glaciers, and ultimately to the acceleration of grounded ice loss. To contextualize current ice mass loss and contribute to accurate model projections for future retreat scenarios, it is …


Antarctic Atmosphere-Ocean-Ice Interactions During Past Warm Climates: An Ice-Proximal Perspective, Imogen Mireille Browne Jun 2024

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 …


Role Of Hypogenesis In The Evolution Of Karst In The Taurus Mountains Range, Turkey, Serdar C. Bayari, Naciye Nur Özyurt, Lütfi Nazik, Koray A. Törk, Noyan İ. Güner, Emrah Pekkan, Pınar Avcı Jun 2024

Role Of Hypogenesis In The Evolution Of Karst In The Taurus Mountains Range, Turkey, Serdar C. Bayari, Naciye Nur Özyurt, Lütfi Nazik, Koray A. Törk, Noyan İ. Güner, Emrah Pekkan, Pınar Avcı

International Journal of Speleology

Field observations and laboratory data collected from the Taurus Mountains Range, Turkey during the last two decades provided evidence for the link between the evolution of hypogene karst and the geodynamic history. Major evidence includes; carbonate-hosted secondary ore deposits that are converted from primarily hypogene minerals by epigene, oxygen-rich groundwater circulating at local to intermediate depths. Another piece of evidence of hypogene karst in the Tauride is the Kırkgöz springs’ huge submerged cave/conduit system, which formed the Antalya Travertine Plateau, which is the world’s largest deposit precipitated by cool karst groundwater. The obruks in central Tauride are giant collapse dolines …


Lead Along Arid Route 66: Concentration, Fate, Surface Transport, And Awareness, Dominic Joel Ombati Jun 2024

Lead Along Arid Route 66: Concentration, Fate, Surface Transport, And Awareness, Dominic Joel Ombati

Loma Linda University Electronic Theses, Dissertations & Projects

Fate and transport of lead (Pb) are well studied in humid, high precipitation environments. Few studies have compared or addressed fate of lead (Pb) in arid, low precipitation areas where the soil binding capacity may differ from classic studies. The goal of this study is to identify the control of fate and transport in the arid section of Route 66 by determining the concentration, chemical forms, and surface transport mechanism of lead (Pb) along the arid section of Route 66. Understanding the fate and transport of lead (Pb) in different environments is key in the environmental mitigation of lead (Pb) …


Using A Novel Chain Of Chemical, Crystallographic, And Isotopic Analytical Techniques To Examine The Formation Histories Of Features In Chondritic Meteorites And Orbicular Granites, Samuel P. Alpert Jun 2024

Using A Novel Chain Of Chemical, Crystallographic, And Isotopic Analytical Techniques To Examine The Formation Histories Of Features In Chondritic Meteorites And Orbicular Granites, Samuel P. Alpert

Dissertations, Theses, and Capstone Projects

Understanding the chemistry, crystallography, and isotopic variability of minerals allows us to place significant constraints on the formation history of their host rocks. These constraints provide insight into everything from the distribution of water in the solar system to the onset of plate tectonics. Electron beam instruments and ion probes are important tools used by modern geologists to obtain crystallographic, chemical, and isotopic data. Here I present a new workflow, using these instruments, combining wavelength dispersive spectrometry (WDS), backscattered electron (BSE) imaging, machine learning algorithms, electron backscatter diffraction (EBSD), and secondary ion mass spectroscopy (SIMS), to place quantitative constraints on …


Searching For The Hyperobject: Crystals As Transscalar Vehicles, Jay Costello Jun 2024

Searching For The Hyperobject: Crystals As Transscalar Vehicles, Jay Costello

Masters Theses

When I touch the street outside my house, I'm touching Los Angeles—a contiguous vector of material bisecting a continent. A slab, a stone, dust and oil, a googolplex of tightly packed anisotropic particles... At nightfall, I sneak to the edge of the highway and break off a piece. 'What does it mean for a worm to be aware of the scale of the planet?' Bruno Latour's evocative questioning of scalar jumps prompts an existentialism that places me somewhere between the hyperlocal and the massively distributed. Like a cosmic traveler floating through the universe, I feel adrift. I look around, grasping …


Geochemistry And Geochronology Of The Steens And Monument Dike Swarm: Implications And Relationships To Magmatic Storage And To Lava Flows Of The Picture Gorge And Steens Basalt, Rachel Anne Sweeten May 2024

Geochemistry And Geochronology Of The Steens And Monument Dike Swarm: Implications And Relationships To Magmatic Storage And To Lava Flows Of The Picture Gorge And Steens Basalt, Rachel Anne Sweeten

Dissertations and Theses

The Columbia River Basalt Group (CRBG) is the youngest and best-preserved example of a continental flood basalt province. Vents and dikes for the four main eruptive units (Steens, Imnaha, Grande Ronde, and Picture Gorge Basalt) are the Monument, Steens and Chief Joseph Dike Swarms located in eastern Oregon, southeastern Washington, and northern Nevada.

Here we report on the compositions and timing of the dikes and sills of the Monument Dike Swarm (MDS), as well as their relationship to the subaerial lava flows of the Picture Gorge Basalt (PGB) with implications for crustal storage of these magmas. We evaluate data from …


Investigating The Formation Of The Zirconium-Rich Lithologies Of The Grenville Province Using Zircon Thermometry Of Granitoids From The Adirondack Mountains, John St. Denny May 2024

Investigating The Formation Of The Zirconium-Rich Lithologies Of The Grenville Province Using Zircon Thermometry Of Granitoids From The Adirondack Mountains, John St. Denny

Theses - ALL

The Grenville Province (1200-980 Ma) is known to consist of many rocks which are abundant in zircon. This is seen by the large size of Grenville-age zircons and their abundance in the detrital record. A possible explanation for this is the temperature at which these rocks formed. This hypothesis states that the melts which formed the zircon-rich Grenville lithologies were exceptionally high temperature, enabling them to incorporate a significant amount of zirconium. As it is believed that most zirconium in a melt is incorporated into zircon, a high concentration of zirconium in a magma would crystallize an abundance of zircon. …