Utilizing Phylogenetic And Geochemical Techniques To Examine Echinoderms Through Time, 2023 University of Tennessee, Knoxville
Utilizing Phylogenetic And Geochemical Techniques To Examine Echinoderms Through Time, Maggie Ryan Limbeck
Doctoral Dissertations
Understanding biotic changes through Earth’s history has been the goal of paleobiology since the inception of the field. Advances in science and technology have progressed allowing us to reassess old questions and new questions that could have not been addressed without these new methods. Echinoderms (sea stars, sea urchins, etc.) appear in the fossil record during the early Cambrian and are still abundant in marine ecosystems today. This persistence through time has made echinoderms model organisms to answer questions about Earth’s past and present. Despite this role as a model organism there are many questions that remain with respect to …
Metagenomic Investigation Of Microbial Dark Carbon Fixation, Viral Interactions, And Horizonal Gene Transfer Within A Convergent Margin Subsurface Ecosystem, 2023 University of Tennessee, Knoxville
Metagenomic Investigation Of Microbial Dark Carbon Fixation, Viral Interactions, And Horizonal Gene Transfer Within A Convergent Margin Subsurface Ecosystem, Timothy Joseph Rogers
Doctoral Dissertations
Convergent margins are geological regions where two or more tectonic plates collide, and the denser “subducting slab” is pushed beneath the less dense overriding plate. As the slab descends, it devolatilizes under higher temperatures and pressures, allowing dissolved inorganic carbon (DIC) and redox active volatile rich fluids to cycle between the upper crust and Earth’s mantle. These fluids migrate through cracks and fissures in the upper mantle and crust, fueling chemolithoautotrophy-based microbial ecosystems in the subsurface before they are expelled on the surface in the form of hydrothermal seeps and springs. Chemolithoautotrophic ecosystems, such as those in the Costa Rican …
Numerical And Experimental Constraints On Trace Element Fractionation During Lunar Magma Ocean Solidification, 2023 University of Tennessee, Knoxville
Numerical And Experimental Constraints On Trace Element Fractionation During Lunar Magma Ocean Solidification, Dian Ji
Masters Theses
Traditional lunar magma ocean (LMO) theory suggests the anorthositic lunar crust formed by floating of buoyant plagioclase, one of the major products of LMO solidification, on the surface of LMO. To test this model, after applying experimentally determined LMO solidification sequences, we compared calculated Rare Earth Element (REE) concentrations of lunar plagioclase to plagioclase in Apollo ferroan anorthosites and lunar anorthositic meteorites. Several initial LMO compositions, and lunar-relevant mineral-melt partition coefficient predictive models were tested (where the partition coefficient is the concentration ratio of a specific element between two phases). Compared with plagioclase in the natural samples, modeled plagioclase directly …
A Hybrid Lateral Flow Sand Filter Wastewater Treatment System: An Evaluation On The Treatment And Disposal Capabilities Of A Modified Sand Filter, 2023 University of South Alabama
A Hybrid Lateral Flow Sand Filter Wastewater Treatment System: An Evaluation On The Treatment And Disposal Capabilities Of A Modified Sand Filter, Harry Mccaskill Iv
Theses and Dissertations
Decentralized wastewater treatment exists primarily in suburban and rural areas where centralized treatment is not an option. Traditional on-site treatment systems usually include the use of a septic tank and a drain field. This orthodox method works well when implemented into environments that are accommodating for the infiltration of effluents, and thus allowing for soil treatment. Unfortunately, there are some circumstances that prevent traditional systems from working such as impermeable soil conditions. The Wastewater Treatment System analyzed in this thesis was created to overcome such inhospitable environments. More specifically, this system is catered towards the rural residences of The Alabama …
Thames River Subwatershed Soil, Sediment, Water Data, 2023 University of Massachusetts Amherst
Thames River Subwatershed Soil, Sediment, Water Data, Justin B. Richardson, Mark J. Butler
Data and Datasets
Trace element and nutrient data are for riparian soils, suspended sediments, eddy bottom sediments, and river water collected between 2019 and 2020 in the Thames River watershed of Connecticut, USA. Trace elements and nutrients were measured using EPA 3050B digestion method and analyzed by ICP-OES or ICP-MS.
Polygonal Faults In The Austin Chalk: Invariance Of Scale From Mud Cracks To Polygons With Implications Of Structural, Geomorphic And Isotopic Data On Polygonal Fault Geometry And Origin., 2023 Southern Methodist University
Polygonal Faults In The Austin Chalk: Invariance Of Scale From Mud Cracks To Polygons With Implications Of Structural, Geomorphic And Isotopic Data On Polygonal Fault Geometry And Origin., Kun Shang
Earth Sciences Theses and Dissertations
The Cretaceous Austin Chalk contains large numbers of fractures and normal faults whose orientations have been attributed to either regional stresses (e.g., the Balcones fault trend) or, by analogy with the mudrocks, to polygonal faulting resulting from compaction. In this study, we present geomorphic data, field study, and stable isotope data to support that the majority of these faults in North Texas are polygonal. Field-measured fault orientations suggest randomly distributed fault strikes, indicating a polygonal fault structure. Using geomorphologic data (topographic and DEM data) on stream orientations suggests that the polygonal fault patterns are best reflected in the headwater (1st …
Environmental Chemical Analysis Method Optimization And Application To Northwest Cuban Marine Sediment, 2023 University of South Florida
Environmental Chemical Analysis Method Optimization And Application To Northwest Cuban Marine Sediment, Thea R. Bartlett
USF Tampa Graduate Theses and Dissertations
A method for gas chromatography tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode has been optimized to quantify 250 compounds of a variety of compound classes such as polycyclic aromatic hydrocarbons (PAHs), oxidized PAHs, organochlorinated pesticides, polychlorinated biphenyls, biomarkers (hopanes, steranes, tri-aromatic steroids, and fecal sterols), aliphatic hydrocarbons, and plastic additives. This method was validated based on available QA/QC standards using several environmental samples, both sediment and biota, and standard reference materials. This contaminant-focused method can be used as a forensic geochemistry tool to evaluate oil contamination and other contaminant histories in future research studies. When applied to …
A Typological And Chemical Analysis Of Roman Oil Lamps From Poggio Del Molino, 2023 The Graduate Center, City University of New York
A Typological And Chemical Analysis Of Roman Oil Lamps From Poggio Del Molino, Brandon Tejo
Dissertations, Theses, and Capstone Projects
Terracotta lamps, known to the Romans as lucernae, are small, handheld, often decorated objects which provided ancient people light. To modern researchers, they serve as tools for dating stratigraphy and iconographic studies. Beyond their immediately apparent aesthetic and symbolic value, the chemical compositions of the clay of these lamps reflect their origin. This study complements archaeological typologies with chemometric analyses to describe 16 Late Republican and Imperial Roman lamps recovered from the villa at Poggio del Molino (PdM), Tuscany. These finds were recovered from the 2021 and 2022 PdM excavations. The combined approach of typology with X-ray Diffraction (XRD) …
Untangling The Nature And Timescales Of Magmatic Processes Driving Eruptions At Quiescent Volcanoes: Examples From Momotombo, Nicaragua, And Cumbre Vieja, Canary Islands, 2023 The Graduate Center, City University of New York
Untangling The Nature And Timescales Of Magmatic Processes Driving Eruptions At Quiescent Volcanoes: Examples From Momotombo, Nicaragua, And Cumbre Vieja, Canary Islands, Samantha Tramontano
Dissertations, Theses, and Capstone Projects
Across all scales of human relationships (i.e. person-to-person, country-to-country, etc.), qualms can take the form of long-standing wars, quick and intense bouts, or petty exchanges. While our understanding of human behavior is ever increasing, reactions and behaviors of self and others may still come as a surprise. Expressions of disagreement can occur suddenly or following years to centuries of accumulated grievances. The solid earth is also a system that behaves (like human emotion) predictably at times and unpredictably at other times. Some volcanoes, a tangible surface expression of solid earth processes, exhibit precursory signals prior to eruption (e.g. the bulging …
Interannual Variation Of Ichthyofaunal Utilization Of A Man-Made Salt Marsh Creek In Mission Bay, California, 2023 University of San Diego
Interannual Variation Of Ichthyofaunal Utilization Of A Man-Made Salt Marsh Creek In Mission Bay, California, Maria Angst
Undergraduate Honors Theses
Marsh restoration and creation are increasingly being used to mitigate Southern California’s drastic decline in wetlands due to human activities. This study used minnow traps to resample the ichthyofauna of a created marsh (Crown Point Mitigation Site; CPMS) and an adjacent natural marsh (Kendall Frost) in Mission Bay, California, 26 years following the marsh creation. Data from this study were compared to data collected immediately after marsh creation from 1995-1998, and from 2021. Fishes captured included Fundulus parvipinnis, Gillichthys mirabilis, Acanthagobius flavimanus, Ctenogobius sagittula, and Mugil cephalus. Species richness and dominance measures were higher in the natural relative to the …
Understanding The Connection Between Gypsum Blooms And Human Health At The Salton Sea, 2023 University of San Diego
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 …
Investigation Of The Sheep Creek Carbonatites, Ravalli County, Montana, 2023 Montana Tech
Investigation Of The Sheep Creek Carbonatites, Ravalli County, Montana, Sarah Risedorf
Graduate Theses & Non-Theses
Carbonatite-related REE-Nb mineralization in southern Ravalli County, Montana was first discovered in the late 1950s and early 1960s. Over 30 discontinuous carbonatite bodies occur in a ~ 10 km2 area centered on Sheep Creek, a tributary to the headwaters of the West Fork of the Bitterroot River (WFBR). The deposits are contained in a belt that extends to the southeast into the Mineral Hill district of Lemhi County, Idaho. Country rocks include a deformed and metamorphosed bimodal igneous suite of diabase and A-type granite, both dated to 1.37 Ga by previous workers. These rocks are locally metamorphosed to amphibolite …
The Impact Of Glacial Proximity On The Elemental Composition Of Leachate Derived From Sediment Weathering, 2023 University of Nebraska at Omaha
The Impact Of Glacial Proximity On The Elemental Composition Of Leachate Derived From Sediment Weathering, Karoline Ford
Theses/Capstones/Creative Projects
This study assesses chemical weathering trends as they relate to glacial retreat. The chemical environment of surfaces exposed to the atmosphere differs significantly from beneath a glacier. As a glacier melts, changes to the biogeochemical processes generate environmental gradients. This study analyzed chemical weathering signals at different distances from a glacial front by comparing the elemental composition of leachate derived from sediments in southeastern Greenland. Samples from proglacial, nonglacial, and moraine locations were weathered in a laboratory setting, and ion chromatography was used to determine the elemental composition of the products. Divergent trends in leachate composition were observed as distance …
Study Of Trace Elements In Southern Nevada Spring Waters And Lakes, 2023 University of Nevada, Las Vegas
Study Of Trace Elements In Southern Nevada Spring Waters And Lakes, Hyejeong Lee
UNLV Theses, Dissertations, Professional Papers, and Capstones
Comprehending the natural water resource is imperative for the entire state of Nevada and of particular significance for Southern Nevada, where rapid population growth and climate change are placing significant strain on supplies. This research underscores the significance of water chemistry in identifying potential water source areas through trace elements. For the first time, the study proposed measuring the compositions of the entire suite of metal elements, ranging from Li to U, in over 40 springs in the Moapa Valley and its upper gradient valleys, utilizing the iCAP Qc ICP-MS (Inductively Coupled Plasma Mass Spectrometer) at UNLV. The research evaluated …
Modeled Uranium Series Disequilibria In A Heterogeneous Mantle Underlying Iceland, 2023 University of Nebraska-Lincoln
Modeled Uranium Series Disequilibria In A Heterogeneous Mantle Underlying Iceland, Dana Andersen
Honors Theses
Regional lithologic heterogeneities in Earth’s mantle may significantly contribute to variations in magma productivity and crustal generation. Such heterogeneities may be a key factor in the anomalously high rates of magmatism and thickened crust of Iceland, which are not fully explained by the presence of a mantle plume. However, the exact lithologic composition of the mantle underlying Iceland is largely unknown. Recent trace element modeling has suggested a two-component melt source beneath Iceland, consisting of a typical upper mantle peridotite mixing with one of several compositions of pyroxenitic material. This study further investigates these potential melt sources by calculating U-series …
Differentiating Biotic Vs. Abiotic Co2 In The Formation Of Pedogenic Carbonate In Agriculture And Natural Dryland Soils, 2023 University of Texas at El Paso
Differentiating Biotic Vs. Abiotic Co2 In The Formation Of Pedogenic Carbonate In Agriculture And Natural Dryland Soils, Valeria Isabel Molina
Open Access Theses & Dissertations
Drylands, characterized by low and sporadic precipitation, require irrigation for crop growth. However, irrigation practices can lead to salt accumulation in soil due to high evaporation rates and reduced leaching. In addition to loading salts to soil, irrigation promotes the accumulation of secondary calcite. In natural systems, the formation of pedogenic carbonate (secondary calcite, CaCO3) is critical, impacting the soil properties hydrologically and biogeochemically, and modifying the global carbon cycle over geological time, albeit at a lower rate. In agricultural sites, irrigation water supplies HCO3- and Ca2+, accelerating the rates of CaCO3 formation and releasing abiotic CO2. This study investigated …
Isotopic Insights Into Water Of Condensation, Cross-Formation Water Flow, And Natural Hydrocarbon Migration In Sedimentary Basins, 2023 University of Texas at El Paso
Isotopic Insights Into Water Of Condensation, Cross-Formation Water Flow, And Natural Hydrocarbon Migration In Sedimentary Basins, Lisa J. Molofsky
Open Access Theses & Dissertations
This dissertation applies geochemical tools to track the movement, transformation, and behavior of water and gases in hydrocarbon-bearing sedimentary basins. During petroleum exploration and production, hydrocarbons are generated at the surface along with other fluids naturally present in the formation, such as formation water. In addition, where hydraulic fracturing is used to stimulate shale gas and oil production, a percentage of the injected fracturing fluid also returns to the surface. Understanding the origin and movement of these water sources, as well as targeted and non-targeted hydrocarbon gases is critical to evaluating reservoir performance and properly managing fluids at the surface. …
Investigating The Petrogenesis Of The Naifeh And Plumeria Seamounts: Insights Into The Geochemical Diversity Of Seamounts Adjacent To The Hawaiian Seamount Chain, 2023 Boise State University
Investigating The Petrogenesis Of The Naifeh And Plumeria Seamounts: Insights Into The Geochemical Diversity Of Seamounts Adjacent To The Hawaiian Seamount Chain, Geoffrey Montour
Boise State University Theses and Dissertations
The Naifeh and Plumeria seamount clusters, which consist of 10 submarine volcanoes located ~220km north of the Northwest Hawaiian Ridge, were mapped and sampled by the E/V Nautilus expedition NA101 in 2018. The origin of these seamounts is unknown, but their unique orientation and location imply several possible mechanisms of formation. Four possible mechanisms of formation include: 1) off-axis upwelling of the Hawaiian mantle plume, 2) ancient arch volcanism, 3) intraplate extension and deformation, 4) hotspot volcanism. Investigating the origin of these seamount clusters will better constrain the composition of the underlying mantle, as well as the depth and extent …
Quantifying Heterogeneity Along A Hillslope Using Seismic Refraction, Structure From Motion, And X-Ray Fluorescence In The Piedmont, South Carolina, 2023 Clemson University
Quantifying Heterogeneity Along A Hillslope Using Seismic Refraction, Structure From Motion, And X-Ray Fluorescence In The Piedmont, South Carolina, Leah Topping
All Theses
The critical zone (CZ) is the life sustaining outer layer of the earth that spans from the top of unweathered bedrock to the tops of the trees. This dynamic zone is always evolving because a variety of chemical, physical, and biological processes transform bedrock into regolith, creating a spatially heterogeneous CZ architecture. This study aims to investigate the relationships between regolith thickness, seismic velocities, and chemical profiles as a function of slope position and it is hypothesized bedrock composition, fracture density, and foliation are the key factors controlling the physical heterogeneity in the top 1-2 meters of the CZ. To …
Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, 2023 Clemson University
Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris
All Theses
Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 105 and 2.14 x106 years (Hu, 2010). Considering these characteristics, 99Tc and 237Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …