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 …
Structural Relationships Across The Sevier Gravity Slide Of Southwest Utah And Implications For Catastrophic Translation And Emplacement Processes Of Long Runout Landslides,
2023
Illinois State University
Structural Relationships Across The Sevier Gravity Slide Of Southwest Utah And Implications For Catastrophic Translation And Emplacement Processes Of Long Runout Landslides, Michael J. Braunagel, William Ashley Griffith, Robert F. Biek, David B. Hacker, Peter D. Rowley, David H. Malone, Danika Mayback, Tiffany A. Rivera, Zachary Loffer, Zachary D. Smith
Faculty Publications - Geography, Geology, and the Environment
The physical processes that facilitate long-distance translation of large-volume gravity slides remain poorly understood. To better understand these processes and the controls on runout distance, we conducted an outcrop and microstructural characterization of the Sevier gravity slide across the former land surface and summarize findings of four key sites. The Sevier gravity slide is the oldest of three mega-scale (>1,000 km2) collapse events of the Marysvale volcanic field (Utah, USA). Field observations of intense deformation, clastic dikes, pseudotachylyte, and consistency of kinematic indicators support the interpretation of rapid emplacement during a single event. Furthermore, clastic dikes and characteristics of …
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 …
Geochemical Analysis And Numerical Modeling Of Central And East Tennessee Mississippi Valley-Type Ore Districts: Constraints On Ore Genesis,
2023
University of Arkansas, Fayetteville
Geochemical Analysis And Numerical Modeling Of Central And East Tennessee Mississippi Valley-Type Ore Districts: Constraints On Ore Genesis, Jackson Price Copeland
Geosciences Undergraduate Honors Theses
A simple two-way stochastic mixing model is presented for analysis of the lead (Pb) isotope compositions of the North American Mississippi Valley-Type (MVT) districts of East Tennessee, Central Tennessee, and Central Kentucky. Four distinct mixing scenarios were run to critically evaluate the stochastic model and examine different hypotheses regarding the genesis of Central Tennessee and Central Kentucky MVT deposits. Additionally, Pb isotope analysis was conducted on sphalerite samples from the Central and East Tennessee MVT districts. Model and sampling results suggest that Central Tennessee and Central Kentucky ores likely formed by mixing of three fluids. In contrast to conclusions from …
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 …
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 …
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 …
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 Program: Senior Projects (Public)
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 …
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. …
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 …
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 …
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 …
Comparing Igneous Geochemical Data From Hawaii And Southern California Via Machine Learning,
2023
Southern Adventist University
Comparing Igneous Geochemical Data From Hawaii And Southern California Via Machine Learning, Miro Manestar
MS in Computer Science Project Reports
Bi-plots are commonly used in geochemical analyses. However, their use can become cumbersome in the case of multi-variate analyses. Therefore, this thesis explores the application of unsupervised machine learning techniques, specifically PCA and K-Means, to analyze large geochemical data sets from two distinct regions, Hawaii and the \acrfull{prb} in Southern California. The IBM Foundational Methodology for Data Science was utilized to ensure proper data preparation and analysis. PCA provided dimensionality reduction, revealing which features correlated most strongly with variances within the data. K-Means clustering allowed for deeper interpretation of the data. The analysis yielded valuable insights into the composition and …
The Phosphorus Puzzle: Why Metal Phosphites Could Be The Missing Piece,
2023
Kennesaw State University
The Phosphorus Puzzle: Why Metal Phosphites Could Be The Missing Piece, Eleanor Boyle, Thomas J. Leyden Iii
Symposium of Student Scholars
It is well understood that phosphorylation of organic molecules is a keystone mechanism toward developing early cell function. However, the source of phosphorous in prebiotic chemistry is under debate. Phosphate minerals were abundant on the early Earth, but they are highly insoluble. In comparison, metal phosphites are significantly more soluble. While they may not have been preserved in the geological record, there are several plausible pathways for their formation under prebiotic conditions. We hypothesize that metal phosphites were a major source of phosphorus. To test our hypothesis, we synthesized and characterized metal phosphites, containing the most abundant cations on the …
Evaluating Fungal Population Response To The Miocene Climatic Optimum: High-Resolution Palynological Insights From The South China Sea And Mcmurdo Sound, Antarctica,
2023
Louisiana State University and Agricultural and Mechanical College
Evaluating Fungal Population Response To The Miocene Climatic Optimum: High-Resolution Palynological Insights From The South China Sea And Mcmurdo Sound, Antarctica, Mallory Pilie
LSU Master's Theses
Fungi play key and specific roles in ecosystems, specifically as many have restricted geographic distributions, known host/substrate preferences, and are important local environmental indicators due to their short dispersal distances. This study of fossil fungi from a time interval of pronounced global warming, the Miocene Climatic Optimum (MCO), allows analysis of fungal response to an analogue for future climate change scenarios. The research presented herein is part of a larger project, Fungi in a Warmer World (FiaWW), which is using globally-distributed sediment samples to provide foundational information on fungal community distribution patterns and will provide the first fungi-based climatological reconstructions …
Concept Validation: Collecting Composite Samples To Understand The Presence Of Per- And Polyfluoroalkyl Substances (Pfas) In Michigan Forested Areas,
2023
Western Michigan University
Concept Validation: Collecting Composite Samples To Understand The Presence Of Per- And Polyfluoroalkyl Substances (Pfas) In Michigan Forested Areas, Nicole Renee Sanabria
Masters Theses
This research discusses the results of a state-wide study conducted by The Michigan Department of Environment, Great Lakes, and Energy to assess the presence of PFAS in shallow soils of state-owned forested areas in Michigan utilizing a composite sampling method. One sample collected from each of Michigan’s 83 counties reveals the presence of PFAS in all but one sample, with total PFAS concentrations ranging from non-detect to 2.016 μg/kg (dry weight). PFOS is generally detected at the highest concentrations, ranging from non-detect to 0.88 μg/kg, followed by PFBA, with concentrations ranging from non-detect to 0.69 μg/kg, and PFOA, with concentrations …
Lithium And Lithium Isotope Behavior During High Temperature Solid/Fluid Exchanges: Examples From Iceland And The Izu-Bonin Forearc,
2023
University of South Florida
Lithium And Lithium Isotope Behavior During High Temperature Solid/Fluid Exchanges: Examples From Iceland And The Izu-Bonin Forearc, Alex Maruszczak
USF Tampa Graduate Theses and Dissertations
The development of a method for lithium isotopic measurement was developed using a quadrupole, single-collector ICP-MS. Measured precision was ±1.00‰ 2σ over a 15-month period based on measurements of international rock standards. A 1-hour leach using cold, HCl was sufficient to remove alteration-related Li in minimally to moderately altered seafloor basalts. Measurements on the Holocene ages lavas from the neovolcanic zones of Iceland suggest no systematic Li isotopic variability among the differing Icelandic sources. Felsic samples from Hekla and Pumice contain elevated Li contents of >18ug/g while the tholeiitic and alkaline basalts are <8ug/g Li. Most of the island lies around MORB values of ~+3 to +5‰ with the exception of Western Volcanic Zone samples that show evidence for seawater inputs. The RN-17 drillcore, which penetrates >3000m through a hydrothermal system in the …
Extreme Differentiation Along Multiple Liquid Lines Of Descent In Strongly Peralkaline Magma Series At Pantelleria (Italy),
2023
Eastern Kentucky University
Extreme Differentiation Along Multiple Liquid Lines Of Descent In Strongly Peralkaline Magma Series At Pantelleria (Italy), John C. White, Ray Macdonald, Bogusław Bagiński, Katarzyna M. Liszewska
EKU Faculty and Staff Scholarship
The liquid line of descent from trachyte to pantellerite is controlled primarily by fractional crystallization of alkali feldspar, with whole rock compositions following a fractionation path along the ‘thermal valley’ in the peralkaline haplogranite system Qz-Ab-Or-Ac-Ns and terminating at a minimum on the feldspar-quartz cotectic. Although whole-rock compositions for different pantelleritic suites follow nearly identical paths in a Qz-Ab-Or projection that terminate near the experimental minimum (Qz40.5Or34.5Ab25 at 100 MPa, projected from Ac-Ns), matrix glass from samples with near-minimum compositions record extreme differentiation and form a ‘cotectic delta’ beyond the terminus of the ‘thermal valley’. Although each glass trend shows …
Assessing Ecosystem Health Through Contaminants In The Tijuana River National Estuarine Research Reserve,
2023
University of San Diego
Assessing Ecosystem Health Through Contaminants In The Tijuana River National Estuarine Research Reserve, Nancy Torres
Theses
Although the Tijuana River Estuary (TRE) remains the largest, most-intact coastal wetland in Southern California, it has a history of major changes, much of this related to its location immediately north of the US / Mexico Border. One of the primary challenges is cross-border flows from the rapidly growing city of Tijuana, Baja California, Mexico, and the delivery of wastewater, debris, and sediment to sensitive coastal wetland ecosystems. There is a need to more fully investigate these environmental changes to assess the ecosystem health of the Tijuana River Estuary over time, especially related to pollution impacts. This can inform an …
