Geology Commons^™

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 …

Geomorphic Evolution Of St. Augustine Inlet, St. Johns County, Florida, Kristen Becker

Theses and Dissertations

Tidal inlets interrupt longshore sediment transport, influencing adjacent beach morphology and allowing the exchange of water and sediment between the open oceans and protected back barrier bay. Inlets evolve through a combination of natural processes and are highly dynamic zones where sediment exchanges cause shifting shoreline positions nearby and create new morphological features. Barrier islands/beaches that are close in proximity to inlets evolve and are an important natural feature that dissipates wave energy and protects inland areas. Both natural and anthropogenic processes that affect barrier islands will be investigated during this study, including storm activity, waves, wind, water level, and …

Applying Positive Unlabeled Learning Techniques And Using The Kullback-Leibler Divergence To Improve Geothermal Surveying Assessments, Martín Thomas Rodriguez

Dissertations and Theses

As we face the current climate crisis, the discovery of geothermal energy resources has the potential to greatly reduce our dependence on fossil fuels worldwide. However, the development of any new energy infrastructure is expensive and depends on the willingness of energy agencies and developers to make initial investments based on calculated risk measures. One such measure, called geothermal favorability, is the likelihood that a site has conditions favorable for geothermal systems containing recoverable energy potential. Its prediction from existing geophysical datasets proves to be a nontrivial task. The prediction of geothermal favorability can be framed as a binary classification …

Visualization Of Paleocurrents On A Web Application Using Gplates, Anjan Sapkota

MS in Computer Science Theses

Paleocurrents are flow directions derived from features of sedimentary rocks that reveal the direction of the current of wind or water that deposited the sediment. In 2015, Brand et al. created a global database of paleocurrents, which contains over 1,000,000 measurements worldwide: North America, South America, Australia, Great Britain, parts of Western Europe, China, Africa are fairly well represented; Antarctica, Eastern Europe, and Asia are modestly represented and Russia is poorly represented. The contribution of this thesis is a web application that uses the GPlates’ Application Programming Interface (API) to visualize global paleocurrents through time in an interactive way based …

Investigating Crystalline Rock Weathering In Distinct Climate And Ecological Settings: Insights From Shallow Seismic Refraction, Rachel Uecker

All Dissertations

Despite decades of research, understanding the subsurface of the critical zone (CZ) remains a challenge, constrained by limited access to information at depth. Traditionally, boreholes, outcrops, soil pits, and near-surface (<1 meter) geochemical measurements provided access to and quantified CZ structure. These methods, though valuable in their detail, are spatially limited, and many landscape-scale weathering hypotheses are based on these observations. In recent years, geophysical techniques have been applied to characterize large-scale CZ structure and test the validity of existing hypotheses. This dissertation harnesses nearly 10 kilometers of seismic refraction data from diverse ecoregions across the United States to challenge prevailing assumptions about weathering patterns and CZ evolution. The objective of this work is to characterize the interpreted range of weathered materials in each ecoregion and connect them to remotely-sensed information like canopy height, elevation, slope, and aspect. To do this, this work first investigates differences in weathering at depth in a north and south-facing slope system in the Laramie Range, Wyoming. The motivation for this work came from nearly a century of soil and geochemical studies from the western United States that show a greater degree and depth of weathering on north-facing slopes when compared to south-facing slopes. Our seismic refraction data were used to show that there is not a significant difference in weathering thickness at depth between north and south-facing aspects at the study site, thus conflicting with the hypothesis that there would be. Next, the hypothesis that the depth of weathering is affected by elevation was tested in the San Jacinto Mountains in southern California. The motivation for this work came from several geochemical studies in the Sierra Nevada Mountains that show ecologically prosperous mid-elevations possess an ideal combination of temperature and precipitation to produce a greater degree and depth of weathering. Again, the seismic results from the San Jacinto Mountains provided observations that conflict with the existing hypothesis that climate conditions dominate the thickness of weathering seen in rocks. Lastly, I used seismic refraction data and topographic curvature to build a groundwater model of a watershed in the Carolina Piedmont. The results of this model reveal that seismic refraction as an application for including more realistic geometry in groundwater models can improve model calibration fits. This model is the first of its kind, and, therefore, is an important step forward in merging geophysical data with the hydrogeologic and modeling field and, with further development, can be used to explore the role of topographic and regional groundwater flow as a driver of CZ evolution.

Tracking Natural Hazards: Bridging Rain-Triggered Lahar Research And Protective Action Decision Making In Wildland Fire Management, Ashley Bosa

Boise State University Theses and Dissertations

Understanding natural hazards is crucial for mitigating risks, protecting lives and property, and building resilience in communities. By enabling communities to prepare, respond effectively, and take protective action against disasters, the devastating impacts of natural hazards can be significantly reduced. However, transitioning from research to tangible community impact involves a multi-step process that bridges the gap between scientific knowledge and practical application. In this dissertation, I present two seismo-acoustic analyses of multiple rain-triggered lahar events at Volcán de Fuego in Guatemala, a granulometry study that attempts drone imagery analysis for lahar deposits, and a case-study review of the roles of …

Creating Place-Based Introductory Geoscience Field Trip Curricula For Indigenous Students, Kitri Spencer

All Graduate Reports and Creative Projects, Fall 2023 to Present

This project seeks to produce and evaluate a place-based geoscience field trip curriculum along the San Juan River designed for Indigenous students. The Geoscience on the San Juan River field trip uses a “place-based” approach to weave scientific concepts with the cultural knowledge and lived experiences of the students. Learning activities were designed to accommodate a wide range of learning preferences and accessibility needs with the hope of increasing Indigenous enrollment in the geosciences. The lesson plan was tested on June 4^th, 2022 during a guided rafting excursion on the San Juan River for students participating in the …

Geology, Alteration And Mineralization At The Cerro Del Medio Porphyry Au-Cu Deposit, Santa Cecilia Project, Maricunga Belt, Northern Chile, Jose David Franco Moraga

Open Access Theses & Dissertations

The Cerro del Medio system, situated within the Santa Cecilia-Caspiche district in the southern segment of the Maricunga Belt, exhibits a complex sequence of magmatic and hydrothermal processes that align with regional geological activity during the late Oligocene to early Miocene (25.2â??24.7 Ma). This study highlights the temporal and spatial (i.e., genetic) relationship between subvolcanic diorite porphyry intrusions, hydrothermal alteration, and copper-gold mineralization, providing a framework for future exploration.The hydrothermal system at Cerro del Medio is defined by four main alteration zones: biotite-magnetite (potassic), chlorite-white mica (chlorite-sericite), white mica (sericitic), and aluminosilicate (advanced argillic lithocap). These zones display a halo …

Microplastic Degradation Compared Among Dated Salton Sea Strandlines, Maria Alejandra Roman Medrano

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis investigates the environmental degradation of plastic materials, with a focus on polyethylene terephthalate (PET), through a multi-phase study conducted at the Salton Sea, a closed-basin lake in a semi-arid region of California. The research addresses three core objectives: (1) developing a microplastic (MP) extraction method tailored for clay-rich sediments, (2) characterizing surface degradation of various plastic types, including PET, BoPET, HDPE, LDPE, and EPS, using advanced microscopy and spectroscopy, and (3) examining the long-term weathering of PET through samples collected from dated lake strandlines.

The extraction protocol successfully isolates MPs without oxidation, using ZnCl₂ and extended soaking to …

Testing For Patterns Of Deformation From The Yellowstone Hotspot Along The Gallatin River, Sw Montana, Jack Willard

All Graduate Theses and Dissertations, Fall 2023 to Present

Yellowstone has fascinated humans for thousands of years. Geologists have addressed many of the region’s mysteries, including the underlying mantle hotspot, the chain of calderas tracking the motion of the North American Plate over this hotspot, and the risks posed by the super volcano. However, the way that the hotspot impacts regional tectonics and topography remains under-studied. Influential previous work recognized the Yellowstone Crescent of High Terrain (YCHT), an arc of high topography around the Yellowstone Plateau with limbs extending to the west and south into central Idaho and northern Utah. The YCHT is also hypothesized to be the pattern …

Where And How Are Undergraduate Students Developing Dispositions Needed For The Geoscience Workforce?, Kaelyn Lagerwall

Boise State University Theses and Dissertations

Dispositions, such as the desire to learn, work ethic, initiative, and organization, are defined as internal attributes, attitudes, or values that stimulate action. Rather than being intrinsic traits, dispositions can be learned and are considered a dynamic and evolving arrangement of interconnected components. Dispositions are highly desired and valuable to the workforce, playing a critical role in gaining and maintaining employment; they are frequently mentioned in job advertisements for bachelor-level geoscientists. Therefore, it is important to understand where and how geoscience students are developing these dispositions as part of their degree programs. We surveyed faculty in geoscience departments at two …

From Classroom To Career: Preparing Future Geoscientists For Workforce Success, Gregory Shafer

Boise State University Theses and Dissertations

The wide range of career opportunities for geoscience students, combined with a changing workforce, makes it more challenging for undergraduate programs to adequately prepare students for their careers. Therefore, it is important for geoscience programs to have a comprehensive view of the workforce needs and what barriers students may encounter when transitioning to the workforce. This dissertation identifies key skills and competencies essential for bachelor-level geoscientists, as well as potential barriers for recent graduates entering the workforce. The study analyzed entry-level geoscience job advertisements using a case-insensitive code matching function in MATLAB and conducted interviews with geoscience employers to identify …

Sedimentary Characteristics Of Flood Deposits In Coastal And Fluvial Environments: Examples From Washover Fans (North Carolina, Usa) And Floodplain Deposits (Mississippi, Usa), Shara Gremillion

Dissertations

Extreme flooding from severe and prolonged meteorological events and / or overbanking rivers are some of the most deadly and expensive disasters globally, impacting millions of lives, the environment, and property. People living in vulnerable areas, such as near coasts and rivers, are the first to be impacted with effects of these flood hazards. Scientific studies and their results can aid communities and officials in planning and preparing for those flood impacts. In this three-part study, flood impacts from coastal storms in North Carolina, and flooding along the Mississippi River (MSR) in the state of Mississippi, USA are assessed from …

Thermal Modeling Of Cooling Time Of Submarine Dacite Lapilli Tuff: Brothers Volcano, Kermadec Arc, Kyler Byrd

Master's Theses

Little is known about submarine volcanoes' eruptive histories and styles, even though they are essential to developing island arc systems and represent the second largest volcanic systems on Earth. Scientific drilling allows for the opportunity to study these systems. This study focused on two drill sites on Brothers volcano from IODP Expedition 376: Site U1528, located on the resurgent cone, and Site U1530, located on the caldera rim. Expedition researchers analyzed samples for clast radius, density, thermal conductivity, and specific heat. This data was then entered into the heat transfer equation of a sphere to create a cooling curve model …

Geochemical Evidence Of Drying During The 4.2 Ka Event In Sediment Cores From The Yucatán Peninsula, Mexico, Derek K. Gibson, Jonathan Obrist-Farner, Alex Correa-Metrio, Alejandra Rodriguez-Abaunza, Carlos Castañeda-Posadas

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Tropical hydroclimate variability during the Middle and Late Holocene was investigated using geochemical indicators of local-scale precipitation and evaporation preserved in sediment cores from two sites in the Mexican Yucatán Peninsula. Scanning X-Ray fluorescence spectroscopy data show generally decreasing precipitation trends during the Early and Middle Holocene. During the transition between the Middle and Late Holocene, geochemical evidence of reduced watershed erosion and increased evaporation indicate that a centennial-scale drying event impacted the region between 4.3 and 4.0 ka (kilo-anum; thousand years before present). These findings suggest that the 4.2 ka drying event, which has been previously recorded in Europe, …

Landslide Inventory And Unstable Slope Monitoring Along Highways In Eastern Tennessee, Robert Mcsweeney

Electronic Theses and Dissertations

This research introduces an unstable slope management program (USMP) for Tennessee based on federal slope management standards, along with improved methods for landslide monitoring with unmanned aerial systems (UAS) lidar and photogrammetry. In mountainous regions, monitoring slope hazards is a critical function of transportation management. A mobile field assessment form created with Survey123 was used to collect 22 unstable slope ratings in eastern Tennessee. Location points were appended with photographs, notes, and site information. Landslide scores ranged from 325 (Fair) to 1005 (Poor). UAS monitoring of a slow-moving soil landslide along I-40 near Rockwood, TN, produced high-resolution lidar and photogrammetry …

Experimental Evaluation Of A Recrosslinkable Co2-Resistant Micro-Sized Preformed Particle Gel For Co2 Sweep Efficiency Improvement In Reservoirs With Super-K Channels, Adel Alotibi, Tao Song, Ali Al Brahim, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A recross linkable CO₂-resistant branched preformed particle gel (CO₂-BRPPG) was developed for controlling CO₂ injection conformance, particularly in reservoirs with super-permeable channels. Previous work focused on a millimeter-sized CO₂-BRPPG in open fractures, but its performance in high-permeability channels with pore throat networks remained unexplored. This study used a sand pack model to evaluate a micro-sized CO₂-BRPPG under varying conditions of salinity, gel concentration, and pH. at ambient conditions, the equilibrium swelling ratio (ESR) of the gel reached 76 times its original size. This ratio decreased with increasing salinity but remained stable …

Assessing Sedimentation Impact Through Dem, Point Cloud, And Discharge Analysis, Shandell Thomas

Open Access Theses & Dissertations

This study focused on five arroyos flowing into the Rio Grande, in the stretch between Caballo Dam and Las Cruces, New Mexico. Drone imagery was acquired from study areas in each arroyo. Photogrammetry was used to create high-resolution digital elevation models (DEMs), point clouds, drone imagery and potential discharges were acquired for each arroyo. Investigation of seven different methods resulted in the selection of the Terrain Ruggedness Map (TRM) as a predictor of surface roughness, along with high-resolution DEMâ??s to illustrate small and low-relief channel features. The five arroyos with varying sediment sizes and characteristics were studied to understand how …

Rockets, Rovers, And Rocks, Oh My!, Tara Lynn Sweeney

Open Access Theses & Dissertations

This body of work undertakes three distinct projects, all with the ultimate goal of improving the future efforts of human space exploration.Chapter 2 is a seismic analysis of rocket launch and landing operations. Being able to identify and understand anthropogenically induced seismic signals in comparison to naturally occurring seismic signals is an important step in characterizing and monitoring both types of signals on the Moon. Relatively few terrestrial studies have been performed to explore this, but there is a growing opportunity to record, discern, and understand the differences between anthropogenic and naturally occurring seismic signals due to the increasing pace …

Heavy Metals In Rural Soils: A Case Study In Jennings County, Indiana, Madeline Hill

All-Inclusive List of Electronic Theses and Dissertations

Heavy metals, such as lead and mercury, can be toxic if exposure levels are too high. People are often concerned about lead exposure from water or paint, but soil is another potential exposure avenue for many metals. While some heavy metals, including mercury and lead, are found in emissions from coal-burning power plants and from incinerators, many metals accumulate in soils from past uses (ex. lead paint, leaded gasoline, chemical spills, industrial emissions, and natural occurrences). It is important to have soil tested to check metal concentrations because consumption or inhalation of these metals can lead to permanent damage and …