Geology Commons^™

Controls On Speleothem Carbon Isotopes, Paloma Marcos

Undergraduate Research Symposium Posters

The Sistema Huautla cave system is the deepest known in the Western Hemisphere. It is located in the Sierra Mazateca Mountain Ranges near Jiménez de Huautla, Oaxaca. There are over 29 separately discovered entrances into this karst environment making it the 28th longest cave system in the world. It can be considered by some as one of the most complex vertical drainage systems on Earth. This extensive study site has been an area of interest among cavers and scientific researchers for nearly 6 decades. Speleothem samples from the study sites have been found to be over 433,000 years old. The …

Uas Vs. In-Situ Measurement Techniques For Stream Substrates, Nathan Watson

Scholars Week

UAS vs. In-situ Measurement Techniques for Stream Substrates

Key words: Geomorphic, Fluvial, ArcGIS Pro, UAS

Traditionally, geomorphic assessments of streams and fluvial structures have been conducted using in-situ field techniques. These techniques include taking Wolman (D50) pebble counts to characterize substrate, measurements of stream dimensions with tape, meter sticks, and Jacob staff. We studied the efficacy of using an uncrewed aerial system (UAS) to measure the substrate composition of a section of stream along the east fork of the Clarks River in Calloway County, Kentucky. The section consists of a 30-meter riffle-pool-run sequence, with variation in substrate size to test …

Stable Isotope Paleoecology In The Bridgerian (Early Eocene): Investigation Of The Bridgerian Crash And The Canopy Effect, Aaron M. English

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The Early Eocene Climatic Optimum (EECO) was the warmest sustained interval of the Cenozoic. Its waning stages coincided with a marked decline in mammalian biodiversity known as the Bridgerian Crash, which was likely driven by increasingly cooler and drier conditions. Paleobotanical evidence suggests the early Eocene supported wet, subtropical to tropical forests at mid-latitudes, however the structure of these forests at the close of the EECO remains poorly understood. In this study, I measure carbon isotope values (d¹³C_E) from the enamel of early Bridgerian (~52.2 – 48.3 Ma) herbivorous mammals from the Greater Green River …

Climatic Controls On Soil Production, Transport And Chemical Erosion: Insights From Modelling Topography, Soils And Cosmogenic Nuclides At Little Lake, Oregon, Miles M. Reed, Ken L. Ferrier, Jill A. Marshall, Josh J. Roering, J. Taylor Perron

Geology Faculty Publications and Presentations

Predicting physical and chemical erosion rate responses to climate change are an ongoing challenge in geomorphology. A promising approach for investigating this is by measuring transient variations in physical and chemical erosion rates during climatically variable time periods, which can be accomplished by measuring cosmogenic nuclide concentrations and chemical depletion in sedimentary deposits. Interpreting such measurements warrants applying landscape evolution models that track variations in topography, cosmogenic nuclide concentrations and chemical depletion in soils. We applied a recently developed model that tracks these quantities at Little Lake, Oregon. Previous studies documented variations in cosmogenic nuclide concentrations and chemical depletion in …

Final Draft Report - Mapping Pfas In Groundwater Of The West Plains, Spokane County, Washington, 2023-2025, Chad Pritchard

EWU PFAS Research Collection

Since 2017, per- and polyfluoroalkyl substances (PFAS) have been detected in West Plains groundwater. Sampling conducted by Fairchild Air Force Base (FAFB) and the Environmental Protection Agency (EPA) have measured PFAS concentrations in private wells that exceed drinking water standards. Two known sources of PFAS have been identified on the West Plains: FAFB and Spokane International Airport (SIA). Washington Department of Ecology (Ecology) awarded the City of Medical Lake an area-wide groundwater grant to develop a groundwater model of PFAS contamination in the West Plains, the grant was originally written by Eastern Washington University (EWU) and Spokane County Water Resources …

Protocol For Assessing And Managing Radon Gas Exposure Risks In Caves: A Case Study Of Altamira And Paleolithic Cave Art Of Northern Spain World Heritage Site, Sergio Sanchez-Moral, Javier Lario, Soledad Cuezva, Juan Carlos Cañaveras, Tamara Martín-Pozas, Angel Fernández-Cortés

International Journal of Speleology

Exposure to radon and its progeny poses a significant health risk for workers in tourist caves. Implementing protective measures is challenging due to increasingly strict gas concentration and dose limits in new regulations. This study evaluates the annual effective radiation doses received by workers and researchers, considering seasonal and spatial radon variability. Radon levels, temperature, and ventilation patterns were continuously monitored for at least one year in each cave. Results show significant radon fluctuations influenced by seasonal ventilation regimes driven by thermal gradients between the cave and external atmosphere. Using International Commission on Radiological Protection guidelines, the study calculates the …

Pre-Calibration Of Δ18O For Paleoclimatic Interpretations Using Stalagmites In Cueva Ensueño, Puerto Rico, Gabriel Enrique López Borobia, Ny Riavo G. Voarintsoa, Ricardo Sánchez-Murillo, Pablo Antonio Llerandi Román

International Journal of Speleology

Stalagmites are invaluable archivers of past climate conditions, as their oxygen isotopic composition (δ¹⁸O_c) closely mirrors the isotopic signature of the drip water (δ¹⁸O_w) from which they precipitate. This isotopic relationship is governed by the fractionation factor (1000ln¹⁸α), which is temperature dependent. In this research, we studied 1000ln¹⁸α within Cueva Ensueño, a cave situated in Puerto Rico’s northern karst region, as a step toward calibrating δ¹⁸O_c for paleoclimate interpretations using stalagmites. We collected drip waters, measured their temperature in situ, and sampled carbonates from ten selected stations within the cave. Sampling was conducted in December …

What Controls Ice Shelf Isotopic Variability? Local And Global Processes Preserved Within Ice Cores Across The Larsen C Ice Shelf, Antarctica, Orion Laurene Schomber

USF Tampa Graduate Theses and Dissertations

The Antarctic Peninsula (AP) is one of the foremost indicators of anthropogenic global warming as it interacts with both atmospheric and oceanic processes. Although ice shelves across the AP have undergone increased rates of disintegration over the last 30 years, limited in-situ measurements have been investigated. Assessment of three short (~30 m) firn cores (J108, J208, and J409) across the Larsen C ice shelf (LCIS) provide insight into local, regional, and global processes. Average core densities and isotopic variability (δ¹⁸O and δ²H) fall within expected ranges for all cores, indicating signal preservation through firn. However, isotopic maxima in J108 and …

Vulnerability Of Blue Carbon In Coastal Freshwater Ecosystems To Sea-Level Rise, Suvrajit Ghosh, Jonathan Obrist-Farner, Jeffery R. Stone, Marta Wojewodka-Przybyt, Ryan Smith, Mark Brenner, Jason H. Curtis, Susan R. H. Zimmerman, Alex Correa-Metrio, Paula Gabriela Echeverrio Galinda, Madeline J. Brosky, Liseth Perez

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Coastal freshwater ecosystems are economically and ecologically important and provide multiple environmental services worldwide. They sequester carbon at rates ten times faster, and store five times more carbon per unit area than do mature tropical forests. Vulnerability of these carbon sinks to marine inundation, however, is expected to increase in response to global sea-level rise (GSLR). To better understand the implications of future GSLR, we investigated the geochemical and biological consequences of episodic Holocene marine incursions into Lake Izabal, a large coastal freshwater ecosystem on the Caribbean coast of Central America. About 8300 cal yr BP, marine incursion transformed Lake …

Integrating Satellite Observations And Modeling Approaches To Study Tectonic And Land Surface Hazards, Jeng Hann Chong

Earth and Planetary Sciences ETDs

The increasing availability of Earth observation satellites, such as SAR and optical platforms, has improved our ability to study the ground deformation processes during, after, and leading up to these natural hazards, such as earthquakes and debris flows. In this dissertation, I analyze satellite geodetic interseismic velocities across the Rakhine-Bangladesh megathrust and the influence of having realistic modeling assumptions for subduction zones to better constrain seismic hazard. I also examined changes in post-fire debris flow likelihood four years after the 2020 Lake Fire in Southern California using a suite of satellite data and field observations. Together, these studies highlight how …

Laboratory Investigation Of High-Temperature Preformed Particle Gels For Fluid Control In Granite Cores For Geothermal Applications, K. Caleb Darko, Yanbo Liu, Thomas P. Schuman, Mingzhen Wei, Baojun Bai

Chemistry Faculty Research & Creative Works

To understand the applicability of high-temperature preformed particle gel (HT-PPG) for control of short-circuiting in enhanced geothermal systems (EGSs), core flooding experiments were conducted on fractured granite cores under varying fracture widths, gel particle sizes and swelling ratios. Key parameters such as injection pressure, water breakthrough pressure, and residual resistance factor were measured to evaluate HT-PPG performance. The gel exhibited strong injectability, entering granite fractures at pressure gradients as low as 0.656 MPa/m; HT-PPG yields a superior sealing performance by significantly reducing the permeability; and dehydration occurs during HT-PPG propagation, with a dehydration ratio ranging from 4.71% to 11.36%. This …

Evaluation Of Towed Tem Potential For Rapid Characterization Of Levee Foundations, Kolawole Arowoogun, Katherine Grote, Jeremy Maurer

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Assessing the geologic conditions of levee foundation soils is a challenging task owing to the extensive length of most levees and the heterogeneity of many alluvial deposits. Traditional investigation techniques (such as boring and cone penetrometer testing [CPT]) are expensive, invasive, and provide spatially-limited information. As a result, they are restricted to pre-identified problematic zones in the levee. To overcome these challenges, geophysical instruments capable of better spatial coverage are proposed for rapid geoelectrical characterization of levees. In this study, we presented a field-based application of the towed time-domain electromagnetic method (tTEM) system in characterizing the subsurface geology adjacent to …

Refining The Geochronologic Framework Of The Early Cretaceous Nonmarine Western Interior Basin, Usa, Jack Fekete

Graduate Theses and Dissertations

The Early to mid-Cretaceous marks a period of dynamic shifts in tectonism, depositional environments, climate, and biota across the mid-North American continent. However, despite their importance for understanding crucial biotic and geologic transitions during this period, nonmarine Early Cretaceous strata of the Western Interior Basin (WIB) remain poorly constrained geochronologically. Radiometric dating of syndepositional detrital minerals, such as ash-fall zircon, offers a solution to refining geochronologic frameworks. However, a magmatic lull in the Cordilleran magmatic arc during the Early Cretaceous limited the delivery of syndepositional zircon to the WIB, impeding such refinement. In this dissertation, I developed and tested new …

Orphan Basalts: Understanding The Origins Of Unassigned Eastern Oregon Basalts, Angela Rae Stetson

Dissertations and Theses

For more than a century, scientists have studied the geologic stratigraphy of eastern Oregon, which chronicles a rich history of volcanic activity spanning millions of years. Recent and ongoing geologic mapping of the northeastern Harney Basin -- along a corridor east of Highway 395 between the towns of Burns and John Day -- provides a more detailed understanding of an area originally mapped only in reconnaissance during the 1960s. At that time, geologic units were poorly delineated, often with entire quadrangles mapped as a single unit. For example, over 90% of the Calamity Butte quadrangle was previously mapped as 'Tba' …

Effect Of Clays On The Spontaneous Imbibition Behavior Of Surfactant Solutions In Shale Oil Reservoirs, Ning Xu, Yanling Wang, Baojun Bai, Chuanbao Zhang, Shizhang Cui, Yu Zhang, Di Li, Wenjing Shi, Wenhui Ding

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Surfactant-enhanced spontaneous imbibition is a proven method of enhancing oil recovery from shale reservoirs. However, a significant knowledge gap concerning the impact of clay minerals on surfactant-enhanced imbibition in shale reservoirs remains. Therefore, this study first analyzed the mineral composition and pore structure of the shale reservoirs. Subsequently, three surfactants were selected for spontaneous imbibition experiments. The influence of various clay minerals on the surfactant imbibition was assessed by considering various properties of the imbibition system. The results showed that the shale pores primarily consisted of macropores (44.03%) and mesopores (43.94%). Surfactants enhance the imbibition recovery by altering the wettability …

Health On The Rocks: Geohealth In Kentucky, Rachel L. Washburn

Special Publication--KGS

Geohealth bridges the earth and life sciences, revealing how Kentucky’s unique geology directly shapes public health risks, clinical outcomes, and opportunities for innovation. This factsheet highlights the critical intersections between geologic processes and human health across the Commonwealth—from landslides, floods, and tornadoes to radon, mine drainage, and microbial contamination. It outlines how natural and anthropogenic forces influence respiratory illness, cancer, trauma, and infectious disease, and how bedrock and weather extremes define local exposure pathways. Beyond risk, it also showcases Kentucky’s leadership in developing geoscience-informed health solutions: bioremediation, microbial drug discovery, and geologic-health monitoring networks that strengthen preparedness and resilience. Understanding …

Paleoseismic Evidence Of Directivity For The 1976 Mw 7.5 Motagua Earthquake, Guatemala, Jonathan Obrist-Farner, Jeremy Maurer, Derek Gibson, Trenton Mcenaney, Andreas Eckert, William F. Kenney, Jeffrey Beeson, Nigel Wattrus, Quin Stangeland, Fatima Reyes

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

On 4 February 1976, a Mw 7.5 earthquake along the Motagua fault, Guatemala, ruptured ∼230 km of the North American and Caribbean plate boundary. Today, the plate boundary remains poorly monitored, and the 1976 earthquake is still not fully understood. Here, we present seismic reflection profiles and radiometrically dated sediment core data from six lakes around the Motagua fault, together with reports of destruction and a quasi-dynamic rupture model, which show that the 1976 earthquake experienced strong directivity that impacted the distribution of shaking. The earthquake left behind a detailed record of event deposits (EDs) in five of the six …

Compound-Specific Isotope Records Of Dust Provenance And Hydroclimate In The North Pacific And Marginal Seas Of East Asia: Integrating N-Alkane Δ13c And Δd With Standardized Analytical Frameworks, Julian W. Traphagan

LSU Doctoral Dissertations

This dissertation presents advancements in compound-specific isotope analysis (CSIA) through methodological innovation and paleoclimate reconstruction in Central and East Asia. Utilizing plant wax n-alkanes from International Ocean Discovery Program (IODP) and Ocean Drilling Program (ODP) sediment cores, this research reconstructs atmospheric circulation shifts responding to tectonic evolution and climate transitions since the Late Miocene.

Chapter 1 investigates hydrogen isotope compositions (δD_wax) from IODP U1430 (Sea of Japan), ODP 886, and ODP 1208 (North Pacific) to trace dust provenance and hydroclimate changes since ~13 Ma. Results reveal persistently segmented source-to-sink systems: the Sea of Japan dominated by westerly …

Geol 64: Planetary Geology - Syllabus, Dara Laczniak

Open Educational Resources

This Open Educational Resources (OER) syllabus is for an introductory planetary geology course that utilizes results from space missions to expose students to the surface features, composition, geological activity, and probable history of the planets, moons, asteroids, and comets of the solar system. It also places space exploration into the context of larger societal issues such as global warming and natural resource availability and addresses topics such as the ethics of space exploration and hazards of space travel. This OER syllabus aims to foster student-centered learning, critical thinking, data analysis and communication skills, and creativity. Assigned readings are compiled into …

Mantle Flow And Fault Zone Related Seismic Anisotropy Revealed By A Dense Linear Broadband Array In Southeast Tibet, Jing Wu, Yinshuang Ai, Stephen S. Gao, Peixi Huang, Fansheng Kong, Deke Xu, Jianguo Song, Xinyu Gao, Mengyi Wei, Long Li, Jien Zhang, Yanbin Zhang, Yingying Zhang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Southeast Tibet, a key region for the southeastward extrusion of the Tibetan Plateau, remains debated in terms of its tectonic deformation in response to the ongoing collision between the Indian and Eurasian plates. In this study, we applied shear-wave splitting analysis of core-refracted phases recorded by a newly deployed dense seismic array and six permanent stations to delineate crustal and mantle deformation processes. The observed fast polarization directions are predominantly aligned NNW–SSE, while the splitting delay times vary across four sub-blocks. The anisotropy pattern suggests a dominantly asthenospheric origin, consistent with southeastward-directed mantle flow associated with the extrusion of the …