Geology Commons^™

High P-T Single Crystal Elasticity Of Zircon And Its Implications For Determining Metamorphic P-T Conditions In Nature, Arlacee Luu

Earth and Planetary Sciences ETDs

Understanding the natural petrologic and tectonic processes, such as slab subduction, requires accurate determination of the pressure (P) and temperature (T) conditions of these processes. Recent development of elastic thermobarometry based on the difference between the elastic evolution of mineral inclusions and their host minerals allows constraining the formation P-T conditions of the inclusion/host system without assuming thermodynamic equilibrium, which is typically needed for the widely used chemistry-based thermobarometry in metamorphic petrology. However, the reliability of elastic thermobarometry heavily depends on the accurate determination of the high P-T single-crystal elastic properties of relevant minerals. In this study, we performed the …

Seismic Shadow Zone Investigation In The Upper Magma Reservoir Of The Yellowstone Caldera, Sarah Nolt-Caraway

Earth and Planetary Sciences ETDs

This study investigates whether the Yellowstone Caldera has enough melt to mute S-waves, creating a seismic shadow zone. Using a dense nodal deployment of ~650 stations, 7-9 earthquakes during the nodal deployment, and 21 broadband stations with 3,000-4,000 events per station; amplitude and noise maps, seismograms, and automatic phase picks probabilities from a deep learning model were analyzed to assess the potential role of melt, crustal attenuation, and noise in affecting body waves, particularly S-phases. The results are inconclusive, with unclear evidence whether observed amplitude decay is normal signal decay due to distance, noise-related, melt, or from scattering and intrinsic …

Weathering, Erosion, And Dust Accumulation At Stoneman Lake, Arizona, Usa: Timescales And Drivers Of Geomorphic Activity Across The Southwest, Spencer Staley, Peter J. Fawcett, R. Scott Anderson, Gonzalo Jiménez-Moreno, Vera Markgraf, Erik T. Brown, Matthew E. Kirby

Earth and Planetary Sciences ETDs

Lengthy and well-dated terrestrial records of the Quaternary Period with the appropriate proxies show how the critical zone responds to environmental change. In southwestern North America, resolving the many effects of aridity through time provides crucial context for addressing contemporary climate issues. However, arid conditions are generally non-conducive to paleo-record preservation, causing knowledge gaps during relevant climatic episodes. An ~80 m-long sediment core (STL14) from Stoneman Lake contains a continuous archive of conditions from local to regional scale since the early Pleistocene (~1.3 Ma) and is, therefore, a unique and immensely valuable scientific resource. STL is situated in a montane …

Evaluating The Feasibility Of Using Strain Measured During Sinusoidal Rate Pumping Tests To Characterize An Aquifer, Riley Blais

All Theses

Pumping tests with sinusoidal variation in pumping rate have been proposed as a method for improving aquifer characterization. These tests can interrogate a larger aquifer volume than slug tests and they can be more sensitive to small variations in drawdown. Current methods of using sinusoidal variations of rate are based on measuring pressure signals from the reservoir or aquifer, which requires access to monitoring wells. An alternative approach has been developed that measures the strain in the vadose zone instead of pressure in the reservoir. An instrument has been developed at Clemson University that can measure small strains using optical …

Constraining High Temperature Deformation And Metamorphism In The Southern Wet Mountains, Colorado, Usa: Implications For The Regional Extent Of The Picuris Orogeny, Sarah Morse

Graduate Theses and Dissertations

The Wet Mountains of Colorado are underlain by exhumed Proterozoic metamorphic rock that lies north of the recently identified 1.46 to 1.40 Ga Picuris orogen in northern New Mexico. The Picuris orogen is inferred to have formed in response to a Mesoproterozoic (ca. 1.49-1.40 Ga) contractional to transpressional event extrapolated to be regional in extent. It has been proposed that the Picuris orogen composes the westernmost tectonic segment of the Pinware-Baraboo-Picuris orogen that formed along an evolving convergent margin that becomes younger from northeast to southwest. This study is focused on the record of high temperature deformation, metamorphism, and plutonism …

Evaluating How Well Active Fault Mapping Predicts Earthquake Surface-Rupture Locations, Chelsea Scott, Ramon Arrowsmith, Rachel Adam, Christopher Madugo, Joseph Powell, John Ford, Brian Gray, Ashley Streig, Multiple Additional Authors

Geology Faculty Publications and Presentations

Earthquake surface-fault rupture location uncertainty is a key factor in fault displacement hazard analysis and informs hazard and risk mitigation strategies. Geologists often predict future rupture locations from fault mapping based on the geomorphology interpreted from remote-sensing data sets. However, surface processes can obscure fault location, fault traces may be mapped in error, and a future rupture may not break every fault trace. We assessed how well geomorphology-based fault mapping predicted surface ruptures for seven earthquakes: 1983 M 6.9 Borah Peak, 2004 M 6.0 Parkfield, 2010 M 7.2 El Mayor–Cucapah, 2011 M 6.7 Fukushima-Hamadori, 2014 M 6.0 South Napa, 2016 …

Growth Of Purple Sulfur Bacteria Allochromatium Vinosum On Solid Phase Metal Sulfides As Sulfur And Electron Sources, Hugo Alarcon

Open Access Theses & Dissertations

Purple sulfur bacteria (PSB) are photosynthetic microorganisms known for their vital roles in geochemical cycles, especially the sulfur cycle, within anoxic photic environments. PSB are also key contributors to the nitrogen, carbon, and oxygen cycles. This study focuses on the autotrophic growth of Allochromatium vinosum, a model strain of PSB, that utilize solid-phase metal sulfides (MS) as both sulfur and electron donors. Through characterizing the growth profiles of A. vinosum on pyrite (FeS2), nickel sulfide (NiS), and iron monosulfide (FeS) nanoparticles, respectively, and investigating the bacteria-MS interaction mechanisms, this work expands our current knowledge of the metabolic capabilities and flexibility …

Paradox Diapir Inclusions As A Window Into Diapiric Processes In Proximity To The Uncompahgre Uplift And The Early History Of The Paradox Basin, Utah And Colorado, Madison Clare Woelfel

Open Access Theses & Dissertations

Layered evaporite sequences, cyclic, kilometer-thick deposits of salt, are among the most unusual and fascinating lithologies that geologists encounter. There is no recent analogue to their formation, and their ability to flow when subject to differential pressure makes them unique. Salt structures serve as sources for halite, bittern salts, metals, and hydrocarbons and can be used for storage of materials, including hydrocarbons, carbon dioxide, hydrogen, and nuclear waste. Basins in which layered evaporite sequences are deposited receive detrital input sporadically from adjacent areas, depositing inclusions of non-evaporite lithologies that are entrained when salt flows. These inclusions are exposed in a …

History Of Ice-Rafting In The Arctic Ocean During Glacial Maxima Through Marine Isotope Stage 6, Shannon M. Cofield

OES Theses and Dissertations

Numerous studies attempted to reconstruct Arctic paleoclimate, specifically ice mass timing and locations, during glacial maxima. While some regions, like the Barents-Svalbard Ice Sheet (BSIS) are well-studied, they may benefit from a high-resolution paleo proxy. Other regions are highly contested, such as the East Siberian Sea or the presence of a central Arctic Ocean ice mass.

This research uses an Fe-grain provenance method to (1) define how the BSIS behaved during Marine Isotope Stage (MIS) 2, 4, and 6, and when it retreated; (2) determine the presence and ages of Shelf Ice Masses (SIMs) in the Beaufort Sea and East …

Lidar Monitoring Of Annual And Storm-Driven Episodic Erosion At Rainsford Island, Alan H. Bartels

Graduate Masters Theses

Boston Harbor and its thirty-four islands are subject to erosion, driven by rain, winds, and waves. Climate change threatens to increase erosion over time as sea levels rise and the frequency and intensity of storms increase. Understanding the dynamics of coastal erosion is key to guiding the design of coastal shoreline protections, the research of which a goal of Stone Living Laboratory at the University of Massachusetts Boston. To better understand the impact of both annual weather and episodic severe storms, the high-resolution Riegl VZ400i LiDAR was deployed four times over 14 months from July 22, 2021 to October 19, …

Measurement Of Microplastics In A Freshwater Micro-Watershed, Cole Bowman

All Theses

The role of microplastics as an emerging contaminant can be complex to study because of the lack of standardization in the collection and analysis of microplastic particles. The purpose of this manuscript is to detail an iterative process of different collection methods in trying to understand microplastic deposition and transport in a freshwater micro-watershed through lab-based and field-based studies. A flume experiment was conducted to test the trapping efficiency of a sediment trap design at two different velocities (1.12 m/s and 2.24 m/s). Eight types of microplastics varying in morphology and density were introduced to the flume in order to …

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

Graduate Theses and Dissertations (2019 - present)

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 …

Chemostratigraphic And Paleoclimatic Studies Of Cloverly Formation, Northern Wyoming, U.S.A, Queen Amarachi Kalu

Graduate Theses and Dissertations

The Early – Late Cretaceous transition in Western North America recorded a period of rapid climatic and tectonic change in Earth’s history. Major climate events associated with large igneous province eruptions caused several instances of ocean anoxic events (OAE) and perturbations to the global carbon (C) – cycle. These perturbations to the global C-cycle are observed in the bulk organic C record of both marine and terrestrial deposits and can be used to correlate units across major depositional basins. Major efforts are being made to generate time-constrained palaeontologic and paleoclimate information from the North American Cordilleran foreland basin and C-isotope …

High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, Gavin Gleasman

All Dissertations

Atmospheric carbon dioxide (CO₂) concentrations have been increasing at an accelerating rate for the past two centuries, profoundly impacting global climate change. Atmospheric CO₂ concentrations are influenced by the global carbon cycle through physical and biogeochemical pathways. Tidal wetland environments play a vital role in the global carbon cycle by offsetting atmospheric CO₂ concentrations through their natural physiochemical processes of high autotrophic productivity, allochthonous organic matter deposition, anoxic soils, and continuous accretion which promotes carbon sequestration with long-term storage at the land-ocean margin. The Intergovernmental Panel on Climate Change (IPCC) and United States Global Change Research …

Magmatic Processes Leading To Compositional Diversity In The Mars Crust, Amanda Marie Ostwald

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ancient Mars crust can yield insights into planet formation and evolution that Earth cannot. Direct investigation of the martian surface is limited to studies on meteorites and rover-obtained analyses. The nakhlites and chassignites, two classes of martian meteorites, are together the largest suite of martian meteorites derived from a single location on the surface. As such, they present a rare opportunity to study the Mars crust in detail using samples bearing a contextual relationship. Rover studies have found a surprising amount of compositional diversity in surface materials, the formation mechanisms of which are not well-constrained. This dissertation leverages meteorites …

Volatile Cycling And Metasomatism In Flat-Slab Subduction Zones Of The Central Andes, Coleman Hiett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Flat-slab subduction, where an oceanic plate subducts horizontally below a continental margin for hundreds of kilometers, is an enigmatic but prevalent tectonic configuration in which chemical cycling and alteration of the continental plate is poorly constrained. Geochemical investigations in regions of modern and ancient flat-slab subduction in the Central Andes afford an opportunity to study this process. Certain elements naturally occur with varying number of neutrons in their nuclei (isotopes), and measurements of isotope ratios within geologic materials inform on chemical sources and geologic processes. This research leverages stable isotope analyses and other geochemical tools to investigate volatiles and other …

Englacial Drainage Drives Positive Feedback Depression Growth On The Debris-Covered Ngozumpa Glacier, Nepal, R. M. Strickland, M. D. Covington, J. D. Gulley, R. B. Kayastha, J. M. Blackstock

Geosciences Faculty Publications and Presentations

The development of hummocky topography is a poorly understood aspect of down-wasting on debris-covered glaciers that is often attributed to variable debris thickness. Thousands of enclosed depressions pit the hummocky topography. To better understand depression growth, we examined the size distribution and geometry of depressions on the Ngozumpa Glacier, in the Everest Region of Nepal. The depressions exhibited a power-law size distribution, fractal perimeters, and power-law depth-area scaling, which suggest positive feedback growth. With a simple model, we showed that positive feedback growth produces similar power-law size distributions. Based on these findings, we propose a “sinkhole” hypothesis for the development …

Surficial Geology Of The Fulton Quadrangle, Avery Merkley, Starr Claussen, Sage Cappi, Chad Heinzel

Summer Undergraduate Research Program (SURP) Symposium

• The Fulton 7.5’ Quadrangle lies within a geographic region known as the East-Central Iowa Drift Plain.
• The East-Central Iowa Drift Plain is characterized by glacial deposits that occurred over 1.8 million years ago. These glacial deposits are part of what makes up the loose soil material, which overlays a bedrock surface that is about 360-485 million years old.
• This area experiences significant change in elevation from the highest points to the lowest points in the Quadrangle.

Rift-Induced Disruption Of Cratonic Keels Drives Kimberlite Volcanism, Thomas M. Gernon, Stephen M. Jones, Sascha Brune, Thea K. Hincks, Martin Palmer, John C. Schumacher, Rebecca M. Primiceri, Matthew Field, William L. Griffin, Suzanne Y. O'Reilly, Derek Keir, Christopher J. Spencer, Andrew S. Merdith, Anne Glerum

Geology Faculty Publications and Presentations

Kimberlites are volatile-rich, occasionally diamond-bearing magmas that have erupted explosively at Earth’s surface in the geologic past^1,2,3. These enigmatic magmas, originating from depths exceeding 150 km in Earth’s mantle¹, occur in stable cratons and in pulses broadly synchronous with supercontinent cyclicity⁴. Whether their mobilization is driven by mantle plumes⁵ or by mechanical weakening of cratonic lithosphere^4,6 remains unclear. Here we show that most kimberlites spanning the past billion years erupted about 30 million years (Myr) after continental breakup, suggesting an association with rifting processes. Our dynamical …

Spatial Variations In Ancient Meteoric Water: An Investigation Of The Rattlesnake Tuff, Julian Michael Cohen

Dissertations and Theses

Volcanic glass has been used extensively as a paleoclimate proxy. Deuterium (²H) concentrations in glass have been found to be stable over geologic timescales, making δD a reliable proxy for ancient water chemistry. However, continued work revolves around better understanding how different factors affect preserved water in ash. Here, I analyze δD in the Rattlesnake Tuff (RST), a widespread ca. 7 Ma ashflow tuff, and create an isoscape to assess variations in δD across Oregon during that time. Additionally, I examine compositional data from glass shards to explore the relationship between δD and shard composition. The RST exhibits …

Hydrology Data For Fern Cave, Alabama (2020-2022), Benjamin Tobin, Benjamin V. Miller, Matthew Niemiller, Andrea Erhardt

Research Data--KGS

Dataset includes water level from four sites within Fern Cave in Jackson County Alabama. Additionally, it includes chemistry of water, sediments and cave-adapted isopods.

Assessing Ecological Relationships Among Late Triassic Vertebrates In Petrified Forest National Park, Alexandra Davis Apgar

Earth and Planetary Sciences ETDs

The complex vertebrate ecosystem of the Late Triassic has not yet been fully understood, largely due to oversimplification of hypothesized trophic hierarchies and limited preservation of direct evidence of faunal interaction. Paleocommunity reconstruction attempts can also fall victim to taphonomic biases, time-averaging inaccuracies, and non-analogue paleoecologies. Utilizing a combination of PAIRS analysis and NMDS ordination, we highlight vertebrate faunal relationships within the Adamanian and Revueltian faunachrons of Petrified Forest National Park, assess the likelihood that these patterns have ecological rather than preservational drivers, and examine how these potential interactions may have been impacted by the Adamanian-Revueltian turnover event. We are …

Collapse Of The Bindschadler Ice Stream At 11.5 Cal Kyr Bp Via Marine Ice Cliff Instability, Anna Sivils

LSU Master's Theses

Previous studies of the Whales Deep Basin (WDB) outer continental shelf showed that the paleo-ice shelf fronting the Bindschadler Ice Stream broke up at 12.3 cal kyr BP. A calving cliff was subsequently maintained until at least 11.5 cal kyr BP. Slightly after that time, the grounding line rapidly retreated creating a 200 km embayment of grounded ice over the foredeepened middle continental shelf. The rapid opening of the embayment is recorded by a backstepping succession of small-scale morainal ridges on the middle continental shelf. The overlapping and end-to-end spacing of morainal ridges requires that the retreating grounding line experienced …

Cratonic Basins As Effective Sediment Barriers In Continent‑Scale Sediment Routing Systems Of Paleozoic North America, Andrea L. Stevens Goddard, Olivia G. Thurston, David H. Malone, Patrick L. Mclaughlin, Jack Stewart

Faculty Publications - Geography, Geology, and the Environment

Provenance studies demonstrate the important control of plate boundary mountain building on continental sediment routing systems. Less well understood is if subsidence and uplift in cratons also has the potential to affect the organization of sediment routing systems on continental scales. New detrital zircon provenance data from the Michigan Basin in the Midcontinent of North America preserve evidence of intrabasin provenance heterogeneity in Cambrian, Ordovician, and middle Devonian strata. These results suggest that cratonic basins serve as effective sediment barriers that prevent mixing within and across basins from 10 to 100 s of millions of years. Internal sediment mixing, sorting, …

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 …

Effects Of Landslides On Terrestrial Carbon Stocks With A Coupled Geomorphic-Biologic Model: Southeast Alaska, United States, Adam M. Booth, Brian Buma, S. Nagorski

Geology Faculty Publications and Presentations

Landslides influence the global carbon (C) cycle by facilitating transfer of terrestrial C in biomass and soils to offshore depocenters and redistributing C within the landscape, affecting the terrestrial C reservoir itself. How landslides affect terrestrial C stocks is rarely quantified, so we derive a model that couples stochastic landslides with terrestrial C dynamics, calibrated to temperate rainforests in southeast Alaska, United States. Modeled landslides episodically transfer C from scars to deposits and destroy living biomass. After a landslide, total C stocks on the scar recover, while those on the deposit either increase (in the case of living biomass) or …

Hurricane Impacts On Land In The Central And Eastern Caribbean Since 1494 Ce From Written Records, Michael Chenoweth, Ian Howard

Geosciences Faculty Publications and Presentations

Written accounts of hurricanes and their impacts in the Caribbean region date back to 1494 CE We report a new compilation of hurricanes in the longest settled regions of the central and eastern Caribbean region (CECR) that is the most complete yet produced and present basic statistics. We assess likely undercounts of hurricanes due to incomplete documentary records in the earliest part of the record by using the most complete reporting from Puerto Rico relative to the remainder of the CECR. We compare our results with other documentary and proxy data from the region and demonstrate using wavelet analysis significant …

Forecasting Sea Level Rise-Driven Inundation In Diked And Tidally Restricted Coastal Lowlands, K. M. Befus, A. P.D. Kurnizki, K. D. Kroeger, M. J. Eagle, T. P. Smith

Geosciences Faculty Publications and Presentations

Diked and drained coastal lowlands rely on hydraulic and protective infrastructure that may not function as designed in areas with relative sea-level rise. The slow and incremental loss of the hydraulic conditions required for a well-drained system make it difficult to identify if and when the flow structures no longer discharge enough water, especially in tidal settings where two-way flows occur through the dike. We developed and applied a hydraulic mass-balance model to quantify how water levels in the diked and tidally restricted coastal wetlands and water bodies dynamically respond to sea-level rise, specifically applied to the Herring River Estuary …

Groundwater Flow And Salt Marsh Migration: The Forest/Marsh Boundary, Camille Rossiello

Theses and Dissertations

Salt marshes migrate landward in response to sea level rise, but the rate of this migration is not constant and can be influenced by pulse disturbances. Long term observations at Sapelo Island, Georgia, show that salt marsh migration has occurred during droughts, but the mechanism for this migration is unclear. Drought is thought to influence salt marsh migration by reducing fresh groundwater discharge from the upland. Rising sea level also encroaches on the upland, which could cause movement of the freshwater lens inland. A two-dimensional numerical model was built to simulate groundwater flow and solute transport based on the Marsh …

Hf Radar: Shining A Light On Ocean Currents, Douglas Cahl

Theses and Dissertations

High Frequency (HF) radar systems are commonly used to estimate surface ocean currents over the coastal ocean. Their range depends on their operational frequency and low frequency systems (≤ 10 MHz) can reach distances up to 200 km from the coastline. These systems are used to estimate surface currents by measuring the phase speed of wind-driven waves and comparing the measured speed with that expected theoretically; deviations from the theoretical still-water phase speed are attributed to ocean surface currents. Although HF radar systems are considered a mature technology and the accuracy of the radar-derived surface current estimates is well studied, …