Physical Sciences and Mathematics Commons^™

Bedrock Geology Map Of The Naomi Peak 7.5' Quadangle, Cache County, Utah And Novel Age Constraints On Its Cambrian Strata, Hannah R. Cothren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geologists use various “rock-clocks” in order to interpret the timing and tempo of events in Earth’s history. These include global geochemical events in the oceans (chemostratigraphy), the evolution of certain fossil species (trilobite biostratigraphy), and the radiogenic decay of uranium to lead in certain mineral such as zircon (U-Pb geochronology). Integrating these methods in the stratigraphic record in one location can provide a well-constrained timeline for a select part of the Geologic, or Deep Time, record. This technique is especially important in the Cambrian Period (538.8 to 486.9 million years; Ma), which sets the stage for life today with the …

Late Pleistocene Piedmont Records In The Grand Staircase Region, Southern Utah, Alexander K. Short

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Today the climate in the southwestern United States is arid, characterized by desert landscapes and habitats, periods of drought, and arroyo streams that frequently fill with, and erode, through fine riverbed sediments. A series of cliffs and benches rising from the Grand Canyon to the southern plateaus of Utah, known as the Grand Staircase - home to Kodachrome Basin State Park, Bryce Canyon, are a classical example of this environment as we know it today. However, a record spanning the past 300 thousand years is preserved on the steps of the staircase indicating periods in the past where the climate …

Pleistocene Deposits Of Lower Wahweap Creek And Its Tributaries, Southern Utah, Noah Slade

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The famous landscapes of the Colorado Plateau have been created over millions of years, primarily by erosive forces of wind and water. Interruptions in the long-term erosion of the landscape occur when streams gain more sediment than they can transport, which causes deposition along channels and floodplains. The resulting sequences of terrace deposits are used by geologists to study when and how river systems have evolved.

Mammoth bones were recently discovered in stream deposits along Wahweap Creek, a tributary of the Colorado River in southern Utah. Previous work indicates that the deposits pre-date the last ice age, making it one …

Natural And Experimental Slow Slip Observed Along Shallow Hematite Faults, Alexandra A. Dimonte

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fault slip relieves stress in the shallow crust by slipping suddenly during earthquakes, but some faults also slip slowly in between earthquakes. Exhumed faults, brought up to the Earth’s surface from depth, preserve a record of fault processes and slip rates informed by fault rock structures, textures, and chemistry. Hematite, a common iron oxide mineral that precipitates on fault surfaces, exhibits crystal textures that potentially indicate past slip rate. Hematite can be dated using the radioisotopic system of (U-Th)/He thermochronometry, which constrains the time when He is trapped within a crystal, a process that is a function of temperature. Exhumed …

Evaluation Of The Geothermal Potential Of The Camas Prairie, South-Central Idaho, Connor J. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The area studied in this thesis was assessed based on the analysis of a water sample collected from the exploratory well USU Camas-1. The water sample was characterized and compared to other water samples collected and analyzed during a previous phase of this project according to its water chemistry.

Lithologic, geophysical, and temperature logs were also used to assess the study area. The depth sensitive data was analyzed to determine the characteristics of the formation as they relate to the favorable parameters of a geothermal resource, those being permeability of the subsurface, heat, and the presence of a clay seal. …

Shallow Composition And Structure Of The San Gabriel Fault, California In Drill Core And Geophysical Logs: Implications For Fault Slip And Energetics, Kaitlyn A. Crouch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Earthquakes are the sudden and intensive release of energy due to slip along faults. This energy may be felt on the Earth’s surface and may cause displacement of the Earth’s crust (seismic slip). As an earthquake ruptures, rocks in and around the fault are damaged and altered. When a fault displaces without earthquakes, it is referred to as aseismic creep. Faults may experience both seismic slip and aseismic creep throughout their cycles. In order to better model earthquake hazards and understand the cause of seismic slip versus aseismic creep in the shallow crust, we need to characterize the properties of …

Isotopic Analysis Of Hydrous Phenocrysts In Lava Flows Of The Peruvian Altiplano Plateau: Testing For A Subduction Signature, Alyssa Schiwal

Student Research Symposium

The process of flat-slab subduction introduces fluids directly into the overlaying lithosphere, leaving behind a unique stable isotope and trace element signature to the surrounding crust/mantle. Fluid alteration of the deep lithosphere can help explain geologic processes that are observed at the surface, such as patterns of crustal deformation (mountain building) and volcanism. The young high-K mafic volcanic rocks found in the Altiplano region of Southern Peru are derived from the melting of an altered mantle source. By analyzing the hydrogen stable isotopes as well as the trace elements of these volcanic rocks we can locate the water source associated …

Detecting Climate Change In Trilobite Time, Michelle Norman

Student Research Symposium

Trilobites are a signature marine fossil of the Cambrian explosion, which took place about 500 Ma (million years ago). By studying these fossiliferous rocks (limestone), we can get an understanding of ecological and environmental change. In fact, we can detect the ancient carbon cycle by measuring stable carbon isotopes in these limestone samples. By studying the carbon environment the trilobites lived in and which trilobite species evolve or go extinct, we can learn more about ancient climate events and constrain them to a certain period of time based off the age of radioactive zircons we find in sandy material around …