Physical Sciences and Mathematics Commons^™

The Interrelationship Between The Bio- And Sequence Stratigraphy Of The Middle Cambrian Spence Shale Of Northern Utah And Southern Idaho, Eva Lyon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was undertaken with the objective of discerning the relationship between sea level change and changes in the fauna of the Spence Shale. A combination of field and lab work was employed to undertake this research. The Spence Shale is rich in fossils from the earliest period of visible life on this planet. It provides a unique window onto the evolution of life and changes in the Earth at this time. It is important to study this relationship between sea level and life changes as these conditions are constantly changing, particularly in this day and age. A better understanding …

Determining Co2 Storage Potential: Characterization Of Seal Integrity And Reservoir Failure In Exposed Analogs, Daniel Corey Barton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sequestration of carbon dioxide (CO₂) into subsurface porous sandstone is proposed as a method for reducing accumulation of anthropogenic emissions of CO₂ into the atmosphere. Natural exposures of reservoir and top-seal pairs in central and southeastern Utah are identified as analogs to proposed CO₂ injection targets. Reservoir and top-seal pairs in natural analog exposures are analyzed in tandem to evaluate evidence for paleo-migration of fluids and/or hydrocarbons from the reservoir through the top seal. The San Rafael Swell and Monument Uplift exhibit similar structure and exposures of Jurassic units yet differ in amount and type of …

From Hillslopes To Canyons, Studies Of Erosion At Differing Time And Spatial Scales Within The Colorado River Drainage, Christopher Tressler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis includes two different studies in an attempt to investigate and better understand the key characteristics of landscape evolution. In the first study, the rate of surface particle creep was investigated through the use of Terrestrial lidar at an archaeological site in Grand Canyon National Park. The second study developed ways to quantify metrics of the Colorado River drainage and reports the role of bedrock strength in the irregular profile of the trunk Colorado River drainage.

Archaeological sites along the Colorado River corridor in Grand Canyon National Park are eroding due to a variety of surficial processes. The nature …

Sedimentological Controls On Fracture Distribution And The Network Development Within Meseverde Group Lithofacies, Uinta Basin, Utah, Ryan Christopher Sonntag

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Mesaverde Group, within the Uinta Basin, Utah, is a source of current significant production and contains several trillion cubic feet of undiscovered natural gas resources. Due to the low permeability of the matrix rock, understanding the geometry and properties of natural fractures is critical to the development of effective ways of finding and producing natural gas. In order to evaluate and model the potential connectivity of hydraulically induced fractures to natural fractures at depth, we examine the nature of the natural fracture network using scanline sampling, imagery analyses, core analyses, and microstructural analyses. Regional fracture sets identified include: N-S …

Stratigraphic, Microfossil, And Geochemical Analysis Of The Neoproterozoic Uinta Mountain Group, Utah: Evidence For A Eutrophication Event?, Dawn Schmidli Hayes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several previous Neoproterozoic microfossil diversity studies yield evidence for a relatively sudden biotic change prior to the first well‐constrained Sturtian glaciations. In an event interpreted as a mass extinction of eukaryotic phytoplankton followed by bacterial dominance, diverse assemblages of complex acritarchs are replaced by more uniform assemblages consisting of simple leiosphaerid acritarchs and bacteria. Recent data from the Chuar Group of the Grand Canyon (770‐742 Ma) suggest this biotic change was caused by eutrophication rather than the direct effects of Sturtian glaciation; evidence includes total organic carbon increases indicative of increasing primary productivity followed by iron speciation values that suggest …

Lithology And Internal Structure Of The San Andreas Fault At Depth Based On Characterization Of Phase 3 Whole-Rock Core In The San Andreas Fault Observatory At Depth (Safod) Borehole, Kelly Keighley Bradbury, James P. Evans, J. S. Chester, F. M. Chester, D. L. Kirshner

Geosciences Faculty Publications

We characterize the lithology and structure of the spot core obtained in 2007 during Phase 3 drilling of the San Andreas Fault Observatory at Depth (SAFOD) in order to determine the composition, structure, and deformation processes of the fault zone at 3 km depth where creep and microseismicity occur. A total of approximately 41 m of spot core was taken from three separate sections of the borehole; the core samples consist of fractured arkosic sandstones and shale west of the SAF zone (Pacific Plate) and sheared fine-grained sedimentary rocks, ultrafine black fault-related rocks, and phyllosilicate-rich fault gouge within the fault …

Discrete Brittle To Distributed Shearing; Results From Analysis Of The Deep Portions Of The Cajon Pass Drill Hole, James P. Evans, D Forand

Geosciences Presentations

We performed systematic structural and geochemical analyses on a suite of cored rocks from the vertical Cajon Pass, California drill hole to characterize the deformation and alteration of fault-related rocks. The drill hole lies 4 km northeast of the San Andreas Fault (SAF), and observations of deformed crystalline rock in core and outcrop provide a sample of a 5-km vertical column adjacent to the steeply dipping Cleghorn fault and span the brittle to semi-brittle deformational regime at hydrothermal conditions. The rocks in the upper 500 m of the borehole are composed of sandstones and granitoid augen gneiss, with narrow fault …