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Full-Text Articles in Earth Sciences

Characterization Of The Synhalokinetic Megaflap Lithofacies And Stratigraphy At Sinbad Valley, Paradox Basin, Western Colorado, Michael David Laase May 2026

Characterization Of The Synhalokinetic Megaflap Lithofacies And Stratigraphy At Sinbad Valley, Paradox Basin, Western Colorado, Michael David Laase

Open Access Theses & Dissertations

This study documents the halokinetic evolution of the Sinbad Valley salt wall and flanking megaflap through the characterization of its lithofacies, stratigraphy, and major structures. Sinbad Valley salt wall is in the northern Paradox Basin, in western Colorado, and is the most proximal salt diapir to the Uncompahgre Uplift, the clastic sediment source for the basin. Megaflaps are recently defined structures involving early minibasin strata that are folded up to form steeply dipping "stratal panels" along the sides of steep diapirs. The Sinbad Valley megaflap crops out as a ~7.5km long and 400m wide panel of folded and deformed Pennsylvanian- …


The Nature And Origin Of The Strodes Creek Member Of The Lexington Limestone, Central Kentucky, Claire J. Mendenhall Jan 2026

The Nature And Origin Of The Strodes Creek Member Of The Lexington Limestone, Central Kentucky, Claire J. Mendenhall

University of Kentucky Master's Theses

The Strodes Creek Member of the Lexington Limestone is a small, unusual member that is largely known for its beds of fragmented and overturned stromatoporoids. The Strodes Creek Member occurs as two distinct stratigraphic bodies, wholly encompassed by the Millersburg Member, which represents a shallow, open-marine, mixed-clastic-carbonate platform, characterized by thin-bedded to nodular, fossiliferous calcarenites and calcirudites interbedded with shale. In contrast to the Millersburg, the Strodes Creek exhibits a lithologic background of dark, organic-rich, calcareous shales with a westward-thickening section of very irregularly bedded, stromatoporoid-rich, fossiliferous calcisiltites (packstones and wackestones). The calcisiltites are commonly associated with hummocky crossbedding, pinch-and-swell …


High-Resolution Event Stratigraphy Of Ostracods In The Ozan Formation Of Texas And Arkansas, Denali L. John Aug 2025

High-Resolution Event Stratigraphy Of Ostracods In The Ozan Formation Of Texas And Arkansas, Denali L. John

Master's Theses

This study focuses on the high-resolution event stratigraphic framework of the lower Campanian Ozan Formation in Northeast (NE) Texas and Southwest AR which is richly fossiliferous in ostracods. Little research has been published on the Ozan Formation and even less dealing with Ozan ostracods. Additionally, correlation of Upper Cretaceous units between Texas and AR is controversial due to the general lack of good exposures in both regions and extensive faulting in Northeast Texas despite similar depositional environment across the region. This study calibrates the ranges of ostracods and creates an event stratigraphic composite that is orders of magnitude higher in …


Geochemical And Stratigraphic Characterization Of The Morrison Formation And Cedar Mountain Formation Contact In The Island Park Quadrangle, Uintah County, Utah, Emily Mcdermott Aug 2025

Geochemical And Stratigraphic Characterization Of The Morrison Formation And Cedar Mountain Formation Contact In The Island Park Quadrangle, Uintah County, Utah, Emily Mcdermott

All Graduate Theses and Dissertations, Fall 2023 to Present

The Upper Jurassic Morrison Formation and Lower Cretaceous Cedar Mountain Formation are among the richest sources of dinosaur fossils. Despite a 24-million-year gap in time (the Jurassic–Cretaceous unconformity), these formations are difficult to distinguish due to their similar rock types and colors. In Utah's Island Park quadrangle (IPQ), these formations are not separated on existing geological maps. This study focuses on identifying and understanding the formational boundary between them using field observations, stable isotope analysis, clay mineralogy, and chemical techniques such as X-ray diffraction (XRD) and X-ray fluorescence (XRF).

Unlike other areas where a conglomerate layer marks the boundary, the …


Thickness Of Devonian Shale, Kentucky-Tennessee Mineral District (Ktmd), John B. Hickman, Alex M. Washburn, Georgina Lukoczki Jul 2025

Thickness Of Devonian Shale, Kentucky-Tennessee Mineral District (Ktmd), John B. Hickman, Alex M. Washburn, Georgina Lukoczki

Research Data--KGS

The deposits of critical minerals have been found in metalliferous shales. To aid in critical mineral assessments of the Devonian Shales in the Kentucky-Tennessee Mineral District (KTMD), this research project produced a map (digital GIS dataset) of the thickness (isopach) of the combined New Albany Shale/Chattanooga Shale/Ohio Shale interval across the region. The subsurface input data are from oil/gas well records and exploratory mineral core. Well and core records for the KTMD were acquired from the state surveys of Tennessee and Kentucky. Along with the GIS files, a summary table of the 6,607 well and core data points used to …


Structure On The Top Of Knox Group, Kentucky-Tennessee Mineral District (Ktmd), John B. Hickman Jul 2025

Structure On The Top Of Knox Group, Kentucky-Tennessee Mineral District (Ktmd), John B. Hickman

Research Data--KGS

The deposits of critical minerals within the Kentucky-Tennessee Mineral District (KTMD) are hosted within the Late Cambrian to Early Ordovician carbonate rocks of the Knox Group. To aid in critical mineral assessments of the region, this research project produced a map (digital GIS dataset) of the subsurface structure of the top of the Knox Group: the Knox Unconformity surface. All the input data is from oil/gas well records and exploratory mineral core records because these rocks are not exposed within the study area. Well and core records for the KTMD were acquired from the state surveys of Tennessee and Kentucky …


Stratigraphic Evidence Of Backwater Morphodynamics And Lowland River Deltas In The Northern Hemisphere Of Mars, C.M. Hughes, J.B. Shaw, A.M. Fernandes, T.E. Swanson Jun 2025

Stratigraphic Evidence Of Backwater Morphodynamics And Lowland River Deltas In The Northern Hemisphere Of Mars, C.M. Hughes, J.B. Shaw, A.M. Fernandes, T.E. Swanson

Geosciences Faculty Publications and Presentations

Backwater morphodynamics describe feedbacks between hydraulics and sedimentation in fluvio-deltaic systems in the coastal backwater zone. On Earth, normalized channel belt width decreases approaching the coastline and drops sharply at the start of the backwater zone. This systematic decrease allows a backwater/belt-width window to be defined, one backwater length upstream from the coast with normalized widths from 2 to 6. We use the backwater/belt-width window to interpret backwater morphodynamics and estimate backwater length on Mars using narrowing channel belts at Aeolis Dorsa. We measure nine belts from martian delta deposits and compare normalized width to distance upstream from an ancient …


Latah Formation: History And Case Studies, Kylee M. Woodworth May 2025

Latah Formation: History And Case Studies, Kylee M. Woodworth

2025 Symposium

The Latah Formation is a series of discontinuous sedimentary interbeds between the flows of the Columbia River Flood Basalts outcropping across northern Idaho and eastern Washington. Ages ranging between the Middle to Upper Miocene, the sediments represent varied fluvio-lacustrine environments. The deposits are predominantly composed of claystones and shales as alternating, laminated couplets, many containing a variety of fossils. Though the sediments may appear similar across localities, they come from different source rocks, ranging from ashes from Yellowstone hotspot to metamorphic rock from nearby hills. These ancient lacustrine and fluvial environments allowed for great preservation of fossils, often in great …


Sedimentary Archives Of Late Quaternary Limnological, Ecological, And Environmental Change In The Eastern Sierra Nevada (California, Usa), Bailee Hodelka Jan 2025

Sedimentary Archives Of Late Quaternary Limnological, Ecological, And Environmental Change In The Eastern Sierra Nevada (California, Usa), Bailee Hodelka

Theses and Dissertations--Earth and Environmental Sciences

The Sierra Nevada essentially serve as the headwaters of California, providing crucial freshwater to the state through seasonal snowmelt. This water supply is threatened by climate change in complex ways that are not fully understood. Geological records provide a valuable source of information on how the hydrology, limnology, and ecology of the Sierra Nevada region has responded to climate changes of the past. This dissertation presents new sedimentary and paleoecological research from Mono Lake and Convict Lake (Mono County, California) and aims to shed light on environmental changes in the eastern Sierra Nevada from ~16 ka to present.

At Mono …


Geology, Paleoecology And Vertebrate Biostratigraphy Of The Hell Creek Formation, Carter County, Montana, Usa, Joshua Collin Mathews Jan 2025

Geology, Paleoecology And Vertebrate Biostratigraphy Of The Hell Creek Formation, Carter County, Montana, Usa, Joshua Collin Mathews

Graduate Research Theses & Dissertations

The Hell Creek Formation of the Northern Great Plains records one of the greatest mass extinction events in Earth’s history, bringing to a close the reign of the dinosaurs at the end of the Cretaceous period. This rock unit comprises one of the most studied geological formations in the world and is one of the few locations on the planet that preserve terrestrial deposits containing ejecta from the bolide impact that slammed into the Yucatan Peninsula 66 million years ago. This profound event in the geologic record has led to numerous studies of paleobiotas, climate change, ecosystem recovery dynamics, and …


New Constraints On The Stratigraphic Architecture And Evolution Of Mississippi River Delta Lobe Activity: Barataria Basin, Southeastern La, Wilke Coleman Dec 2024

New Constraints On The Stratigraphic Architecture And Evolution Of Mississippi River Delta Lobe Activity: Barataria Basin, Southeastern La, Wilke Coleman

LSU New Orleans Theses and Dissertations

Barataria Basin is a shallow water, interdistributary estuary that has evolved in response to dynamic depositional regimes governed by distributary avulsion and reworking of sediments by coastal processes. In the Mississippi River delta plain, the migratory nature of the River has produced an evolving landscape constructed through episodes of regressive and transgressive sedimentation. These processes produce unique depositional signatures in the stratigraphic record, however the transgressive component of the delta cycle often results in obliteration of the regressive phase. This study uses a modern suite of geophysical and sediment core data to construct a revised geologic framework in Barataria Basin, …


Shaking Off The Rust: Unraveling The Depositional And Diagenetic History Of Enigmatic Ferroan Dolostones In The Cambrian Bright Angel Formation, Tonto Group, Grand Canyon, Joseph J. Clevenger Aug 2024

Shaking Off The Rust: Unraveling The Depositional And Diagenetic History Of Enigmatic Ferroan Dolostones In The Cambrian Bright Angel Formation, Tonto Group, Grand Canyon, Joseph J. Clevenger

All Graduate Theses and Dissertations, Fall 2023 to Present

Within the siliciclastic-sediment-dominated Bright Angel Formation (BAF) of the iconic Cambrian sedimentary strata (Tonto Group) in Grand Canyon National Park, Arizona, workers have identified and named prominent reddish-brown cliffs breaking up the generally slope-forming unit near, but separated from, its upper contact with the limestone-dominated Muav Formation, the "Rusty Brown Dolostones" (RBDs). Previous hypotheses suggest that the RBDs are chemically and physically altered tongues of the Muav Formation intercalated with the BAF at increasingly higher stratigraphic positions from west to east within the Canyon. A genetic association between the Muav Formation and the RBDs, as well as between the RBDs …


Investigating Gulf Coast Aquifer System: Stratigraphy Reconstruction, Inverse Modeling, And Groundwater Stress Assessment, Shuo Yang Mar 2024

Investigating Gulf Coast Aquifer System: Stratigraphy Reconstruction, Inverse Modeling, And Groundwater Stress Assessment, Shuo Yang

LSU Doctoral Dissertations

The Mississippi Embayment aquifer system (MEAS) and the Coastal Lowlands aquifer system (CLAS) provide substantial groundwater resources for human activities in the U.S. Gulf Coastal Plain. However, the overexploitation has led to groundwater depletion in the MEAS and the CLAS, threatening sustainable groundwater use. Such concern highlights the crucial need for an advanced understanding of stratigraphy and groundwater in these aquifer systems, which is essential for effective regional groundwater management. This dissertation presents a comprehensive investigation of MEAS and CLAS in the Louisiana and southwestern Mississippi region, encompassing three fundamental dimensions: stratigraphy reconstruction, groundwater modeling, and groundwater stress assessments. A …


Lower Bound On Preserved Flood Duration In Fluvial Bedform Stratigraphy (Experimental Dataset), Robert C. Mahon, Vamsi Ganti, Madeline M. Kelley, Debsmita Das, Victoria Sanchez, Giancarlo Portocarrero, Mayson Fredricks Mar 2024

Lower Bound On Preserved Flood Duration In Fluvial Bedform Stratigraphy (Experimental Dataset), Robert C. Mahon, Vamsi Ganti, Madeline M. Kelley, Debsmita Das, Victoria Sanchez, Giancarlo Portocarrero, Mayson Fredricks

Lower Bound on Preserved Flood Duration in Fluvial Bedform Stratigraphy (experimental dataset)

This data is collected to assess the role of hydrograph timescale relative to dune migration on the preservation of cross sets in the stratigraphic record. The data presented here are of dune evolution under steady-state conditions, as well as three hydrographs of the same magnitude but varying timescales.

Methodology:

We collected data from four experiments tracking bedform evolution in a 22-m-long, 0.56-m-wide, 0.9-m-deep flume at the University of New Orleans Dynamics of Sedimentation laboratory. We conducted an equilibrium experiment (discharge value 0.027 m3/s) and three flood experiments, which were characterized by a symmetrical flood wave. In all flood experiments, the …


Integrated Geochronological And Chemostratigraphic Study Of Middle Miocene Strata (Ogallala Group) At The Eastern Margin Of The North American Great Plains, J. J. Smith, Robert Matthew Joeckel, H. L. Field, G. A. Ludvigson, A. Moller, A. Layzell, S. T. Tucker Jan 2024

Integrated Geochronological And Chemostratigraphic Study Of Middle Miocene Strata (Ogallala Group) At The Eastern Margin Of The North American Great Plains, J. J. Smith, Robert Matthew Joeckel, H. L. Field, G. A. Ludvigson, A. Moller, A. Layzell, S. T. Tucker

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Tectonic Evolution Of The Northern Margin Of North America, Karol Faehnrich Mar 2023

Tectonic Evolution Of The Northern Margin Of North America, Karol Faehnrich

Dartmouth College Ph.D Dissertations

The northern margin of North America records a protracted history of Neoproterozoic–early Paleozoic rifting and passive margin development, followed by the middle Paleozoic accretion of continental fragments. Contrasting tectonic models have been proposed for the history of continent separation, the role of strike-slip displacement during terrane accretion, and the Mesozoic opening of the Arctic Ocean. Here, I explore several of these models by investigating Neoproterozoic–early Paleozoic sedimentary and volcanic rocks across the northern margin of North American, as well as the main faulted boundaries between displaced terranes and autochthonous rocks of North America. First, I present a new tectonic model …


Impacts Of Tectonic Subsidence On Basin Depth And Delta Lobe Building, Tian Y. Dong, Jeffrey A. Nittrouer, Brandee Carlson, Brandon Mcelroy, Elena Il’Icheva, Maksim Pavlov, Hongbo Ma Feb 2023

Impacts Of Tectonic Subsidence On Basin Depth And Delta Lobe Building, Tian Y. Dong, Jeffrey A. Nittrouer, Brandee Carlson, Brandon Mcelroy, Elena Il’Icheva, Maksim Pavlov, Hongbo Ma

School of Earth, Environmental, & Marine Sciences Faculty Publications

Channel avulsions on river deltas are the primary means to distribute sediment and build land at the coastline. Many studies have detailed how avulsions generate delta lobes, whereby multiple lobes amalgamate to form a fan-shaped deposit. These studies often assume steady subsidence and uniform basin depth. In nature, however, lobe building is disrupted by variable subsidence, and progradation of lobes into basins with variable depth: conditions that are prevalent for tectonically active areas. Herein, we explore sediment dispersal and deposition patterns across scales using measurements of delta and basin morphology compiled from field surveys and remote sensing, collected over 150 …


The Geology Of El Paso, William Cornell, Diane Doser, Richard Langford, Joshua Villalobos, Jason Ricketts Jan 2023

The Geology Of El Paso, William Cornell, Diane Doser, Richard Langford, Joshua Villalobos, Jason Ricketts

Books & Monographs

The Geology of El Paso describes the history of El Paso, Texas and its surrounding region from the Precambrian formation of the continent to the modern use of geologic resources. This book is written in an easy to digest format, with definitions or links for specific geologic terms and references for further reading. It reviews the formation and evolution of local landmark features such as the Franklin Mountains, Cerro Cristo Rey, and the Sierra de Juarez. Fossils and stratigraphic units of the El Paso area are described as well as important geologic features. The book puts the events that shaped …


Paleoenvironmental Changes Across The Devonian-Carboniferous Transition, Audrey M. Warren Dec 2022

Paleoenvironmental Changes Across The Devonian-Carboniferous Transition, Audrey M. Warren

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Devonian-Carboniferous (D-C) transition was a critical interval in earth history, witnessing profound environmental changes associated with plant and animal evolution and extinction. Two first-order mass extinctions occurred leading up to the D-C boundary: the Kellwasser Event at the Frasnian-Famennian (F-F) boundary (~371 Ma) and the D-C boundary Hangenberg Event (~359 Ma). Both events were associated with significant sea level changes and major carbon cycle perturbations, evidenced by widespread deposition of black shale and positive carbon isotope (δ13C) excursions, all of which have been used to correlate these events across the globe. Because preservation of black shale requires anoxic conditions, …


Characterization Of Quaternary Stratigraphy In The Mississippi Sound To Evaluate The Influence Of Geologic Heterogeneity On Submarine Groundwater Transport And Discharge, Zachary Peoples May 2022

Characterization Of Quaternary Stratigraphy In The Mississippi Sound To Evaluate The Influence Of Geologic Heterogeneity On Submarine Groundwater Transport And Discharge, Zachary Peoples

Theses and Dissertations

Submarine Groundwater Discharge (SGD) through seafloor sediments is gaining recognition as an important component of coastal water quality. Stratigraphic features creating geologic heterogeneity, such as incised paleochannels, may influence preferential pathways for SGD. The central Mississippi Sound is underlain by paleochannels that were incised into Pleistocene sediments while the area was subaerially exposed during the last glacial maximum and are now buried by transgressive Holocene deposits. In this thesis, newly collected chirp, previously published seismic reflection, and sediment core data are used to characterize the three-dimensional structure of the Holocene-Pleistocene contact. Results indicate that Pleistocene paleochannels cross-cut the study area, …


Detrital Zircon U-Pb Geochronology Of Upper Mississippian Siltstone, Oklahoma And Arkansas, Linnea Johnson Dec 2021

Detrital Zircon U-Pb Geochronology Of Upper Mississippian Siltstone, Oklahoma And Arkansas, Linnea Johnson

Graduate Theses and Dissertations

Although Upper Mississippian strata have been characterized extensively using lithostratigraphy, sequence stratigraphy, and biostratigraphy across the North American midcontinent, the origin of the silt comprising the Meramec STACK (Sooner Trend Anadarko Basin, Canadian and Kingfisher counties) reservoirs of the Anadarko Basin in west-central Oklahoma and age equivalent units is not well understood, despite its economic importance as an unconventional petroleum reservoir. Previously published models have variously invoked fluvial, marine, and aeolian sediment transport for Upper Mississippian siltstone present along the paleo-shelf edge of the Laurentian craton. This study uses detrital zircon U-Pb geochronology and grain morphology, handheld x-ray fluorescence (hXRF) …


Deposition And Diagenesis Of The Blossom Sand, Panola County, Texas, Hannah Chambers Jun 2021

Deposition And Diagenesis Of The Blossom Sand, Panola County, Texas, Hannah Chambers

Electronic Theses and Dissertations

The Late Cretaceous Blossom Sand within the Austin Group is a historic gas reservoir in the East Texas basin, located at depths of approximately 2,000 ft below the surface. Since the discovery of the Carthage Field in 1918 in the East Texas Basin, the Blossom Sand has produced approximately 26 BCF of gas with minor amounts of oil. Despite its notoriety in the Carthage Field, there is very little research that has been conducted on this unit, although it crops out in northeast Texas and is found in the subsurface of southwest Arkansas, western Louisiana, and the East Texas Basin. …


Terrestrial Soldier Crab (Coenobita Clypeatus, Fabricius 1787) And Cerion Spp. (Röding 1798) Shell Relationship On San Salvador Island, Bahamas, Harley Hunt May 2021

Terrestrial Soldier Crab (Coenobita Clypeatus, Fabricius 1787) And Cerion Spp. (Röding 1798) Shell Relationship On San Salvador Island, Bahamas, Harley Hunt

Biology Theses

The Caribbean terrestrial soldier crab, Coenobita clypeatus(Fabricius 1787), coexist and utilize the shells of numerous species of land and marine gastropods. Soldier crabs rely on gastropod shells for protection as the crabs have a soft abdomen, leaving them vulnerable for predation and desiccation, threatening their survival. This creates a strong pressure to obtain well-fitting shells that provide adequate protection against water loss. Cerion of Röding (1798) shells are one of the most commonly used shells among living colonies of C. clypeatuson San Salvador Island. This study is interested in the frequency of shell use by C. clypeatus crabs …


The Microfossil Association Of The Upper Part Of The Salesville Formation (Lower Missourian, Pennsylvanian) Near Mineral Wells, North-Central Texas, Billy Allen Williams May 2021

The Microfossil Association Of The Upper Part Of The Salesville Formation (Lower Missourian, Pennsylvanian) Near Mineral Wells, North-Central Texas, Billy Allen Williams

Earth & Environmental Sciences Theses - Archive

The microfossil association of the Salesville Formation (Strawn Group, Missourian, Pennsylvanian) of small foraminifers, fusulinids, conodonts, ostracodes, holothurian sclerites, and rare radiolarians, has received very little study. The upper part of the Salesville Formation, as exposed at two sections near Mineral Wells, North-Central Texas, represents deposits of the upper Salesville major cycle and is the stratigraphic interval of interest in this study whose primary objective is to evaluate the biostratigraphic significance of the microfossil association found at the two exposures of this cycle. The distribution of the early Missourian microfaunas is used to interpret the depositional environments of the major …


Characterizing The Geomagnetic Field At High Southern Latitudes: Evidence From The Antarctic Peninsula, Joseph Biasi, Joseph Kirschvink, Roger Fu Jan 2021

Characterizing The Geomagnetic Field At High Southern Latitudes: Evidence From The Antarctic Peninsula, Joseph Biasi, Joseph Kirschvink, Roger Fu

Other Staff Materials

Due to a dearth of data from high-latitude paleomagnetic sites, it is not currently clear if the geocentric axial dipole (GAD) hypothesis accurately describes the long-term behavior of the geomagnetic field at high latitudes. Here we present new paleomagnetic and paleointensity data from the James Ross Island (JRI) volcanic group, located on the Antarctic Peninsula. This data set addresses a notable lack of data from the 60°–70°S latitude bin and includes 251 samples from 31 sites, spanning 0.99–6.8 Ma in age. We also include positive fold, conglomerate, and baked contact tests. Paleointensity data from three methods (Thellier- Thellier, pseudo-Thellier, and …


Aeolian Sand Stringers In The Upper Midwest, Usa: Morphology, Stratigraphy, And Paleoenvironmental Significance, Kenzie L. Shandonay Jan 2021

Aeolian Sand Stringers In The Upper Midwest, Usa: Morphology, Stratigraphy, And Paleoenvironmental Significance, Kenzie L. Shandonay

All Graduate Theses, Dissertations, and Other Capstone Projects

Sand stringers are subtle (~1-10 m high), elongate (several km long, up to 100 m wide) aeolian landforms that lack a slip face and generally have a northwest-southeast orientation. They are ubiquitous across the Upper Midwest, including southeast Minnesota and western Wisconsin. Despite their prevalence, the timing, processes, and environmental conditions during sand stringer formation and evolution are poorly understood. This research aims to describe sand stringer morphology and stratigraphy, reconstruct regional paleoclimate, and characterize the timing and geomorphic processes of sand stringer formation and evolution in response to shifts in environmental conditions. This study investigates two sand stringers: Good-1 …


Tsunami Deposits And Tsunami Modeling Of The 900 Ad Seattle Fault Event In Northern Puget Sound, Andrew A. Raulerson Jan 2021

Tsunami Deposits And Tsunami Modeling Of The 900 Ad Seattle Fault Event In Northern Puget Sound, Andrew A. Raulerson

All Master's Theses

Puget Sound has a history of earthquakes and tsunamis with an ever-expanding knowledge of these events. The focus of this study is the Seattle fault earthquake and resulting tsunami 1100 years ago. This study aimed at refining the extent of tsunami inundation north of the fault using a two-phased approach: a field study at Elger Bay and tsunami modeling. Tsunami deposits dating to this event have been observed in six sites total sites in Puget Sound, and four of them are in northern Puget Sound. At Elger Bay I found one tsunami deposit in cores from the southwest corner of …


Stratigraphy And Geochemistry Of Paleocene-Aged Bauxites From North Mississippi, Timothy Brendan Clark Jan 2021

Stratigraphy And Geochemistry Of Paleocene-Aged Bauxites From North Mississippi, Timothy Brendan Clark

Electronic Theses and Dissertations

Bauxite is a heavily-mined aluminum ore that forms through the relative depletion of silica to aluminum. In North Mississippi, bauxite occurring within the Upper Midway and Lower Wilcox groups has been the subject of study for over a century. Despite the abundance and duration of research, controversy surrounds the subjects of bauxite genesis and economic value. The last detailed study of North Mississippi bauxite was in the 1980’s, so the goal of this project is to apply newly available technologies and modern hypotheses on bauxite formation to refine and obtain new data. Fieldwork observations yielded pisoliths, horizonation, and possible rhizoliths, …


Stratigraphy, Petrology, Diagenesis, Paleontology, And Depositional Environments Of The Harrisburg Member Of The Kaibab Formation In Northern Arizona And Southern Utah, Zachery T. Case Dec 2020

Stratigraphy, Petrology, Diagenesis, Paleontology, And Depositional Environments Of The Harrisburg Member Of The Kaibab Formation In Northern Arizona And Southern Utah, Zachery T. Case

Electronic Theses and Dissertations

The Kaibab Formation has two members, the Fossil Mountain Member below and the Harrisburg Member above. They were deposited in shallow-marine shelf to restricted coastal settings. Stratigraphically above are the Rock Canyon Conglomerate and the Moenkopi Formation; consisting of the Timpoweap and Lower Red members; which are the only members present in the study area. The Rock Canyon Conglomerate was deposited in depressions and as a regolith. The Timpoweap and Lower Red members were deposited in shallow marine to tidal environments.

Nine stratigraphic units were identified in the Harrisburg Member. Units one, two, three, five, six, seven, and nine are …


Plate Boundary Trench Retreat And Dextral Shear Drive Intracontinental Fault-Slip Histories: Neogene Dextral Faulting Across The Gabbs Valley And Gillis Ranges, Central Walker Lane, Nevada, Jeffrey Lee, Andrew K. R. Hoxey, Andrew Calvert, Peter Dubyoski Jul 2020

Plate Boundary Trench Retreat And Dextral Shear Drive Intracontinental Fault-Slip Histories: Neogene Dextral Faulting Across The Gabbs Valley And Gillis Ranges, Central Walker Lane, Nevada, Jeffrey Lee, Andrew K. R. Hoxey, Andrew Calvert, Peter Dubyoski

All Faculty Scholarship for the College of the Sciences

The spatial-temporal evolution of intracontinental faults and the forces that drive their style, orientation, and timing are central to understanding tectonic processes. Intracontinental NW-striking dextral faults in the Gabbs Valley–Gillis Ranges (hereafter referred to as the GVGR), Nevada, define a structural domain known as the eastern Central Walker Lane located east of the western margin of the North American plate. To consider how changes in boundary type along the western margin of the North American plate influenced both the initiation and continued dextral fault slip to the present day in the GVGR, we combine our new detailed geologic mapping, structural …