Physical Sciences and Mathematics Commons^™

Holocene Sedimentary Responses To Growth Faulting In A Back-Barrier Setting: East Matagorda Peninsula, Texas, Phillip Wolfe

Theses and Dissertations--Earth and Environmental Sciences

The structural framework of the northern Gulf of Mexico coastal zone is characterized by numerous growth fault systems. Neotectonic processes in coastal marshes in this region have been shown to be important drivers of relative sea-level rise as well as having significant influence on marsh accretion processes. One active growth fault has been identified at East Matagorda Peninsula, Texas. To characterize the Holocene behavior of this fault and the consequent sedimentary responses, a suite of fallout radionuclides (⁷Be, ¹³⁷Cs, ²¹⁰Pb) and radiocarbon, supplemented by sediment physical property data have been used to determine sediment mixing depths, …

Application Of The Kalman Filter On Full Tensor Gravity Gradiometry Data Around The Vinton Salt Dome, Louisiana, Mahnaz Sepehrmanesh

Theses and Dissertations--Earth and Environmental Sciences

Full tensor gravity (FTG) data are known for their high resolution but also for higher noise in its components due to the dynamic nature of the platform used for data acquisition. Although a review of the literature suggests steady increase in the success of gravity gradiometry, we still cannot take advantage of the full potential of the method, mostly because of the noise with the same amplitude and wavenumber characteristics as the signal that affects these data. Smoothing from common low pass filters removes small wavelength features and makes it difficult to detect structural features and other density variations of …

Paleoseismic And Structural Characterization Of The Hines Creek Fault: Denali National Park And Preserve, Alaska, Sara E. Federschmidt

Theses and Dissertations--Earth and Environmental Sciences

The Hines Creek fault (HCF) is a Holocene-active fault in central Alaska. Its trace has been mapped several times, but data on the history of fault displacement is scarce. As a major crustal-scale geologic boundary with uncertain Quaternary tectonic activity, it is a priority for more to be known about the activity of this fault to better understand the hazards it presents to the Denali National Park and Preserve and Alaskan infrastructure. This study characterizes the late Quaternary activity of the HCF through surficial geologic mapping and paleoseismic investigations. Mapping revealed a very steep (~84°-88° apparent dip), north dipping fault …

Age Of The Walden Creek Group, Western Blue Ridge Province: Resolving A Decades-Old Controversy Via Detrital Mineral Geochronology And Sedimentary Provenance Analysis, Evan A. Kelly

Theses and Dissertations--Earth and Environmental Sciences

Originally mapped as Precambrian and uppermost Ocoee Supergroup (OS), recent discoveries of Paleozoic microfossils have placed the Walden Creek Group (WCG), eastern Tennessee, into a younger depositional framework (Silurian or younger). In this study, monazite geochronology using SIMs, detrital zircon U-Pb geochronology determined by LA-ICP-MS, feldspar compositions determined by microprobe, zircon-tourmaline-rutile (ZTR) indices, and framework mineral modes were used to characterize provenance of sandstones of the WCG. Monazite ages cluster at 450 and 1050 Ma. All Ordovician ages are from grains that, in BSE images, have inclusion-rich microtextures interpreted as diagenetic and/or metamorphic, thus requiring that the WCG was deposited …

A Petrographic Characterization Of The Leatherwood Coal Bed In Eastern Kentucky, Michelle N. Johnston

Theses and Dissertations--Earth and Environmental Sciences

The Eastern Kentucky Coal Field is located in the central portion of the Appalachian Basin. The Pennsylvanian Breathitt Formation in this region is characterized by numerous sequences of bituminous coal-bearing sedimentary rocks. These coals have distinct maceral compositions due to variations in depositional environments. Coal characterization is an important method for determining conditions that influenced peat accumulation and overall depositional settings of mires.

This study focuses on the characterization of the maceral composition of the Middle Pennsylvanian-age Leatherwood coal bed. It utilizes petrographical, palynological, and geochemical analyses to describe specific depositional environments and associated peat accumulation conditions.

Petrographic analyses indicate …

Instrument Correction And Dynamic Site Profile Validation At The Central United States Seismic Observatory, New Madrid Seismic Zone, Clayton M.J. Brengman

Theses and Dissertations--Earth and Environmental Sciences

The Central United States Seismic Observatory (CUSSO), is a fifteen-element array of three-component accelerometers and seismometers in the New Madrid seismic zone, within the upper Mississippi embayment. Its location within the thick (up to 1 km) sequences of unlithified sediment comprising the embayment, make CUSSO a unique array in its ability to directly measure seismic wave propagation, including ground motion site effect; however, before the observational data can be used for analysis, the orientation and instrument response of the CUSSO array must be defined. This study used cross-correlation and direct comparisons to filter out the instrument response and determine the …

Geology Of The West Half Of The Cove Creek Gap Quadrangle And Adjacent Areas, Western North Carolina: Insights Into Eastern Great Smoky Mountains Tectonometamorphism, Daniel F. Spaulding

Theses and Dissertations--Earth and Environmental Sciences

Three outstanding problems related to the tectonic evolution of the Western Blue Ridge in the eastern Great Smoky Mtns. (GSM) include: (1) the nature of the Greenbrier Fault, previously interpreted as a younger over older pre-Taconic thrust fault with ~24 km of displacement between the Snowbird and Great Smoky Groups; (2) the relationship of regional metamorphism, expressed by the growth of porphyroblastic index minerals, to folding and foliation development in pelitic metasediments; (3) the relation of deformation to regional Taconian metamorphism. These problems were addressed in previous studies that did not have detailed mapping and petrography as a context. By …

The Nature And Origin Of Cyclicity In The Cleveland Member Of The Ohio Shale (Upper Devonian), Northeastern Kentucky, U.S.A., Alice C. O'Bryan

Theses and Dissertations--Earth and Environmental Sciences

The Cleveland Shale displays a characteristic and distinctive pattern of promontories and recessed intervals on weathered outcrops, which appears to represent cyclicity. This weathering pattern can be observed in other shales, both within and outside the Appalachian Basin; so determining the nature of these cycles may be critical for understanding the origin of, not only the Cleveland Shale, but also of black shales in general. Cyclicity in the Cleveland was examined on a decimeter-to-meter scale using lithologic characterization, gamma-ray stratigraphy and x-ray fluorescence, and on a millimeter-to-centimeter scale using organic petrography. Lithologic characterization and gamma-ray stratigraphy revealed Milankovitch-band fourth- and …

Determining Hillslope Diffusion Rates In A Boreal Forest: Quaternary Fluvial Terraces In The Nenana River Valley, Central Alaska Range, Laurel Anne Walker

Theses and Dissertations--Earth and Environmental Sciences

The subarctic boreal forest biome is predicted to experience higher magnitudes of warming than other biomes due to climate change. The effects of this warming will be pronounced in areas underlain by discontinuous permafrost where melting permafrost and distinct changes in vegetation patterns are expected. To better understand rates of hillslope diffusion in the boreal forest I have used a geomorphic process modeling approach, using data from a sequence of Quaternary fluvial terraces located in the Nenana River valley of central Alaska. I hypothesized that diffusion rates here would be slower when compared to the mid-latitudes, and faster on north …

Temporal And Spatial Characterization Of Macondo 252 Signatures In Gulf Of Mexico Shelf And Slope Sediments, Olivia P. Woodruff

Theses and Dissertations--Earth and Environmental Sciences

The long-term fate of hydrocarbons in the Gulf of Mexico (GOMx) following the 2010 Deepwater Horizon oil spill has yet to be fully characterized. Elemental (% C and % N), stable isotopes (δ¹³C_organic), and polycyclic aromatic hydrocarbon (PAH) molecular signatures were investigated in shelf and slope sediments collected in October 2010 and 2011 to gain insight into processes affecting the distribution and fate of spilled Macondo oil. Particulate organic carbon (POC) ranged between 1.55 and 2.22 wt. % in 2010 and 0.55 and 2.06 % in 2011 while the corresponding δ¹³C_organic ranges were …

Late Quaternary Crustal Deformation At The Apex Of The Mount Mckinley Restraining Bend Of The Denali Fault, Alaska, Corey A. Burkett

Theses and Dissertations--Earth and Environmental Sciences

The tallest mountain in North America, Mount McKinley is situated inside a sharp bend in the right‐lateral Denali fault. This anomalous topography is clearly associated with the complex geometry of the Denali fault, but how this topography evolves in conjunction with the adjacent strike‐slip fault is unknown. To constrain how this fault bend is deforming, the Quaternary fault‐related deformation on the opposite side of the Denali fault from Mount McKinley were documented through combined geologic mapping, active fault characterization, and analysis of background seismicity. My mapping illustrates an east‐west change in faulting style where normal faults occur east of the …

Science And Public Policy Of Earthquake Hazard Mitigation In The New Madrid Seismic Zone, Alice M. Orton

Theses and Dissertations--Earth and Environmental Sciences

In the central United States, undefined earthquake sources, long earthquake recurrence intervals and uncertain ground motion attenuation models have contributed to an overstatement of regional seismic hazard for the New Madrid Seismic Zone on the National Seismic Hazard Maps. This study examined concerns regarding scientific uncertainties, overly stringent seismic mitigation policies and depressed local economy in western Kentucky through a series of informal interviews with local businessmen, public officials, and other professionals in occupations associated with seismic mitigation. Scientific and relative economic analyses were then performed using scenario earthquake models developed with FEMA’s Hazus-MH software. Effects of the 2008 Wenchuan …