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Emplacement Of The Dadeville Complex Of The Southernmost Inner Piedmont Within The 7.5 Min. Cusseta Quadrangle, Chambers County, Alabama: Channel Flow, Klippe Kinematics, Or Orogen Parallel Translation, Timothy Black

Master's Theses

The Appalachian Mountains have a complex geologic history spanning three orogenic periods, the Taconic, the Acadian/Neoacadian, and Alleghanian orogenies. The Inner Piedmont of the Appalachian Mountains within Alabama contains two distinct lithologic complexes, the Dadeville Complex, and the Opelika Complex separated by the Stonewall Line. These complexes were formed during an arc-back arc fringing system during the Taconic orogeny and emplaced and recorded peak metamorphism during the Acadian orogeny.

The Dadeville Complex is an allochthonous arc terrain built on extended Laurentian crust. The mode of transportation and accretion after formation is not well understood, which has implications for the role …

Origins And Relationships Of The Units In And Adjacent To The Ross Lake Fault Zone, North Cascades, Washington, Leonard Hogan

Master's Theses

The North Cascades of Washington preserves a wide range of crustal levels in andadjacent to a Cretaceous magmatic arc. Field, petrographic, and detrital zircon geochronological research focused on a discontinuous, 55-km-long belt of metasedimentary rocks in the NW-striking Ross Lake fault zone (RLFZ) within the North Cascades. In the NW, metapelitic rocks of the Little Jack unit have an Early Jurassic maximum depositional age (MDA) and strong ductile fabrics in contrast to clastic rocks on the E with an Early Cretaceous MDA and primary structures, confirming the presence of the dextral Hozameen fault. To the SE, the oldest unit (~110 …

The Shallow Benthic Invertebrate Recovery From The End-Cretaceous Mass Extinction Across The Gulf Coastal Plain, Ronan B. Beltracchi

Master's Theses

The Gulf Coastal Plain, in the southeastern United States, contains several sites with well-preserved fossil assemblages from the Cretaceous- Paleogene boundary (K/Pg). Changes in benthic macroinvertebrate assemblages after mass extinction events commonly include reduction in body size of surviving organisms and preferential survival based on ecospace occupation. This study examines patterns of functional ecology and body size change in mollusk fossils from bulk samples collected throughout the post-extinction recovery interval at a well-studied boundary site from Darting Minnow Creek in Brazos, Texas USA and a recently described K/Pg boundary section on the Ouachita River in Malvern, Arkansas USA. The proportional …

The Spatial Distribution Of Mercury Contamination In The Yolo Bypass, California, Thomas S. Mykytyn

Master's Theses

Gold and mercury mining in the latter half of California’s 19th century resulted in massive and lingering alterations to downstream ecosystems through sedimentation and mercury contamination. Located at the confluence of Sierra Nevada and Coast Range watersheds, the Yolo Bypass is a critical conveyor of flood waters from the Lower Sacramento Valley to the Sacramento–San Joaquin Delta. Sedimentation in the bypass diminishes its flood conveyance capacity, and Hg contamination is hazardous to humans and ecosystems. The purpose of this study is to locate and quantify mercury contamination in the Yolo Bypass. Concentrations of total mercury ([THg]) were measured in 22 …

The Effect Of Submarine Volcanism On Foraminifera At Axial Seamount Of Juan De Fuca Ridge, Gabriela Marie Diaz Santana

Master's Theses

Submarine volcanoes contribute more than 75% of global volcanic eruptions annually and have the potential to change the surrounding submarine ecosystems. The species richness, abundance of foraminifera assemblages and the average test size of samples recovered from marine sediment cores are a proxy for past environmental changes on the seafloor and in the water column. This study evaluates the ecosystem impact of multiple eruptions that formed a massive caldera at Axial Seamount between 1300 and 800 years before present (BP). An examination of the diversity, abundance, and size of planktic and benthic foraminifera assemblages recorded in volcanic and hemipelagic sediments …

Quaternary Geologic Slip Rates For The Northern Rodgers Creek Fault, Near Windsor, Ca, Alianora Walker

Master's Theses

New Quaternary geologic slip rates were determined for the northern Rodgers CreekFault at two sites near Windsor, CA. Slip rates were determined through Quaternary mapping and geochronologic dating, specifically in situ cosmogenic 10Be, and infrared stimulated luminescence dating. At the Shiloh Ranch Regional Park site, a terrace dated to ~3.2 ka – 7.9 ka and offset 18 m – 45 m yielded a preliminary slip rate of 6.1 mm/yr ± 4.5 mm/yr. At the Foothill Regional Park site, an older Quaternary terrace and a younger alluvial fan deposit are reconstructed with source drainages across the fault. Reconstructing the ~68.8 ka …

Deformation History Of The Pasayten Fault Zone, North Cascades, Washington And British Columbia, Natasha Budimirovic

Master's Theses

The Pasayten fault extends ~250 km from Washington to British Columbia (BC), roughly following the controversial, paleomagnetically defined “Baja BC” boundary. This study investigated the deformation history of the Pasayten fault zone through mapping contacts, measuring orientations of foliations, lineations, and folds, and examining kinematic indicators in the northern segment in BC and in the southern projection of the fault in Washington. In the northern area, the ~110-105 Ma Pasayten fault separates the Jurassic-Cretaceous Methow basin from the Middle Jurassic to mid-Cretaceous Eagle Plutonic Complex and Permian Eastgate-Whipsaw metamorphic belt to the northeast. Structural orientations and kinematic indicators in outcrops …

Dye Tracing And The Effects Of Infrastructure In Hidden River Cave, Horse Cave, Ky, Alexa G. Franks

Master's Theses

Hidden River Cave is a stream cave system found in Horse Cave, KY with continuous water flow of its two branches, Wheet River and East River. The infrastructure of the city of Hose Cave, KY was originally designed to utilize natural sinkholes for drainage of all wastewaters. The city uses many of these, now modified, sinkholes for wastewater disposal and storm water drainage. Historically, Hidden River Cave has been severely impacted by unmonitored dumping of contamination. To better understand and identify specific flow paths from sinkholes and infrastructure into Hidden River Cave, this study documented various sinkholes and other infrastructure, …