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Geology

2013

University of South Carolina

Articles 1 - 7 of 7

Full-Text Articles in Physical Sciences and Mathematics

Volcanic And Tectonic Processes Along Anomalous Mid-Ocean Ridges, Julia Kathryn Howell Jan 2013

Volcanic And Tectonic Processes Along Anomalous Mid-Ocean Ridges, Julia Kathryn Howell

Theses and Dissertations

The morphological and structural characteristics of the global spreading ridge system are systematically related to spreading rate and magma supply (e.g. Macdonald, 1982). Because intermediate spreading-rate ridges (ISRs) spreading between 60 and 80 mm/yr have characteristics of both fast and slow spreading ridges, they are ideal environments to study the differences controlling upper crustal accretion. We examine the distribution of seamounts along spreading ridges to understand the relationship between seamount volcanism and axial morphology along four ISRs: the Juan de Fuca Ridge (JdFR), the Galápagos Spreading Centers (GSC), the Southeast Indian Ridge (SEIR), and the Eastern Lau Spreading Centers (ELSC). …

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Tidal Flux Of Trace Metals And Rare Earth Elements In A Barrier Island Salt Marsh, Ryan Antle Jan 2013

Tidal Flux Of Trace Metals And Rare Earth Elements In A Barrier Island Salt Marsh, Ryan Antle

Theses and Dissertations

Barrier island salt marshes are known as sources of nutrients to the coastal ocean but it is unclear whether they are also sources or sinks of trace metals in regards to coastal waters. Salt marshes are characterized by steep redox and biogeochemical gradients, which constantly fluctuate as a result of tidal pumping. While several studies have examined metal budgets between terrestrial fresh water, estuarine subterranean fluids, and coastal saline waters, there is little data regarding fluid chemistry for metals in salt water estuaries in the absence of fresh water input. This study investigated a back barrier salt marsh on Cabretta …

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Subsurface Imaging And Petrophysical Analysis Of The South Georgia Rift Basin, South Carolina, Olusoga Martins Akintunde Jan 2013

Subsurface Imaging And Petrophysical Analysis Of The South Georgia Rift Basin, South Carolina, Olusoga Martins Akintunde

Theses and Dissertations

The Triassic-Jurassic South Georgia Rift (SGR) basin, buried beneath Coastal Plain sediments of southern South Carolina, southeastern Georgia, western Florida, and southern Alabama, consists of an assemblage of continental rift deposits (popularly called red beds), and mafic igneous rocks (basalt flows and diabase sills). The red beds are capped by basalts and/or diabase sills, and constitute the target for supercritical CO2 storage as part of a Department of Energy funded project to study feasibility for safe and long-term sequestration. This study addresses key stratigraphic, structural and petrophysical issues critical to determine subsurface suitability for CO2 storage as well as improved …

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Tectonics Of The South Georgia Rift, David Michael Heffner Jan 2013

Tectonics Of The South Georgia Rift, David Michael Heffner

Theses and Dissertations

Triassic rifting of the supercontinent Pangea left behind numerous basins on what is now the eastern North American margin. The South Georgia Rift (SGR) was thought to be the best preserved of these basins having been capped by thick basalt flows of the Central Atlantic Magmatic Province (CAMP) and later buried beneath the Cretaceous and younger Coastal Plain. Because it is buried beneath the Coastal Plain, the SGR is only known through sparse drilling and geophysical methods. Despite this limited dataset, the SGR is the only one of the eastern North American Triassic basins known to overlie the ancient Alleghanian …

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Benthic Boundary Layer Processes: Bedform Evolution And Bottom Turbulence, Timothy Robert Nelson Jan 2013

Benthic Boundary Layer Processes: Bedform Evolution And Bottom Turbulence, Timothy Robert Nelson

Theses and Dissertations

Bedform roughness, caused by ripples on the seabed, plays an important role in controlling sediment dynamics in the nearshore region. In this dissertation, the temporal and spatial evolution of ripples from two field sites located in the South Atlantic Bight, offshore Long Bay, SC and Georgia are used to relate wave-induced ripple geometry (wavelength and orientation) to near bed directional wave velocities. 2-D spectral analysis techniques were developed to automate detection of ripple wavelength, direction, and irregularity. This analysis showed that magnitude, direction, and duration of wave forcing controls ripple geometry and irregularity. During highly energetic events, ripple geometry changes …

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Geochemical Source Components In Seafloor Lavas In The Aleutian Back-Arc, Max Thomas Siegrist Jan 2013

Geochemical Source Components In Seafloor Lavas In The Aleutian Back-Arc, Max Thomas Siegrist

Theses and Dissertations

Whole-rock compositions of seafloor lavas are used to constrain the processes and source characteristics contributing to the formation of geochemically distinctive, primitive magma types located in the Aleutian back-arc. Samples were dredged primarily from small volcanic cones on the seafloor, located between the emergent volcanoes and in the back-arc up to 60 km from the volcanic front. Compositions vary from basalt to dacite, with 48-70 % SiO2 and 4-13 % MgO. Nearly 30% of the samples are primitive, with Mg/Mg+Fe >0.60. Most primitive samples are basalts, which fall into two groups, based on minor and trace element abundances. Low/med-K …

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Amplitude Vs. Offset Effects On Gas Hydrates At Woolsey Mound, Gulf Of Mexico, Walter R. Anderson Jan 2013

Amplitude Vs. Offset Effects On Gas Hydrates At Woolsey Mound, Gulf Of Mexico, Walter R. Anderson

Theses and Dissertations

Due to the estimated massive quantities of natural methane hydrates, they represent one of the largest sources of future alternative energy on Earth. Methane hydrates have been found in the shallow sub-seafloor of the Northern Gulf of Mexico where the water depth is in excess of ~900 m. Mississippi Canyon Block 118 has been chosen by the Gulf of Mexico Hydrates Research Consortium to be the site of a multi-sensor, multi-discipline sea-floor observatory for gas hydrate research. First evidence for gas hydrates at MC 118 was observed at Woolsey Mound. Subsurface evidence for gas hydrates has subsequently been substantiated by …

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