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Utilizing Structure-From-Motion Photogrammetry And Unmanned Aerial Vehicles To Characterize Variability In Fluvial Deposits From The Salt Wash Member Of The Morrison Formation, East-Central Utah, John Chesley

Theses and Dissertations

Modern fluvial systems are highly variable, often containing the entire spectrum of fluvial styles (e.g., braided to meandering). This variability is difficult to capture in ancient fluvial deposits due to limited 1- and 2-dimesional exposures, which provide only a snapshot of the depositional history at one location. As a result, researchers are forced to interpolate between exposures and develop regional scale models that often underestimate the complexity and variability seen in modern environments. Outcrops of the Upper Jurassic Salt Wash Member of the Morrison Formation in east-central Utah, USA provide a relatively unique opportunity to examine ancient fluvial sandstone bodies …

Tectonic Studies Of Southeastern North America: The Suwannee Basin, Brunswick Suture Zone, Osceola Arc, And Pangean Transcurrent Fault System, Susannah Katherine Boote

Theses and Dissertations

A series of exotic terranes with complex tectonostratigraphic relationships construct the North American margin and record information critical to understanding the evolution of the Appalachian orogen. The Coastal Plain cover remains a challenge in this region; however, synthesis of seismic reflection, seismic refraction, well, and aeromagnetic data allows for a substantially revised interpretation of the basement rocks and structures that comprise the pre-Mesozoic crust of southeastern North America. These data reveal: (1) a Neoproterozoic subduction zone and paired continental-margin arc are preserved in Gondwanan crust in southeastern North America, (2) the Gondwanan Suwannee Basin of Early to Mid-Paleozoic age is …

Serpentinization And Synthesis: Searching For Abiotic And Biotic Non-Volatile Organic Molecules In The Subsurface Of The Atlantis Massif, Katherine A. Hickok

Theses and Dissertations

High concentrations of hydrogen created during serpentinization can promote the formation of abiotic organic carbon molecules such as methane, formate, and short chain hydrocarbons and, in laboratory experiments, larger molecules containing up to 32 carbon atoms. Subsurface archaeal and bacterial communities can use these reduced compounds for metabolic energy. International Ocean Discovery Project Expedition 357 drilled 17 boreholes into the Atlantis Massif with the goals of investigating carbon cycling and the presence of life in a zone of active serpentinization. The expedition recovered multiple lithologies including gabbros, basalts, carbonate sands, and serpentinites. A subset of contrasting lithologies were analyzed for …

Behavior Of Rare Earth Elements And High-Field Strength Elements During Peridotite - Seawater Interaction, Carl Pasquale Frisby

Theses and Dissertations

Serpentinized abyssal peridotites are evidence for active communication between the Earth’s hydrosphere and the upper mantle, where exchange and retention of both major and trace elements occur. Rare earth elements (REE) and high-field strength elements (HFSE: Ti, Zr, Hf, Nb, Ta) are generally thought of as immobile during serpentinization. In partially serpentinized abyssal peridotites, clinopyroxenes typically retain radiogenic Nd and Hf isotopic signatures that have been used to infer the composition and high temperature processes in the upper mantle. However, bulk rock Nd isotopes in some serpentinized abyssal peridotites less radiogenic values that approach that of seawater, which has been …

An Integrated Structural Analysis On Seismic Of A Paleo Mound Development (Woolsey Mound, Northern Gulf Of Mexico), Ricardo Tomas Troco Kabila

Theses and Dissertations

Woolsey Mound is ~1 km diameter thermogenic gas hydrate and cold seep (GHCS) complex system. It is located at ~900 m water depth in the Mississippi Canyon Lease Block 118 (MC–118) on the upper continental slope of the northern Gulf of Mexico (GOM). Due to its complex geology, widespread hydrate seepage activity and presence of benthic habitat, the mound serves as a permanent research site for a multidisciplinary seafloor observatory, thus providing insights into the dynamics of shallow fluid expulsion, their spatial and time variations and possible geological forcing mechanisms.

This study utilizes a set of high resolution 2D autonomous …

Small Mud And Sand Filled Paleochannels Offshore Charleston, Sc, Erin Smoak

Theses and Dissertations

The spatial variations of Quaternary sediments on the continental shelf record the progression of depositional environments during the latest sea-level rise, and are fundamental controls on submarine groundwater discharge (SGD) flow. SGD on continental shelves is an important but poorly constrained process. Spatial variations of lithologies on continental shelves, such as sand-filled paleochannels, are assumed to play a fundamental role in controlling where SGD occurs but coincident seismic mapping and sedimentological data are rare. Here we combine seismic mapping of paleochannel locations with sediment cores to examine the sedimentary characteristics of paleochannel fill and interfluvial deposits. To establish paleochannel locations …

From Near And Far: Utilization Of In-Situ And Remotely Sensed Satellite Data From Nasa And Noaa, Jessica Rochelle Price Sutton

Theses and Dissertations

Satellite remote sensing observations have been used for numerous studies to better understand physical and biological properties over varying spatial and temporal scales. Depending on the satellite and sensor, the satellite-derived observations can provide high spatial and temporal resolution for many important physical and biological variables. While there are many limitations in utilizing satellite remote sensing products, there are also many advantages. This dissertation investigates three different applications for satellite remote sensing products to address climatological and ecological concerns. This dissertation is motivated by two overall research questions: (1) How can satellite remote sensing products be used to address important …

Platinum Decoupling From Pge In Peridotitic Sulfides From The St. Elena Ophiolite In Costa Rica, Jessica A. Holm

Theses and Dissertations

The platinum group elements (Os, Ir, Ru, Rh, Pt, Pd) are important petrogenetic tracers of mantle processes and the Re-Os isotope system an important tool for tracing ancient depletion and refertilization processes in the mantle. A key characteristic of these elements is that they are siderophile and chalcophile, and their abundance in the Earth’s mantle is thought to be controlled by sulfides. Existing thermodynamic data suggests that at reducing conditions similar to those found at the early stages of serpentinization, PGE may exist as alloys in the mantle. While numerous studies report on the bulk peridotite PGE and sulfide PGE …

Ecohydrology And Groundwater Dynamics In A Salt Marsh Island, Andrea L. H. Hughes

Theses and Dissertations

Tidal salt marshes are extraordinarily productive and valuable ecosystems that provide via groundwater a not insignificant portion of coastal solute and nutrient budgets. Among the many goods and services they provide are habitat for diverse wildlife, protection for coastal communities during storms, and protection for coastal surface waters by filtering anthropogenic pollutants. One threat to the health of tidal salt marshes along the East Coast have been episodes of Acute Marsh Dieback (AMD) from 1999 to 2001. Dieback was observed at North Inlet salt marsh from 2000 to 2001. Since salt marsh hydrology is dominated by the local tidal regime, …

Delineation Of The Lower Permian Gas Sand Via Calibrated Avo And Pre-Stack Seismic Inversions In Majhol Field, Saudi Arabia, Abdullah Alhashel

Theses and Dissertations

The lower Permian formation in the central region of Saudi Arabia is a key hydrocarbon siliciclastic reservoir. However, in Majhol field, the reservoir properties vary laterally due to diagenesis and facies changes. Conventional seismic interpretation has failed to map the heterogeneities of the reservoir properties that control the gas production of this field. Therefore, there was an opportunity to employ more advanced quantitative seismic techniques to delineate the productive gas sand facies in the field.

The Majhol field was initially planned to be developed as an unconventional tight reservoir. Well-1 was drilled based on conventional seismic interpretation on the crest …

Utilization Of Satellite-Derived Salinity For Enso Studies And Climate Indices, Caroline Mary Corbett

Theses and Dissertations

Conventionally, El Niño-Southern Oscillation (ENSO) is studied using sea surface temperature (SST) observations in the central and eastern equatorial Pacific Ocean. Recently, sea surface salinity (SSS) in the equatorial Pacific has been studied in relation to the phases of ENSO. Previously, SSS was observed in the equatorial Pacific using the Tropical Ocean Global Atmosphere (TOGA) / Tropical Atmosphere Ocean (TOA), the Argo float network, and Oceanic General Circulation Models (OGCM). The launch of NASA’s Aquarius Salinity Mission and ESA’s Soil Moisture Ocean Salinity (SMOS) opened a new era in which high resolution global near real-time SSS observations are readily available. …

Alongshore Momentum Balance Over Shoreface-Connected Ridges, Fire Island, Ny, Conor Ofsthun

Theses and Dissertations

Bathymetric variations, such as shoreface-connected ridges (SFCRs), modify inner shelf circulation, altering the significance of and relationships between alongshore momentum balance terms. The inner shelf of Fire Island, NY provides a study site representative of SFCRs around the world. During the winter of 2014, hydrodynamic observations (~12 m depth) from 6 ADCPs, 3 SeaGauge pressure sensors, 2 tide gauges, and 2 meteorological buoys were collected over a region of the inner shelf spanning a full wavelength of one such SFCR. Analysis of the data, under westward wind forcing, revealed a predominantly alongshore circulation with localized offshore (onshore) current veering over …

Three Dimensional Thermobaric Modeling Of A Gas Hydrate System, Amanda Quigley Williams

Theses and Dissertations

Seismic imaging is recognized as the most cost effective method for identifying the presence of gas hydrate resources. The base of the gas hydrate stability zone is recognized by the presence of regionally extensive bottom simulating reflectors (BSR). However, in some areas such as the Gulf of Mexico, regionally extensive BSRs are not found. In such cases, an understanding of the thermobaric conditions may be used to determine the location of gas hydrates and the base of the gas hydrate stability zone. The aim of this research is to combine seismic velocity analysis and thermal modeling to predict the base …

Neuro-Fuzzy Classification Of Felsic Lava Geomorphology At Alarcon Rise, Mexico, Christina Hefron Maschmeyer

Theses and Dissertations

The Alarcon Rise is the only submarine oceanic spreading ridge setting where rhyolitic lavas have been found. This intermediate-rate spreading ridge provides a unique natural laboratory for studying the geomorphology of felsic submarine lava flows at oceanic spreading ridges. Seafloor observations of felsic lava indicate the flow morphology differs from typical submarine basaltic lava at the few other oceanic spreading ridges where differentiated compositions have been recorded. Morphologic variation between mafic and felsic lava flows, especially rhyolites, was also observed at Alarcon Rise.

The Monterey Bay Aquarium Research Institute conducted mapping surveys with autonomous underwater vehicle D Allan B. in …

Submarine Groundwater Discharge And The Configuration Of The Freshwater-Saltwater Interface At The Nearshore And Embayment Scales, Tyler Brandon Evans

Theses and Dissertations

Submarine groundwater discharge (SGD) rivals riverine discharge to the world’s oceans but remains poorly understood. Until the early 1990’s, geochemical budgets for the ocean were developed using material fluxes from rivers only. SGD has been shown to carry high concentrations of dissolved nutrients, metals and carbon. However, SGD is a difficult to measure, complex phenomenon driven by multiple physical processes. Groundwater flow and the resultant chemical exchange at the land-sea interface are heavily impacted by the hydrodynamic effects of mixing between variable-density fluids. In order to better understand SGD, investigations have focused on the configuration of the freshwater-saltwater interface in …

3d Seismic Depth Imaging And Velocity Model Building In Anisotropic Media: Serri Oil And Gas Field, Saudi Arabia, Ali Jomaah Alsalem

Theses and Dissertations

Seismic imaging is a significant element in hydrocarbon exploration to locate drilling prospects and it relies mainly on an accurate velocity model. Prestack depth migration (PreSDM) versus traditional post-stack time migration has become a common method for seismic velocity model building and imaging. This methodology accounts for seismic velocity anisotropy of the propagating waves in the subsurface with a higher level of accuracy in positioning the seismic events in their true positions in the subsurface.

In this thesis, we examine a 303 km2 of 3D seismic data acquired by Saudi Aramco in the Serri field of North-West Saudi Arabia. The …

Implications Of Hf-Nd Isotopes In West Philippine Basin Basalts For The Initiation And Early History Of The Izu-Bonin-Mariana Arc, Benjamin D. Hocking

Theses and Dissertations

Drilling at Site U1438, located immediately west of Kyushu-Palau Ridge (KPR), the site of IBM subduction initiation, penetrated 1,460 m of volcaniclastic sedimentary rock and 150 m of underlying basement. Biostratigraphic controls indicate a probable age for the oldest sedimentary rocks at around 55 Ma. This is close to the 48-52 Ma time period of IBM subduction initiation, based on studies in the forearc. There, the first products of volcanism are tholeiitic basalts termed FAB (forearc basalt), which are more depleted than average MORB and show subtle indicators of geochemical enrichment due to subduction. Site U1438 basement basalts share many …

Detrital Zircon Analysis Of The Taza-Guercif Basin And The Adjacent Rif And Middle Atlas Mountains Of Morocco And X-Ray Fluorescence Chemofacies Analysis Of The Maness Shale Of East Texas, Jonathan Richard Pratt

Theses and Dissertations

The research in this compilation encompasses three studies leveraging quantitative chemical analyses to interpret the sedimentary record to reconstruct geologic history. The first study surveys the detrital zircon U-Pb and zircon fission-track geochronology of the sedimentary Cretaceous Ketama and Tisiren units of the Rif Mountains, and the Bou Rached sandstones of the Middle Atlas Mountains. All analyzed samples contain a population of Mesoproterozoic crystallization ages formerly unknown to northwest Africa. Possible sources for these ages include the Avalonian terranes now present on the northeastern seaboard of North America, and/or zircons derived from the Amazonian craton and preserved in the Pan-African …

3-D Numerical Simulation Of Carbon Dioxide Injection Into The South Georgia Rift Basin For Geologic Storage, Daniel Eric Taylor Brantley

Theses and Dissertations

This study numerically simulated the injection of supercritical phase CO2 into the South Georgia Rift (SGR) basin to evaluate the feasibility and efficacy of long term geologic storage. The injection simulation modeling was divided into two phases. During phase one of the modeling, very little geologic and reservoir dynamics data was known about the SGR basin. Due to lack of basin data, an equilibrium model was used to estimate the initial hydrostatic pressure, temperature and salinity gradients that represent our study area. For the equilibrium model, the USGS SEAWAT program was used and for the CO2 injection simulation, TOUGH2-ECO2N was …

Complexity In Overmarsh Circulation, Jessica Chassereau Sullivan

Theses and Dissertations

Overmarsh circulation is highly complex with variations in current direction over very short timescales and flowpaths that differ substantially between flood and ebb cycles. Understanding such flow complexities in salt marshes is important because they inherently impact the distribution of sediment, larvae and nutrients throughout the marsh, and hence, the ecogeomorphic feedbacks that control landscape evolution. The purpose this Ph.D. research is to quantitatively evaluate the effects of salt marsh topography on overmarsh circulation in a Georgia salt marsh. This dissertation is comprised of three parts. First, digital elevation models (DEMs) were compared to characterize how well airborne lidar (light …

Proxy Development And Application For Reconstructing The Surface Ocean Carbonate System, Brittney J. Marshall

Theses and Dissertations

Over the last two centuries, human activities have led to an unprecedented rate of carbon input into the atmosphere and oceans resulting in an alarmingly rapid decline in surface ocean pH, a process referred to as ocean acidification (OA). This process is leading to an observed decline in the carbonate ion concentrations ([CO3 2-]) in seawater – an ion that a large number of marine organisms (e.g. corals, foraminifera) utilize to secrete their skeletons and shells. The ability to identify past ocean acidification events using the marine sedimentary record can shed light on future impacts of the modern OA dilemma. …

The Geologic Implications Of The Factors That Affected Relative Sea-Level Positions In South Carolina During The Pleistocene And The Associated Preserved High-Stand Deposits, William Richardson Doar Iii

Theses and Dissertations

This work utilizes the current understanding of South Carolina geology to provide a stratigraphic review of the late-Pliocene and Pleistocene marine deposits. Almost two centuries of recorded geological study includes geomorphic and stratigraphic units that were described, proposed, revised, abandoned, and revived. Along with the history of the age assignments, changes in geological time scales, and the changes in the understanding of geological concepts, this review is necessary because two concurrent and conflicting stratigraphies exist for late-Pliocene and Pleistocene marine sediments that record multiple sea-level transgressions that were more often destructive than constructive. The result, when tested against existing geological …

Temporal Constraints On Holocene Initiation And Termination Of Mound Development At An Episodic Gas Hydrate And Cold Seep System, Woolsey Mound, Northern Gulf Of Mexico, Nathan Robinson

Theses and Dissertations

Woolsey Mound is a thermogenic gas hydrate and cold seep system in the deepwater (900m) Gulf of Mexico. A set of sub-bottom seismic profiles acquired at MC-118 Woolsey Mound provide decimeter-scale vertical resolution of the upper ~50m of the subsurface throughout the lease block. Integration of these data with radiocarbon, lithostratigraphic, and biostratigraphic data from shallow gravity cores provides the basis for detailed interpretation of the mound evolution within the last 12,000 years. Uniform sedimentation during the Last Glacial Maximum and following changes in sediment distribution over MC-118 suggests modern mound activity did not begin until at least ~12ka. Development …

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 …

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 …

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 …

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 …

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 …

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 …

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). …