Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Geochemistry (4)
- Antarctica (2)
- Palynology (2)
- Anoxic event (1)
- Aquafacies (1)
-
- Arbuckle Simpson Aquifer (1)
- Archean (1)
- Bathymetry (1)
- Beryllium-7 (1)
- Black shale (1)
- Brine (1)
- CO2 (1)
- Carbonate (1)
- Clinothem mechanics (1)
- Conodonts (1)
- Continental shelf (1)
- Cretaceous (1)
- Cumulative throw (1)
- Cyclothem (1)
- Dehydration (1)
- Delta front (1)
- Depositional center (1)
- Eocene (1)
- False River (1)
- Fine-grained sediment transport (1)
- Geochronology (1)
- Geophysical logging (1)
- Geothermal energy (1)
- Geothermal gradient (1)
- Grounding line (1)
Articles 1 - 20 of 20
Full-Text Articles in Entire DC Network
Using Foraminifera Shell Geochemistry To Test Proxies For Paleoenvironmental Reconstruction, Catherine Hudson
Using Foraminifera Shell Geochemistry To Test Proxies For Paleoenvironmental Reconstruction, Catherine Hudson
Honors Theses
No abstract provided.
Deposition And Characteristics Of West Bay Sediment In The Mississippi River Delta, And The Effects Of Polymers On Sediment Erodibility, Patrick Robichaux
Deposition And Characteristics Of West Bay Sediment In The Mississippi River Delta, And The Effects Of Polymers On Sediment Erodibility, Patrick Robichaux
Honors Theses
No abstract provided.
Tracing Sediment In The Subsurface Using Beryllium-7: Green River Basin, Ky, Caroline Adams Broderick
Tracing Sediment In The Subsurface Using Beryllium-7: Green River Basin, Ky, Caroline Adams Broderick
LSU Master's Theses
As water flows through areas of limestone, karst inevitably develops, creating sinking streams and sinkholes that transport alumino-silicate particles from the surface into the subsurface. Sediment budget studies on short term scales through karst are rare. Thus, a feasibility study using beryllium-7 (7Be), which attaches to soil particles and can be used as a short-term (2-3 month) tracer of the movement of fine-grained sediment in karst was investigated. Sediment samples were collected from a karstic catchment within Green River basin, Kentucky, both on the surface and in the subsurface along a cave stream. Samples were collected prior to and immediately …
Augite In Komatiitic Basalts: A Study Of The Mobility Of Trace Elements During Rock Alteration, Alesha C. Morabito
Augite In Komatiitic Basalts: A Study Of The Mobility Of Trace Elements During Rock Alteration, Alesha C. Morabito
LSU Master's Theses
Komatiitic basalts are ultramafic rocks formed from volcanic liquids containing less than 18 wt.% magnesium oxide that can be linked, spatially, geochemically and texturally to komatiites. Archean komatiites and komatiitic basalts are critical to models of early Earth’s mantle evolution. Major and trace elements in these rocks are poorly preserved due to early sub-seafloor alteration with superimposed regional metamorphism: in particular the alkali, alkaline earths, and other elements with low valence numbers. Current analytical methods focus on analyzing whole rock, fresh olivines and melt inclusions to evaluate elemental concentrations and for petrogenetic studies. Although these methods establish elemental concentrations, REE, …
Potential For Geothermal Energy In Northern Louisiana: Analysis Of The Subsurface Environment In Union And Morehouse Parishes, Tessa Shizuko Hermes
Potential For Geothermal Energy In Northern Louisiana: Analysis Of The Subsurface Environment In Union And Morehouse Parishes, Tessa Shizuko Hermes
LSU Master's Theses
Efforts to mitigate greenhouse gas emissions and reduce dependence on fossil fuels have led to renewed focus on the exploration and development of alternative energy production. One such option is hydrothermal binary geothermal energy production from geothermal reservoirs with temperatures of at least 100 °C at depths no greater than 5 km. In the U.S., such systems have the potential to provide 5,400 % of 2013 total U.S. energy consumption. This study evaluates the potential for geothermal energy systems implementation in Morehouse and Union Parishes, Louisiana, by using publicly available bottom hole temperature (BHT), mud weight (MW), logged formation top …
Using Fault Kinematics To Evaluate The Relationship Between Cenozoic Fault Activity, Sedimentation Rates And Salt Movement In The Gulf Of Mexico - A Comparison Between Southwest Louisiana And Southeast Louisiana, Abah Philip Omale
LSU Master's Theses
ABSTRACT Fault initiation and reactivation across south Louisiana during the Cenozoic was driven by either clastic sediment progradation mobilizing underlying salt or by sediment progradation inducing tensional bending stresses during lithospheric flexure. Climate and tectonics within the North American continent during the Cenozoic created differences in the source location, amount of sediments transported, as well as the spatial and temporal distribution of sediments transported into the Gulf of Mexico. This study analyzes 140 fault intercepts along 11 regional cross sections containing well log data in south Louisiana. Cumulative throw, incremental throw, and fault slip rates indicate fault activity punctuated by …
Rare Earth Element Patterns In Conodont Apatite From The Upper Ordovician: Testing Enrichment Sources And Possible Oceanographic Changes, Cody Christian Schulte
Rare Earth Element Patterns In Conodont Apatite From The Upper Ordovician: Testing Enrichment Sources And Possible Oceanographic Changes, Cody Christian Schulte
LSU Master's Theses
The Mohawkian series of the Middle Late Ordovician was a time of great lithological and faunal changes that coincide with a positive ä13C excursion known as the Guttenberg Isotopic Carbon Excursion (GICE). Two prevailing hypotheses have been proposed to explain the cause of these changes. The “cold-water” hypothesis suggests that global cooling caused the tropical belt to shrink and cold water to invade the epicontinental sea while the “tectonic-forcing” hypothesis suggests that increased weathering rates led to basinal deepening, resulting in cooler oceanic waters invading the midcontinent sea. This study tests if regional tectonics caused by the Taconic Orogeny led …
Sub-Marine Sediment Instability Near Southwest Pass Of The Mississippi River: Evidence Of Mass Movements From Raciochemistry And Other Proxies, Gregory Paul Keller
Sub-Marine Sediment Instability Near Southwest Pass Of The Mississippi River: Evidence Of Mass Movements From Raciochemistry And Other Proxies, Gregory Paul Keller
LSU Master's Theses
Mass wasting events are an important geomorphic control on the Mississippi River Delta Front. Short multicores (<50cm) and longer gravity cores (<3m) were collected seaward of the Southwest Pass of the Mississippi River Delta and were analyzed to assess the frequency, extent, and potential causes of submarine mass wasting events. Cores were analyzed for radionuclide activity, grain size, and density at 2cm resolution. Short-term sedimentation rates calculated from 7-Be are 2-16cm/y, while longer-term accumulation from 210-Pb are only 1.3-7.3 cm/y. In most cores, 210-Pb activity steadily decreases downcore without displaying a “stairstep” nature. However, seven cores have layers of low 210-Pb activity stratigraphically above layers with higher activity. In a gravity core from a mudflow gully, 210-Pb steadily decreases for the upper 70 cm before stabilizing for the remaining 150 cm. Clay content generally ranges between 25-40% and sand ranges between 5-15% with silt making up the rest of each sample. Sediment accumulation rates derived from 210-Pb in the short cores indicate that proximity to the river mouth has stronger influence than depositional environment (mudflow gully, depositional lobe, prodelta). This finding may be explained by rapid sedimentation rates coupled with a reduced tropical cyclone activity over the delta in the last seven years (2006-2013) which is a known cause of mass wasting events. The regions of decreased 210-Pb activity may be evidence of scavenging effects of plume sedimentation because they do not correspond with decreases in clay fraction. The layer of homogenized activity below 70cm in the gully core corresponds with a layer of decreased density. This layer occurs at a depth equivalent to 9-18 years, indicating mixing on a decadal scale from mudflows. These results may be explained by a lack of recent mass failures corresponding with lulls in tropical cyclone activity over the delta, preceded by a period of more active hurricane-driven mudflow activity.
Chlorine Enrichment Of Hydrous Minerals In Archean Granulite Facies Ironstone From The Beartooth Mountains, Montana, Usa: Implications For High-Grade Metamorphic Fluids, Nicholas Michael Daigle
Chlorine Enrichment Of Hydrous Minerals In Archean Granulite Facies Ironstone From The Beartooth Mountains, Montana, Usa: Implications For High-Grade Metamorphic Fluids, Nicholas Michael Daigle
LSU Master's Theses
The amount of chlorine present in hydrous minerals influences mineral stability and may serve as a monitor of the evolving fluid phase during progressive metamorphism. Chlorine contents of amphibole and biotite vary as a function of temperature, pressure, crystallochemical factors, and fluid composition. The sensitivity of these minerals to serve as a monitor of Cl in aqueous fluids is particularly effective in Fe-rich amphibole and biotite such as those found in ironstones. Ironstones from the eastern Beartooth Mountains, Montana are typified by dominantly anhydrous mineral assemblages of quartz + magnetite + orthopyroxene + garnet ± clinopyroxene and have equilibrated during …
Distribution Of Uranium In A Black Shale Across The Shelf Of The Late Pennsylvanian Midcontinent Sea, Maxwell A. Lindaman
Distribution Of Uranium In A Black Shale Across The Shelf Of The Late Pennsylvanian Midcontinent Sea, Maxwell A. Lindaman
LSU Master's Theses
Uranium paleoredox proxies such as enrichment factors and 238U/235U ratios can be used to reconstruct redox conditions in ancient water masses on local and global scales based on the differential behavior of uranium in oxic, suboxic, and anoxic environments. Many studies have focused on black shales due to their high levels of metal enrichment and association with climactic events. However, the influence of local effects on uranium accumulation is uncertain, particularly in ancient epeiric sea environments. This study consists of two parts: an evaluation of common sequential extraction methods for U analysis (particularly the Tessier-type sequential extraction) and the application …
A Palynological Analysis Of Seymour Island And King George Island Off The Antarctic Peninsula: A Dating And Climatic Reconstruction, Caven Madison Kymes
A Palynological Analysis Of Seymour Island And King George Island Off The Antarctic Peninsula: A Dating And Climatic Reconstruction, Caven Madison Kymes
LSU Master's Theses
During the Cretaceous and early Paleocene, Antarctica was covered by lush vegetation. However, Antarctica today is covered with ice and snow leaving less than 1% of the continent inhabited by vegetation. By studying this decline in vegetation and reconstructing past environments, we can gain a better understanding of environmental changes and use this knowledge to predict future changes. In this thesis, I present my results and interpretations of palynological changes across the Antarctic Peninsula during the Late Eocene, Middle Oligocene, and Miocene. The first study discusses a paleoenvironmental reconstruction of the upper La Meseta formation (Late Eocene), Seymour Island, and …
Magnetic Susceptibility Of North American Ordovician Epicontinental Seas: Spatial Variability And Sandbian-Katian Boundary Correlation, Thomas J. Schramm
Magnetic Susceptibility Of North American Ordovician Epicontinental Seas: Spatial Variability And Sandbian-Katian Boundary Correlation, Thomas J. Schramm
LSU Doctoral Dissertations
Magnetic susceptibility (χ) has gained increased usage as a stratigraphic correlation tool. This project evaluates the utility of a χ correlation tool, including its shortcomings, and attempts its integration with other datasets. The Upper Ordovician of eastern North America represent the stratigraphic interval in which these experiments were conducted. 4566 samples were collected for the purposes of this study, and χ was measured on 3345 of the samples. This project includes three major facets, 1) the spatial variability of χ, 2) correlation of Sandbian-Katian boundary interval strata in eastern North America using χ, and 3) utility of χ for interpreting …
Using Trace Fossils To Determine The Role Of Oceanic Anoxic Event Ii On The Cretaceous Western Interior Seaway Paleoenvironment, Jacob Frederick Grosskopf
Using Trace Fossils To Determine The Role Of Oceanic Anoxic Event Ii On The Cretaceous Western Interior Seaway Paleoenvironment, Jacob Frederick Grosskopf
LSU Doctoral Dissertations
Did well-oxygenated benthic conditions exist in all parts of the Cretaceous Western Interior Seaway (CWIS) during the deposition of Bed 63 at the onset Oceanic Anoxic Event II (OAE II), as suggested by findings from two cores from the central portion of the CWIS? This problem was approached by categorizing the bioturbation that is prevalent through Bed 63 into oxygen-related ichnofabrics (ORI) in order to describe benthic oxygen conditions. These data were collected from outcrop and core among seven different sites along West–East and North–South transects that traversed portions of the CWIS with differing depositional settings and proximities to the …
The Influence Of Marine Topography On The Antarctic Ice Sheet, Daniel Michael Mullally Jr
The Influence Of Marine Topography On The Antarctic Ice Sheet, Daniel Michael Mullally Jr
LSU Master's Theses
The primary controls on Antarctic Ice Sheet (AIS) volume and extent include changes in water temperature, precipitation, atmospheric temperature, and sea level. Here we evaluate the influence of a 5th control, the depth of the continental shelf. Shelf depth affects ice sheet mass balance in the marine environment by controlling the flux of ice that can be exported to the marine environment. This is significant because heat exchange between ocean and ice sheet have been demonstrated to be a dominant control on marine ice volume (Pollard and DeConto, 2009). We used the Parallel Ice Sheet Model (PISM) to simulate AIS …
Seismic Velocity Characteristics Of Partially Saturated Unconsolidated Sediments, Jie Shen
Seismic Velocity Characteristics Of Partially Saturated Unconsolidated Sediments, Jie Shen
LSU Doctoral Dissertations
Seismic velocity models of the near-surface (< 30 m) better explain seismic velocities when all elements of total effective stress are considered, particularly in materials with large cohesive and soil suction stress such as clays. Traditional constitutive elastic models assume interparticle and soil suction stresses are negligible. This study proposes a new methodology which corrects total effective stress in Hertz-Mindlin theory for interparticle and soil suction and calculates the elastic moduli by extending Biot-Gassmann theory to include pressure effects induced by water saturation changes and cohesion. The proposed model predicts seismic velocities that correlate well with measured field velocities from the literature. Soil density, porosity, elastic moduli and the soil-water characteristic curve (SWCC) are important properties for soil characterization. Currently, geotechnical and laboratory tests for soil properties are costly and limited to point sampling sites. Seismic surveys can potentially provide laterally continuous soil property values that may complement geotechnical borehole tests with low cost. We propose a new method to invert for soil properties and the SWCC from seismic P- and S-wave velocity-vs.-depth profiles interpreted from shallow (< 25 m depth) unconsolidated sediments under conditions of near-full saturation (> 99%). The results from seismic soil property inversion are validated by comparison to geotechnical and laboratory results conducted independently in the same area as the seismic survey. Knowledge of homogeneous and heterogeneous fluid-distribution patterns is important for the estimation of oil reserves, reservoir simulation, the interpretation of time-lapse seismic, and the selection of remediation techniques for groundwater contamination. Problems exist in determining in-situ fluid-distribution patterns in unconsolidated sediments because laboratory tests on core samples may not be representative of in-situ conditions. We propose a new method to determine in-situ fluid-distribution patterns by inverting …
The Stratal Architecture Of The False River Point Bar (Lower Mississippi River, La), Alexandra Lechnowskyj
The Stratal Architecture Of The False River Point Bar (Lower Mississippi River, La), Alexandra Lechnowskyj
LSU Master's Theses
The False River point bar system is located roughly thirty miles north of Baton Rouge, LA. It is an oxbow lake cut off from the Mississippi River, and represents a large-scale modern analogue to the ancient systems of northeastern Alberta, Canada, specifically those of the Athabasca Oils Sands. While previous work has been done regarding the general architecture of a point bar, there is still omplexity associated with larger scale systems, as studies have been mostly based on small and medium-scale examples. Examination of the point bar was done through a combination of coring and geophysical logging, followed by software …
Interpretation Of Geochemical Signatures From Modern Carbonate Springs To The Rock Record, Benjamin Maas
Interpretation Of Geochemical Signatures From Modern Carbonate Springs To The Rock Record, Benjamin Maas
LSU Doctoral Dissertations
Despite the importance of carbonate aquifers as reservoirs of oil, of water, and of carbon dioxide, questions remain about the diagenetic processes that enhance porosity and permeability. Some of the questions are: 1) what are the water-rock interactions that control the geochemistry of spring waters; 2) are the geochemical signatures of saline-fresh water mixing zones preserved in the carbonate rock record; and 3) how much carbon dioxide outgases along spring runs? To address these questions, two field sites, one in Oklahoma (the site of an active saline-fresh water mixing zone) and the other in Colorado, the location of a former …
Holocene Palynology Of The Gulf Of Papua, Papua New Guinea: Using Modern Palynomorph Distribution To Better Constrain Paleoenvironmental Changes, Marie Louise Thomas
Holocene Palynology Of The Gulf Of Papua, Papua New Guinea: Using Modern Palynomorph Distribution To Better Constrain Paleoenvironmental Changes, Marie Louise Thomas
LSU Doctoral Dissertations
Multiple NSF (National Science Foundation)-funded MARGINS Source-to-Sink cruises were conducted in the Gulf of Papua (GoP), Papua New Guinea (PNG), from 2003 through 2005 to better understand how sediment is created, transported, and deposited. Although much work has been done on the data collected during these cruises, palynological analysis has never been conducted on the hundreds of available cores. The first phase of this project (Chapters 2 and 3) examines the connection between modern depositional regimes in the GoP and species assemblages recovered. Statistical analysis of palynomaceral assemblages (Chapter 2) indicates a correlation between their distribution and bathymetry, sedimentation rate, …
Developing Recognition Criteria For Current-Wave-Enhanced Sediment Gravity Flows, Kathryn Christine Denommee
Developing Recognition Criteria For Current-Wave-Enhanced Sediment Gravity Flows, Kathryn Christine Denommee
LSU Doctoral Dissertations
Sedimentary fabrics preserved in the rock record provide some of the best evidence for interpreting paleo-depositional conditions. Muddy sediments in particular are important paleoenvironmental archives, preserving the most complete stratigraphic record of any rock type in basinal settings. However, the full range of mechanisms responsible for the deposition of muddy sediments, particularly in high-energy settings, remains poorly understood. Although frequently observed in modern settings, muddy prodeltaic deposits are rarely identified in the rock record, in part because no catalogue of easily distinguishable recognition criteria exists for this class of mudstones. In order to help overcome this deficiency, this dissertation project …
Neodymium Isotope Ratios And A Positive Δ13c Excursion: Connecting Oceanographic And Climate Changes Near The M4-M5 Sequence Boundary Of The Late Ordovician, Zachary Wright
LSU Master's Theses
A significant positive carbon isotope excursion first described from the Guttenberg Member of the Decorah Formation in Iowa called the GICE is a defining feature of Late Ordovician chemostratigraphy. It occurs near the M4-M5 sequence boundary of the Late Ordovician and has been correlated across the globe using prominent K-bentonite ash beds and conodont biomarkers. The cause of the GICE has been debated, with some arguing that it represents the initiation of a glacial period in a greenhouse climate 10 Ma before the end Ordovician glaciation and extinction. A variety of cooling signals have been identified across the M4-M5 sequence …