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Articles 1 - 30 of 54
Full-Text Articles in Sedimentology
Sedimentary Archives Of Late Quaternary Limnological, Ecological, And Environmental Change In The Eastern Sierra Nevada (California, Usa), Bailee Hodelka
Sedimentary Archives Of Late Quaternary Limnological, Ecological, And Environmental Change In The Eastern Sierra Nevada (California, Usa), Bailee Hodelka
Theses and Dissertations--Earth and Environmental Sciences
The Sierra Nevada essentially serve as the headwaters of California, providing crucial freshwater to the state through seasonal snowmelt. This water supply is threatened by climate change in complex ways that are not fully understood. Geological records provide a valuable source of information on how the hydrology, limnology, and ecology of the Sierra Nevada region has responded to climate changes of the past. This dissertation presents new sedimentary and paleoecological research from Mono Lake and Convict Lake (Mono County, California) and aims to shed light on environmental changes in the eastern Sierra Nevada from ~16 ka to present.
At Mono …
Geochemical And Sedimentological Signals Of Bottom Water Oxygen Dynamics From Lake Tanganyika (Zambia), Njahi Mwangala
Geochemical And Sedimentological Signals Of Bottom Water Oxygen Dynamics From Lake Tanganyika (Zambia), Njahi Mwangala
Theses and Dissertations--Earth and Environmental Sciences
Lake Tanganyika is a large, ancient freshwater body with exceptional biodiversity that is located in the East African Rift System. Lake Tanganyika’s size and longevity make its sedimentary record useful for understanding environmental changes that cross spatial and temporal boundaries. Lake Tanganyika is known to be susceptible to global warming given its tropical location. Over 12 million people living within Lake Tanganyika’s watershed rely on fishing for their income and nutrition. Changes to limnological function driven by climate could therefore have serious implications for human health and biodiversity conservation. This study focuses on using geochemical properties of modern lake bottom …
Late Holocene Paleolimnology Of Lake Tanganyika (East Africa), Leandro Domingos Luz
Late Holocene Paleolimnology Of Lake Tanganyika (East Africa), Leandro Domingos Luz
Theses and Dissertations--Earth and Environmental Sciences
Understanding the long-term responses of ecosystems to climate variability is crucial for predicting and mitigating future changes in the Afrotropics, a region where a significant portion of the population is highly vulnerable to extreme climatic events. Lake Tanganyika, the largest rift lake in East Africa, offers a unique sedimentary archive that can be used to investigate the limnological changes, hydroclimatic shifts, and vegetation dynamics across various timescales. A multi-proxy approach was employed to assess the landscape responses to hydroclimatic fluctuations in the Late Holocene, integrating paleoenvironmental records from radiocarbon-dated sediment cores. This approach involved sedimentology, mineralogy, geochemistry, phytolith analysis, and …
Geochronologic Constraints On The Meso-Neoproterozoic Tectonic Evolution Of Eastern Laurentia: An Investigation Of Sediment Recycling During And After The Grenvillian Orogeny, John M. Clay Iii
Theses and Dissertations--Earth and Environmental Sciences
The Grenvillian orogeny and Midcontinent Rift shaped the Mesoproterozoic basement of eastern Laurentia. Their convergence beneath Kentucky and Ohio formed a foreland basin, preserved as the Middle Run Formation. Detrital zircon U-Pb geochronology constrains deposition to ~1.0 Ga, reflects Grenville unroofing phases, includes Midcontinent Rift input, and minor Ottawan components. This formation constitutes the most proximal preserved segment of the Grenvillian clastic wedge in Laurentia.
Neoproterozoic-Cambrian rifting followed by Cambrian transgression formed the Great Unconformity in eastern Laurentia. Detrital zircon and basement U-Pb ages from Kentucky and the Appalachians constrain sediment provenance and recycling. Kentucky basement shows Eastern Granite-Rhyolite crust …
Recent Paleolimnological History Of Jackson Lake, Grand Teton National Park, Wyoming (Usa), Hillary Johnson
Recent Paleolimnological History Of Jackson Lake, Grand Teton National Park, Wyoming (Usa), Hillary Johnson
Theses and Dissertations--Earth and Environmental Sciences
This study utilizes a recently acquired, high-resolution CHIRP seismic reflection dataset and a deepwater sediment core to analyze the recent stratigraphy of Jackson Lake (Wyoming, USA). The western shoreline of Jackson Lake is situated adjacent to the Teton fault, a down-to-the-east normal fault that produces the spectacular high topography of Grand Teton National Park. The sediments of Jackson Lake are underexplored and consequently, their value as indicators of hydroclimatic and tectonic changes is unknown. Here, the sedimentary fill of Jackson Lake is explored as a natural archive of environmental change, specifically in reference to the influence of human outlet engineering …
Re-Examination Of A Middle Mississippian Carbonate Mud-Mound Complex From The Fort Payne Formation In South-Central, Kentucky, Maxwell Mickelson
Re-Examination Of A Middle Mississippian Carbonate Mud-Mound Complex From The Fort Payne Formation In South-Central, Kentucky, Maxwell Mickelson
Theses and Dissertations--Earth and Environmental Sciences
This study examines the origin of a 213-m (700-ft) long, Middle Mississippian, carbonate “mud-mound complex” in the Fort Payne Formation of south-central Kentucky. The complex’s well-exposed, easily accessible, and well-preserved nature provides an opportunity to understand how mounds like this developed during a time of sediment starvation, basinward of the largely abandoned Borden-Grainger Delta complex.
The mound complex is formed of small, accretionary mounds that accreted onto the flanks of an eroded structural high and onto the backs of each other, apparently for protection from storms. Each sub-mound is composed of micrite-rich wackestone, comprising one of two biofacies: 1) alternating …
High Resolution Sedimentary Investigations Of Extant Lakes In North America, John Dilworth
High Resolution Sedimentary Investigations Of Extant Lakes In North America, John Dilworth
Theses and Dissertations--Earth and Environmental Sciences
Investigation of past lake environments forms the discipline of paleolimnology. Paleolimnological studies seek to evaluate geophysical, geochemical, and ecological proxies and indicators contained within lake sediment archives. Using these potential stores of high-resolution environmental information, questions regarding climate, biological, and geochemical changes experienced by a lake and its watershed can be investigated. This dissertation research utilized lake sediment records from two lakes within North America to study different aspects of environmental change. This dissertation consists of three separate studies presented in three chapters.
Chapter Two presents a retrospective environmental assessment of Jackson Lake, Wyoming to investigate the impacts of dam …
Using 3-Dimensional Mapping To Determine The Possibility Of Structural Control On Development Of The Upper Ordovician Lexington Limestone, Central Kentucky, U.S.A., Sean Davis
Theses and Dissertations--Earth and Environmental Sciences
The upper Lexington Limestone of Late Ordovician age has been interpreted to represent a structurally controlled, complex, facies mosaic. This facies mosaic has historically been interpreted to be a carbonate buildup of shoal complexes with interbedded shale units with intertonguing facies. Due to relatively recent advances in geographic-information-systems (GIS) mapping technologies, it is possible to generate three-dimensional (3-D) compatible maps to offer insight to the complexities of the upper Lexington Limestone and to determine if structural control affected the distribution of members. The resulting two-dimensional (2-D) and 3-D maps show that basement faults likely exerted a significant influence on facies …
A Source-To-Sink Analysis Of The Pantanal Basin (Brazil): Implications For Weathering, Erosion, And Landscape Evolution In The World's Largest Wetland, Edward L. Lo
Theses and Dissertations--Earth and Environmental Sciences
Large back-bulge retro-arc basins have limited information about the sediment composition, yet they comprise important parts of the stratigraphic rock record. The exorheic Pantanal Basin is the world's largest continental wetland that regulates many valuable ecosystem services (water storage, nutrient cycling, agriculture, ranching, tourism, and transportation). This dissertation is composed of three studies that utilize a suite of tools to examine the most fundamental basin-wide source-to-sink sediment processes and controls that affect the characteristics and distribution of modern sediments.
The first paper consists of a metadata analysis of 76 shallow tropical floodplain lakes in the literature with bathymetric data and …
Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese
Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese
Theses and Dissertations--Earth and Environmental Sciences
Terrestrial paleoseismological records along the Teton fault have historically indicated two-to-three major post-Pinedale (~14 ka) earthquake events, leaving an unresolved 6-9 m offset along the modern scarp. Recent studies of Jenny Lake have augmented this record, but the triggering mechanism is still equivocal until new paleo-earthquake records are developed. The earthquake record of the Teton fault is complicated by quiescence from ~5 ka to present, demonstrating the need for additional paleoseismic investigations. Compressed, high-intensity radar pulse (CHIRP) reflection data from Jackson Lake indicates multiple potentially seismically-induced mass transport deposits (MTDs). At least six MTD Groups representing chronostratigraphic intervals were interpreted …
Distribution Of Particulate Organic Carbon – Fluxes And Inventories – In Growth-Faulted Coastal Wetlands, Samuel Joel Whitehead
Distribution Of Particulate Organic Carbon – Fluxes And Inventories – In Growth-Faulted Coastal Wetlands, Samuel Joel Whitehead
Theses and Dissertations--Earth and Environmental Sciences
Coastal wetlands along the Northern Gulf of Mexico (NGOMx) are critically important but threatened environments which provide significant and diverse economic, social, and environmental value. These environments are essential components to the global carbon cycle, serving as one of the most efficient terrestrial carbon sinks. Since onset of the Industrial Revolution increasing rates of coastal wetland loss have been documented due to a variety of anthropogenic activities, neotectonic processes, subsidence, and rising sea-levels. This research utilized an array of methods and sedimentological analyses to test the hypothesis that growth-fault induced changes at Earth’s surface affects the delivery to, and storage …
“The Tale Of 3,000 Zircons”: An Investigation Of Grenville Sedimentation In Amazonia Using U/Pb Detrital Zircon Geochronology, Felicia R. Harris
“The Tale Of 3,000 Zircons”: An Investigation Of Grenville Sedimentation In Amazonia Using U/Pb Detrital Zircon Geochronology, Felicia R. Harris
Theses and Dissertations--Earth and Environmental Sciences
The continental collision between Laurentia and Amazonia that generated Rodinia and the Grenville Orogen is proposed to be one of the largest, hottest and longest-lived orogens in Earth history. Subsequent erosion and weathering led to a mountain range’s worth of sediment recycled into clastic systems across North America, otherwise known as the “Great Grenville Sedimentation Event”. The Sunsas orogeny in Amazonia is correlative to the Grenville in North America and is proposed to be the result of final Rodinian collision at 1200-1000 Ma. Despite the connection between the two ranges and the robust sedimentary record in North America, little work …
A Multi-Method Investigation Of The Modern Sedimentation And Late Holocene Paleolimnology Of June Lake (Mono County, Ca), And A Survey-Based Analysis Of Ninth Graders’ Attitudes Towards Geology, Eva Lyon
Theses and Dissertations--Earth and Environmental Sciences
Three distinct manuscripts comprise this dissertation. The first analyzes the modern sedimentary basin of June Lake, a small glacial lake in the eastern Sierra Nevada of California (USA) using a number of data sets, including bathymetry, surface sediment composition, and seismic stratigraphy. The seismic survey revealed sublacustrine morphological features that suggest the basin originated due to ice scour, as well as four acoustically distinct stratigraphic units that reflect the history of sedimentation following glacial scouring. Corroborating the seismic record, sediment cores from the youngest unit are composed of hemipelagically deposited, organic-rich, laminated diatomaceous oozes alternating with coarse tephra beds. The …
Vegetation And Environmental Changes In Tropical South America From The Last Glacial To The Holocene Documented By Multiple Cave Sediment Proxies, Valdir F. Novello, Francisco W. Cruz, Michael M. Mcglue, Corinne I. Wong, Brittany M. Ward, Mathias Vuille, Rudney A. Santos, Plinio Jaqueto, Luiz C. R. Pessenda, Tiago Atorre, Ligia M. A. L. Ribeiro, Ivo Karmann, Eline S. Barreto, Hai Cheng, R. Lawrence Edwards, Marcos S. Paula, Denis Scholz
Vegetation And Environmental Changes In Tropical South America From The Last Glacial To The Holocene Documented By Multiple Cave Sediment Proxies, Valdir F. Novello, Francisco W. Cruz, Michael M. Mcglue, Corinne I. Wong, Brittany M. Ward, Mathias Vuille, Rudney A. Santos, Plinio Jaqueto, Luiz C. R. Pessenda, Tiago Atorre, Ligia M. A. L. Ribeiro, Ivo Karmann, Eline S. Barreto, Hai Cheng, R. Lawrence Edwards, Marcos S. Paula, Denis Scholz
Earth and Environmental Sciences Faculty Publications
δ18 O values in speleothems have been utilized to document past changes in South American monsoon intensity. However, changes in regional vegetation and ecosystems have not been part of this discussion, and other cave proxies such as speleothem δ13 C values, a useful proxy for vegetation reconstruction, have been neglected due to interpretive complexities. Here we report δ13 C values and 87 Sr/86 Sr ratios in stalagmites, together with XRF-derived elemental chemistry, δ13 C org values and carbon content from a sedimentary profile from the same cave where the stalagmites were collected. In combination with a previously published δ18 O …
Testing For Sedimentary Recycling Using Detrital Monazite Geochronology, Zircon “Double Dating”, And Textures In Pennsylvanian Arenites Of The Central Appalachian Basin, Eastern Kentucky: Implications For Single Mineral Sedimentary Provenance Analysis, Steve C. Zotto
Theses and Dissertations--Earth and Environmental Sciences
Detrital monazite Th-Pb and detrital zircon U-Pb and U-Th/He double-dating coupled with sandstone petrography and exhumation rates can be used to test for sediment recycling in Pennsylvanian sandstones within the Alleghenian clastic wedge. The Alleghenian clastic wedge is a logical system in which to test for sediment recycling as four major collisional events (Grenville, Taconic, Acadian and Alleghenian orogenies) likely reworked the continental margin and recycled siliciclastic sediment. The combination of these geochronologic and thermochronologic methods provide a more accurate assessment of the proportion of recycled sediment in the Grundy Formation (sublitharenite) and the Corbin Sandstone (quartz arenite), which past …
Effects Of Depositional Processes On Strength And Compressibility Of Sediments Using Elastic Shear Wave Velocity, Wisam Razzaq Muttashar
Effects Of Depositional Processes On Strength And Compressibility Of Sediments Using Elastic Shear Wave Velocity, Wisam Razzaq Muttashar
Theses and Dissertations--Earth and Environmental Sciences
Depositional processes are the most critical, complicated conditions that govern sediment properties and their variations, which in turn significantly affect the geotechnical behavior of the sediment. The complexity of depositional and post-depositional processes, which results in a variety of depositional environments, makes constructing a plausible model for the consolidation process of sediments difficult. The mutual influence between the temporal and spatial variation of depositional environments with their resultant physical and mechanical properties cause several compression issues, such as consolidation settlement and land subsidence, which mostly occur in estuarine-riverine regions throughout the world.
The first aim of this study is proposing …
A Joint Xrf-Δ13CCarb Chemostratigraphic Approach For Characterizing Paleo-Environmental Processes In The Mudstone-Dominated Wolfcamp Formation Of West Texas, Frank Tamakloe
Theses and Dissertations--Earth and Environmental Sciences
The Late Paleozoic Ice Age represents a dynamic period in Earth system history recording a shift from icehouse to greenhouse conditions. Concomitant with this change was a series high-frequency, high-amplitude sea level fluctuations leading to the deposition of “Kansas type” cyclothems in the Mid-Continent, and a similar rhythmic expression of interbedded shales and carbonates in the Midland Basin. Stable isotope geochemistry is a particularly powerful tool when examining these mud-rich successions because changes in organic matter partitioning may be recorded first in δ13CDIC of sea-water and consequently in δ13Ccarb of marine rocks. The δ …
The Forestry Reclamation Approach: Measuring Sediment Mass Accumulation Rates In Reclaimed Mine Lands And Naturally Regenerated Logged Forests Of Eastern Kentucky, William E. Bond
Theses and Dissertations--Earth and Environmental Sciences
The spread of surface coal mining has resulted in loss of forests in the Appalachian region. The Forestry Reclamation Approach (FRA) was developed to provide guidance for restoring forests on reclaimed mined land. This study hypothesizes that the FRA will result in larger magnitude of sediment accumulation rates in reclaimed mine sites compared to those reclaimed using grassland reclamation. Three sediment cores and six trenches were sampled within four reclaimed mined and three previously logged sites in eastern Kentucky. Samples were processed for radionuclides, grain-size, stable isotopes (δ13C), and POC. LIDAR data were used to identify valley …
The Links Between Gulf Of Mexico Seafloor Characteristics And Petroleum Hydrocarbons Following The Deepwater Horizon Oil Spill, Kimberly J. Schindler
The Links Between Gulf Of Mexico Seafloor Characteristics And Petroleum Hydrocarbons Following The Deepwater Horizon Oil Spill, Kimberly J. Schindler
Theses and Dissertations--Earth and Environmental Sciences
The Gulf of Mexico (GoMx) is among the most productive regions for offshore oil and natural gas recovery. In 2010, the Deepwater Horizon (DWH) drilling rig exploded, burned for three days, sank, and released over 4 million barrels of oil in the subsequent 84 days before it was capped. Some oil was buoyant enough to float to the ocean surface, where some was removed via a myriad techniques. Importantly, a plume of oil remained suspended in the water column at approximately 1,100 m water depth, where it drove a marine snow event, and deposited large quantities of oil on the …
Overview Of The Kentucky Geological Survey No. 1 Hanson Aggregates Well, Carter County, Kentucky, J. Richard Bowersox, Stephen F. Greb, David C. Harris
Overview Of The Kentucky Geological Survey No. 1 Hanson Aggregates Well, Carter County, Kentucky, J. Richard Bowersox, Stephen F. Greb, David C. Harris
Information Circular--KGS
The Kentucky Geological Survey drilled the No. 1 Hanson Aggregates well in northern Carter County, Ky., to assess the carbon dioxide storage capacity and confining intervals in the Middle Cambrian–Upper Ordovician section in the southern Appalachian Basin, north of the Rome Trough. The well was drilled to a total depth of 4,835 ft, penetrating the Mississippian–Middle Cambrian Paleozoic section and 120 ft of Neoproterozoic Grenville granite gneiss. Steel casing was cemented to the surface at 350 ft and 2,944 ft to isolate the deep wellbore from the near-surface aquifer and provide anchors for pressure-control equipment. Eight cores totaling 453 ft …
Stratigraphy And Organic Geochemistry Reveal Patterns Of Late Quaternary Paleo-Productivity At Mono Lake, California, Bailee Nicole Hodelka
Stratigraphy And Organic Geochemistry Reveal Patterns Of Late Quaternary Paleo-Productivity At Mono Lake, California, Bailee Nicole Hodelka
Theses and Dissertations--Earth and Environmental Sciences
Mono Lake (CA) is a hydrologically closed lacustrine basin well-known for its paleo-shorelines, which record fluctuations in water level for the last deglacial and late Holocene. Mono Lake is a sentinel of California’s water supply, situated in the rain shadow of the Sierra Nevada, a mountain range whose snowpack is a vital source of freshwater for urban and agricultural districts to the west and south. Recent droughts, floods, and wildfires show that California is threatened by climate change, but how these changes impact and get recorded by Mono Lake sediments remains poorly known. Here, we use a new radiocarbon-dated deepwater …
Occurrence And Attributes Of Two Echinoderm-Bearing Faunas From The Upper Mississippian (Chesterian; Lower Serpukhovian) Ramey Creek Member, Slade Formation, Eastern Kentucky, U.S.A., Ann Well Harris
Theses and Dissertations--Earth and Environmental Sciences
Well-preserved echinoderm faunas are rare in the fossil record, and when uncovered, understanding their occurrence can be useful in interpreting other faunas. In this study, two such faunas of the same age from separate localities in the shallow-marine Ramey Creek Member of the Slade Formation in the Upper Mississippian (Chesterian) rocks of eastern Kentucky are examined. Of the more than 5,000 fossil specimens from both localities, only 9–34 percent were echinoderms from 3–5 classes. Nine non-echinoderm (8 invertebrate and one vertebrate) classes occurred at both localities, but of these, bryozoans, brachiopods and sponges dominated. To understand the attributes of both …
The Fate Of Carbon In Sediments Of The Xingu And Tapajós Clearwater Rivers, Eastern Amazon, Dailson J. Bertassoli Jr., André O. Sawakuchi, Henrique O. Sawakuchi, Fabiano N. Pupim, Gelvam A. Hartmann, Michael M. Mcglue, Cristiano M. Chiessi, Matthias Zabel, Enno Schefuß, Tatiana S. Pereira, Rudney A. Santos, Samantha B. Faustino, Paulo E. Oliveira, Denise C. Bicudo
The Fate Of Carbon In Sediments Of The Xingu And Tapajós Clearwater Rivers, Eastern Amazon, Dailson J. Bertassoli Jr., André O. Sawakuchi, Henrique O. Sawakuchi, Fabiano N. Pupim, Gelvam A. Hartmann, Michael M. Mcglue, Cristiano M. Chiessi, Matthias Zabel, Enno Schefuß, Tatiana S. Pereira, Rudney A. Santos, Samantha B. Faustino, Paulo E. Oliveira, Denise C. Bicudo
Earth and Environmental Sciences Faculty Publications
The Xingu and Tapajós rivers in the eastern Amazon are the largest clearwater systems of the Amazon basin. Both rivers have “fluvial rias” (i.e., lake-like channels) in their downstream reaches as they are naturally impounded by the Amazon mainstem. Fluvial rias are widespread in the Amazon landscape and most of the sedimentary load from the major clearwater and blackwater rivers is deposited in these channels. So far, little is known about the role of Amazon rias as a trap and reactor for organic sediments. In this study, we used organic and inorganic geochemistry, magnetic susceptibility, diatom, and pollen analyses in …
Stratigraphic, Geochemical, And Geochronological Analysis Of The Wolfcamp-D Interval, Midland Basin, Texas, Zachary S. Perlman
Stratigraphic, Geochemical, And Geochronological Analysis Of The Wolfcamp-D Interval, Midland Basin, Texas, Zachary S. Perlman
Theses and Dissertations--Earth and Environmental Sciences
Subsurface data derived from ~388 ft of drill core from Martin County (TX) were used to understand the depositional setting of the Wolfcamp-D, a petroleum producing interval in the Midland Basin. Elemental geochemistry collected via x-ray fluorescence revealed a highly variable depositional history marked by the deposition of diverse siliciclastic and carbonate lithofacies. Integration of multiple datasets resulted in the interpretation of nine lithofacies, whose deposition appears cyclical. Correlations between molybdenum and total organic carbon indicate slow recharge of bottom waters and anoxic/euxinicconditions within the basin. The presence of phosphatic nodules coinciding with siliceous black mudrocks suggested high levels of …
The Oligocene West Elk Breccia: Evidence For Massive Volcanic Debris Avalanches In The Eastern Gunnison River Valley, West-Central Colorado, U.S.A., Patrick J. Whalen
The Oligocene West Elk Breccia: Evidence For Massive Volcanic Debris Avalanches In The Eastern Gunnison River Valley, West-Central Colorado, U.S.A., Patrick J. Whalen
Theses and Dissertations--Earth and Environmental Sciences
The West Elk Breccia has been studied since the late 1800’s with many interpretations regarding its origin. One unrecognized possibility is that parts of it are debris-avalanche deposits. This study has recognized evidence for this interpretation at three scales: volcano scale, outcrop scale, and intra-outcrop scale. At the volcano scale, a scarp in the old volcano reveals underlying Mesozoic bedrock, suggesting sector collapse. At the outcrop scale, megablocks of the original edifice, up to hundreds of meters in length, have atypical orientations and are surrounded by a gravel matrix. At the intra-outcrop scale, jigsaw-fit fracturing and rip-up clasts are common …
Sedimentary Responses To Growth Fault Slip And Clay Shrink And Swell Induced Elevation Variations: East Matagorda Peninsula, Texas, Wei Ji
Theses and Dissertations--Earth and Environmental Sciences
East Matagorda Peninsula in southwestern Texas is characterized geologically by active, regional-scale and near-surface growth faulting. Decimeter scale (up to 0.42 m) vertical displacement was recorded at the study site over a period of four years, not believed to be associated with growth faulting. This research tested the hypotheses that fault slip rates were correlated with sediment accumulation rates, and that the observed vertical displacement was produced by shrink-and-swell clays in near surface sediments. To quantify sediment accumulation rates, a suite of radionuclides (7Be, 137Cs, and 210Pb) were used. To understand the effects of shrink-and-swell clays, …
Fluvial-Lacustrine Processes Shaping The Landforms Of The Distal Paraguay Fluvial Megafan, Edward Limin Lo
Fluvial-Lacustrine Processes Shaping The Landforms Of The Distal Paraguay Fluvial Megafan, Edward Limin Lo
Theses and Dissertations--Earth and Environmental Sciences
Tropical wetlands such as the Pantanal help regulate global biogeochemical cycles, but climate change is modifying these environments. Controls on environmental changes can potentially be assessed from ancient, well-dated lacustrine sedimentary records. An integrated field and laboratory approach was undertaken to study the limnogeology of Lake Uberaba in the northern Pantanal, and test whether the lake has preserved a reliable record of environmental change in its strata. This study was designed to understand how the basin accumulates sediment and to assess its sensitivity to hydroclimatic variability. The data showed that modern Lake Uberaba is a highly dynamic, freshwater fluvial-lacustrine basin. …
Stratigraphic, Geochemical, And Well Log Analysis Of The Wolfcamp-D Unconventional Play In The Central Midland Basin, Texas, Patrick Thomas Ryan
Stratigraphic, Geochemical, And Well Log Analysis Of The Wolfcamp-D Unconventional Play In The Central Midland Basin, Texas, Patrick Thomas Ryan
Theses and Dissertations--Earth and Environmental Sciences
This M.S. thesis utilizes diverse subsurface datasets from the central Midland Basin, a recently reinvigorated petroleum producing region, to better understand the depositional history of the prospective Wolfcamp-D interval. An integrated set of methods were applied to ~320 ft of drill core from Midland County (Texas). Elemental chemostratigraphy collected via x-ray fluorescence highlights the pervasive fine-scale variability in the stratigraphy of the core, and aided in the classification of three different mudrock facies types. Organic-rich, siliceous mudrocks are cyclically interbedded with aluminum-rich mudrocks and carbonates throughout the Wolfcamp-D. Trace metal correlations with total organic carbon indicate slow bottom-water recharge from …
Assessing The Relative Mobility Of Submarine Landslides From Deposit Morphology And Physical Properties: An Example From Kumano Basin, Nankai Trough, Offshore Japan, Zachary T. Moore
Theses and Dissertations--Earth and Environmental Sciences
A prominent landslide deposit in the Slope Basin seaward of the Megasplay Fault in the Nankai Trough was emplaced by a high-mobility landslide based on analysis of physical properties and seismic geomorphology. Slide acceleration is a critical variable that determines amplitude of slide-generated tsunami but is many times a variable with large uncertainty. In recent controlled laboratory experiments, the ratio of the shear stress to yield strength (defined as the Flow Factor) controls a wide spectrum of mass movement styles from slow, retrogressive failure to rapid, liquefied flows. Here, we apply this laboratory Flow Factor approach to a natural landslide …
Fluvial Responses To Growth Faulting In The West Pearl River, Louisiana, Stephen A. Prosser
Fluvial Responses To Growth Faulting In The West Pearl River, Louisiana, Stephen A. Prosser
Theses and Dissertations--Earth and Environmental Sciences
The Pearl River Delta (PRD) in southeastern Louisiana is an actively deforming deltaic complex displaying surface and near-surface evidence of growth faulting. Active growth faults in these environments are rarely identified at the surface, in part because the downthrown blocks often experience increased rates of sediment deposition leading to an obscured and low-relief, or entirely absent, surface expression. Faulting can be expressed in fluvial systems as changes in channel gradient, which often result in coincident changes in channel sinuosity, migration rates, planform deflections, and/or ponding features within the deformed zone. The study area is focused on a meander bend of …