Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
- Publication
Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Cenozoic Extension Of The Lake Tanganyika Rift, East Africa: Structures, Tectonostratigraphy And Paleoenvironmental Reconstruction, Shaidu Shaban
Cenozoic Extension Of The Lake Tanganyika Rift, East Africa: Structures, Tectonostratigraphy And Paleoenvironmental Reconstruction, Shaidu Shaban
Dissertations - ALL
Active continental rifts are ideal sites for understanding the break-up of continents, and long-lived rift lake environments are known as important reservoirs for endemic communities and biodiversity. The sedimentary fill of extensional continental rifts within the East Africa Rift System (EARS) records a long history of continental extension and variable tropical climate that is unparalleled in its duration and fidelity. Continental extensional basins are sensitive to variations caused by the interplay between tectonics, sedimentary processes, and climate change. However, to discern the sedimentary fill history and its related tectonostratigraphy, as well as for reconstructing past climate changes, high-fidelity data such …
Testing Detrital Zircon Age Bias In Tectonic Provenance: Examples From Modern Alluvium In The South Island, New Zealand, Will Sparhawk Fisher
Testing Detrital Zircon Age Bias In Tectonic Provenance: Examples From Modern Alluvium In The South Island, New Zealand, Will Sparhawk Fisher
Theses - ALL
Detrital zircon (DZ) grains from 13 drainages across the South Island, New Zealand, were U-Pb dated to ascertain how accurately their ages reflect the geologic record of exposed bedrock. With the proliferation of inexpensive and easily accessible ion microprobes and laser ablation inductively coupled plasma mass spectrometers, DZ dating has become the dominant chronometer for elucidating tectonic systematics. Zircon’s physical and chemical resilience makes it an ideal candidate for U-Pb geochronometry, but is also a potential source of bias. Zircon’s resilience in sedimentary systems means it rarely occurs as first order detritus. N = 966 zircon grains from Modern alluvium …
Heterogeneous Strain Distribution & The Effects Of High Frequency Climate Change On The Evolution Of Early-Stage Rift Systems: Case Studies From Lakes Tanganyika And Malawi (Nyasa), East Africa, Lachlan Wright
Dissertations - ALL
The break-up of the earth’s crust through the formation of continental rift basins is a fundamental aspect of plate-tectonics and the first step that ultimately leads to plate-spreading, new continent formation, and the creation of ocean basins. Within continental rifts, processes associated with extensional faulting drive uplift and subsidence of the landscapes forming rift valleys, and climatically influenced processes act upon these transient landscapes, erode them, modify relief, and produce sediments that infill the rift valleys creating the stratigraphic record. Continental rifts are highly sensitive to the interplay between extensional faulting, sedimentary processes, and climate change, and variations in the …
Studying Redox Conditions Of Devonian And Neoproterozoic Oceans Using I/Ca Proxy From Bulk Carbonate Rocks, Ruliang He
Studying Redox Conditions Of Devonian And Neoproterozoic Oceans Using I/Ca Proxy From Bulk Carbonate Rocks, Ruliang He
Dissertations - ALL
Iodine is an important trace element in biogeochemical and redox reactions. It has a nearly consistent concentration of ~0.46 μmol/L in the seawater and the inorganic speciation (IO3− and I−) of iodine is primarily controlled by redox conditions in water columns. Iodate (IO3−), not iodide (I−), is the only species that can be incorporated into carbonate minerals. Therefore, I/Ca ratio from carbonate rocks can be used to constrain the redox condition in the water column over a range of time scale. This dissertation contains three chapters that utilizes I/Ca ratio from bulk carbonate rocks to reconstruct ocean redox changes during …
Assessing Impact Of Unconventional Oil And Gas Development On Groundwater Quality In The Northern Appalachian Region With Mixed Land Uses, Favour C. Epuna
Assessing Impact Of Unconventional Oil And Gas Development On Groundwater Quality In The Northern Appalachian Region With Mixed Land Uses, Favour C. Epuna
Theses - ALL
Over the past decade, the rapid growth of unconventional oil and gas development (UOGD) has raised public concerns about its potential impact on groundwater quality. High methane and salt levels in groundwater have been the most widely cited UOGD-related impairments. The attribution of these contaminants to UOGD is usually complex, especially in regions with mixed land uses. Here, we compiled a large hydrogeochemistry dataset containing 13 geochemical analytes for 17,794 groundwater samples from the rural northern Appalachia, i.e., 19 counties located on the boundary between Pennsylvania (PA; UOGD is permitted) and New York (NY; UOGD is banned). With this dataset, …
Subsurface Geophysical Investigations Of Oneida Lake Ny: Insights Into Ice Sheet Processes And Deglaciation At Termination I, Nicholas John Zaremba
Subsurface Geophysical Investigations Of Oneida Lake Ny: Insights Into Ice Sheet Processes And Deglaciation At Termination I, Nicholas John Zaremba
Dissertations - ALL
Reconstructing the retreat of the Laurentide Ice Sheet (LIS) provides insight into understanding end-Pleistocene climate, a critical set of boundary conditions prior to the onset of Holocene climates that were optimal for human dispersal and societal growth. Constraining ice sheet dynamics, glacier retreat rates, and the timing of still-stands and readvances requires identifying glacial landforms such as moraines, drumlins, and mega-scale glacial lineations (MSGLs). Drumlins and MSGLs indicate ice sheet flow directions and provide the location of paleo-ice streams, which were accelerated and localized pathways for ice discharge. Ice streams control ice sheet mass balance; therefore, identifying the location of …