Physical Sciences and Mathematics Commons^™

Estimating Sea Level Due To Crustal Stretching In The Margin Of The Indian Ocean, Kisa Mwakanyamale

Masters Theses

Continental crust extension is a precursor to the formation of a new ocean. The overall crustal extension causes change in the volume of global oceans hence change in sea level. The break-up of Gondwana that began during Late Triassic to Early Jurassic time caused continental crustal extension prior to forming the Indian Ocean. Extension started 184 Ma with rifting between SE Africa, Madagascar and Antarctica. This was followed by rifting between Greater India, Australia and Antarctica beginning about 160 Ma. The most recent episode of extension occurred 34 Ma involving separation between Arabia and Horn of Africa. Gridded data sets …

Major And Trace-Element Chemistry Of Minerals In Lithologies A And B In Martian Meteorite Eeta79001: Petrogenesis Revisited, Michael Joseph Mellin

Masters Theses

EETA79001 is a unique shergottite composed of two mafic lithologies (termed LithA and LithB) that are separated by an igneous contact. Both lithologies have basaltic compositions; however, LithA contains megacrysts of olivine, orthopyroxenes, and chromite whereas LithB does not; also, LithA is finer-grained than LithB. Currently, the literature is in disagreement regarding the formation of this unique meteorite, especially regarding LithA. Different formational theories (e.g. fractional crystallization, magma mixing, assimilation, and impact melting) have their own constraints (chemical, thermal, or petrographic). This study uses petrographic observations combined with major- and trace- element compositions within minerals to investigate the petrogenesis of …

Laboratory Precipitation And Geochemical Investigation Of Unstable Caco3 Polymorphs: Implications For The Origin Of Precambrian “Molar-Tooth” Microspar, Emily Elizabeth Goodman

Masters Theses

Molar-tooth (MT) microspar is a volumetrically significant, globally distributed carbonate fabric that occurs almost exclusively in Mesoproterozoic and early Neoproterozoic shallow marine successions. It occurs as uniform, equant crystals, averaging 9 –15 μm in diameter (Figure 1), that characteristically fill MT structures—interconnected networks of spheroidal, spindle, and ribbon-shaped voids that formed within unlithified sediment in shallow, subtidal environments. Cathodoluminescence (CL) analysis of MT microspar reveals two chemically distinct phases: a dully luminescent spheroidal core enclosed by a luminescent, polygonal rim. Crystal size distribution analysis of MT microspar indicates spontaneous nucleation, rapid growth and varying degrees of recrystallization by Ostwald ripening, …

Factors Influencing Persistence Of Fecal Bacteroides In Stream Water, Alyssa K. Bell

Masters Theses

Fecal contamination leads to increased risk of exposure to enteric pathogens in aquatic environments used for drinking water, recreation, and commercial shellfishing. Current indicators of fecal contamination recommended by the EPA such as E. coli and enterococcus can fall short of meeting ideal indicator criteria by having widely-varying persistence in the environment, reproducing in the environment, occurring in the gut in low and variable concentrations, and requiring time-consuming assays. Furthermore, both these indicators lack the degree of host specificity needed for use in identifying sources of fecal contamination, which is an important tool for identifying and reducing fecal inputs to …

Tectonics Of The Northeastern Inner Piedmont, Northwestern Nc, From Detailed Geologic Mapping, Geochronologic, Geochemical, And Petrologic Studies With Structural Analyses Of Ductile Fault Zones, Matthew Patrick Gatewood

Masters Theses

New field and laboratory data collected for the northeastern Inner Piedmont (IP) reveal the structure and composition of a portion of the southern Appalachian crystalline core, delimited the timing of orogenesis, and provide new insight into the nature of deep crustal processes during orogenesis. Previously recognized lithologies are continuous throughout the study area and comprise two distinct crystalline thrust sheets: the Marion and Brindle Creek thrust sheets, or eastern Tugaloo and western Cat Square terranes, respectively. Western IP Precambrian- Cambrian(?) metasedimentary lithologies and Ordovician metaigneous lithologies make up the Marion thrust sheet northwest of a Neoacadian suture, the Brindle Creek …

Towards A Better Understanding Of The Hydrology Of The Tigris- Euphrates System And Its Marshlands, Christopher K. Jones

Masters Theses

Rising demands for fresh water supplies are leading to water management practices that are altering natural flow systems world-wide. One of the most devastated of these natural systems is the Tigris-Euphrates watershed that over the past three decades has witnessed the construction of over 60 engineering projects that eliminated seasonal flooding, reduced natural flow and dramatically reduced the areal extent (1966: 11000 km² ; 2002: 750 km²) of the Mesopotamian Marshes downstream. We constructed a continuous (1964 to 1998) catchment-based rainfall runoff model for the entire Tigris-Euphrates watershed (area: one million km²) using the SWAT …

Stratigraphy And Organic Carbon Contents Of Glacial Deposits In The City Of Portage, Michigan, U.S.A., Nathaniel A. Barnes

Masters Theses

The objectives of this study are to characterize the stratigraphy of the glacial drift in an area located in Portage, Michigan using four complete rotasonic cores, and to determine the variation of organic carbon content in the drift that may explain the high iron concentrations in the groundwater typically obtained in moderate to deep wells in southwestern Michigan. The four cores were characterized in detail in terms of lithology, textural and statistical analyses, gamma ray logging, S¹³C variation and organic carbon analyses. Clay minerals were characterized using X-ray diffraction analysis.

Results of this study identified two main diamicton …