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Full-Text Articles in Physical Sciences and Mathematics
Petrology And Geochemistry Of Olivine-Bearing Diogenites And A Group Of Paired Howardites, Andrew William Beck
Petrology And Geochemistry Of Olivine-Bearing Diogenites And A Group Of Paired Howardites, Andrew William Beck
Doctoral Dissertations
Asteroid 4 Vesta, the largest differentiated body in the asteroid belt, is a protoplanet, much like those that accreted to form the Earth. Understanding the geology of Vesta furthers understanding of early differentiation processes that occurred on Earth and helps define igneous processes occurring on other differentiated bodies in the early solar system. Howardite, eucrite and diogenite (HED) meteorites, which are thought to have originated from Vesta, can be analyzed to better understand the geology of that asteroid. Here my colleagues and I investigate the petrology and geochemistry of two groups of HEDs. This work is timely, in that the …
Remote Sensing Of Sediments And Volatiles On The Martian Surface And Terrestrial Analog Sites, Craig James Hardgrove
Remote Sensing Of Sediments And Volatiles On The Martian Surface And Terrestrial Analog Sites, Craig James Hardgrove
Doctoral Dissertations
The role of water and volatiles in the solar system is of critical interest in planetary science. Evidence for the past action of water or direct observation of water on a planetary body can indicate the potential to harbor life and is critical to human exploration of the solar system. We study two very different remote sensing techniques that address the issue of identifying water-related processes on the surface of other planetary bodies, and in particular, Mars. The first technique, combined thermal infrared and visible imaging, has been used extensively on Mars for determining the thermal inertia of surface materials. …
Carbon And Sulfur Cycling In Early Paleozoic Oceans, Cara Kim Thompson
Carbon And Sulfur Cycling In Early Paleozoic Oceans, Cara Kim Thompson
Doctoral Dissertations
Here, I evaluate biospheric evolution during the Ordovician using high-resolution inorganic carbon and sulfur (carbonate-associated sulfate and pyrite) isotope profiles for Early Ordovician to early Late Ordovician strata from geographically distant sections in Western Newfoundland and the Argentine Precordillera. Additionally, I present new, high-resolution U-Pb ages for volcanic ash beds within strata of the Argentine Precordillera. Carbon isotope data record subdued variation that is typical of Early- to Middle Ordovician strata worldwide. By contrast, sulfur-isotopic compositions of carbonate-associated sulfate reveal a complex signal of short-term, rhythmic variation superimposed over a longer-term signal. This short-term, rhythmic variation occurs in all sections …