Physical Sciences and Mathematics Commons^™

Characterizing Silicate Materials Via Raman Spectroscopy And Machine Learning: Implications For Novel Approaches To Studying Melt Dynamics, Blake O. Ladouceur

Doctoral Dissertations

Silicate melt characteristics impose dramatic influence over igneous processes that operate, or have operated on, differentiated bodies: such as the Earth and Mars. Current understanding of these melt properties, such as composition, primarily comes from investigations on their volcanic byproducts. Therefore, it is imperative to innovate on modalities capable of constraining melt information in environments where a reliance on laboratory methods is severed. Recent investigations have turned to Raman Spectroscopy and amorphous volcanics as a suitable pairing for exploring these ideas. Silicate glasses are a proxy for igneous melts; and Raman spectroscopy is a robust analytical technique capable of operating …

Metagenomic Investigation Of Microbial Dark Carbon Fixation, Viral Interactions, And Horizonal Gene Transfer Within A Convergent Margin Subsurface Ecosystem, Timothy Joseph Rogers

Doctoral Dissertations

Convergent margins are geological regions where two or more tectonic plates collide, and the denser “subducting slab” is pushed beneath the less dense overriding plate. As the slab descends, it devolatilizes under higher temperatures and pressures, allowing dissolved inorganic carbon (DIC) and redox active volatile rich fluids to cycle between the upper crust and Earth’s mantle. These fluids migrate through cracks and fissures in the upper mantle and crust, fueling chemolithoautotrophy-based microbial ecosystems in the subsurface before they are expelled on the surface in the form of hydrothermal seeps and springs. Chemolithoautotrophic ecosystems, such as those in the Costa Rican …

Large-Scale Volcanism On The Terrestrial Planets, Keenan Ben Golder

Doctoral Dissertations

Evidence for mafic volcanism has been found on each planet in the inner Solar System. Lava flows on these planets range in size from 10s to 1000s of kilometers in extent. I investigated large-scale lava flows on Mercury, Earth, and Mars throughout the chapters in this dissertation. Each of these lava flows provides an avenue to study the emplacement and evolution of lava on various planets and under differing conditions, the factors that affect their overall extent, and potential source areas.

Chapter One investigates large-scale lava flows in the Cerberus region on Mars, specifically to understand their emplacement history, material …

Natural, Experimental, And Educational Explorations Of The Interiors Of Terrestrial Planetary Bodies, Nadine L. Grambling

Doctoral Dissertations

Planetary interiors are enigmatic, inaccessible, and vital to the processes that have formed the rocks we see on the surface of bodies in the inner Solar System today. Based on geophysical explorations of the Moon and Earth, along with information gleaned from rocks at the surface today, there is understanding of the basic structure and processes at depth. Using a combination of natural samples and experimental studies, we attempt to learn more about the physical conditions beneath the surface, and their effect on material properties and tectonics processes in the mantle.

On Earth, mid-ocean ridge processes have long been debated, …

Petrogenesis Of Basaltic Lavas In Iceland And The Springerville Volcanic Field, U.S.A.: The Influence Of Tectonic Setting, Depth Of Melting And Volatiles, Marissa Mnich

Doctoral Dissertations

Icelandic basalts were long thought to be low in water (e.g. Gunnarsson et al., 1998), but more recent studies suggest that hotspots, like the Iceland mantle plume, may be a source of hydrous basaltic melts (Nichols et al., 2002). To explore a possible link between location, volatile concentration and resulting petrogenetic implications, samples were collected from eleven volcanic centers throughout Iceland. Water concentrations were measured in melt inclusions and phenocrysts using Fourier transform infrared (FTIR) spectroscopy. Results for a subset of samples indicate variable water in melt inclusions ranging from approximately 50 ppm to over 3000 ppm. Samples from southwestern …