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Articles 1 - 6 of 6
Full-Text Articles in Cosmochemistry
Halogen And Non-Traditional Isotope Geochemistry Of Planetary And Terrestrial Materials, Anthony Gargano, Zachary Sharp, Justin Simon, Charles Shearer, Adrian Brearley, James Day
Halogen And Non-Traditional Isotope Geochemistry Of Planetary And Terrestrial Materials, Anthony Gargano, Zachary Sharp, Justin Simon, Charles Shearer, Adrian Brearley, James Day
Earth and Planetary Sciences ETDs
This dissertation presents the advances in non-traditional isotope geochemistry of planetary and terrestrial materials encompassing chlorine, sulfur, and zinc isotopes, as well as halogen geochemistry. A wide breadth of materials was studied throughout the completion of this work including iron meteorites, achondrites, chondrites, Apollo lunar samples, as well ancient marine chert, and carbonate sediments. Much of the focus involved the development of a method capable of simultaneously measuring the halogen contents and chlorine isotope compositions of geological materials. Here, I present these data sets to broadly characterize the process of devolatilization of planetary materials, and specifically the problem of ‘halogen-poisoning’ …
Petrology And Geochemistry Of Evolved Achondrites: Planetesimal Mantles And Crusts, Zoltan Vaci
Petrology And Geochemistry Of Evolved Achondrites: Planetesimal Mantles And Crusts, Zoltan Vaci
Earth and Planetary Sciences ETDs
Melting and differentiation are fundamental to early solar system evolution on planetary bodies that accreted enough material to heat up radioactively or through impacts and breach their solidi. Partially and fully melted material is present in the meteorite record in the form of primitive achondrites and achondrites, which are fragments of planetesimals that underwent heating events in the first few million years of solar system history. Although the vast majority of this material is mafic or ultramafic, new evolved samples, recovered in the last few decades, are pushing the petrologic and geochemical boundaries of planetesimal melting, differentiation, and crust formation. …
Magmatic Hydrothermal Alteration And Secondary Post-Shock Features In Martian Olivine-Phyric Basalt Northwest Africa 10416; Petrology And Geochemistry Of Primitive Achondrite Northwest Africa 11042, Zoltan Vaci
Earth and Planetary Sciences ETDs
The Martian olivine-phyric basalt Northwest Africa (NWA) 10416 contains large olivine xenocrysts whose cores have been stained brown by hydrothermal alteration and whose rims are composed of pristine olivine overgrowths. Microanalysis of these olivine cores reveals various degrees of amorphization, some of which have been overprinted by terrestrial weathering, evident as part of a weathering rind along the exposed surface of the meteorite. Studies of a completely unweathered terrestrial analogue basalt from southern Colorado reveal similar features and indicate that both basalts were altered in a supersolidus magma chamber setting. The alteration features in NWA 10416 thus imply the presence …
Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali
Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali
Chemistry Faculty Publications
How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence …
Geochemical And Field Relationships Of Pillow And Dike Units In A Subglacial Pillow Unit Undirhliđar Quarry, Southwest Iceland, Lindsey J. Bowman
Geochemical And Field Relationships Of Pillow And Dike Units In A Subglacial Pillow Unit Undirhliđar Quarry, Southwest Iceland, Lindsey J. Bowman
Senior Independent Study Theses
Undirhlíðar quarry is located on the Sveifluhals ridge, a Pleistocene subglacial pillow ridge within the NE-SW trending Krísuvík fissure swarm on the Reykjanes peninsula in Southwest Iceland. The walls of Undirhlíðar quarry provide excellent exposures of the internal architecture of the pillow ridge, yielding insights into the sequence of eruptive and intrusive events that construct subglacial ridges. In particular, the south and east walls expose at least 5 different pillow units and 3 dikes. Also seen in the east wall is a black, glassy breccia unit that appears on both the north and south sections of the east wall. Preliminary …
The Continental Crust: Its Composition And Evolution, Stuart Ross Taylor, Scott M. Mclennan
The Continental Crust: Its Composition And Evolution, Stuart Ross Taylor, Scott M. Mclennan
Department of Geosciences Faculty Publications
Graduates in geology, geochemistry and geophysics will find this book a valuable reference text. The book begins by describing the known composition of the present upper crust, then deals with possible compositions for the total crust and the inferred composition of the lower crust. The question of the uniformity of crustal composition throughout geological time is discussed, the rate of growth of the crust and the effects of extraction of the crust on mantle compositions are considered. Finally, the question of early pre-geological crusts on Earth is debated and comparisons are given with crusts on the Moon, Mercury, Mars, Venus …