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Full-Text Articles in Physical Sciences and Mathematics
Granulometry And Geochemistry Of Dust Emission From Owens (Dry) Lake, California, Analila Rojo
Granulometry And Geochemistry Of Dust Emission From Owens (Dry) Lake, California, Analila Rojo
Open Access Theses & Dissertations
Owens (dry) Lake, the terminus of Owens River, is located in the Basin and Range physiographic province in east–central California. The transformation of Owens Lake into a desiccated desert playa (approximately 280 km2) via diversion of the river into the Los Angeles Aqueduct (in 1913) led to extensive wind erosion, making the playa one of the most intense sources of airborne dust in the Western Hemisphere. The processes that direct the chemical and mineralogical composition of surface sediments at Owens (dry) Lake and the physical mechanisms of wind erosion, saltation and dust emission at Owens (dry) Lake are well–understood. However, …
Mineralization In The San Juan Mountains, Colorado, William M. Sheriff
Mineralization In The San Juan Mountains, Colorado, William M. Sheriff
Open Access Theses & Dissertations
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Application Of Copper And Zinc Isotopes To Fingerprint Metal Sources And Identify Attenuation Mechanisms In The Abandoned Waldorf Mine Area, Clear Creek County, Colorado, Suzan Aranda Luna
Application Of Copper And Zinc Isotopes To Fingerprint Metal Sources And Identify Attenuation Mechanisms In The Abandoned Waldorf Mine Area, Clear Creek County, Colorado, Suzan Aranda Luna
Open Access Theses & Dissertations
Acid rock drainage (ARD) is caused by the oxidative weathering of sulfide minerals. Sulfur is oxidized by dissolved oxygen or Fe(III) and sulfate ions, metals, and protons are released into the environment. Hence, the pH of nearby water and soils often decreases in response to ARD while metal concentrations increase. Because a large part of the Rocky Mountains of Colorado are highly mineralized (i.e., the Colorado Mineral Belt), ARD is a serious problem in this region. Moreover, the many abandoned mining areas in the Rocky Mountains that include waste rock piles, tailings impoundments, and surface disturbances add to the problem …
Characterization Of Mantle/Crust Interactions Using Pb Isotope Analyses Of Lavas In The Southern Rio Grande Rift, New Mexico, Lynnette Crocker
Characterization Of Mantle/Crust Interactions Using Pb Isotope Analyses Of Lavas In The Southern Rio Grande Rift, New Mexico, Lynnette Crocker
Open Access Theses & Dissertations
The Pb isotope composition of volcanic rocks in the Rio Grande Rift (RGR) can be used to investigate the interaction of mantle melts with continental lithosphere, and has important implications for the composition of the lithosphere. We suggest some compositional signatures may pre-date current tectonic processes. Existing data from several volcanic fields in New Mexico show a converging pattern on a very limited Pb isotope range, corresponding to lower crustal xenolith compositions from Kilbourne Hole. The different volcanic fields show Pb isotope trends diverging from this lower crustal composition, likely depicting mixing with different upper crustal reservoirs. These very common, …
Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete
Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete
Open Access Theses & Dissertations
Copper isotopes may prove to be a useful tool for investigating bacteria-metal interactions recorded in natural waters, soils, and rocks. However, experimental data that constrain Cu isotope fractionation in biologic systems are limited and unclear. In this study we utilized Cu isotopes (65Cu) as a tool to investigate Cu-bacteria interactions, including surface adsorption and intracellular incorporation. Experiments were conducted with individual Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial species as well as with bacterial consortia from several natural environments. Adsorption experiments were conducted with live or dead cells over the pH range 2.5 to 6. Surface adsorption of Cu …