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Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Understanding The Chemical Weathering Rate And Element Mobility Of Soils: Using U-Series, Nd-Sr Isotopes Ree And Quantum Chemistry Computational Simulation, Jiye Guo
Open Access Theses & Dissertations
Soil played as the central role in the interaction of biosphere, hydrosphere, lithosphere and atmosphere and is the heart of earth's critical zone study. The weathering and element mobility of soils have drawn considerable attention in soil studies since the complexity of these processes and the critical influence towards the earth and humanity, e.g., the global carbon cycles and fertilization. However, the interaction between soils and various factors including precipitation, bedrock ages, altitude is not well understood. Basse-Terre Island at French Guadeloupe, a small volcanic tropical island that has steep environmental gradients of bedrock ages, topography and precipitation, can be …
Cycling Of Gypsiferous White Sands Aerosols In The Shallow Critical Zone At White Mountain, New Mexico, Patrick Richard Rea
Cycling Of Gypsiferous White Sands Aerosols In The Shallow Critical Zone At White Mountain, New Mexico, Patrick Richard Rea
Open Access Theses & Dissertations
Dry deposition significantly affects evolution of the critical zone by nutrient supply and contributing to soil genesis. Dust influx and cycling in soils are difficult to quantify because dust sources can be chemically similar to local soils. White Sands, New Mexico, emits gypsum dust with a unique chemical and isotopic signature, providing an opportunity to investigate dust deposition and its movement in soils. This study evaluated the mobility of White Sands dust particles in the critical zone at White Mountain, New Mexico, a highland 100 km downwind. Four soil profiles were collected over limestone, igneous, mixed limestone and dolostone, and …
Uranium-Series And Strontium Isotope Ratios In Soils From Basse-Terre Island, French Guadeloupe: Insights For Rapid Soil Formation And Impact Of Dust In A Tropical Volcanic Setting, Yvette Pereyra
Open Access Theses & Dissertations
Chemical weathering of silicate rocks generates soils that contain mineral nutrients, sustain ecosystems, modify water chemistry in the hydrosphere, and regulate the global carbon cycle. Understanding the timescales of soil formation and sources of soil mineral nutrients has great implications for securing the future of agriculture and food production. However, few tools are currently available to directly quantify the rates of chemical weathering and timescales of soil formation. Uranium-series isotopes fractionate during chemical weathering and the activity ratios of (234U/238U), (230Th/238U), (238U/232Th) and (230Th/232Th) have great potential to constrain the rates and timescales of chemical weathering and soil formation in …
Evaluating Suspended Dust Particulate Matter From Anthropogenically - Altered Lands, Roberto Velarde
Evaluating Suspended Dust Particulate Matter From Anthropogenically - Altered Lands, Roberto Velarde
Open Access Theses & Dissertations
Substantial dust loads are transported from drylands including the Saharan, Asian, and Chihuahuan Desert deposits by localized to planetary-scale processes to nearby and distal sites. These dusts may carry harmful constituents. To evaluate dust movement patterns and characteristics relative to carried constituents, three studies are presented comprising (A) Localized displacement of uranium and progeny radionuclides from high-grade uranium ore storage piles at Peña Blanca, Chihuahua, Mexico; (B) Long-distance transport of plutonium via Saharan and Asian aeolian pathways; and (C) Dust movement patterns in military maneuvering and non-maneuvering areas at White Sands Missile Range (WSMR), New Mexico. Study (A) evaluated surface …