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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 33 for “"Weathering processes"”.
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Pedogenesis, weathering processes, and elemental distribution along a soil climosequence in the southern Piedmont
… complex effects of climate and geomorphic age on weathering intensity, soil profile development, mineral stability, and elemental flux within the pedoenvironment. Upland soils formed in similar granitic parent materials along a climatic gradient in the nonglaciated Southern Piedmont Province were …
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Meteoric 10Be as a Tracer for Subglacial Chemical Weathering in East Antarctica
Subglacial chemical processes in Antarctica are potentially significant contributors to global geochemical cycles, but current understanding of their scale and nature is limited. A sequential chemical extraction procedure was developed and tested to investigate the utility of meteoric 10Be as a …
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Soil weathering under mountain pine beetle killed trees, Grand County, Colorado
… of this study is to assess differences in soil weathering processes under mountain pine beetle killed trees, as compared to soil weathering under living trees. As pine beetle (Dendroctonus pondersoae) infected trees die, pine needles are shed and accumulate on the forest floor, which may lead to …
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Contributions to Exceptional Fossil Preservation
… conditions, geomicrobiological activities, and weathering processes, which influence the conservation of original biological features within exceptionally preserved fossils and control their occurrences in time and space. An improved understanding of these critical factors involved in …
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Distribution of precious metals and geochemistry of lateritic ores
… geochemical behaviour of the elements during the weathering processes.
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Evolution of chemical composition along river drainage networks
… in the underlying bedrock. Other indices of weathering rates and processes showed strong similarities despite the change in bedrock. The dominance of silica, alkalinity, calcium and sodium (after sea-salt correction) in surface waters suggests that anorthite and albite are the dominant …
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Fault segmentation, fault linkage, and hazards along the Sevier fault, southwestern Utah
… young slip rate is 0.018 mm/yr. (5) Mechanical weathering processes or seismicity induced 14 landslides and similar future slope failures are likely.
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Deterioration of excavated rockslopes : mechanisms, morphology and assessment
Results are reported of laboratory simulated weathering processes on a range of sedimentary rocks and the investigation of the deterioration of rock masses as observed on engineered and quarried rockslopes. The simulated weathering processes include freeze-thaw, wetting and drying, salt weathering …
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Silicate weathering in the Himalayas: Constraints from the Li isotopic composition of river systems
Chemical weathering of silicate rock consumes atmospheric CO2 and supplies the oceans with cations, thereby controlling both seawater chemistry and climate. The rate of CO2 consumption is closely linked to the rate of CO2 outgassing from the planetary interior, providing a negative feedback loop …
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Distribution of hydrocarbons in a salt marsh ecosystem after an oil spill and physiological changes in marsh animals from the polluted environment
… the oil with time due to physical and chemical weathering processes and biochemical degradation of hydrocarbons, 4) on the effects of oiled sediments on the population distribution, behavior, and survival of the intertidal fiddler crab, Uca pugnax, 5) on the relatively small ability of Uca to …
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Non-invasive methods for in situ assessing and monitoring of the vulnerability of rock art monuments
… of sandstone and the type and severity of weathering features present. A study of rock art panels in situ is given, to characterise the host rock and provide quantitative assessment of the vulnerability of the panels to weathering processes. The relative impact of natural weathering and …
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The effects of winter cover crops and soil compaction treatments on soil properties and soybean production in Illinois
… levels of soil organic carbon and of natural weathering processes. Soybean growth parameters, yield components and grain yield showed no significant differences due to compaction treatments, WCC or their interactions. Results from this study show that one growing season is not enough time to …
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The Evolution and Impact of Weddell Sea Deep Water
… water with the floating ice shelves. These processes are crucial for the evolution of the climate in the past and future, but remain generally poorly constrained. In this dissertation, the evolution and impact of Antarctic Bottom Water sourced from the Weddell Sea is investigated by use of …
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Sediment chemistry as an archive of provenance and weathering in the Mekong River Basin
The chemical weathering of rocks, in particular silicate weathering, has been proposed to be an important natural carbon-removal process that regulates the Earth’s climate over millions of years. Tectonically active regions, such as the sub-Himalayan region, are considered a hotspot of silicate …
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Surface characteristics of near-earth objects
… the main belt. Scientists now believe that space weathering processes, such as solar wind ion implantation and bombardment by micrometeorites, can affect the upper few millimeters of an asteroid's surface to produce the higher red slope and reduced absorption bands seen in spectra. However, …
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Catchment Structure Regulates Hydrodynamic Drivers of Chemical Weathering in Shallow Forest Soils
… when, and how subsurface flow affects soil processes and the resulting arrangement of soil development along flow paths is challenging. While hydrologic regime and soil solution acidity are known to influence weathering rates and soil transformation processes, an integrated understanding of …
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Assessment of Petroleum Hydrocarbon Contamination In Terrestrial Ecosystems Using Conventional and Novel Approaches
… heterogeneous nature of PHC mixtures and natural weathering processes that influence the bioavailability of individual compounds, make it difficult to predict the toxicity of PHC-contaminated sites. Despite their usefulness in accurately determining risks at PHC-contaminated sites, traditional …
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Authigenic kaolinite in the Bear Den Member (Paleocene) of the Golden Valley Formation, in southwestern North Dakota
… <p>Two different theories, either in place weathering or detrital deposition, have developed as to the origin of the kaolinite in the lower member. Early workers suggest that the kaolinite of the member is detrital in origin for the following reasons:</p> <p>1. No unconformity is present at …
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The Experimental Silicification of Bacillus subtilis
… quartz is chemically and physically resistant to weathering. Microorganisms are commonly incorporated into silica deposits formed by silica precipitation from geothermal fluids that are over saturated with respect to silica. Silica deposits have provided the oldest evidence of life identified on …
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The Experimental Silicification of Bacillus subtilis
… quartz is chemically and physically resistant to weathering. Microorganisms are commonly incorporated into silica deposits formed by silica precipitation from geothermal fluids that are over saturated with respect to silica. Silica deposits have provided the oldest evidence of life identified on …
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