Global ETD Search
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 9 of 9 for “"thermal migration"”.
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Making oceanic plagiogranite bodies by thermal migration: evidence from the Agros transect, Troodos ophiolite, Cyprus
… and isotopically heavy. This process, thermal migration, whereby elements diffuse in a manner driven by mineral-melt equilibrium within a temperature gradient, should also be apparent as isotopic gradients in a natural transect of differentiated rocks. A spreading center melt lens, with …
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Patterns and Mechanisms of Melt Distribution in Partially Molten Harzburgite under Hydrostatic Pressure
… surface tension, lithologic partitioning and thermal migration as potential driving forces. The scale of the melt fraction variations and the speed at which they develop appear compatible with the thermal migration model.
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Studies of Magmatism by Trace Element Partitioning Between Clinopyroxene and Silicate Melt, Uranium-Series Disequilibria in Lavas From Subduction Zones, and Non-Traditional Stable Isotopes
… I report results of Fe-Mg isotopic analyses of a thermal migration experiment. Significant mass-dependent Fe-Mg isotopic fractionations occur in the melt-present portion of the experiment. I conclude that the positive co-variation of Fe-Mg isotopes could be an important fingerprint of magma …
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GATE DIELECTRIC BREAKDOWN PHYSICAL ANALYSIS AND STUDIES -2D MODELING OF BREAKDOWN THERMAL EFFECT
… model has been built based on the electro-thermal migration phenomenon to predict the size of DBIE under the influence of current density and temperature. TEM micrograph observations during the formation of DBIE have been verified by constructing a 2-D transient thermal model using Finite …
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Understanding the evolution of compositional zoning in San Juan Volcanic Field ignimbrites using iron isotope ratios
… after a short residence time. A process such as thermal migration could produce the trace element and isotopic zonation observed in flow units without substantial major element differentiation occurring. The data presented here provide new insight into and evaluation of differentiation processes …
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Variations in δ56Fe during magma differentiation at Cedar Butte volcano: signatures of thermal diffusion?
… of Saskatchewan for Ca isotope analysis by thermal ionization mass spectrometry (TIMS). Analyzed Cedar Butte samples ranged from 58 wt% SiO2 to 75 wt% SiO2. Results show a smooth, upwardly curving progression of δ56FeIRMM-14 with increasing SiO2. The most silicic samples have δ56Fe of ~0.40 …
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Spatially controlled Fe isotope variations at Torres Del Paine
… (3) late stage fluid exsolution and (4) thermal migration. Assimilation of isotopically light country rock would not produce the isotopically heavy Torres del Paine granites. Likewise, experimentally determined equilibrium fractionation factors argue against fractional crystallization …
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Investigation of iron isotope variability in the bimodal Aztec Wash Pluton, Eldorado Mountains, Nevada
… members within a temperature gradient is called thermal migration zone refining (Lundstrom, 2009). In addition to the compositional changes that occur within the temperature gradient, an isotopic signature was also observed: heavy isotopes of Fe, Mg, O, H and Li became enriched in the cold, …
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The isotope geochemistry of uranium: Igneous petrology, ore deposits, and groundwater contamination
… the previous work on the isotopic effects of thermal diffusion into the heavy elements, and presents new research on the mineralogical development of a basalt under a thermal gradient. There are five studies in this work: 238U/235U is first applied to detect the effect of a thermal gradient on …