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 20 of 31 for “"Trace element geochemistry."”.
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Trace element geochemistry of marine biogenic particulate matter
… necessary to prevent contamination for major and trace-chemical analysis. Immediately after collection, the samples were subjected to a series of physical and chemical leaching-decomposition experiments designed to identify the major and trace element composition of particulate carrier phases. …
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Trace Element Geochemistry of Compositionally Layered Impact Spherules
… focuses on the heterogeneity of textures and geochemistry produced during the cooling and crystallization of spherules within a vapor plume. Type 4b spherules are layered phyllosilicate spherules with discrete differences in texture and composition between the inner and outer layer, even after …
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Trace element geochemistry of marine biogenic particulate matter
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1981.
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Sr, Nd and Pb isotope and trace element geochemistry of the New England seamount chain
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1984.
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Experimental studies bearing on the nature of silicate melts and their role in trace element geochemistry.
Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences.
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Sr, Nd, Pb isotope and trace element geochemistry of calc-alkaline and alkaline volcanics, Eastern Turkey
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1984.
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Trace element geochemistry of oceanic peridotites and silicate melt inclusions : implications for mantle melting and ocean ridge magmagenesis
… nonexistent. This dissertation examines the trace element compositions of abyssal peridotites and discusses how they preserve details of the melting process that are not recognizable in mid-ocean ridge basalts. The results support fractional melting as the dominant melting process in the …
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Trace element geochemistry of oceanic peridotites and silicate melt inclusions--implications for mantle melting and ocean ridge magmagenesis
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, and Woods Hole Oceanographic Institution, 1990.
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Trace Element Geochemistry of Volcanogenic Massive Sulfide Deposits in Archean Greenstone Belts: Implications for Metal Endowment and Geodynamic Settings
… The range of settings is reflected in the trace metal signatures of their ores. This study examines the trace element geochemistry of pyrite from 55 different Archean volcanogenic massive sulfide (VMS) deposits in Canada to test the relationship to their host rocks, the deposit sizes and …
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Crystallisation history of rhyolite magmas at Tarawera volcano, New Zealand, from in-situ 238U-230Th disequilibrium dating and trace element geochemistry of zircon
… New SIMS 238U-230Th disequilibrium dating and trace element analyses (U, Th, Y, Hf, Ce, Ti) of individual zircon crystals provide insight to the timescales of silicic magma system processes. Zircon geochronology reveals protracted yet disparate crystallisation histories in all of the erupted …
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Primitive magmas of the Earth and Moon : a petrologic investigation of magma genesis and evolution
Field studies, major and trace element geochemistry, isotopes, petrography, phase equilibrium experiments and thermodynamics are used investigate and understand primitive melts from the Earth and the Moon. Chapter 1 investigates spinifex orthopyroxene compositions from the komatiites of Commondale, …
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Spatial heterogeneity in isotope and biomarker distributions : insights from the End-Devonian OAE in Western Canada.
… nutrients, such as nitrogen, phosphorus, and trace elements, fundamentally influences biological production. This is especially critical in tropical regions where stable thermal stratification in the water column is periodically disrupted by surface ocean current divergence experience …
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Geochemical Constraints of Porphyry Cu Deposits-Forming Magmas in Sonora, Mexico
… magmatic systems in Sonora, Mexico. Using zircon trace-element geochemistry, U–Pb geochronology, and thermobarometry, I assess the magmatic conditions under which PCDs and barren rocks formed, and identify key proxies, such as REE anomalies, H₂O content, and oxidation state, that distinguish …
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Sediment-hosted Zn-Pb-Ag (+ Cu) deposits in the Mount Isa region: An epigenetic approach to mineralisation
… texturally coeval. Furthermore, the variation in trace element geochemistry of sphalerite, galena, and chalcopyrite across the Cu to Zn-Pb-Ag transition suggests that the separation of Cu and Zn-Pb-Ag mineralisation likely resulted from a small (>50ºC) temperature gradient across the orebody. …
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Jurassic limestone-marl sequences in northern spain: detecting diagenetic signals using rare earth and trace elements
… these limestone-marl rhythmites. Rare earth and trace element geochemistry is an overlooked method to distinguish the presence of a primary signal from a diagenetic one. The main objective of this study was to test the validity of using rare earth and trace elements as a method for determining …
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Small-scale heterogeneity in sediments : experimental and modelling investigations
… 3) analysis of the relationship between trace metal (cobalt) and iron and manganese in a marine sediment using DGT, although this is not directly related to microniches, these data are useful in modelling the release of microniche trace metal from authigenic oxides; 4) the development and …
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Petrogenesis of the reversely zoned Turtle pluton, Southeastern California
… mineral textures, and chemistries, major and trace element geochemistry, and isotopic variability support a petrogenetic model of in situ, concomitant, magma mixing, and fractional crystallization of rhyolitic magma progressively mixed with an increasing volume of andesitic magma, all without …
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Paleoenvironmental Reconstruction of an Upper Ordovician Rocky Shoreline: The Lindsay Formation of Heywood and Partridge Islands, Ontario
… of muds in slightly deeper water. Major and trace element geochemistry of the Lindsay Formation mudrocks suggests that the detritus was derived from a mixed mafic-felsic source. The felsic component was eroded from quartz-rich Paleoproterozoic basement, whereas the mafic material may have …
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Classification and petrogenesis of the Tongo dike-01 from the Tongo-Tongoma cluster, Sierra Leone: constraints from bulk rock geochemistry
… have been analysed for their bulk-rock major and trace elements as well as Sr-Nd-Pb isotope geochemistry. The primary objectives of this study are: 1) provide detailed petrographic observations of the dike, 2) classify the dike relative to kimberlites worldwide, 3) constrain the geochemical …
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Patterns of distal alteration zonation around Antamina Cu-Zn skarn and Uchucchacua Ag-base metal vein deposits, Peru : mineralogical, chemical and isotopic evidence for fluid composition, and infiltration, and implications for mineral exploration
… portions of these deposits. The main alteration tracers employed included mineralogy, major and trace element geochemistry, oxygen and carbon isotopes, and the fluorescent signature of calcite veins associated with the fluids conduits. Two areas were selected for this study: the large Cu-Zn …
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