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Showing 1 to 12 of 12 for “"magmatic differentiation"”.
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Experimental studies of magmatic differentiation and the effects of water on phase stability
… of mineral phases, and how this affects both the differentiation of magmas and the modification of the upper mantle by hydrous fluid release during subduction. Chapter 1 models the crystallization of the asteroid Vesta, which melted almost completely during the early history of the solar system. …
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Mineralogy and Geochemistry of the Dumper Dew Pegmatite, Oxford County, Maine
… These trends illustrate an enhanced degree of magmatic differentiation relative to other pegmatites in the area.
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Geochemistry of igneous rocks from the southern coast belt plutonic complex, southwestern British Columbia
Source materials and magmatic differentiation have been constraint by Nd, Sr and Pb isotopic analyses and major, trace and rare earth element data for calc-alkaline plutonic and volcanic rocks collected along a 180 km transect from Vancouver to Anderson Lake in the southern Coast Plutonic Complex …
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The petrology of the Elephant's Head dyke and New Amalfi sheet
… olivine-dolerite magma. A considerable degree of magmatic differentiation in the latter magma has led to the production of a great variety of rock types. In the dike such types are represented by picrites and olivine-dolerites, whereas the dolerites of the sheet range from olivine-bearing types to …
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The controls of radioelement distribution in the Etive and Cairngorm granites: Implications for heat production
… Scotland. These studies throw light on the magmatic history of the intrusions and. more particularly. on their radioelement geochemistry and heat production which is interpreted in a geothermal context. <br></br><br></br>The Etive Complex is a multiphase intrusion, ranging from diorite to …
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Igneous life cycles: geochemistry of magma from mantle to surface and back again
… may undergo episodic changes in the extent of magmatic differentiation or the nature of eruption on rapid (<100 kyr) timescales. Slow-slip megathrust events in the Hikurangi forearc region, New Zealand, may be related to seamount subduction. We examine differences in the clast origins, …
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The 'Ins' and 'Outs' of the Bushveld Complex Upper Zone
… relatively little is known about the nature of magmatic differentiation in the uppermost portions of the Bushveld. As a first order, I quantify the chemical composition of the preserved stratigraphy (i.e. the bulk composition) from the geochemical base of the Upper Zone (the Pyroxenite Marker) …
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Historic and prehistoric volcanic activity on St Kitts and Nevis, West Indies: Controls on future hazard
… magma into the reservoirs led to mixing and magmatic differentiation. The geochemistry also showed that rapid crystallization, reheating and partial melting occurred in the shallow crust before eruption. Magma mingling occurred shortly before or syn-eruption. 9 Crystal Size Distribution (CSD) …
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The isotope geochemistry of uranium: Igneous petrology, ore deposits, and groundwater contamination
… techniques two three geologic settings: basalt differentiation, uranium ore genesis, and the remediation of a uranium-contaminated groundwater system. In the latter two cases, 238U/235U is used as a tracer of uranium reduction. 238U preferentially enters the reduced (solid) U phase, thus …
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Spatially controlled Fe isotope variations at Torres Del Paine
… stable isotope ratios in igneous rocks with differentiation index. We present new Fe isotope data for the Torres del Paine igneous complex in southern Chile. The multi-composition pluton consists of a 1.5 km vertical exposure of homogenous granite overlying a contemporaneous and possibly …
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The high temperature geochemistry of vanadium: From isotope ratios in ocean island basalt to thermal diffusion processes at the core-mantle boundary
… metal used widely to understand terrestrial magmatic processes. Measurements of the V isotopic composition of peridotites, the dominant rock of upper mantle, and primitive meteorites show significant offset with the peridotites heavier by ~0.2 ‰, the largest offsets among all metal stable …
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Origin and evolution of parental magmas associated with Pliocene-Quaternary low-silica volcanism within the Altiplano-Puna Volcanic Complex of northern Chile
… are therefore difficult to recognize due to the differentiation of mantle-derived magma during ascent through the thickened crust and a corresponding lack of erupted primitive lavas. However, a rare concentration of less evolved rocks is located marginal to the partially molten Altiplano-Puna …