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Showing 1 to 20 of 29 for “"silicate melt"”.
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Silicate Melt Inclusions in Igneous Petrogenesis
Silicate melt inclusions are ubiquitous in quartz phenocrysts, yet there are few studies of such inclusions from porphyry copper systems. A melt inclusion forms when magma is trapped in a growing phenocryst. If a phenocryst is able to preserve the original parent magma, then accurate information …
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The dependence on oxygen fugacity of nickel and cobalt partitioning between olivine and silicate melt
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1991.
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Carbon in Silicate Melt - Experimental Constraints and Applications for the Subduction Zone and Magma Ocean Carbon Cycles
… of CO2 solubility on natural hydrous rhyolitic melts. These studies are applicable to subduction zone settings of the Earth throughout its history. Carbon concentrations and speciation were measured using FTIR, and in the process, we determined absorption coefficients for the CO2 species …
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Trace element geochemistry of oceanic peridotites and silicate melt inclusions : implications for mantle melting and ocean ridge magmagenesis
The mantle melting process is fundamental to basalt genesis and crustal accretion at mid-ocean ridges. It is believed that melts ascend more rapidly than the surrounding mantle, implying a process similar to fractional melting may be occurring, but geochemical evidence for this has been lacking. …
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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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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
… 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 differentiation in a temperature gradient.
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Ghost granophyre: A new texture with implications for plagiogranite differentiation and Ti-in-Quartz thermometry
… flow of recently described low temperature silicate liquids which span the magmatic-hydrothermal transition, as well as a way to make granophyre without the involvement of a silicate melt. These findings expand the definition of the term granophyre, which still sees heavy usage in the …
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Geochemical Evolution at White Island, New Zealand
… deposits. In this study, the geochemistry of the silicate melt at White Island has been characterized through detailed studies of silicate melt inclusions, phenocrysts, and matrix glass contained in recent ejecta (1977-1991). Most melt inclusions contained only glass, however, daughter minerals …
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Development of New Methods to Control Redox Conditions in High-pressure Experiments and their Application to Study Ore Metal Solubilities in Sulfur-bearing Magmatic Fluids
… comparing redox-dependent Cu solubilities in silicate melts at fO2 imposed by redox buffers and identical target fO2 imposed by the hydrogen membrane confirmed consistency between the two methods within 0.3 log units fO2 deviation at T=1000⁰C and P=2000 bar. Experiments using Fe(II)-Mg …
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The partial molar volume of carbon dioxide in peridotite partial melt at high pressure
The partial molar volume of CO2 (VCO2) in silicate melt was determined for a komatiite composition using high pressure sink/float experiments in a multi-anvil press. The density of the experimental melt at pressure was determined by observing sinking and floating of pure forsterite (Fo100) and 90% …
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The Early Evolution of Terrestrial Planets: Impact Simulations and Planetary Chemistry
… the interacting atmosphere and impact- generated silicate melt. We analyse the production of reduced atmospheric species (e.g., H<sub>2</sub>, CH<sub>4</sub>, NH<sub>3</sub>), which are important to proposed prebiotic chemical pathways. We also analyse the geochemical signatures that such impacts …
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Melt Inclusion Geochemistry
Silicate melt inclusions (MI) are small samples of melt that are trapped during crystal growth at magmatic pressures and temperatures. The MI represent a sample of the melt that was isolated from the magma during host crystal growth. Thus, MI provide a valuable tool for constraining the magmatic …
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Characterization of Impact Melt Rocks and Hydrothermal Mineralization at the Haughton Impact Structure, Devon Island, Canada: An Investigation of Impacts into Carbonate Targets
… impact, in particular whether they undergo melting or decomposition, is actively debated. The dominant process is significant as decomposition would cause severe climatic effects due to release of large amounts of carbon dioxide into the atmosphere. At the root of the problem is the …
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Platinum-group elements in the ultrabasic rocks of the Braganca and Morais massifs, northern Portugal
… the chromite mineralisation was derived from melts of boninitic affinity. The relatively high Pd/Cu ratios calculated for a silicate melt from which the chromite crystallised are consistent with this. The composition of the chromite grains, having 1000r/(Cr+Al) ratios clustering around 75, is …
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Metal-silicate Partitioning Behavior of Molybdenum, Tungsten, and Nickel: Implications for Core Formation
… solid state convection and thus decompression melting and hot spot volcanism. Therefore determining how Earth's core formed and if that process was unique to our planet in the solar system is of great scientific interest. Core formation can be studied experimentally by examining the …
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Using Lunar Apatite to Assess the Volatile Inventory of the Lunar Interior
… volatiles (H<sub>2</sub>O, Cl, F) within lunar melt inclusions, glass beads, and the mineral apatite have challenged the previously held notion that the Moon is depleted in volatiles. As the most widespread volatile-bearing phase, apatite has been the focus of many studies aiming to constrain …
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The X-discontinuity: Seismic signatures of a heterogeneous upper mantle
… transition and/or the presence of carbonated silicate melt, shedding insight into the nature of mantle plumes and their role in mantle convection. I study the presence of the X beneath Africa, using continuous observations and a vote map style procedure to understand the length scales of the …
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Origin of the Kleva Ni-Cu sulphide mineralisation in Småland, southeast Sweden
… a basaltic magma that formed through partial melting of a metasomatically refertilised mantle wedge underneath an Andean-type continental magmatic arc. Lu-Hf signatures of zircon, together with other rocks of Palaeoproterozoic Fennoscandia indicate alternating stages of extension and …
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Experimental constraints on the thermodynamic modelling of siderophile element distribution during core-segregation and basalt petrogenesis
… edge structure (XANES) spectroscopic study of silicate glasses, synthesized at high pressure and quenched isobarically, has been conducted in order to assess the effect of pressure on the coordination environment of divalent Ni, Co, Fe, trivalent Fe and hexavalent W. The principle Ni …
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Experimental constraints on the thermodynamic modelling of siderophile element distribution during core-segregation and basalt petrogenesis
… edge structure (XANES) spectroscopic study of silicate glasses, synthesized at high pressure and quenched isobarically, has been conducted in order to assess the effect of pressure on the coordination environment of divalent Ni, Co, Fe, trivalent Fe and hexavalent W. The principle Ni …
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