Entries by James Eguchi

Geochemical Perspectives Letters: Redox state of the convective mantle from CO2-trace element systematics of oceanic basalts

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Redox state of the convective mantle from CO2-trace element systematics of oceanic basalts By: James Eguchi, Rajdeep Dasgupta Abstract: The redox state of mantle lithologies, based on xenoliths from continental lithospheric mantle, has been shown to decrease with depth and reach oxygen fugacities (fO2) at which graphite/diamond will be the stable form of carbon at […]

Chem Geo: A CO2 solubility model for silicate melts from fluid saturation to graphite or diamond saturation

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A CO2 solubility model for silicate melts from fluid saturation to graphite or diamond saturation By: James Eguchi, Rajdeep Dasgupta Abstract: A model based on a thermodynamic framework for CO2 concentrations and speciation in natural silicate melts at graphite/diamond-saturated to fluid-saturated conditions is presented. The model is simultaneously calibrated with graphite-saturated and fluid-saturated conditions allowing for consistent model predictions across the […]

CO2 content of andesitic melts at graphite-saturated upper mantle conditions with implications for redox state of oceanic basalt source regions and remobilization of reduced carbon from subducted eclogite

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James Eguchi, Rajdeep Dasgupta DOI: 10.1007/s00410-017-1330-8 We have performed experiments to determine the effects of pressure, temperature and oxygen fugacity on the CO2 contents in nominally anhydrous andesitic melts at graphite saturation. The andesite composition was specifically chosen to match a low-degree partial melt composition that is generated from MORB-like eclogite in the convective, oceanic […]