Entries by Rajdeep Dasgupta

AJS: Volatile-bearing partial melts beneath oceans and continents – Where, how much, and of what compositions?

Volatile-bearing partial melts beneath oceans and continents – Where, how much, and of what compositions? Abstract: Besides depth and temperature, CO2 and H2O, are the two most important variables in stabilizing partial melts in the Earth’s mantle. However, despite decades of experimental studies on the roles of these two volatile species in affecting mantle melting, […]

GCA: New high pressure experiments on sulfide saturation of high-FeO* basalts with variable TiO2 contents – Implications for the sulfur inventory of the lunar interior

New high pressure experiments on sulfide saturation of high-FeO* basalts with variable TiO2 contents – Implications for the sulfur inventory of the lunar interior Shuo Ding, Taylor Hough, Rajdeep Dasgupta Abstract: In order to constrain sulfur concentration in intermediate to high-Ti mare basalts at sulfide saturation (SCSS), we experimentally equilibrated FeS melt and basaltic melt […]

JGR-Planets: Carbon contents in reduced basalts at graphite saturation: Implications for the degassing of Mars, Mercury, and the Moon

Abstract: Carbon contents in reduced Martian basalts at graphite saturation were experimentally studied at 1400-1550 °C, 1-2 GPa, and logfO2 of IW-0.4 to IW+1.5 (IW denotes the Fe-FeO buffer). The results show that carbon solubility in Martian basalts, determined by SIMS, is 20 to 1400 ppm, increasing with increasing fO2. Raman and FTIR measurements on […]

Rise of Earth’s atmospheric oxygen controlled by efficient subduction of organic carbon

Duncan, M. S. and Dasgupta, R. Abstract: The net flux of carbon between the Earth’s interior and exterior, which is critical for redox evolution and planetary habitability, relies heavily on the extent of carbon subduction. While the fate of carbonates during subduction has been studied, little is known about how organic carbon is transferred from […]

Experimental determination of CO2 content at graphite saturation along a natural basalt-peridotite melt join: Implications for the fate of carbon in terrestrial magma oceans

Megan S. Duncan, Rajdeep Dasgupta, Kyusei Tsuno Abstract Knowledge of the carbon carrying capacity of peridotite melt at reducing conditions is critical to constrain the mantle budget and planet-scale distribution of carbon set at early stage of differentiation. Yet, neither measurements of CO2 content in reduced peridotite melt nor a reliable model to extrapolate the […]

The fate of sulfide during decompression melting of peridotite – implications for sulfur inventory of the MORB-source depleted upper mantle

Shuo Ding and Rajdeep Dasgupta Abstract: Magmatism at mid ocean ridges is one of the main pathways of S outflux from deep Earth to the surface reservoirs and is a critical step in the global sulfur cycle, yet our understanding of the behavior of sulfide during decompression melting of the upper mantle is incomplete. In […]

Carbon and sulfur budget of the silicate Earth explained by accretion of differentiated planetary embryos

Li, Y., Dasgupta, R., Tsuno, K., Montelone, B. & Shimizu, N. (2016). Carbon and sulfur budget of the silicate Earth explained by accretion of differentiated planetary embryos. Nature Geoscience. doi:10.1038/ngeo2801   The abundances of volatile elements in the Earth’s mantle have been attributed to the delivery of volatile-rich material after the main phase of accretion. […]

Effects of water, depth and temperature on partial melting of mantle-wedge fluxed by hydrous sediment-melt in subduction zones

Ananya Mallik, Rajdeep Dasgupta, Kyusei Tsuno, Jared Nelson   Mallik, A., Dasgupta, R., Tsuno, K., Nelson, J. (2016). Effects of water, depth and temperature on partial melting of mantle wedge fluxed by hydrous sediment melt in subduction zones. Geochimica et Cosmochimica Acta. doi:10.1016/j.gca.2016.08.018   Abstract: This study investigates the partial melting of variable bulk H2O-bearing […]