Carbon partitioning between metal and silicate melts during Earth accretion
نویسندگان
چکیده
In the accreting Earth and planetesimals, carbon was distributed between a core forming metallic melt, silicate hot, potentially dense atmosphere. Metal melt droplets segregating gravitationally from magma ocean equilibrated near its base. To understand distribution of carbon, partitioning two melts is experimentally investigated at 1.5–6.0 GPa, 1300–2000 °C oxygen fugacities ?0.9 to ?1.9 log units below iron-wuestite reference buffer (IW). One set experiments performed in San Carlos olivine capsules investigate effect depolymerization (NBO/T), second graphite expand data higher pressures temperatures. Carbon concentrations were analyzed by secondary ionization mass spectrometry (SIMS) Raman spectra collected identify C-species melt. Partition coefficients are governed solubility C which varies 0.01 0.6 wt%, while metal contain ?7 wt% most samples. correlates strongly with NBO/T, which, capsules, mostly function temperature. partition DCmetal/silicate 1.5 1300–1750 decrease 640(49) 14(3) NBO/T increasing 1.04 3.11. For 2.6, 34(9). Pressure fugacity show no clear on partitioning. The present results differ those previous studies that comparatively higher, rendering be about an order magnitude less siderophile, discrepancies may attributed differences experimental protocols. Applying new scenario, assuming day mantle 120 795 ppm, implies 0.4–2.6 resulting 0.14–0.9 this element for bulk Earth. These values upper limits, considering some modern has very likely been delivered late veneer.
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ژورنال
عنوان ژورنال: Earth and Planetary Science Letters
سال: 2021
ISSN: ['1385-013X', '0012-821X']
DOI: https://doi.org/10.1016/j.epsl.2020.116659