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The carbon content of Earth and its core.

ABSTRACT: Earth's core is likely the largest reservoir of carbon (C) in the planet, but its C abundance has been poorly constrained because measurements of carbon's preference for core versus mantle materials at the pressures and temperatures of core formation are lacking. Using metal-silicate partitioning experiments in a laser-heated diamond anvil cell, we show that carbon becomes significantly less siderophile as pressures and temperatures increase to those expected in a deep magma ocean during formation of Earth's core. Based on a multistage model of core formation, the core likely contains a maximum of 0.09(4) to 0.20(10) wt% C, making carbon a negligible contributor to the core's composition and density. However, this accounts for ?80 to 90% of Earth's overall carbon inventory, which totals 370(150) to 740(370) ppm. The bulk Earth's carbon/sulfur ratio is best explained by the delivery of most of Earth's volatiles from carbonaceous chondrite-like precursors.

SUBMITTER: Fischer RA

PROVIDER: S-EPMC7183175 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

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The carbon content of Earth and its core.

Fischer Rebecca A RA Cottrell Elizabeth E Hauri Erik E Lee Kanani K M KKM Le Voyer Marion M

Proceedings of the National Academy of Sciences of the United States of America 20200330 16

Earth's core is likely the largest reservoir of carbon (C) in the planet, but its C abundance has been poorly constrained because measurements of carbon's preference for core versus mantle materials at the pressures and temperatures of core formation are lacking. Using metal-silicate partitioning experiments in a laser-heated diamond anvil cell, we show that carbon becomes significantly less siderophile as pressures and temperatures increase to those expected in a deep magma ocean during formati ...[more]

PMID: 32229562

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