The carbon content of Earth and its core
The carbon content of Earth and its core
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DOI：
10.1073/pnas.1919930117
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发表时间：
2020-04-21
影响因子：
11.1
通讯作者：
Le Voyer, Marion
中科院分区：
文献类型：
--
作者：
Fischer, Rebecca A.;Cottrell, Elizabeth;Le Voyer, Marion
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 similar to 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.
