JpGU-AGU Joint Meeting 2020

Presentation information

[E] Poster

S (Solid Earth Sciences ) » S-IT Science of the Earth's Interior & Techtonophysics

[S-IT31] Planetary cores: Structure, formation, and evolution

convener:Hidenori Terasaki(Faculty of Science, Okayama University), Eiji Ohtani(Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University), Gerd Steinle-Neumann(Bayerisches Geoinstitut, Universitaet Bayreuth), William F McDonough(Department of Earth Science and Research Center for Neutrino Science, Tohoku University, Sendai, Miyagi 980-8578, Japan)

[SIT31-P03] Metal-silicate partitioning of carbon at the core formation

*Yutaro Tsutsumi1, Naoya Sakamoto2, Kei Hirose3, Shunpei Yokoo1, Shoh Tagawa4, Hisayoshi Yurimoto5 (1.The University of Tokyo, 2.Creative Research Institution, Hokkaido University, 3.Earth-Life Science Institute, Tokyo Institute of Technology, 4.Department of Earth and Planetary Science, The University of Tokyo, 5.Department of Natural History Sciences, Hokkaido University)

Keywords:Outer core, Light elements, Melting experiments, Carbon, Hydrogen

Carbon has been considered to be one of the possible major light elements in the Earth’s core. While carbon is known to be strongly siderophile (iron-loving) at relatively low pressures, its metal-silicate partitioning under high pressure and temperature (P-T) conditions, typical for those of core segregation from silicate (~50 GPa, 3500 K), has been least examined yet. Here we performed melting experiments on Fe metal + MORB glass at such high P-T conditions in a laser-heated diamond-anvil cell (DAC). The metal-silicate partitioning of carbon was examined by using two different sets of starting materials; carbon was included in Fe in one set of experiments, and it was contained as CO2 in silicate glass in another set. After melting at high P, samples were recovered from a DAC, and their cross sections were prepared with a focused ion beam (FIB). Textural and compositional characterizations were made by electron microprobes. Subsequently carbon concentrations in coexisting molten iron and silicate melt were obtained by using a high-resolution imaging technique with secondary ion mass spectrometry (SIMS). These experimental results and the possible concentration of carbon in the core will be discussed at the meeting.