Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5779918 | Earth and Planetary Science Letters | 2017 | 7 Pages |
Abstract
Melting experiments were performed on the Fe-Fe3S system at high pressures between 34 and 254 GPa in a laser-heated diamond-anvil cell (DAC), using starting materials of fine-grained homogeneous mixtures of Fe and FeS (<500 nm) prepared by induction melting and rapid quenching techniques. Melting phase relations including the liquid/solid partitioning of sulfur were examined on the basis of textural and chemical characterizations of recovered samples using a focused ion beam (FIB) and electron microprobes. The results demonstrate that the sulfur content in eutectic liquid decreases substantially with increasing pressure. The eutectic liquid Fe with 5.7(±0.3) wt.% S coexisted with both solid Fe3S and Fe containing 3.9(±0.4) wt.% S at 254 GPa and 3550 K. The eutectic liquid at inner core boundary (ICB) pressure includes less sulfur than is required to account for the density deficit of the outer core (â¥10 wt.% S). Furthermore, the difference in sulfur concentration between coexisting liquid and solid is not sufficient to account for the observed density jump across the ICB. These indicate that sulfur cannot be a predominant light element in the core.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Earth and Planetary Sciences (General)
Authors
Yuko Mori, Haruka Ozawa, Kei Hirose, Ryosuke Sinmyo, Shigehiko Tateno, Guillaume Morard, Yasuo Ohishi,