气候变化领域集成服务门户(CCPortal): Thermal state and solidification regime of the martian core: Insights from the melting behavior of FeNi-S at 20 GPa

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DOI	10.1016/j.epsl.2020.116285
	Thermal state and solidification regime of the martian core: Insights from the melting behavior of FeNi-S at 20 GPa
	Gilfoy F.; Li J.
发表日期	2020
ISSN	0012821X
卷号	541
英文摘要	A series of multi-anvil experiments have been conducted to define the iron-rich liquidus of the iron-nickel-sulfur (FeNi-S) system at 20 GPa, the estimated pressure of the martian core-mantle boundary (CMB). The liquidus curve of FeNi-S containing about 9 wt.% Ni has a concave up shape, and is as much as 400 K lower than the liquidi previously applied to the martian core with sparse experimental constraints. Unlike existing liquidi of Fe-S and FeNi-S at 23 GPa, which predict a fully molten core for a narrow range of sulfur content between 14 and 15 wt.% S, our results are consistent with a molten state for all proposed core compositions, and establishes a new minimum CMB temperature of 1500 K for 10 wt.% S and 1250 K for 16 wt.% S. Extrapolating our FeNi-S liquidus to high pressures and comparing it to calculated areotherms, we find that three core crystallization regimes are possible. For a martian core with moderate sulfur content (10 to 13 wt.%) or lower, crystallization takes the form of iron snow near the CMB, while for cores with higher sulfur content (15-16 wt.%), solidification occurs near the center of the planet in the form of solid Fe3S. At an intermediate sulfur content of 14 wt.%, Fe3S would precipitate over a broad depth range and may appear fully molten to surface observations. © 2020 Elsevier B.V.
关键词	core crystallization dynamo iron snow liquidus curve Mars phase diagram
英文关键词	Iron; Solidification; Sulfur; Core composition; Core-mantle boundary; Crystallization regimes; Higher sulfur contents; Liquidus curve; Melting behavior; Sulfur contents; Surface observation; Iron compounds; core (planetary); core-mantle boundary; fractional crystallization; Mars; partial melting; solidification; temperature anomaly
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202608
作者单位	Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States
推荐引用方式 GB/T 7714	Gilfoy F.,Li J.. Thermal state and solidification regime of the martian core: Insights from the melting behavior of FeNi-S at 20 GPa[J],2020,541.
APA	Gilfoy F.,&Li J..(2020).Thermal state and solidification regime of the martian core: Insights from the melting behavior of FeNi-S at 20 GPa.Earth and Planetary Science Letters,541.
MLA	Gilfoy F.,et al."Thermal state and solidification regime of the martian core: Insights from the melting behavior of FeNi-S at 20 GPa".Earth and Planetary Science Letters 541(2020).