气候变化领域集成服务门户(CCPortal): Oxygen controls on magmatism in rocky exoplanets

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DOI	10.1073/pnas.2110427118
	Oxygen controls on magmatism in rocky exoplanets
	Lin Y.; Van Westrenen W.; Mao H.-K.
发表日期	2021
ISSN	0027-8424
卷号	118 期号:45
英文摘要	Refractory oxygen bound to cations is a key component of the interior of rocky exoplanets. Its abundance controls planetary properties including metallic core fraction, core composition, and mantle and crust mineralogy. Interior oxygen abundance, quantified with the oxygen fugacity (fO2), also determines the speciation of volatile species during planetary outgassing, affecting the composition of the atmosphere. Although melting drives planetary differentiation into core, mantle, crust, and atmosphere, the effect of fO2 on rock melting has not been studied directly to date, with prior efforts focusing on fO2-induced changes in the valence ratio of transition metals (particularly iron) in minerals and magma. Here, melting experiments were performed using a synthetic iron-free basalt at oxygen levels representing reducing (log fO2 = 211.5 and 27) and oxidizing (log fO2 = 20.7) interior conditions observed in our solar system. Results show that the liquidus of iron-free basalt at a pressure of 1 atm is lowered by 105 6 10 °C over an 11 log fO2 units increase in oxygen abundance. This effect is comparable in size to the well-known enhanced melting of rocks by the addition of H2O or CO2. This implies that refractory oxygen abundance can directly control exoplanetary differentiation dynamics by affecting the conditions under which magmatism occurs, even in the absence of iron or volatiles. Exoplanets with a high refractory oxygen abundance exhibit more extensive and longer duration magmatic activity, leading to more efficient and more massive volcanic outgassing of more oxidized gas species than comparable exoplanets with a lower rock fO2. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Fe-free basalt; High-temperature experiments; Magmatism; Oxygen fugacity
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/238314
作者单位	Center for High Pressure Science and Technology Advanced Research, Beijing, 100094, China; Department of Earth Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, 1081 HV, Netherlands
推荐引用方式 GB/T 7714	Lin Y.,Van Westrenen W.,Mao H.-K.. Oxygen controls on magmatism in rocky exoplanets[J],2021,118(45).
APA	Lin Y.,Van Westrenen W.,&Mao H.-K..(2021).Oxygen controls on magmatism in rocky exoplanets.Proceedings of the National Academy of Sciences of the United States of America,118(45).
MLA	Lin Y.,et al."Oxygen controls on magmatism in rocky exoplanets".Proceedings of the National Academy of Sciences of the United States of America 118.45(2021).