气候变化领域集成服务门户(CCPortal): Buoyancy and Structure of Volatile-Rich Silicate Melts

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DOI	10.1029/2020JB021045
	Buoyancy and Structure of Volatile-Rich Silicate Melts
	Solomatova N.V.; Caracas R.
发表日期	2021
ISSN	21699313
卷号	126 期号:2
英文摘要	The early Earth was marked by at least one global magma ocean. Melt buoyancy played a major role for its evolution. Here we model the composition of the magma ocean using a six-component pyrolite melt, to which we add volatiles in the form of carbon as molecular CO or CO2 and hydrogen as molecular H2O or through substitution for magnesium. We compute the density relations from first-principles molecular dynamics simulations. We find that the addition of volatiles renders all the melts more buoyant compared to the reference volatile-free pyrolite. The effect is pressure dependent, largest at the surface, decreasing to about 20 GPa, and remaining roughly constant to 135 GPa. The increased buoyancy would have enhanced convection and turbulence, and thus promoted the chemical exchanges of the magma ocean with the early atmosphere. We determine the partial molar volume of both H2O and CO2 throughout the magma ocean conditions. We find a pronounced dependence with temperature at low pressures, whereas at megabar pressures the partial molar volumes are independent of temperature. At all pressures, the polymerization of the silicate melt is strongly affected by the amount of oxygen added to the system while being only weakly affected by the specific type of volatile added. © 2020. The Authors.
英文关键词	buoyancy; early Earth; magma ocean; pyrolite; silicate melt; volatiles
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187359
作者单位	CNRS, Ecole Normale Supérieure de Lyon, Laboratoire de Géologie de Lyon LGLTPE UMR5276, Centre Blaise Pascal, Lyon, France; The Center for Earth Evolution and Dynamics (CEED), University of Oslo, Oslo, Norway
推荐引用方式 GB/T 7714	Solomatova N.V.,Caracas R.. Buoyancy and Structure of Volatile-Rich Silicate Melts[J],2021,126(2).
APA	Solomatova N.V.,&Caracas R..(2021).Buoyancy and Structure of Volatile-Rich Silicate Melts.Journal of Geophysical Research: Solid Earth,126(2).
MLA	Solomatova N.V.,et al."Buoyancy and Structure of Volatile-Rich Silicate Melts".Journal of Geophysical Research: Solid Earth 126.2(2021).