DOI: 10.1029/2012GL054116
论文题名: Simultaneous partitioning of silicon and oxygen into the Earth's core during early Earth differentiation
作者: Tsuno K. ; Frost D.J. ; Rubie D.C.
刊名: Geophysical Research Letters
ISSN: 0094-9398
EISSN: 1944-9129
出版年: 2013
卷: 40, 期: 1 起始页码: 66
结束页码: 71
语种: 英语
Scopus关键词: Bulk silicate earth
; Core density deficits
; Core-mantle boundary
; Diamond-anvil cell experiments
; Element concentrations
; Pressure dependence
; Temperature dependence
; Thermodynamic model
; Experiments
; Liquid metals
; Metals
; Oxygen
; Silicates
; Structural geology
; Temperature measurement
; Silicon
; core-mantle boundary
; high temperature
; outer core
; oxygen
; silicon
; thermodynamics
英文摘要: Silicon and oxygen are potential light elements in the Earth's core and may be involved in metal-silicate reactions at the present day core-mantle boundary. We have performed multianvil experiments at 25 GPa and 2770-3080K to understand the simultaneous partitioning of these elements between liquid iron-rich metal and silicate melt. The presence of O in liquid Fe at high temperatures influences the partitioning of Si, causing more Si to partition into the metal than would be expected based on lower temperature measurements. Although Si and O are mutually exclusive in Fe metal at <3000 K, the level at which both element concentrations are similar in the liquid metal rises above 1 wt % at >3000 K. We have developed a thermodynamic model based on these experiments that accounts for the interaction between O and Si in the liquid metal. Comparison between this model and the previous results of diamond-anvil cell experiments up to 71 GPa indicates very little pressure dependence but a strong temperature dependence for O and Si partitioning. Our model predicts that subequal concentrations of Si and O, sufficient to explain the outer core density deficit, would have partitioned into core-forming metal if equilibration occurred between the metal and a magma ocean with a bulk silicate Earth composition at an average depth of ~1200km (~50GPa and ~3300K). An O- and Si enriched buoyant layer may have developed at the top of the outer core as a result of subsequent equilibration with the overlying mantle. © 2013. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84874894497&doi=10.1029%2f2012GL054116&partnerID=40&md5=48b242e0641a24e662f17596c36842f3
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/6662
Appears in Collections: 气候减缓与适应
There are no files associated with this item.
作者单位: Bayerisches Geoinstitut, Universität Bayreuth, D-95440, Bayreuth, Germany
Recommended Citation:
Tsuno K.,Frost D.J.,Rubie D.C.. Simultaneous partitioning of silicon and oxygen into the Earth's core during early Earth differentiation[J]. Geophysical Research Letters,2013-01-01,40(1).