Simultaneous partitioning of silicon and oxygen into the Earth’s core during early Earth differentiation
| dc.citation.firstpage | 66 | |
| dc.citation.journalTitle | Geophysical Research Letters | en_US |
| dc.citation.lastpage | 71 | |
| dc.citation.volumeNumber | 40 | en_US |
| dc.contributor.author | Tsuno, Kyusei | |
| dc.contributor.author | Frost, Daniel J. | |
| dc.contributor.author | Rubie, David C. | |
| dc.contributor.publisher | American Geophysical Union | en_US |
| dc.date.accessioned | 2013-04-01T17:28:33Z | |
| dc.date.available | 2013-10-02T05:10:04Z | |
| dc.date.issued | 2013-01-16 | en_US |
| dc.description.abstract | 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 Sienriched buoyant layer may have developed at the top of the outer core as a result of subsequent equilibration with the overlying mantle. | en_US |
| dc.embargo.terms | 6 months | en_US |
| dc.identifier.citation | Tsuno, Kyusei, Frost, Daniel J. and Rubie, David C.. "Simultaneous partitioning of silicon and oxygen into the Earth’s core during early Earth differentiation." <i>Geophysical Research Letters,</i> 40, (2013) 66-71. http://dx.doi.org/10.1029/2012GL054116. | * |
| dc.identifier.doi | http://dx.doi.org/10.1029/2012GL054116 | en_US |
| dc.identifier.uri | https://hdl.handle.net/1911/70888 | |
| dc.language.iso | eng | en_US |
| dc.title | Simultaneous partitioning of silicon and oxygen into the Earth’s core during early Earth differentiation | en_US |
| dc.type | Journal article | en_US |
| dc.type.dcmi | Text | en_US |