Other
Scientific paper
Dec 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003agufm.t42a0273t&link_type=abstract
American Geophysical Union, Fall Meeting 2003, abstract #T42A-0273
Other
3630 Experimental Mineralogy And Petrology, 3924 High-Pressure Behavior, 5114 Permeability And Porosity, 8125 Evolution Of The Earth, 8147 Planetary Interiors (5430, 5724)
Scientific paper
The separation of liquid metal from a crystalline silicate mantle during planetary core formation could have only operated to completion if the liquid metal fraction formed an interconnected network. Interconnectivity depends on the dihedral angle between liquid metal and crystalline silicates at low melt fractions. Gaetani and Grove (1999) showed that liquid Fe-alloy can wet an olivine matrix at high O and S fugacities at ambient pressure. Therefore, it is important to understand the effects of the compositions of Fe alloy and the silicate phase on the dihedral angle behaviour systematically under high pressure conditions. The result is also applicable to core formation mechanisms on other terrestrial planets. For example, the Martian mantle is believed to be more Fe-rich and the Martian core more sulphur-rich compared to the Earth, which may have resulted in important differences in silicate-liquid metal dihedral angles during core formation. We have investigated the effects of the metallic and silicate phase compositions on the dihedral angle up to 20 GPa and 2200 K by varying the sulphur content of an Fe-S alloy (S = 22 ˜ 50 at.%) and the FeO content of a coexisting olivine assemblage (FeO = 0 ˜ 67 mol.%). Using a multianvil apparatus, experiments at high pressure and temperature were performed for 12 hours, which corresponds to the time scale for textural equilibration. Graphite was used as the capsule material. In the olivine stability field, texturally equilibrated dihedral angles decrease with increasing sulphur content and decrease dramatically with increasing FeO content of olivine. Increasing the FeO content of olivine results in an increase in both the oxygen fugacity and oxygen solubility in the sulphide melt. Dihedral angles also decrease slightly with increasing temperature. The minimum value determined for the dihedral angle between iron-sulphide and olivine was 65° , which is still slightly higher than the critical angle for wetting of 60° . These results show that melting of the silicate is required to obtain complete metal-silicate separation and therefore support a magma ocean scenario during core formation.
Frost Dan J.
Langenhorst Falko
Rubie David C.
Terasaki Hidenori
No associations
LandOfFree
Compositional effect on the dihedral angle between olivine and Fe-S liquid up to 20 GPa: Possibility of percolative core formation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Compositional effect on the dihedral angle between olivine and Fe-S liquid up to 20 GPa: Possibility of percolative core formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compositional effect on the dihedral angle between olivine and Fe-S liquid up to 20 GPa: Possibility of percolative core formation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1426382