Trace Element Partitioning Between Earths Lower Mantle Minerals and Iron Alloy Melts

Details Trace Element Partitioning Between Earths Lower Mantle Minerals and Iron Alloy Melts Trace Element Partitioning Between Earths Lower Mantle Minerals and Iron Alloy Melts

Dec 2004

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004agufmmr43a0872v&link_type=abstract

American Geophysical Union, Fall Meeting 2004, abstract #MR43A-0872

Physics

8125 Evolution Of The Earth, 5410 Composition, 3630 Experimental Mineralogy And Petrology, 3670 Minor And Trace Element Composition, 3924 High-Pressure Behavior

Scientific paper

The physical conditions (pressure-temperature-oxygen fugacity) and iron alloy compositions involved in the formation of Earths core are relatively poorly constrained. Current geochemical core formation models rely heavily on arguments related to how trace elements are distributed between metal and silicate during metal segregation. Hypotheses concerning the timing of Earths accretion and core segregation also require knowledge of metal-silicate partition coefficients for parent and daughter isotopes in key isotopic systems (e.g., W-Hf, U-Pb). Many studies (e.g., Righter, Ann Rev Earth Planet Sci 2003) have focused on metal melt - silicate melt partitioning at upper mantle and transition zone pressures (P < 25 GPa) and high temperatures. In contrast, little is known about the partitioning of trace elements between metals and lower mantle minerals and melts, even though the later stages of core formation, characterised by high-energy processes related to collisions of Mars-sized objects, likely involved liquid iron alloys percolating through a solid or molten lower mantle matrix. We will present results of a systematic study of the distribution of trace elements between lower mantle minerals (Ca and Mg perovskite, and ferropericlase) and a range of iron alloy melts, to assess the redistribution of trace elements as metallic melts percolate through the lower mantle. Experiments are performed using a 10/3.5 assembly in a conventional Walker-type multi-anvil press (P < 26 GPa), and using a 7/2 assembly in a spherically-constrained multi-anvil press with sintered diamond pressure-transmitting cubes (P > 30 GPa). Starting materials include end-member silicates (wollastonite, enstatite), MgO, and Fe-light element (S, Si) mixtures. Trace elements added include slightly siderophile (Mn, V, Cr), moderately siderophile (P, W, Co, Ni, Mo) and highly siderophile elements, as well as key parent-daughter pairs, and run products are analysed by laser ablation ICP-MS. Implications of our data for core formation models will be discussed.

Affiliated with

Also associated with

No associations

Rating

Trace Element Partitioning Between Earths Lower Mantle Minerals and Iron Alloy Melts 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 Trace Element Partitioning Between Earths Lower Mantle Minerals and Iron Alloy Melts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Trace Element Partitioning Between Earths Lower Mantle Minerals and Iron Alloy Melts will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1455916