Osmium-187 enrichment in some plumes: Evidence for core-mantle interaction?
Calculations with data for asteroidal cores indicate that Earth's outer core may have a rhenium/osmium ratio at least 20 percent greater than that of the chondritic upper mantle, potentially leading to an outer core with an osmium-187/osmium-188 ratio at least 8 percent greater than that of chondrites. Because of the much greater abundance of osmium in the outer core relative to the mantle, even a small addition of metal to a plume ascending from the D??? layer would transfer the enriched isotopic signature to the mixture. Sources of certain plume-derived systems seem to have osmium-187/osmium-188 ratios 5 to 20 percent greater than that for chondrites, consistent with the ascent of a plume from the core-mantle boundary.
Citation Information
Publication Year | 1995 |
---|---|
Title | Osmium-187 enrichment in some plumes: Evidence for core-mantle interaction? |
Authors | R.J. Walker, J. W. Morgan, M.F. Horan |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Science |
Index ID | 70019081 |
Record Source | USGS Publications Warehouse |