Coupled 186 Os and 187 Os Evidence for Core-Mantle Interaction
- 5 June 1998
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 280 (5369) , 1570-1573
- https://doi.org/10.1126/science.280.5369.1570
Abstract
Osmium isotopic analyses of picritic lavas from Hawaii show enrichments in the osmium-186/osmium-188 ratio (186Os/188Os) of 0.008 to 0.018%, relative to a chondritic upper mantle, that are positively correlated with enrichments in 187Os/188Os of 5.4 to 9.0%. The most viable mechanism to produce these coupled 186Os and187Os enrichments is by addition of 0.5 to 1 weight percent of outer core metal to a portion of the D" layer and subsequent upwelling of the mixture. These data suggest that some plumes originate at the core-mantle boundary and that Os isotopes may be used to distinguish plumes derived from shallow versus deep mantle sources.Keywords
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