Coupled 186Os and 187Os evidence for core-mantle interaction
Brandon AD, Walker RJ, Morgan JW, Norman MD, Prichard HM. 1998. Coupled 186Os and 187Os evidence for core-mantle interaction. Science. 280(5369):1570-1573
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 and 187Os 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.
- Type
- Journal Article
- Authors
- Brandon, Alan; Walker, Richard; Morgan, John; Norman, Marc; Prichard, Hazel
- Units
- HAVO
- Keywords
- Chemical Analysis, Geochemistry, Hawaii (Big Island), Isotopes, Koolau Volcano, Loihi, Mantle, Mauna Loa Volcano, Oahu, Osmium (Os), Source