Mantle plumes and entrainment: isotopic evidence
Hart SR, Hauri EH, Oschmann LA, Whitehead JA. 1992. Mantle plumes and entrainment: isotopic evidence. Science. 256(5056):517-520
Many oceanic island basalts show sublinear subparallel arrays in Sr-Nd-Pb isotopic space. The depleted upper mantle is rarely a mixing end-member of these arrays, as would be expected if mantle plumes originated at a 670-kilometer boundary layer and entrained upper mantle during ascent. Instead, the arrays are fan-shaped and appear to converge on a volume in isotopic space characterized by low 87Sr/86Sr and high 143Nd/144Nd, 206Pb/204Pb, and 3He/4He ratios. This new isotopic component may be the lower mantle, entrained into plumes originating from the core-mantle boundary layer.
- Type
- Journal Article
- Authors
- Hart, S; Hauri, E; Oschmann, L; Whitehead, J
- Units
- HAVO
- Keywords
- Chemical Analysis, Geochemistry, Helium (He), Isotopes, Lead (Pb), Mantle, Neodymium (Nd), Ocean Island Volcanism, Source, Strontium (Sr)