Mantle plumes and entrainment: isotopic evidence.
Science
; 256(5056): 517-20, 1992 Apr 24.
Article
en En
| MEDLINE
| ID: mdl-17787949
ABSTRACT
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 (87)Sr/(86)Sr and high (143)Nd/(144)Nd, (206)Pb/(204)Pb, and (3)He/(4)He ratios. This new isotopic component may be the lower mantle, entrained into plumes originating from the core-mantle boundary layer.
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Banco de datos:
MEDLINE
Idioma:
En
Revista:
Science
Año:
1992
Tipo del documento:
Article