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Ascending subducted oceanic crust entrained within mantle plumes
Author(s) -
Yasuda Atsushi,
Fujii Toshitsugu
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/98gl01230
Subject(s) - geology , diapir , oceanic crust , subduction , peridotite , adakite , transition zone , crust , mantle (geology) , mantle wedge , geophysics , basalt , underplating , petrology , geochemistry , tectonics , seismology
Upward migration of subducted oceanic crust from deep in the upper mantle is discussed based on high‐pressure experimental data. Numerical calculation reveals that a subducted oceanic crust, which is negatively buoyant in the present upper mantle, can ascend from the transition zone and be observed as a discrete magma source at the surface only when it has been broken into fragments comparable in dimension with its thickness and involved in a solid diapir of heated peridotite. For example, a solid diapir of heated peridotite with a temperature excess of 200°C can contain up to 15∼20 vol% of fragments of oceanic crust when it passes through the upper mantle, and it may cause extensive basaltic volcanism at the surface.