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Melting features along the Ryukyu slab tear, beneath the southwestern Okinawa Trough
Author(s) -
Lin JingYi,
Hsu ShuKun,
Sibuet JeanClaude
Publication year - 2004
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 - 10.1029/2004gl020862
Subject(s) - geology , crust , andesite , subduction , slab , trough (economics) , volcanism , volcano , basalt , mantle (geology) , rhyolite , geochemistry , seismology , oceanic crust , volcanic rock , petrology , tectonics , geophysics , macroeconomics , economics
The present‐day active volcanic front associated with the Ryukyu subduction zone extends from Japan to the Ilan plain (northern Taiwan) and is located within the Okinawa Trough, 80–100 km above the Ryukyu slab. An abnormal amount of arc volcanism, which consists of basalt, andesite and rhyolite occurs within the southwestern Okinawa Trough, above a slab tear of the Ryukyu subduction zone (CBVT). The power spectrum analysis of magnetic data shows the occurrence of a thin crust above the slab tear and a thick crust beneath this volcanic area. We suggest that an excess of H 2 O‐rich fluid might occur at the slab tear and might increase the melt flux. Both are conveyed obliquely to the uppermost mantle and lower crust CBVT magmas. After interactions, basaltic magmas would rise up, accounting for the contrast of magnetization between this volcanic body and the adjacent OT crust.