کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4680750 | 1634936 | 2006 | 12 صفحه PDF | دانلود رایگان |
New Sr, Nd, and Pb isotopic data for Cenozoic basalts from northwest Kyushu, Japan and the Okinawa Trough, suggest that mantle sources feeding the Ryukyu ‘back-arc’ side volcanoes, represent a mixture of Pacific N-MORB mantle with EM2-rich components, with little or no EM1. The compositions of these basalts differ fundamentally from those characterizing northern Kyushu and the Japan Sea, which tap DUPAL-like (i.e. EM1-rich) sources similar to those prevailing beneath east and southeast Asia and western Pacific marginal basins. The apparent decrease in mantle DUPAL-like character to the east of northern Kyushu and the Sea of Japan, and its relative insignificance in mantle beneath the Ryukyu ‘back-arc’ region, suggest that Pacific MORB mantle may have been trapped within the mantle wedge during Philippine Sea plate subduction, thereby confining sub-Eurasian DUPAL-type asthenosphere to the west and restricting its flow to the east.
Journal: Earth and Planetary Science Letters - Volume 249, Issues 3–4, 30 September 2006, Pages 229–240