Dehydration and melting process in deep subduction zone-Zircon geochemistry from the Sanbagawa eclogite-

在白垩纪俯冲至上地幔的三巴川榴辉岩中发现了部分熔融结构。从榴辉岩中分离出锆石。锆石在岩心-地幔上呈扇形分带。SHRIMP U-Pb年龄测定和锆石稀土元素分析表明，上地幔深部年轻（热）板块发生了部分熔融。熔融反应是由白云石分解引起的。锆石和石榴石在熔体的作用下生长在一起。

Partial melting texture was discovered from the Sanbagawa eclogoite which had been subducted down to upper mantle at Cretaceous time. Zircons were separated from the eclogite. The zircons exhibit sector zoning on the core to mantle under the CL images. SHRIMP U-Pb age dating and REE analysis from the zircons indicate that the partial melting had occurred in the case of young (hot) slab at upper mantle depth. The melting reaction was due to phengite decomposition. The zircon and the garnet were grown together in the presence of melt.