Bidirectional Subduction of the Middle Tethys Oceanic Basin in the West Segment of Bangonghu-Nujiang Suture, quot;urn:schemas-microsoft-com:office:smarttags" />quot;on">quot;on">Tibet: Evidence from Zircon U-Pb LAICPMS Dating and Petrogeochemistry of Arc Granites

详细信息   

• 责任者：Du Dedao (State Key Laboratory of Geological Processes and Mineral Resources ; School of Earth Science and Mineral Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Qu Xiaoming
• 刊名：Acta Petrologica Sinica
• 出版年：2011
• 卷期：27(7)
• 关键词：板块俯冲 ; subduction ; 花岗岩 ; granite ; 铀—铅计时 ; U-Pb dating ; 西藏 ; Tibet
• 页码：p.1993-2002
• 图表：6 illus., 2 tables, 23 refs.
• 分类号：0801
• 出版序号：166
• issnNo：ISSN1000-0569
• isbnNo：CN11-1922/P

摘要

 quot;EnDivSummary">Through geological surveys in Tibet, the authors have discovered arc granite batholiths both in the north side of Shiquanhe-Gerze-Dongcuo ophiolite zone and in the south side of Laguocuo ophiolite zone in the western segment of Bangonghu-Nujiang suture zone. These granite bodies are lithologically dominated by mid-grain granodiorite, and petrochemically rich in large-ion incompatible elements(LILE, e.g. Rb, Th, U, K, Pb)and depleted in high field strength elements (HFSE, e.g. Nb, Ta, Ti), and show essential characteristics of arc magmatic rocks, indicating there were bidirectional subduction of the Bangonghu Middle Tethys oceanic basins.