The fragment of Paleo-Tethys ophiolite from central Qiangtang, Tibet:Geochemical evidence of meta-basites in Guoganjianian

作     者：ZHAI QingGuo1,2, LI Cai2 & HUANG XiaoPeng2 1 Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China 2 College of Earth Sciences, Jilin University, Changchun 130061, China 

作者机构：Institute of Geology Chinese Academy of Geological Sciences Beijing China College of Earth Sciences Jilin University Changchun China 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2007年第50卷第9期

页      面：1302-1309页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 

基　　金：Supported by China Geological Survey (Grant Nos. 200313000054 20031300015 and 1212010561605) 

主　　题：Qiangtang, metabasite, Paleo-Tethys, ophiolite 

摘      要：N-MORB-type metabasites are discovered in the Guoganjianian area, central Qiangtang, Tibet, which are mainly metagabbro with cumulate structure and metabasalt. The rocks are distributed nearly from west to east unconformably underlying the Wanghuling Group of upper Triassic. On the basis of geo- chemical analysis, we find that the content of SiO2 is 43.03%―53.42%, and TiO2 1%―2.67%, Al2O3 16.75%―21.52%, CaO 7.03%―11.13%, K2O 0.05%―0.38%; the REE pattern is slight depletion or flat, and the trace spider diagram is like that of N-MORB, so we consider that the metabasite was formed under the setting of mid-ocean ridge or adult back-arc basin, and it is the fragment of Paleo-Tethys ophiolite.