%0 Journal Article
%T Geochemistry and Sr-Nd-Pb istopic features of the Ganlongtang-Nongba ophiolite from the Changning-Menglian suture zone
昌宁-孟连缝合带干龙塘-弄巴蛇绿岩地球化学及Sr-Nd-Pb同位素组成研究
%A LAI ShaoCong
%A QIN JiangFeng
%A LI XueJun
%A ZANG WenJuan
%A
赖绍聪
%A 秦江锋
%A 李学军
%A 臧文娟
%J 岩石学报
%D 2010
%I
%X This paper presents the major- and trace elements and Sr-Nd-Pb isotopes of the meta-basalts from the Ganlongtang-Nongba ophiolitic mélange which is situated at the middle part of the Changning-Menglian Paleo-Tethys suture zone. The Nongba basalts are mainly composed of alkaline and tholeiitic basalts. The tholeiitic basalts have high TiO2 and Th/Yb, low K2O and Zr/Nb and depleted light rare earth elements (LREEs), and show(La/Yb)N ratio (1.87~2.38) and Sr-Nd-Pb isotopes similar to those of enriched mid-ocean ridge basalt (E-MORB), suggesting that they may originate from an enriched mantle source or a mixture of depleted asthenosphere mantle and mantle plume. The Nongba alkaline basalts have high TiO2 (2.38%) and K2O (2.37%) and (La/Yb)N (~11), similar to that of the oceanic island basalts (OIB), indicating that they were derived from a hot spot through the oceanic crust. The Ganlongtang tholeiitic basalts show typical characteristics of N-MORB in terms of TiO2, Mg#, K2O and LILEs, but have variable Sr-Nd-Pb isotopic compositions probably resulted from crustal contamination. It is proposed that the Changning-Menglian ancient ocean basin experienced a complete growth process from an embryonic to a mature ocean basin.
%K Geochemistry
%K Ophiolite
%K Sr-Nd-Pb isotopes
%K Changning-Menglian suture zone
地球化学
%K 蛇绿岩
%K Sr-Nd-Pb同位素
%K 昌宁-孟连缝合带
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=2013B5467E3054B1614CEC199353FCED&aid=11B9F416BEB894F41DC5D6875F9E4E6A&yid=140ECF96957D60B2&vid=96C778EE049EE47D&iid=708DD6B15D2464E8&sid=AFCD3F338AF00150&eid=69B79AFFE576C0B3&journal_id=1000-0569&journal_name=岩石学报&referenced_num=0&reference_num=39