Geochemistry, Geochronology, Sr-Nd Isotopic Compositions of Jiang Tso Ophiolite in the Middle Segment of the Bangong- Nujiang Suture Zone and Their Geological Significance
Geochemistry, Geochronology, Sr-Nd Isotopic Compositions of Jiang Tso Ophiolite in the Middle Segment of the Bangong- Nujiang Suture Zone and Their Geological Significance
复制标题
班公怒江缝合带中段江左蛇绿岩地球化学、年代学、Sr-Nd同位素组成及其地质意义
DOI：
10.1111/1755-6724.12437
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Xia Bin
中科院分区：
文献类型：
--
作者：
Huang Qiangtai;Li Jianfeng;Cai Zhourong;Xia Lianze;Yuan Yajuan;Liu Huichuan;Xia Bin
江左蛇绿岩位于班公湖-怒江缝合带中段，是切里湖蛇绿岩亚带最东端的一部分，靠近旁湖蛇绿岩南部。江左蛇绿岩岩石组合较完整，主要由变质橄榄岩、辉长岩和闪长岩组成。与N-MORB相比，蛇绿岩富Mg，低Ti、K、Na、P，贫Nb、Ta、Hf、Th，富Rb、Sr、Ba。江左蛇绿岩的地球化学特征表明它是弧后盆地扩张脊中形成的超俯冲带类型。锆石SHRIMP U-Pb年龄为188.1± 4.1Ma（MSWD=1.4），表明姜厝蛇绿岩形成于早侏罗世晚期。Sr、Nd同位素组成表明特提斯地幔域为亏损地幔（DM），具有富集地幔域II（EM II）。它们具有与印度洋MORB型相同的Sr、Nd同位素组成。
The Jiang Tso ophiolite, situated in the middle segment of the Bangong‐ Nujiang Suture Zone, is a part of the easternmost Qieli Lake ophiolite subzone and is close to the south of Pung Lake ophiolite. The rock association of Jiang Tso ophiolite is relatively complete and is mainly composed of metamorphic peridotite, gabbro and diabase. Comparing with N‐MORB, the ophiolite is high in Mg and low in Ti, K, Na, P, and is depleted in Nb, Ta, Hf, Th and enriched in Rb, Sr and Ba. Geochemical characteristics of the Jiang Tso ophiolite indicate it is of a supra‐subduction zone type formed in the spreading ridge of back arc basin. The SHRIMP U‐Pb dating of zircons from the gabbro yielded a weighted average age of 188.1±4.1 Ma (MSWD=1.4), indicating the Jiang Tso ophiolite was formed in the late stage of early Jurassic. The Sr, Nd isotopic compositions show that the Tethyan mantle domain is the depleted mantle (DM), with enriched mantle domain II (EM II). They have the same Sr, Nd isotopic composition with the India Ocean MORB type.