Geochronological and geochemical constraints on the origin of the Yunzhug ophiolite in the Shiquanhe–Yunzhug–Namu Tso ophiolite belt, Lhasa Terrane, Tibetan Plateau
Geochronological and geochemical constraints on the origin of the Yunzhug ophiolite in the Shiquanhe–Yunzhug–Namu Tso ophiolite belt, Lhasa Terrane, Tibetan Plateau
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青藏高原拉萨地体狮泉河-云珠-纳木措蛇绿岩带云珠蛇绿岩成因的年代学和地球化学约束
DOI：
10.1016/j.lithos.2017.11.025
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发表时间：
2018-02
期刊：
影响因子：
3.5
通讯作者：
Huang F.
中科院分区：
文献类型：
--
作者：
Zeng Y.C.;Xu J.F.;Chen J.L.;Wang B.D.;Kang Z.Q.;Huang F.
青藏高原拉萨地体中狮泉河-云珠-纳木错蛇绿混杂岩带(SNMZ)的形成是认识该地体中生代构造演化的关键。根据层状岩墙杂岩中辉长岩样品的锆石U-Pb定年结果，表明SNMZ中段的云珠蛇绿岩形成于~150 Ma。在地球化学上，这些镁铁质岩石以E-MORB型成分为主，并有少量P-MORB型成分的岩石。样品还具有较高的εNd(T)值，没有Nb、Ta负异常。所有样本的数据在Th/Yb-Nb/Yb图上绘制在MORb阵列内。因此，这些镁铁质岩石很可能形成于缓慢扩张的大洋环境或萌芽海洋，而不是像以前假设的那样形成于弧后盆地。结合区域地质特征，我们认为云珠蛇绿岩是一条独特的蛇绿岩带的一部分，代表了拉萨地体内形成于萌芽洋中的物质，为拉萨地体侏罗纪构造演化提供了新的认识。
The formation of the Shiquanhe–Yunzhug–Namu Tso ophiolite mélange zone (SNMZ) within the Lhasa Terrane, Tibetan Plateau, is key to understanding the Mesozoic tectonic evolution of this terrane, which remains controversial. We show that the Yunzhug ophiolite in the central segment of the SNMZ formed at ~ 150 Ma, based on U–Pb dating of zircons from a gabbroic sample in a well-developed sheeted dike complex. Geochemically, these mafic rocks are dominated by E-MORB-type compositions, along with minor amounts of rocks with P-MORB-type compositions. The samples also exhibit high εNd(t) values and lack negative Nb and Ta anomalies. Data for all the samples plot within the MORB array on a Th/Yb–Nb/Yb diagram. Therefore, these mafic rocks most likely formed in either a slow spreading oceanic setting or an embryonic ocean, and not in a back-arc basin as has been previously assumed. Taking into account the regional geology, we propose that the Yunzhug ophiolite is part of a distinct ophiolitic belt and represents material formed in an embryonic ocean within the Lhasa Terrane, which provides new insights into the Jurassic tectonic evolution of the Lhasa Terrane.
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影响因子：
3
作者：
Weiliang Wang;J. Aitchison;C. Lo;Q. Zeng
通讯作者：
Weiliang Wang;J. Aitchison;C. Lo;Q. Zeng
DOI：
10.1130/2014.2507(03
发表时间：
2014-08
期刊：
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影响因子：
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作者：
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通讯作者：
John E. Volkmer;P. Kapp;B. Horton;G. Gehrels;J. Minervini;L. Ding
影响因子：
4.9
作者：
Kai‐Jun Zhang;B. Xia;Guangzhe Wang;Yong-tie Li;H. Ye
通讯作者：
Kai‐Jun Zhang;B. Xia;Guangzhe Wang;Yong-tie Li;H. Ye
影响因子：
2.6
作者：
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通讯作者：
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DOI：
--
发表时间：
2005
期刊：
Regional Geology of China
影响因子：
--
作者：
Wang Yong-sheng;Qu Yong-gui;Wang Zhongheng;Zheng Chun-zi;Xie Yuan-he;Sun Zhonggang;Zhang Ningke
通讯作者：
Wang Yong-sheng;Qu Yong-gui;Wang Zhongheng;Zheng Chun-zi;Xie Yuan-he;Sun Zhonggang;Zhang Ningke