Geochemical and zircon U–Pb age constraints on the origin of the Mesozoic Xigaze ophiolite, Yarlung Zangbo suture zone, SW China
Geochemical and zircon U–Pb age constraints on the origin of the Mesozoic Xigaze ophiolite, Yarlung Zangbo suture zone, SW China
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地球化学和锆石U-Pb年龄对雅鲁藏布江缝合带中生代日喀则蛇绿岩成因的制约
DOI：
10.1080/00206814.2017.1385034
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发表时间：
2018-07
影响因子：
2.6
通讯作者：
Wei Huang
中科院分区：
文献类型：
--
作者：
Xi-chen Wang;Wei-liang Liu;Yun Zhong;Xi-chong Hu;Bin Xia;Wei Huang
日喀则中生代蛇绿岩是研究雅鲁藏布江缝合带构造演化的关键。日喀则蛇绿岩的形成时代和成因至今仍存在争议。本文提供了日喀则蛇绿岩中基性岩脉（闪长岩、粗玄岩）、熔岩和辉长岩的新的年代学和地球化学资料，以制约日喀则蛇绿岩的成因。结合前人的研究，对两个辉长岩和一个粗粒岩样品的锆石U-Pb年龄表明，日喀则蛇绿岩形成于174 - 149 Ma和137 - 123 Ma两个不同的阶段。全岩地球化学数据表明，这些岩石具有N-MORB的特征，但辉长岩更缺乏微量元素，属于堆积。地球化学特征结合其正ε Nd（t）值（+3.2~+9.6）表明，这些样品来自亏损地幔源区，板片流体的影响较小。结合前人对雅鲁藏布江缝合带的研究，日喀则蛇绿岩可能形成于一个活动大陆边缘弧前盆地，其形成模式与雅鲁藏布江新特提斯洋向北俯冲至拉萨盆地之下有关。中晚侏罗世蛇绿混杂岩（174 - 149 Ma）是板片回滚的结果，随后在~150 Ma发生板片断裂。弧前岩石圈可能在~150 - 137 Ma冻结，与冈底斯弧岩浆活动在此期间结束一致。早白垩世蛇绿混杂岩（137-123Ma）的形成与新特提斯洋壳俯冲的重新启动、俯冲带的退缩以及弧前盆地的形成有关。
ABSTRACT The Mesozoic Xigaze ophiolite is a key to understanding the tectonic evolution of the Yarlung Zangbo suture zone. Although many studies have been reported, the formation age and petrogenesis of the Xigaze ophiolite remain controversial. In this paper, new geochronological and geochemical data for mafic dikes (diabase, dolerite), lavas, and gabbros of the Xigaze ophiolite are provided to constrain the origin of the Xigaze ophiolite. Combined with previous studies, three new zircon U–Pb ages of samples from two gabbro and one dolerite samples show that the Xigaze ophiolite was produced at two distinct stages of 174–149 Ma and 137–123 Ma. Whole-rock geochemical data indicate that these rocks exhibit N-MORB-like features, but the gabbros are more depleted in trace elements and belong to cumulates. Geochemical characters, combined with their positive εNd(t) values (+3.2 to +9.6), suggest that these samples originated from depleted mantle sources with minor influence of slab-derived fluids. Considering the previous studies on the Yarlung Zangbo suture zone, the Xigaze ophiolite was likely generated in an active continental margin fore-arc basin with a multistage model associated with the northward subduction of the Yarlung Zangbo Neo-Tethys Ocean beneath the Lhasa terrane. The Middle–Late Jurassic ophiolitic massifs (174–149 Ma) were produced as the result of slab rollback and were followed by subsequent slab break-off at ~ 150 Ma. The fore-arc lithosphere may be frozen at ~150–137 Ma, consistent with the termination of the Gangdese arc magmatism during this period. The Early Cretaceous ophiolitic massifs (137–123 Ma) were developed in relation to the reinitiation of the Neo-Tethyan oceanic lithosphere subduction, the retreat of the subduction zone, and the creation of a fore-arc basin with strong hyperextension in a new cycle.
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影响因子：
5.3
作者：
Wentao Huang;D. Hinsbergen;M. Maffione;D. Orme;G. Dupont‐Nivet;C. Guilmette;L. Ding;Zhaojie Guo;P. Kapp
通讯作者：
Wentao Huang;D. Hinsbergen;M. Maffione;D. Orme;G. Dupont‐Nivet;C. Guilmette;L. Ding;Zhaojie Guo;P. Kapp
DOI：
10.1007/s11430-006-0348-y
发表时间：
2006-03
期刊：
Science in China Series D
影响因子：
--
作者：
Jie Zhu;Yuansheng Du;Zaoxue Liu;Q. Feng;Wangxue Tian;Jin-Ping Li;Chang-Liang Wang
通讯作者：
Jie Zhu;Yuansheng Du;Zaoxue Liu;Q. Feng;Wangxue Tian;Jin-Ping Li;Chang-Liang Wang
影响因子：
2.7
作者：
S. Ziabrev;J. Aitchison;A. Abrajevitch;Badengzhu;Aileen M. Davis;Hui Luo
通讯作者：
S. Ziabrev;J. Aitchison;A. Abrajevitch;Badengzhu;Aileen M. Davis;Hui Luo
影响因子：
2.7
作者：
S. Ziabrev;J. Aitchison;A. Abrajevitch;Badengzhu;Aileen M. Davis;Hui Luo
通讯作者：
S. Ziabrev;J. Aitchison;A. Abrajevitch;Badengzhu;Aileen M. Davis;Hui Luo
影响因子：
3.5
作者：
S. Whattam;R. Stern
通讯作者：
S. Whattam;R. Stern