Mesozoic crustal evolution of southern Tibet: Constraints from the early Jurassic igneous rocks in the Central Lhasa terrane
Mesozoic crustal evolution of southern Tibet: Constraints from the early Jurassic igneous rocks in the Central Lhasa terrane
复制标题
藏南中生代地壳演化：拉萨地体中部早侏罗世火成岩的制约
DOI：
10.1016/j.lithos.2020.105557
复制
发表时间：
2020-08
期刊：
影响因子：
3.5
通讯作者：
He Zhenyu
中科院分区：
文献类型：
--
作者：
Dong Xin;Niu Yaoling;Zhang Zeming;Tian Zuolin;He Zhenyu
陆壳的中生代生长是地球科学的重要研究课题之一。本文系统地研究了藏南拉萨地区中生代火山岩，包括二叠堆晶岩、花岗二叠堆晶岩、镁铁质岩浆包体和寄主花岗岩类。这些岩浆岩的锆石U-Pb结晶年龄为199-189 Ma。根据组成矿物和大块岩石成分，堆晶岩最好理解为来自镁铁质安山质岩浆的角闪石、斜长石和钛铁矿结晶。寄主花岗岩类也显示出与安山质岩浆的角闪-斜长石分离结晶相一致的成分系统。MMEs与寄主花岗岩类具有许多共同特征，包括相同的结晶时代、相似的矿物学、矿物化学和锆石同位素组成，代表了与寄主岩石来自同一岩浆系统的早期堆积岩。研究的早侏罗世火成岩的岩浆母体最好解释为水合洋壳与不同大陆物质部分熔融的结果。在~215-170 Ma期间，拉萨中部复式岩体的锆石εHf（t）值随时间增加，表明其地幔贡献逐渐增加。本文介绍了拉萨地区早中生代地壳的演化。
Phanerozoic growth of continental crust on our planet is one of the important research themes in Earth Science. Here, we present the results of a systematic study of newly found and previously reported Mesozoic igneous rocks, including diorite cumulate, granodiorite cumulate, mafic magmatic enclaves (MME) and host granitoids in the central Lhasa terrane, southern Tibet. These igneous rocks give zircon Usingle bondPb crystallization ages of 199–189 Ma. Based on constituent mineral and bulk-rock compositions, the cumulates are best understood as resulting from amphibole, plagioclase and titanite crystallization from a mafic andesitic magma. The host granitoids also show compositional systematics consistent with amphibole-plagioclase fractional crystallization from andesitic magma. The MMEs share many characteristics with their host granitoids in common, including identical crystallization age, similar mineralogy, mineral chemistry and zircon isotopic compositions, representing earlier cumulate derived from the same magmatic system as their host rocks. The magma parental to the studied Early Jurassic igneous rocks is best explained as resulting from partial melting of hydrated ocean crust together with varying continental material. The increasing zircon εHf(t) values of multiple plutons in the central Lhasa terrane with time during ~215–170 Ma indicate its gradual increase in mantle contribution. We present the Early Mesozoic crustal evolution in the Lhasa terrane.
登录
查看更多内容
早侏罗世新特提斯洋板俯冲过程中的壳幔相互作用——来自西藏拉萨地南部东嘎辉长岩杂岩体的证据
影响因子：
3.5
作者：
Rui-Qiang Wang;Jian-Sheng Qiu;Si-Bin Yu;Jiao-Long Zhao
通讯作者：
Jiao-Long Zhao
影响因子：
6.1
作者：
Yuanku Meng;Zhiqin Xu;M. Santosh;Xuxuan Ma;Xijie Chen;G. Guo;Fei Liu
通讯作者：
Yuanku Meng;Zhiqin Xu;M. Santosh;Xuxuan Ma;Xijie Chen;G. Guo;Fei Liu
影响因子：
1.8
作者：
Yang Zhi
通讯作者：
Yang Zhi
影响因子：
3
作者：
Jingsui Yang;Zhiqin Xu;Zhaoli Li;Xiangzhen Xu;Tianfu Li;Yufeng Ren;Huaqi Li;Songyong Chen
通讯作者：
Jingsui Yang;Zhiqin Xu;Zhaoli Li;Xiangzhen Xu;Tianfu Li;Yufeng Ren;Huaqi Li;Songyong Chen
影响因子：
3.8
作者：
Xin Dong;Zeming Zhang;Y. Niu;Z. Tian;L. Zhang
通讯作者：
Xin Dong;Zeming Zhang;Y. Niu;Z. Tian;L. Zhang