西藏东喜马拉雅错那地区亚马荣淡色花岗岩的年代学、地球化学与岩石成因

发布时间：2018-05-21 06:16

本文选题：东喜马拉雅 + 淡色花岗岩　；参考：《岩石学报》2017年08期

【摘要】：本文通过对东喜马拉雅错那地区亚马荣岩体的地球化学、锆石U-Pb年代学和Hf同位素研究,试图探索亚马荣岩体的形成机制,解释地壳深熔作用过程。锆石U-Pb定年获得两期年龄,分别为14.4Ma和17Ma,结合前人已有结果,本文认为错那地区的深熔作用至少持续5Myr时间。亚马荣岩体具有较高Si O2(71.85%~72.91%)、Al2O3(15.30%~15.67%)含量,较低的Fe2O3T(0.58%~0.90%)、Ca O(0.72%~1.05%)含量,铝饱和指数(A/CNK)为1.08~1.22;锆石Ti温度计、εHf(t)的变化以及大离子亲石元素Rb/Sr比值和Ba含量之间的协变关系都说明,错那淡色花岗岩形成过程中存在多种熔融方式,经历了脱水熔融和水致熔融的转变,发生熔融反应的转变可能与藏南东-西向伸展构造的启动有关。
[Abstract]:By studying the geochemistry, zircon U-Pb chronology and HF isotopes of the Yamarong body in the eastern Himalayas, this paper attempts to explore the formation mechanism of the Yamarong rock body and to explain the process of crustal deep melting. Zircon U-Pb dating was obtained at two stages, 14.4Ma and 17Ma. combined with the previous results, it is considered that the deep penetration in Dhongna area lasted at least for 5Myr time. The Yamarong massif has a higher Sio _ 2O _ 2 ~ 71.85 ~ 72.91and a higher Al _ 2O _ 3N _ (15.30) and 15.67 contents, and the lower Fe _ 2O _ 3T _ (0.58) and 0.90 Ca _ 2O _ (0.72N) contents, the aluminum saturation index (A _ (r) / C _ (CNK) = 1.081.22), the variation of zircon Ti thermometer, 蔚 Hftt), and the covariation relationship between the Rb/Sr ratio and Ba content of the large ion lithophile elements. There are many melting modes in the formation of tinted granites, which have undergone dehydration and water melting. The transformation of melting reaction may be related to the initiation of east-west extensional tectonics in southern Tibet.
【作者单位】：地质过程与矿产资源国家重点实验室中国地质大学地球科学与资源学院;
【基金】：国家重点研发计划(2016YFC0600304) 国家"973"项目(2015CB452604) 国家自然科学基金项目(41273044、41225006) 中国地质调查局工作项目(1212011121260、1212011121066) 长江学者和创新团队发展计划(IRT1083) 中央基本科研业务费专项资金项目(53200859514、53200859758)联合资助
【分类号】：P588.121

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