藏南亚东混合岩的成因及地质意义  

Petrogenesis and geological implications of the Yadong migmatites, South Tibet

作　　者：苟正彬[1] 刘函[1] 李俊[1] 张士贞 赵晓东 王生伟[1] GOU Zhengbin;LIU Han;LI Jun;ZHANG Shizhen;ZHAO Xiaodong;WANG Shengwei(Chengdu Center,China Geological Survey,Chengdu 610081,China)

机构地区：[1]中国地质调查局成都地质调查中心,四川成都610081

出　　处：《沉积与特提斯地质》2022年第2期279-287,共9页Sedimentary Geology and Tethyan Geology

基　　金：国家自然科学基金项目(41802071);中国地质调查局项目(DD20221635)。

摘　　要：高喜马拉雅结晶岩系中广泛发育规模不等、形态各异的混合岩,是研究地壳部分熔融作用的天然实验室。尽管观察表明,藏南许多混合岩与淡色花岗岩具有一定的时空联系,但混合岩与淡色花岗岩是否具有成因联系还存在较大的争议。本文对藏南亚东地区的混合岩中进行了野外地质、岩相学、岩石地球化学和年代学等研究。研究结果表明,亚东混合岩主要是部分熔融作用的产物,具有(近)原地熔融的特征,熔融方式以白云母和黑云母脱水熔融为主,并叠加了分离结晶作用。亚东混合岩与淡色花岗岩在成因上具有紧密联系。相关认识为建立造山带构造演化模型提供新的信息。Migmatites are widely distributed in the Higher Himalayan Crystalline Sequence at different scales and shapes,forming a natural laboratory for studying the partial melting of the crust.However,the petrogenetic links between migmatites and leucogranites remains controversial,although their tempo-spatial link had been confirmed by many studies.In this study,we conducted field structural investigations,petrography,geochemistry and chronology of the Yadong migmatites.The results show that migmatites were likely derived from partial melting of the Higher Himalayan Crystalline Sequence in situ,and were most derived from the muscovite-and biotite-dehydration melting,accompanying crystallization.This study also confirms that there is a petrogenetic links between migmatites and leucogranites.The study provides new information on the structural evolution model of the orogen.

关 键 词：混合岩 淡色花岗岩 部分熔融 成因联系 高喜马拉雅结晶岩系 

分 类 号：P588[天文地球—岩石学]