内蒙古达茂旗北部早古生代花岗岩类SHRIMP U-Pb年代学  

SHRIMP Dating of Early Paleozoic Granites from North Damaoqi,Inner Mongolia

作　　者：张维[1,2] 简平[2] 

机构地区：[1]中国地质大学(北京),北京100083 [2]中国地质科学院地质研究所,北京离子探针中心,北京100037

出　　处：《地质学报》2008年第6期778-787,共10页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号40672048)资助的成果

摘　　要：本文对内蒙古达茂旗北部的岛弧侵入岩进行了精确的SHRIMP锆石U-Pb定年研究和地球化学研究。该侵入岩具有正常岛弧和埃达克岩的双重地球化学性质。SHRIMP锆石U-Pb定年表明,这套侵入岩中的闪长岩形成于452±3Ma和440±2Ma,石英闪长岩形成于446±2Ma,花岗闪长岩形成于440±2Ma,它们记录了晚奥陶纪末的洋壳消减事件。在一个细粒闪长岩中,分辩出了1967±13Ma(n=3)的继承性锆石,指示这一岛弧可能具有一个前寒武纪的大陆基底。We provide new geochronological and geochemical constraints on the formation and evolution of an early to mid-Paleozoic arc pluton, from north of Damaoqi, Inner Mongolia. This pluton has a transitional normal arc/adakite geochemical affinity. SHRIMP zircon U-Pb ages suggest that diorites was emplaced at 452±3 Ma and 440±2 Ma, quartz diorite at 446±2 Ma, and granodiorite at 440±2 Ma, which represents an Ordovician oceanic subduction event. Precambrian zircon inheritance （ca. 1967 Ma） occurs in a finegrained diorite which indicates that the arc was built on a Precambrian continental crust.

关 键 词：SHRIMP锆石U-PB年代学 岛弧深成岩 奥陶纪 内蒙古达茂旗 

分 类 号：P597.3[天文地球—地球化学]