内蒙古阿巴嘎旗早二叠世花岗岩岩石学特征及其构造意义  

Geochemical Characteristics and Geological Significance of Early Permian Granodiorite in Abaga Banner,Inner Mongolia

作　　者：尤建功 杨多[1,2] 王福林 臧好评 南天浩 陈琦 王献 张金龙[1,2] 贾彬 龚照程[1] Yong Jiangong;Yang Duo;Zang Fulin;Zang Haoping;Nan Tianhao;Chen Qi;Wang Xian;Zhang Jinlong;Jia Bin;Gong Zhaocheng(NO.4 Gold Geological Party of CAPF;LangFang Natural Resource Comprehensive Survey Center of China Geological Survey;Liaoning Institute of Geology and Mineral Resources)

机构地区：[1]武警黄金第四支队 [2]中国地质调查局廊坊自然资源综合调查中心 [3]辽宁省地质矿产研究院有限责任公司

出　　处：《现代矿业》2020年第3期1-7,16,共8页Modern Mining

摘　　要：对内蒙古阿巴嘎旗阿尔音呼都格地区早二叠世侵入岩进行了锆石U-Pb测年和岩石地球化学研究,对该岩石形成时代、岩石成因及构造背景给予制约。该区域侵出的花岗岩主要为中细粒文象花岗岩,其锆石U-Pb年龄为291.8±3.1 Ma(MSWD=1.5),形成于早二叠世;岩石地球化学特征表明,中细粒文象花岗岩具有高硅、富碱、富集(LILEs)Rb、Th、U、K,亏损Ba、Sr以及高场强元素(HFSEs)Nb、P、Ti和中等较强负Eu异常的特征,具有A型花岗岩的特征,形成于陆壳岩石的部分熔融。结合岩石学及研究区区域构造特征,认为研究区早二叠世中细粒文象花岗岩为后造山拉张环境下的产物。Zircon U-Pb dating and petrogeochemical studies were performed on the Early Permian intrusive rocks in the Algyin Huduge area of Abaga Banner,Inner Mongolia,and restrictions were imposed on their formation age,petrogenesis,and tectonic setting.The granites that intruded in this area are mainly medium-fine grain Wenxiang granite,with a zircon U-Pb age of 291.8±3.1 Ma(MSWD=1.5),formed in the Early Permian;rock geochemical characteristics indicate Elephant granite has the characteristics of high silicon,alkali-rich,enriched(LILEs)Rb,Th,U,K,deficient Ba,Sr,and high field strength elements(HFSEs)Nb,P,Ti,and moderately strong negative Eu anomalies.A type of granite is characterized by partial melting of continental crust rocks.Combining petrology and regional structural characteristics of the study area,it is considered that the fine-grained anomalous granite from the Early Permian in the study area is the product of the post-orogenic tension environment.

关 键 词：A型花岗岩 锆石年龄 拉张伸展环境 早二叠世 

分 类 号：P58[天文地球—岩石学]