哀牢山造山带南段中二叠世晚期娘宗岩体厘定  

Disintegration of Niangzhong Rock Mass in the Later Period of the Middle Permian Epoch in the South Part of Ailaoshan Orogen

作　　者：赵德军[1] 陈洪德[2] 王道永[1] 王国芝[1] 李娜[1] 

机构地区：[1]成都理工大学地球科学学院,成都610059 [2]成都理工大学沉积研究院,成都610059

出　　处：《地质科技情报》2013年第3期19-25,共7页Geological Science and Technology Information

基　　金：中国地质调查局项目"云南省绿春县骂泥街等四幅1:5万区域地质调查"(121200011120582);矿物学岩石学矿床学国家重点(培育)学科建设项目(SZD0407)

摘　　要：位于哀牢山造山带西侧、歪古村组(原高山寨组)分布范围之内的岩浆岩(娘宗岩体)一直被认为是火山岩,属歪古村组的组成部分,其形成时间为晚三叠世。通过综合分析娘宗岩体与围岩之间接触界线的宏观地质特征、岩体岩相学、岩石学、矿物学、LA-MC-ICP MS锆石测年结果,认为岩体东侧地层不属歪古村组,而属古生界马邓岩群,二者之间为侵入接触关系;岩体西侧与歪古村组为沉积不整合接触关系,岩体不属歪古村组的组成部分;岩体形成时间约为(263.1±2.3)Ma,属中二叠世晚期。The study area is located in the west side of Ailaoshan orogen.The Niangzhong rock mass is distributed in the Yaiguchun Group range.The previous studies held that the Niangzhong rock mass is lava and a part of the Yaiguchun Group.Its formation time is Late Triassic epoch.By the observation of the the concect relation between the Niangzhong rock mass and adjoining rock,analysis of its petrography,petrology,mineralogy and the LA-MC-ICP MS zircon U-Pb age,the results of study show that the stratum layer located on the west side of Niangzhong rock mass does not belong to the Yaiguchun group,but to the Paleozoic Madeng rock group.The connecting relation between the two groups is intrusive contacting.The connecting relation between the Niangzhong rock mass and the Yaiguchun group is sedimentary contacting.The Niangzhong rock mass is not part of the Yaiguchun Group.Formation time of the rock mass is（263.1±2.3）Ma.The No.Ⅱ rhyolite porphyry vein in Niangzhong rock mass invasive time is（260.0 ±1.7）Ma.Formation time of the rock mass is not the Late Triassic epoch,but the later period in the middle Permian epoch.

关 键 词：哀牢山造山带 娘宗岩体 形成时代 接触关系 

分 类 号：P588.12[天文地球—岩石学]