冈底斯中段林子宗火山岩^(40)Ar-^(39)Ar年龄及其意义  

^(40)Ar-^(39)Ar Dating of Linzizong Volcanic Rocks in the Central Gangdise Area and Its Geological Implication

作　　者：李再会[1] 郑来林[1] 李军敏[1] 夏祥标[1] 

机构地区：[1]成都地质矿产研究所,成都610082

出　　处：《矿物岩石地球化学通报》2009年第3期223-227,共5页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：中国地质调查局"西藏普迟亚地区矿产远景调查"项目资助

摘　　要：广泛分布在冈底斯岩浆岩带上的林子宗火山岩及与下伏地层间的区域不整合提供了印度-亚洲大陆碰撞的重要证据。本文对冈底斯中段谢通门地区林子宗火山岩年波组下段玄武安山岩中斜长石进行了40Ar-39Ar测年分析。结果表明,年波组火山岩形成于51.67±0.29 Ma,与林周地区年波组火山岩年龄基本一致,均为始新世。结合该区林子宗火山岩岩石学及岩石地球化学特征,指出谢通门地区林子宗火山岩形成于印度-亚洲大陆碰撞过程中。The widely developed Linzizong volcanic rocks in the Gangdise magmatic belt and the regional unconformity between the volcanic rocks and the underlain strata are important evidences for the collision of Indian-Asian continents. In this work, a basalt-andesite sample was collected from the low layer of the Nianbo Formations in Xietongmen area for plagioelase Ar-Ar dating analysis. The result indicates that the Nianbo Formation eruped at 51.67 ±0.29 Ma. In combination with the petrological and geochemical characteristics of Linzizong volcanics in area, it is believed that the Nianbo Formation was formed during the collision of India-Asian continents.

关 键 词：林子宗火山岩 40AR-39AR年龄 印度-亚洲大陆碰撞 冈底斯中段 

分 类 号：P588.1[天文地球—岩石学]