阿尔泰地区中、新生代岩浆活动的同位素年龄证据  

EVIDENCE FROM ISOTOPIC AGE FOR PRESENCE OF MESOZOIC-CENOZOIC MAGMATIC ACTIVITIES IN ALTAI REGION,XINJIANG

作　　者：张前锋[1] 胡蔼琴 张国新[1] 范嗣昆[1] 蒲志平[1] 李启新 

机构地区：[1]中国科学院地质新技术研究所,新疆地质局第一区域地质调查大队

出　　处：《地球化学》1994年第3期269-280,共12页Geochimica

摘　　要：长期以来，对阿尔泰地区有无印支、燕山期岩浆活动一直存在争议。本研究得到以下年龄结果：将军山花岗岩（４０Ａｒ／３９Ａｒ坪年龄）２２０Ｍａ、康布铁堡花岗岩（４０Ａｒ／３９Ａｒ高温视年龄）２１４Ｍａ、尚可兰花岗岩（Ｒｂ－Ｓｒ全岩等时线年龄）１７６Ｍａ、阿拉尔花岗岩（４０Ａｒ／３９Ａｒ坪年龄）１３１Ｍａ。以上数据和与本区处在同一构造单元的前苏联矿区阿尔泰及山区阿尔泰１２个浅色花岗岩结石Ｕ－Ｐｂ年龄１８０－２００Ｍａ的结果一致；从而确定在阿尔泰地区存在印支、燕山期岩浆活动。本文还通过对哈拉乔拉玄武岩的同位素年龄研究，首次确认新疆北部有新第三纪火山活动。The debate on the presence of Indosinian-Yanshanian magmatism in the Altai region has continued for a long time. This study obtained significant isotopic ages as following: 220 Ma (40Ar/39Ar plateau age) for Jiangjunshan granite, 214Ma (40Ar 39Ar apparent age at high temperature) for Kangbutiebao granite, 176Ma (Wholerock Rb-Sr isochron age) for Shankelan granite, and 131 Ma (40Ar/39Ar plateau age) for Altai granite. These age data are consistent with those (Zircon U-Pb ages, 180 -200Ma) of the leucocratic granites from the Mining Altai and Mountainous Altai of the former Soviet Union, which are located in the same tectonic unit as the studied region. These favor the presence of Indosinian-Yanshanian magmatism. In addition,Neogene volcanic activities were also identified through isotopic dating of the Halaqiaola basalt, which has an age of 18 Ma (40Ar/39Ar age).

关 键 词：阿尔泰 同位素年龄 岩浆活动 

分 类 号：P597[天文地球—地球化学]