藏北巴毛穷宗羌巴欠火山岩K-Ar和^(40)Ar-^(39)Ar年代学研究  

STUDY OF ^(40)Ar-^(39)Ar AND K-Ar DATING ON THE HIGH-K VOLCANIC ROCK FROM BAMAOQIONGZONG TO QIANGBAQIAN IN THE NORTHERN TIBET

作　　者：刘红英[1] 夏斌[1] 邓万明[2] 张玉泉[1] 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《矿物岩石》2004年第1期71-75,共5页Mineralogy and Petrology

基　　金：中国科学院知识创新工程重要方向性项目(KZCX2 SW 117;KZCX2 101)

摘　　要：　两种方法(K Ar和40Ar/39Ar)测定藏北火山岩同位素地质年龄表明其相当于渐新世到中新世:巴毛穷宗钾质碱性火山岩为32Ma～19Ma,涌波错和羌巴欠为17Ma和14Ma～12Ma等,同位素地质年龄范围在32Ma～12Ma,而且火山喷溢作用,从南到北逐渐变新。其中在巴毛穷宗火山岩区获得32Ma的年龄,证实青藏高原的隆升至少在32Ma以前已经开始。The high-K volcanic rock from Bamaoqiongzong,Qiangbaqian and Yongbocuo in the northern Tibet have been dated with ^(40)Ar-^(39)Ar technique and K-Ar dilute technique.The result showed that the age of Bamaoqiongzong is 32 Ma～19 Ma, Yongbocuo is 17 Ma and Qiangbaqian is 14 Ma～12 Ma,ranging from the Oligocene Epoch to the Miocene Epoch, but the time becomes new gradually from south to north. According to the relation between the uplift of the northern plateau and the volcanism, the authors infer that the beginning of the main uplift of the northern plateau occurred at least 32 Ma ago.

关 键 词：同位素地质年龄 K-AR ^40AR-^39AR 高钾火山岩 

分 类 号：P597.2[天文地球—地球化学]