摘要
青藏高原中段渐新世发育大规模逆冲推覆构造,在地块边界与汇聚部位形成大型逆冲推覆构造体系,典型实例如东昆仑南部逆冲推覆构造系统、羌塘地块北侧逆冲推覆构造系统、伦坡拉—安多—索县逆冲推覆构造系统、冈底斯逆冲推覆构造系统、喜马拉雅山脉主中央逆冲系。大部分逆冲断层呈现叠瓦状排列,指示自北向南逆冲推覆构造运动方向,与印度大陆北向俯冲存在动力学成因联系。高精度同位素测年资料显示,喜马拉雅山脉主中央逆冲系与羌塘地块北侧风火山逆冲推覆构造初始发育时代均早于35 Ma,东昆仑南部逆冲推覆构造运动与风火山相关岩浆侵位年龄为28.8～26.5 Ma。青藏高原腹地强烈逆冲推覆构造运动结束于早中新世五道梁群湖相沉积之前。青藏高原渐新世逆冲推覆构造运动对地壳缩短增厚与均衡隆升具有重要贡献。
Regional thrusting occurred widely in Oligocene and formed large-scale thrust systems in the TibetanPlateau,such as South Kunlun Thrust（SKT）,North Qiangtang Thrust（NQT）,Lunpola-Amdo-Suoxian Thrust（LST）,Gangdise Thrust System（GTS） and Main Central Thrust（MCT）.Imbricate arrangement of faults indicatessouthward thrusting in Oligocene,which was evidently caused by northward subduction of India continental platebeneath Eurasia continent.According to isotopic dating of high resolution,thrusting in central Himalayas andFenghuoshan area in north Qiangtang block started before 35 Ma,and thrusting in south Kunlun Mountains andgranite emplacement was caused by thrusting in Fenghuo Mountain.Both occurred in 28.8-26.5 Ma.Majorthrusting ended before the formation of Early Miocene lacustrine strata of Wudaoliang Group in central TibetanPlateau.Oligocene thrusting made great contribution to shortening and thickening of the crust and isostatic upliftof the Tibetan Plateau.
出处
《中国地质》
CAS
CSCD
北大核心
2011年第3期522-536,共15页
Geology in China
基金
深部探测专项Sinoprobe-02地质课题与科技部国际科技合作重点项目(2006DFB211330)联合资助
关键词
逆冲推覆构造
地壳增厚
古构造
渐新世
青藏高原
thrust system
crustal thickening
palaeo-tectonics
Oligocene
Tibetan Plateau
