印度-亚洲大陆碰撞的时限  

On the timing of India-Asia continental collision.

作　　者：莫宣学[1] 赵志丹[1] 周肃[1] 董国臣[1] 廖忠礼[2] 

机构地区：[1]中国地质大学(北京)地质过程及矿产资源国家重点实验室,地球科学与资源学院,北京100083 [2]国土资源部成都地质矿产研究所,四川成都610082

出　　处：《地质通报》2007年第10期1240-1244,共5页Geological Bulletin of China

基　　金：国家重点基础研究计划项目(编号:G1998040800;2002CB41260);国家自然科学基金项目(编号:40172025;40103003;40473020;40572048;40672044;49772107和49802005);国土资源部青藏高原重点研究计划项目(编号:2003009);中国地质调查局工作项目<青藏高原岩浆岩与大陆碰撞过程综合研究>(编号:1212010610104)

摘　　要：印度-亚洲大陆碰撞的起始时间是国际地学界争论的热点,至今尚无一致的认识,从主张晚白垩世(约70Ma)到主张始新世/渐新世之交(约34Ma)等各种观点都有。根据主碰撞带中具同碰撞性质的林子宗火山岩(40.84～64.47Ma)、南冈底斯花岗岩(47～52.5Ma,峰值50Ma左右)、白云母型强过铝花岗岩(56～50Ma),以及沉积学和地层学的综合证据,特别是横贯整个冈底斯带延伸达1500km的巨大区域性角度不整合的时间(约65Ma),认为印度-亚洲大陆开始碰撞的时间在西藏为65Ma左右,完成碰撞的时间在40/45Ma左右。Indo-Asian continental collision is one of the most important geological events in recent earth＇s history. However, it is still highly debated for the timing of initiation of Indo-Asian collision, The discrepancy lles between the idea of late Cretaceous （-70 Ma） and that of E2/E3 boundary （-34Ma）, The authors believe that Indo-Asian continental collision started at c,65 Ma and completed by 45/40 Ma according to multi-evldences, especially a huge regional angular unconformity between the Paleogene Linzizong volcanic strata （40.84～64,47 Ma）and the underlain Permian- upper Cretaceous strata,extending for more than 1500 km long over the entire　Gangdese belt. There arc dramatic changes in sedimentary thcics, and the style and intensity, of detbnnation across the unccmformity. The coexal syncollisional granitoids in southern Gangdese inchldiug the Quxu granite batholith （47 52.5 Ma, with a peak at 50 Ma） and muscovite bearing granites （56-50 Ma）, as well as the stratigraphy, paleontology and sedimentology in southern Tibet, also support this idea.

关 键 词：印度-亚洲大陆碰撞 青藏高原 巨大的不整合 林子宗火山岩 同碰撞花岗岩 

分 类 号：P542.4[天文地球—构造地质学]