摘要
印度-亚洲大陆碰撞形成了青藏高原,影响了中亚、东南亚、东亚直到西太平洋的构造变形,改变了从岩石圈地幔到大气圈的多个圈层状态,是研究青藏高原形成和演化的前提和基础,但是,至今对最初在何时、何地发生碰撞仍意见不一。文中以近10a来该项研究的成果为基础,通过一些问题的讨论,展现研究进展,突出存在矛盾,探讨下一步的研究重点。讨论的问题有:1)初始碰撞时亚洲南缘的古纬度是多少?2)大印度有多大?3)定日地区最高海相层的年龄有多大?4)55MaBP前后的碰撞是陆-陆碰撞还是陆-弧碰撞?5)外喜马拉雅的岩浆活动能否厘定初始碰撞?6)最后归纳了2004年以来初始碰撞时限研究的一些结果。从近10a的研究结果看,印度-亚洲初始碰撞时限集中在K/E、E_1/E_2和E_2/E_3界线附近。与以前的结果相比,是在向更早和更晚扩展。文中认为,不同观点的争论对发现研究中存在的问题、促进研究发展有推动作用;提出未来的印度-亚洲碰撞研究,除了要面对和解决各种资料、论据的不确定性外,还要更精确地限定印度和亚洲在晚白垩世和古近纪期间的古地理位置,确定新特提斯洋内岛弧或微陆块在此期间的位置、大小,以及弧-陆碰撞与陆-陆碰撞在标志和效应等方面的差别,总之,要深入探索碰撞过程的复杂性。
It is widely accepted that the India-Eurasia continental collision has created the Tibetan plateau,affecting tectonic deformation from Central Asia,Southeast Asia,East Asia to the West Pacific. This event has changed the states of many spheres of the Earth including from lithosphere to the atmosphere,thus is fundamental for research of motion and evolution of the Tibetan plateau. It remains,however, controversial when and where the initial collision between these two plates occurred. Based on the studies of the recent nearly 10 years,this paper attempts to review the advancements,existing important problems in this field,as well as the focused research subjects in the future. The specific issues discussed are：（ 1） What is the ancient latitudes of the southern margin of Asia when the initial collision began？（ 2） How big was Greater India？（ 3） What was the age of the uppermost marine strata in the Dingri area？（ 4） The collision before 55 Ma was continent-continent collision or continent-arc collision？ And（ 5） Can magma activity in the Trans-Himalaya determine the initial collision？ Finally,this paper summarizes some studies on the timing of the initial collision,which were reported since 2004. These results suggest that the times are concentrated around K / E,E1/ E2,and E2/ E3,much earlier or later than that the precious work proposed. The author considers that the dispute among different points of views can help find existing problems and advance the study on this subject. It is also pointed out that in addition to uncertainties of various data and evidence,more efforts should be made to define precisely the ancient geographic positions of India and Asia,locations and sizes of island-arcs or micro continents in the Neo-Tethys ocean during late Cretaceous and Eogene times as well as differences in marks and effects between arc-continent and continentcontinent collisions. In sum,the complexity during this collision process should be one of the focused issues to be deeply explored in the future.
出处
《地震地质》
EI
CSCD
北大核心
2016年第3期783-796,共14页
Seismology and Geology
基金
国家自然科学基金(41490611)资助
关键词
印度-亚洲大陆碰撞
古地磁学
大印度
最高海相层位
外喜马拉雅
India-Asia continental collision
paleomagnetism
Greater India
uppermost marine strata
Trans-Himalaya
