青藏高原新生代隆升研究现状

摘要

Lots of research work has been devoted to the tectonic uplift process of the Tibetan Plateau. Previous researches tried to determine the initial collage time between India and Eurasian plates (the collision between India and Eurasian plates), the uplift stages and the spatial-temporal oudine, the time when the plateau reached the present elevation, the uplift dynamical mechanism, the relationship between the mineralization and the uplift of the plateau, the environmental variation and its response to the uplift of the Tibetan Plateau during Cenozoic in different areas by using a series of means or methods, such as geological structure analysis, tectonic thermo-chronology, sedimentology, palaeotology and paleomagnetism, and paleoaltimetry. The existing estimates of the time when India plate collided with Eurasian plate include 70Ma, 65Ma, 55Ma, 50Ma, 45 Ma, and 40~34Ma. The collision was not completed at a certain time, but lasted for 10~15Ma or so. There are several opinions concerning the collision style, i.e., the migration from west to east, the migration from east to west, and the migration in other directions. The uplift processes of the plateau were very different inrnspace and time during Cenozoic. There were many dissimilar sub-divisions of the uplift stages, such as 3, 4, and 5 uplift stages. As for the time when the plateau reached the present elevation, there are five opinions, holding that it took place at 3.6 Ma, 13~8Ma, 26~ 20Ma, 40~35Ma and 55~45Ma respectively. There is still controversy concerning the uplift dynamical mechanism of the plateau, and four mechanisms are existent, i.e., collision, subduction, lateral extrusion, and lithosphere delamination. The multi-phases uplift and tectonic-magmatic evolution of the plateau resulted in complex and varied continental ore-forming processes. The uplift of the Tibetan Plateau during Cenozoic was coupled with the changes in environment and climate.%新生代青藏高原的隆升过程倍受世界关注.国内外学者从不同角度围绕青藏高原成为统一整体(印度-欧亚碰撞)的时限、隆升阶段性和空间差异性、青藏高原作为高海拔高原形成的时间、青藏高原隆升的动力机制等重大事件进行了深入的研究.对印度板块-欧亚板块的碰撞时间存在70Ma、65Ma、55Ma、50Ma、45Ma和40～34Ma等多种观点.印度板块与欧亚板块碰撞不是在某个时间点完成的,其碰撞持续时间约10～15Ma.碰撞方式存在由西向东迁移、由东向西迁移等多种观点.青藏高原的隆升过程具有强烈的时空差异性.青藏高原新生代隆升阶段存在多种划分方案,流行的有3阶段、4阶段和5阶段强隆升过程.青藏高原作为高海拔高原形成的时间可归纳为约3.6Ma以来、13～8Ma、26～20Ma、40～35Ma和55～45Ma 5类观点.青藏高原的形成机制模型存在较大分歧,流行的模式可分为碰撞、俯冲、挤出和拆沉-板片断离4类.青藏高原多阶段隆升及构造-岩浆演化造就了高原复杂多样的大陆成矿作用.高原隆升与环境和气候演变具耦合关系.