青藏高原的隆升不仅是印度板块与亚洲板块碰撞导致的地球内部岩石圈地球动力学作用过程的结果,并且对全球和亚洲气候变化、亚洲地貌和地表环境过程及大量地内和地表矿产资源的形成分布产生了深刻影响。因而研究高原隆升的历史不仅对解决上述重大科学问题提供重要途径,而且可为高原区域资源环境的开发和可持续发展提供理论依据。简要回顾和梳理了国内外近年来,围绕青藏高原隆升所取得的主要进展。研究表明新生代青藏高原经历了多阶段、多幕次、准同步异幅且高原南北后期加速隆升的演化过程。具体可划分为55~30、25~10及8~0 Ma 3个主要生长隆升期次。其中55~30 Ma的高原早期隆升,主要集中在高原中南部的拉萨地块和羌塘地块,并且可能隆升到接近3 km高度,或甚至更高,有人称之为原西藏高原,但其周缘存在准同步异幅的变形隆升响应;25~10 Ma的中期隆升,原西藏高原南北缘的喜马拉雅山和可可西里昆仑山开始强烈隆升, 原西藏高原率先隆升到目前高度并开始向东西两侧挤出物质、拉张形成南北向裂谷,高原北缘普遍产生广泛变形隆升但幅度有限;从约8 Ma开始的晚期隆升,高原南、北部边缘的喜马拉雅山和昆仑山西秦岭以北的高原东北部隆升显著加速,经历一系列短暂快速的多幕次构造变形和生长隆升,最终形成现今高原面貌。
英文摘要:
The uplift of the Tibetan Plateau is the result of the collision of the India-Asia Plates with the result of the geodynamic process of the earth's lithosphere, and has profound impacts on the global and Asian climate changes, the Asian geomorphology and surface environment, and the abundant surface and underground mineral resources. Thus, the study of the uplift history of the Tibetan Plateau can not only solve the major scientific problems mentioned above, but also provide a theoretical basis for the plateau regional environmental resource exploitation and sustainable development. In this paper, we briefly review the main progresses of recent studies concerning the uplift of the Tibetan Plateau. It is shown that the Tibetan Plateau has experienced uplift processes of multiple stages and episodes, quasisynchronous but with different amplitudes, which are accelerated in a later period. The uplift processes can be divided into three main uplift stages, those during 55~30 Ma, 25~30 Ma, and 8~0 Ma, respectively. The early uplift mainly happens in the Qiangtang and Lhasa terrains of the central-southern Tibetan Plateau during 55~30 Ma, which might be close to the modern plateau elevation and is called theProto-Tibetan Plateau; they are deformation uplifts in the peripheral area, quasisynchronous but with different amplitudes. The second stage uplift mainly occurs in the Himalaya and Hoh Xil-Kunlun Mountains in the north and south of theProto-Tibetan Plateauduring 25~10 Ma. TheProto-Tibetan Plateaumay have first reached its present elevation and started to squeeze its materials out to both E-W sides, resulting in the N-S extensional rifts, accompanied by a widespread deformation and uplift of the northern part of the plateau, but with limited magnitudes. Since ~8 Ma, the Himalayas and NE Tibetan Plateau in the southern and northern margins of the major plateau begins to experience an accelerated uplift, manifesting as a set of episodic short intense tectonic deformation events, and finally develops into its present configuration.