西昆仑山古近纪隆升变形:时间、证据和争论

Palaeogene uplift and deformation in West Kunlun Mountains:timing,evidence and controversy

西昆仑山新生代隆升变形过程对于中亚的地貌与水系演化、资源和能源矿产分布、气候及环境变迁等都具有重要的影响,然而至今尚没有形成统一的认识。西昆仑山新生代初始隆升与变形的时间存在三种不同观点,分别为古新世、中—晚始新世、渐新世末期—中新世早期。本文通过对塔西南地区地层学、沉积学、物源分析和热年代学的研究综述,详细讨论了西昆仑山古新世、中—晚始新世隆升变形的时间、证据、解释和争议。在此基础上,确定了西昆仑山在古新世发生了隆升变形,中—晚始新世是新生代变形中的一个加速节点。这两期隆升变形分别对应于印度—亚洲大陆初始碰撞、新特提斯洋俯冲板片断离的远程响应,反映了印度板块向北的碰撞拼贴与持续挤压的过程。

The Cenozoic uplift and deformation process of the West Kunlun Mountains has an important impact on many aspects, including the geomorphology and hydrography evolutions, the distribution of ore deposit and hydrocarbon reservoir, and the climate and environment change in Central Asia. However, there still lack a common understanding on the timing of the initial uplift and deformation in the Cenozoic West Kunlun Mountains, which were proposed to be the Paleocene, the Middle-Late Eocene and the late Oligocene-early Miocene, respectively. This article summarizes the studies of stratigraphy, sedimentology, provenance analysis and thermochronology in the Southwestern Depression in Tarim Basin, and discusses the timing, evidence, explanation and controversy of the Paleocene and Middle-Late Eocene uplift and deformation of the West Kunlun Mountains. On this basis, we determined that the West Kunlun was uplifted in the Paleocene and proposed the Middle-Late Eocene was an accelerated node in the Cenozoic deformation process. These two uplifts and deformations correspond to the remote response of the initial collision of the Indian-Asian continent and the slab breakoff of the Neo-Tethyan subduction respectively, which reflects the process of India-Asia collision and continuous compression of the Indian plate to the north.