Gao Yuan, Mi Wentian, Yang Wenguang, Ji Guozhong, Luo Yuhang, Miao Ke
College of Resource and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China.
Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China.
ACS Omega. 2025 May 23;10(22):22562-22575. doi: 10.1021/acsomega.4c10175. eCollection 2025 Jun 10.
A series of terrestrial sedimentary basins along the Bangong-Nujiang Suture Zone (BNSZ) record a wealth of information regarding the uplift and geomorphological evolution of the central Tibetan Plateau. The uplift, exhumation, and sedimentation processes in these basins and the surrounding orogenic belts are of significant scientific importance for understanding the tectonic evolution of the central Tibetan Plateau. Taking the Gaize Basin as the research focus, low-temperature thermochronology and thermal history modeling were conducted on sandstone samples to analyze their exhumation history and driving mechanisms during the Late Cretaceous to Paleogene. Based on stratigraphy and the youngest detrital zircon ages, the samples were collected from the Upper Jurassic to Lower Cretaceous Shamuluo Formation; thermal history modeling using apatite and zircon (U-Th)/He (AHe/ZHe) results reveals two significant exhumation events: 87-70 and 56-26 Ma. The rapid cooling-exhumation event during the Late Cretaceous is associated with crustal shortening and thickening caused by the collision of the Lhasa-Qiangtang terrane; the Paleogene exhumation event is linked to tectonic uplift driven by the India-Asia collision and the continued northward subduction of the Indian continent. Continuous thrusting and uplift on both sides of the basin strengthened river cutting and erosion and gradually converted the external drainage system to an internal drainage system, and the high-relief terrain was progressively leveled and filled. The height of the surface uplift brought on by sediment accumulation was approximately 0.4 km. After Oligocene, high-altitude, low-relief terrain had already been established.
班公湖-怒江缝合带（BNSZ）沿线的一系列陆相沉积盆地记录了关于青藏高原中部隆升和地貌演化的丰富信息。这些盆地及其周边造山带的隆升、剥露和沉积过程对于理解青藏高原中部的构造演化具有重要的科学意义。以改则盆地为研究重点，对砂岩样品进行了低温热年代学和热历史模拟，以分析其在晚白垩世至古近纪期间的剥露历史和驱动机制。根据地层学和最年轻的碎屑锆石年龄，样品采集自上侏罗统至下白垩统沙木洛组；利用磷灰石和锆石（U-Th）/He（AHe/ZHe）结果进行的热历史模拟揭示了两次显著的剥露事件：87-70Ma和56-26Ma。晚白垩世的快速冷却-剥露事件与拉萨-羌塘地体碰撞导致的地壳缩短和增厚有关；古近纪剥露事件与印度-亚洲碰撞和印度大陆持续向北俯冲驱动的构造隆升有关。盆地两侧的持续逆冲和隆升加强了河流下切和侵蚀，并逐渐将外流排水系统转变为内流排水系统，高起伏地形逐渐被夷平和充填。沉积物堆积导致的地表隆升高度约为0.4千米。渐新世之后，高海拔、低起伏的地形已经形成。
