Deep structure of the Kumkol basin in the northern Tibetan Plateau and its resource environmental implications  

作　　者：Wenhui LI Zhanwu LU Rui GAO Xiaofan DENG Jingyuan LI Guangwen WANG Zhanxuan SUN 

机构地区：[1]Sinoprobe Laboratory of Ministry of Natural Resources,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China [2]School of Earth Sciences and Engineering,Sun Yat-sen University,Guangzhou 510275,China [3]South Branch of Sinopec Petroleum Engineering Geophysics Co.,Ltd,Chengdu 610041,China

出　　处：《Science China Earth Sciences》2024年第11期3421-3435,共15页中国科学（地球科学英文版）

基　　金：supported by the Second Tibetan Plateau Scientific Expedition and Research Project (Grant No. 2019QZKK0701-02);the National Natural Science Foundation of China (Grant Nos. 42174124, 42274135)。

摘　　要：The Kumkol basin is located in the northern Tibetan Plateau and is a closed plateau basin with an average altitude of>4000 m and an area of nearly 20000 km^(2). Its boundaries are limited by the Altyn Tagh fault, East Kunlun orogen and Qimantag orogen. Studying the deep structure of the Kumkol basin reveals 2 significant implications:(1) the basin has developed a large thickness of >7000 m Cenozoic continental sediments, recording the uplift history of the northern Tibetan Plateau, and(2)preliminary work indicates that the basin is likely to have oil and gas prospects. However, owing to the adverse natural conditions of the area and the strong tectonic activity in the Cenozoic, the latter of which was not conducive to hydrocarbon preservation,only regional geological mapping and petroleum exploration route surveys have been carried out, and there is no consensus on strata, structure and tectonic evolution. From 2021 to 2022, a deep seismic reflection profile implemented by the Second Tibetan Plateau Scientific Expedition and Research(STEP) project was the first high-resolution geophysical survey across the Kumkol basin. This study uses seismic reflection migration profiles, first-arrival wave tomographic imaging and previous research results to analyze the deep structure of the basin. The final merged model contains many features of tectonic and resource significance:(1) The Kumkol basin is ~90 km wide from north to south, with a basement depth of >9000 m. The main component is the Cenozoic continental deposits, which are divided into two major parts: the southern composite basin and the northern faulted basin. Owing to the later compression, the southern composite basin experienced significant deformation, but most parts still preserved their original sedimentary formations.(2) The structural deformation characteristics of the basin reveal a two-stage tectonic evolution process of the northern Tibetan Plateau in the Cenozoic: from the Oligocene to the Pliocene, the main mechanism was vertical differential uplift

关 键 词：Kumkol basin Seismic reflection TOMOGRAPHY Northern Tibetan Plateau Oil and gas prospect 

分 类 号：P618.13[天文地球—矿床学]