祁连山及邻区古-新近纪地层分区与构造-沉积演化

发布时间：2018-10-13 11:11

【摘要】：位于青藏高原东北缘的祁连山由一系列平行的山系及其山间盆地相间组成,其新生代山体隆升与盆地演化是关系到青藏高原隆升扩展乃至中国一二级阶梯地势形成的关键问题.本文以祁连山腹地及外围新生代沉积盆地为研究对象,综合考虑区域位置、盆地形成与演化等要素,基于不同盆地区域地层对比,进行动态地层区划,进而恢复祁连山地区构造-沉积演化过程.结果表明,古近纪早期(古-始新世)祁连山地区为一隆起带,南北两侧的柴达木盆地与酒泉盆地以及腹地兰州-西宁盆地独立演化;渐新世青藏高原隆升并向东北方向扩张逆冲,西秦岭北缘贵德-西宁-兰州-临夏压陷盆地形成,祁连山东部地区压陷盆地全面接受沉积,祁连山西部地区的南祁连古隆起与北祁连古隆起之间苏里盆地开始形成并接受沉积.中新世祁连山地区陆内挤压造山与盆地裂解,拉脊山、青海南山、积石山、六盘山等山体相继隆起,将古近纪统一大型压陷盆地分割为贵德、共和、青海湖、西宁、兰州、临夏及天水等盆地,分别归属新近纪贵德-西宁-兰州地层区中各地层分区,疏勒南山隆起将苏里盆地裂解为多个小盆地,同归新近纪苏里地层区.与此同时,南、北祁连开始向外逆冲扩展,柴达木盆地与酒泉盆地范围较古近纪缩小,且在盆地边缘形成次一级沉降中心,分属新近纪柴达木地层区和肃北-酒泉地层区.
[Abstract]:The Qilian Mountains, located in the northeastern margin of the Qinghai-Tibet Plateau, consist of a series of parallel mountain systems and their intermountain basins. The Cenozoic uplift and basin evolution are the key problems related to the uplift and extension of the Qinghai-Tibet Plateau and the formation of the first and second steps of China's stepped topography. Taking the Cenozoic sedimentary basins in the hinterland and periphery of Qilian Mountains as the research object, the dynamic stratigraphic regionalization is carried out based on the regional stratigraphic correlation of different basins, considering the regional location, formation and evolution of the basins, and so on. Then the tectonic-sedimentary evolution process in Qilian Mountain area was restored. The results show that the early Paleogene (Paleo-Eocene) Qilian Mountains area is a uplift belt with the Qaidam basin and Jiuquan basin on both sides of the north and south and the Lanzhou Xining basin in the hinterland independently evolving. The Oligocene Qinghai-Xizang Plateau uplifted and thrust northeast, the Guide-Xining Lanzhou Linxia depression basin was formed in the northern margin of the West Qinling Mountains, and the depression basin in the eastern part of the Qilian Mountains accepted the deposits. The Su Li basin between the South Qilian paleouplift and the North Qilian paleouplift in the western Qilian Mountains began to form and accept the deposits. In the Miocene Qilian Mountains, the intracontinental compressional orogeny and basin splitting, the Laki Mountains, the Southern Qinghai Mountains, the Jishi Mountains and the Liupan Mountains have been uplifted one after another, dividing the Paleogene unified large depression basins into Guide, Gonghe, Qinghai Lake, Xining and Lanzhou. Linxia and Tianshui basins belong to the stratigraphic zones of the Neogene Jigui De-Xining Lanzhou stratigraphic area respectively. The uplift of Sunan Mountain splits Su Li basin into several small basins and belongs to the Neogene Gisuri stratigraphic area. At the same time, the south and north Qilian began to extend outward thrust, the range of Qaidam basin and Jiuquan basin was smaller than that of Paleogene, and the secondary subsidence center was formed in the margin of the basin, belonging to the Neogene Qaidam stratigraphic area and Subei Jiuquan stratigraphic area.
【作者单位】：西北大学地质学系大陆动力学国家重点实验室;国土资源部岩浆作用成矿与找矿重点实验室中国地质调查局西安地质调查中心;
【基金】：中国地质调查局工作项目(编号:DD20160345-16) 国家自然科学基金项目(批准号:40382039,41372020,41372036,41472035)资助
【分类号】：P534.6;P542

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