青藏高原北部盆地构造沉积演化与高原向北生长过程

TECTONIC AND SEDIMENTARY EVOLUTION OF BASINS IN THE NORTH OF QINGHAI-TIBET PLATEAU AND NORTHWARD GROWING PROCESS OF QINGHAI-TIBET PLATEAU

从可可西里到河西走廊的青藏高原的北部地区 ,地貌具有独特的“盆—岭”相间的特征 ,是青藏高原隆升增长过程中长期地质作用的产物 ,沉积盆地记录了这一过程的演化历史。对可可西里盆地、柴达木盆地和酒泉盆地新生代的沉积充填与盆地动力学背景的研究发现 ,3个盆地的演化序列具有相似性 ,盆地的早期为走滑盆地或伸展盆地性质 ,中期发育前陆盆地 ,最后以山间盆地结束。以南北向挤压短缩为动力背景的前陆盆地是高原北部造山带运动的直接响应。高原北部前陆盆地的发育时序为 :可可西里前陆盆地 (5 3～ 2 3Ma)、柴达木前陆盆地 (46～ 2 .4 5Ma)和酒泉前陆盆地 (2 9.5～ 0 .13Ma) ,反映了青藏高原北部在新生代具有向北阶段性生长的特征。

In the north of Qinghai-Tibet plateau from Hoh Xil basin to Hexi Corridor basin, geomorphy hasbasin-ridgestructure, which is the result of long-term geological process of uplift and increase in Qinghai-Tibet plateau. Some of geological evolution process in Qinghai-Tibet plateau and wererecorded in corresponding basins. By the research of sedimentary filling pattern and dynamic background at Cenozoic in Hoh Xil basin, Qaidam basin and Jiuquan basin, we can find that evolution sequences of these three basins are similar: strike-slip basin or extensional basin at the early stage, foreland basin at the middle stage, intermontane basin at the end. Foreland basins are the direct responding result of orogenetic action in the north of Qinghai-Tibet plateau, which were forming at dynamic background of north-southward extruding and shortening. Foreland basins in north of Qinghai-Tibet Plateau have the following evolution time sequencing: 53～23 Ma in Hoh Xil foreland basin, 46～2.45 Ma in Qaidam foreland basin, 29.5～0.13 Ma in Jiuquan foreland basin. This evolution time sequencing and process proves that north part of Qinghai-Tibet plateau grew northward by stages atCenozoic.