柴达木盆地西南缘更新世地震事件层年龄测定及意义

柴达木盆地西南缘新近纪以来受昆仑山断裂活动影响,地震活动强烈,发育一系列与地震活动有关的软沉积物变形构造,主要包括: 负荷构造、火焰构造、球—枕状构造、地震角砾、震裂缝、层内震褶曲和同沉积微断层等。通过区域地质调查、实测剖面、点上解剖和样品测试分析,初步认为柴达木盆地西南缘区分别于1.8—1.2,Ma、0.8,Ma、0.15,Ma发生过3次强烈构造活动,这些事件均伴随强烈的古地震活动,作为这些隆升事件的沉积和构造响应,盆地更新统中形成了一系列典型软沉积物变形以及相关的震积构造,对于研究青藏高原板内不均匀隆升过程及其隆升构造—地震—沉积效应具有重要意义。

Chronology test and its significance of ancient earthquakes in the Pleistocene in southwestern margin of Qaidam Basin

The southwestern margin of the Qaidam Basin was intensely affected by a series of faulting movement of the Neocene in the north of Kunlun Mountain,and developed serious soft sediment deformation structure such as load structures,flame structures,ball-and-pillow structures,seismic breccias,ground fissure,vibrational liquefaction deformation structure and synsedimentary micro-fault faults. The regional geological survey,the measured sections and sample tests all analysis that there were three strong uplift of mountains in 1.8-1.2 Ma,0.8Ma and 0.15Ma,these uplift events were accompanied by a strong ancient seismic activity. As the sedimentary and structural response in the uplift event,it formed a series of typical continental facies interplate seismites and the construction signs of seismites. It has a important significance to research the interplate uneven uplift of the Qinghai￣Tibet Plateau and relationship among tectonic uplift,earthquake,deposition effects.