• 责任者：Su Dechen (Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Sun Aiping
• 刊名：Acta Petrologica Sinica
• 出版年：2013
• 卷期：29(6)
• 关键词：古地震 ; paleoearthquakes ; 区域构造 ; regional tectonics ; 祁连山 ; Qilian Mountains
• 页码：p.2223-2232
• 图表：illus., 38 refs.
• 分类号：0300
• issnNo：ISSN1000-0569
• isbnNo：CN11-1922/P

     It has been generally accepted that the geo-morphological features and the basic tectonic framework of the northeastern margin nf Qinghai-Tibetan Plateau are controlled by the Altun sinistral strike-slip fault, the East Kunlun sinistral strike-slip fault and Haiyuan sinistral strike-slip fault. Theoretically, the earthquakes should have been very popular accompanying the subduction, the collision and the orogenic processes of these faults. In 2011 and 2012, the authors have conducted the geological survey and study on the seismic event deposits along the northeastern margin of the plateau and found a number of soft-sediment deformation structures and some other syndepositional faults which could be explained as seismites in the successions from the Upper Triassic to the Quaternary, with the only exception of Jurassic. The main types of seismites include convolute bedding in the Upper Triassic at Baojishan ; the load, ball-pillow features in the Lower Cretaceous at Mitan village; the liquefied diapers in the Lower Cretaceous at Changma village; the liquefied veins, slumps and the micro intra-strata fauhs in the Quaternary at Chijinpu village and Ciyaokou village. All of these seismites are spatially located in the vicinity of the major fault. The time and space distribution of these seismites can be used to rebuild the regional long-term seismicity and to recover the activity history of major faults. Based on the findings of large amount of liquefied seismites in the Upper Triassic near Haiyuan fault, the authors propose that the initial activity time of Haiyuan fault is probably from Late Triassic.