地质学报2017，Vol.91Issue(7)：1401-1415,15.
东昆仑断裂东端塔藏断裂压剪活动与高原隆升作用讨论
Discussion on the Compression-Shear Activity of the Tazang Fault in East Kunlun and Uplift of Plateau
摘要
Abstract
Tazang fault in the eastern section of East Kunlun fault traverses the interior and boundary of the eastern margin of the Qinghai-Tibet plateau.As the northeastern boundary of the southeastward movement of Bayankala terrane,its active features and sliding rate in Late Quaternary are extremely important to understanding the tectonic deformation of the Qinghai-Tibet plateau.Combined with interpretation of the high-resolution remote sensing images obtained through SPOT and ASTER DEM,this study carried out detail research on offset strata and landform and geochronology using seismic data and morphological features (such as streams,mountain ridges,displaced fluvial fans,terrace,fault valley,reversed camp,and so on),so as to understand the distribution,activity and strike-slip rate of the Tazang faults in late Quaternary.The Tazang fault can be divided into from west to east:Luocha section in the Qinghai-Tibet plateau,Dongbeicun section and Majiamo section in the margin of the Qinghai-Tibet plateau,with each section trending to 113°,142° and 130° respectively,and gradually turning toward south.Its activity in late Quaternary is characterized by multiple stages and episodes.The Luocha section was dominated by sinistral shear strike-slip in company with compression during Holocene,with a sinistral strike-slip rate of 2.43～2.89 mm/a.Since 0.66±0.04ka BP when the latest offsetting event occurred,the fault surface is characteristic of nearly vertical strike slipping and well-developed tensional filled fractures.The Tazang fault is one of the major faults in the eastern extension of the East Kunlun fault system.The Majiamo section may be the active fault in Holocene,and 9.0±0.8ka stratum was faulted,with the fault surface dipping north up to 58°.Therefore,comparative analysis of activities of each segment in the Tazang fault shows that the western section was predominantly horizontal shear movement,the eastern section had a decreasing strike-slip motion component,and north-dipping of fault surface and uprising of northern hanging wall both resulted in gradually increasing of the vertical component.Strikeslip of East Kunlun fault zone and Tazang fault tended to decrease eastward in late Quaternary,and was converted into horizontal thrusting and plateau uplift,which is consistent with the features of the "imbricated thrust conversion-limited extrusion" model.关键词
塔藏断裂/东昆仑断裂带/滑动速率/压剪活动/有限挤出模型Key words
East Kunlun fault/Tazang fault/Late Quaternary stike-slip rate/compression-shear activities/limited extrusion model引用本文复制引用
胡朝忠,任金卫,杨攀新,熊仁伟,陈长云,付俊东..东昆仑断裂东端塔藏断裂压剪活动与高原隆升作用讨论[J].地质学报,2017,91(7):1401-1415,15.基金项目
本文为国家自然科学基金项目(编号41302171、41272233)、国家重点基础研究发展计划(编号2008CB42570)和地震预测研究所基本科研业务经费(编号2017IES0302、2017IES010204)联合资助成果. （编号41302171、41272233）
