Activity characteristics and engineering effects of the Gangpengqing fault zone on the western margin of the Peiku Co graben in southern Tibet
The Gangpengqing fault zone,a controlling active fault zone on the east side of Mala Mountain,is located in the north of the Himalayas and the southwest of the Peiku Co-Cuoqin rift.In this paper,regional geological background analysis,space and aerial remote sensing technology,ground survey,physical exploration and trench exploration are used to find out the accurate location,spatial distribution characteristics,fault combination and deep structure of the Gangpengqing fault zone.Based on the field measurement of fault geomorphology and paleoseismic chronology analysis of terrace and trench,the activity intensity,activity period and activity rate of the fault zone since Late Quaternary are determined in this paper.The central and northern section of the Gangpengqing fault zone shows three secondary faults,F1,F2 and F3,respectively,from west to east.F1 and F2 are non-Holocene active faults with earlier active time,while F3 is a Holocene active fault with later active time.The vertical slip rate of F3 fault is moderate,the Late Pleistocene verti-cal slip rate is about 0.28 mm/a,the Holocene vertical activity rate is about 0.10-0.60 mm/a,the fault activity period is about 6 000-8 000 a,and the latest activity time is about 7 000 a.BP.The Gangpengqing fault zone is characterized by long-term,segmented and multi-phase activity.The geomorphic characteristics,spatial distribution and deep structure of different fault sections are obviously dif-ferent,and the engineering effects resulted from such differences are quite different.This type of active fault is widely developed in the rift region of southern Tibet,and the research results can provide important foundation support for the scheme selection,engineering setup and structural design of linear traffic engineering across this type of active fault in southern Tibet.
fault characteristicfault activityancient earthquakelinear engineeringGangpengqing fault zonesouthern Tibet
万方数据
维普
