Study On The Activity Of Neotectonic Period In Yangzhou Section Of Wuxi-Suqian Fault

The Wuxi-Suqian fault is located in the eastern Yangtze River delta plain of the eastern part of China.It is a buried fault.There are many difficulties in obtaining the accurate spatial location of the fault,the burial depth of the upper break point and the latest activity era.This paper takes the "Wuxi-Suqian fault Yangzhou section" as the research object,and systematically analyzes and summarizes the previous research results,combined with the actual geological structure of the study area.Two magnetotelluric lines MT1 and MT2 were arranged at the north and south ends of the ShaBo Lake in Yangzhou.Due to the limitations of the MT method itself.Therefore,we have arranged four shallow seismic exploration lines for L1,L2,L3 and L4 across ShaoBo Lake.On the basis of the magnetotelluric and shallow seismic exploration for the Wuxi-suqian fault,in order to further obtain the research of the near surface fault,the depth of the upper break point and the latest active age,etc.1 drill holes and geological sections were constructed,and 4 drilling holes were arranged.Finally,the magnetotelluric,shallow seismic exploration,drilling exploration and other methods are combined with the results of the known boreholes in the surrounding area.The accurate spatial position of the Yangzhou section of the Wuxi-suqian fault zone and the active characteristics of the Neogene since the Neogene are given,and the future seismic risk of the area is evaluated with regional seismo geological features.The main results are as follows.(1)The exact location of the Wuxi-suqian fault in Yangzhou began in Gaoyou lake and passed through Lake Shaw.It passed through Shaobo Town West,Tai'an town west to Phoenix river.(2)There is a significant difference between the Middle Pleistocene and the previous stratigraphic interfaces on both sides of Shao Bohu.According to the bottom boundary drop of the quaternary system and the upper Miocene,the vertical movement rate of the fracture is 0.010-0.015mm/a,which belongs to the weak active fault.(3)Although the activity of the Wuxi-suqian fault is relatively weak,it still needs to pay more attention to the geological background of moderate strong earthquakes at the intersection of the North East fault.