RESEARCH ON THE MAJOR ACTIVE FAULTS IN ZHENJIANG, JIANGSU AND THEIR LATE QUATERNARY ACTIVITIES

Combined with a series of measures from geophysical exploration, drilling and trench, through surveying the geomorphology and interpreting the remote sensing image at Zhenjiang, Jiangsu province, we discussed the age of Quaternary strata at both sides of Zhenjiang fault, then confirmed the activity mechanism and activity time of the fault. Research showed that the faults formed in different periods divided by directions include NE-NEE, NW, nearly EW, nearly NS and strike thrust (eversed) faults associated with fold, etc. Strike thrust (eversed) faults and early nearly EW trending faults formed in the late Indosinian to early Yanshanian fold orogenesis, NE-NNE trending and NW trending faults are the largest faults, formed mainly in Yanshan regional fault blockperiod. Nearly SN and late nearly EW trending tectonics controlled the spacial distribution of the Cenozoic sedimentary depression, which formed in late Yanshanianto Himalayan period. The faults that have inheritance activities include Mufushan-jiaoshan fault, Maoshan fault (belt) and fault along the river since the Quaternary, they are the main fault tectonics to Shape the modern landscape. Combining the regularity of seismic occurrence at Zhenjiang region with the charactristics of stress field, we consider the last activity time of the fault tectonics in Zhenjiang region is Pleistocene, activity is weak at Holocene, and then tends to be stable.