The structural deformation characteristics of different layers

zones and stages at the Dajiaoshiba area were analyzed based on seismic and regional geological data.Thereafter

we summarized the differential deformation patterns of the north and south sections

and discussed the mechanism for the formation of the S-N oriented Wujiang and Daershan structural fault deformation zones.The results show that four sets of structural deformation layers occur vertically in the Dajiaoshiba area

while horizontally it can be divided into thrust-fold belt

thrust-decollement fold belt and decollement-fold belt from east to west

which have undergone SE-NW-trending

nearly WE-trending and NE-SW-trending compressive stress since the Yanshan Movement.The studied area represents the front belt of the thrust nappe structure

and the major decollement formation shifts from the Precambrian to the Cambrian

which has gone through the piggy-back progressive deformation from east to west.Due to the segmentation of the Qiyueshan fault and the structural difference of the Precambrian basement decollement fault

the composition of east to west deformation zones changes along the trend of the nearly SN-trending Daershan and Wujiang structures

with a deformation pattern of thrusting-compresso-shearing-fault-detaching-decollement in the northern section

thrusting-compresso-shearing-fault-propagation-decollement in the middle section and thrusting-fault-bending-fault-propagation-decollement in the southern section

respectively.