The fault depression structure developed well, and had deeper depression, wide slope, many faults, lots of unconformity and many kinds of sandstone body in Ban-qiao sag.

• 板桥凹陷内断陷结构发育完善,具有凹深、坡广、断裂多、不整合面多的地质结构,并且发育了多种类型的砂体。