In the middle Triassic residuum in mid Sichuan basin, there exist not only hydrocarbon traps such as old grottoes and buried hills but also many minor faults.

• 在川中地区中三叠统风化壳中,不仅分布着古岩溶、古潜丘等类型的油气圈闭,而且还有一定数量的小断层。