In this area sandstone diagenesis of Carbonic-Permian system is very strong and there are less protosomatic intergmular pores.Most intergranular pore space is shaped after corrosion.

• 本区石炭-二叠系砂岩成岩作用强烈，原生粒间孔保存较少，大部分的粒间孔隙是由于后期溶蚀作用形成的。