The depositional covers in the eastern Sichuan region could be classified into four layer gliding systems according to the differences in rock features

rock mechanic parameters

rock physical parameters and seismic reflective characterisitics.The Lower Cambriam

Upper Ordovician Lower Silurian

Upper Permian and Middle Lower Triassic Systems in the studied area are the major gliding systems.These systems are composed of mudstone

shales

gypsum and coal-beds

and characterized by low appearent resistivity competent

lower physical parameters

strong seismic reflective

lower appearant resistivity.The mechanical metamorphic and the rheologic deformation of the outcrops and computer restored balanced cross-profiles proved the existanc of the gliding systems.Combining it with petroleum geology

it is found that almost all glided layers are hydrocarbon source rocks and regional caprocks of gas and oil reserviors.