The Carboniferous and Permian System in North China Platform and its adjacent area can be divided into 4 facies zones

12 facies and 8 subfacies.Within the area

lagoon facies

carbinate paraplat form facics and deltaic facies well developed in the Carboniferous

while alluvial facies

deltaic distributary plain facies and lacustrine faciee well developed in the Permian. Paleo-geographically speaking

the platform was surrounded by an old land

anticlises(underwater uplifts) and chain islands respectively in north

west and south.The distribution of the facies were controlled predominently by Yinchan oldland

and the peleoclimate changed from warm and moisture to hot and dry.