The seismic analysis of the Early Cretaceous fault-subsidence stage in South Songliao Basin suggests that the depositional system including alluvial fan-delta

subaqueous fan

delta and fan-delta developed well

and they are favourable for oil and gas accumulation. The Denglouku Formation in the study area could be divided into shallow buried-weak compacted diagenetic factes

supergene dissolution diagenetic factes

deep-buried dissolution diagenetic factes and deep-buried compaction-dissolution diagenetic factes. The first two kinds are favourble factes for hydrocarbon accumulation.