- Sand bar sub - facies of lagoon , front delta , sheet sandstone of offshore sea are the best sedimentary facies belts for the oil & gas accumulation
- Touke stratum was laid down in the pliocene and early pleistocene epochs . it is some 1500 meters thick on average , and rich in fossils . the fossil beds of tsailiao creek in tsochen were made famous by the discovery there in 1971 of the skull of " tsochen man .
- Based on available data , the study on regional structure , sedimentary reservoir and source rock characteristics shows that the basins in south china sea had experienced sedimentary evolution in faulting period and depression period , deposited thick cenozoic formation , upwardly developed alluvial fan facies , river - lake facies coastal swamp facies coastal facies , neritic facies and bathyal deposit system , regionally had 3 source rocks of eocene , oligocene and miocene , 3 reservoirs of pre - cenozoic basement buried bill , oligocene sandstone and miocene reef , with pliocene and pleistocene neritic facies and bathyal shale as regional caprock