The lacustrine carbonate rocks in the wudaoliang group consist of boundstone ( stromatolite ) , micritic limestone , grainstone and micritic dolostone which were laid down in the shallow - water to bathyal , high - salinity and enclosed to semi - enclosed lake systems 五道梁群湖相碳酸盐岩分为生物粘结灰岩（叠层石） 、泥晶灰岩、颗粒灰岩与泥晶白云岩四大类，反映出沉积环境为一个具有浅水半深水、高盐度、半封闭封闭特点的综合湖泊系统。
3.
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 摘要以现有资料为基础，通过对区域构造、沉积储层、烃源岩特征等基础石油地质条件研究，认为南海海域各盆地经历了断陷期和坳陷期沉积演化，沉积了巨厚的新生代地层，自下而上发育了冲积扇相、河湖相、滨岸沼泽相、滨海相、浅海相、半深海相沉积体系，区域上存在始新统、渐新统和中新统3套烃源岩，前新生代基岩潜山、渐新统砂岩、中新统生物礁3套储层，区域盖层为上新统和更新统浅海半深海相泥岩。
