In the sequence of dimidiate tracts, mud.stone and oil shale in the lake expansion system tract are good source rocks and seals, providing favorable conditions for forming giant oil/gas fields.

• 这类砂体成藏条件优越。往往形成大型油气藏；三分体系域层序的低位域砂体成藏条件优越，地震剖面易于识别，是隐蔽油气藏勘探的主要目标。