The top transgressive system tract, whose sedimentation center is well zone G30-28 and G13-13, was formed in the later lake extension period, during which the two sedimentation centers migrated northward and eastward.

• 上部湖进体系域形成于湖盆大面积扩张时期,其沉积中心(G30-28井区以及G13-13井区)相对于下部体系域两个沉积中心,分别向北和东迁移。