sequence boundary SB 2 was discovered between the upper formation and the lower formation of S 3 member. The duration of the developing period of SB 2 is the remained accommodation when the channel sand bodies filled along the palaeo_geomorphologic low.

• 该不整合面的形成期正是河道砂储集体沿层序SQ2 TST沉积初期残留可容纳空间的充填期 ,因此循着层序界面SB2 寻找沉积古地貌低洼区是预测砂岩储集体的关键。