The Sha 1 Member of Tertiary in Qikou Sag could be divided into three sequences in the third class, which are consisted of LST, TST and HST.

• 低位和高位体系域多发育三角洲和水下扇成因的砂砾岩，这些沉积砂砾岩目前处于成岩演化的中期。