DIVISION OF SEQUENCE STRATIGRAPHY OF PINGHU FORMATION IN XIHU SAG IN EAST CHINA SEA

We have totally recognized five 3rd sequence boundaries,that is, T₃⁶,T₃⁵(Sb1),T₃⁴(Sb2),T₃²(Sb3)and T₃⁰(Sb4) and three systems tract boundaries f₁, T₃³(f₂) and f₃. The Pinghu Formation has six sections, divided into three 3rd sequences. The Pinghu sixth section has not been seen to the bottom, and the depositional cycle are unclear. The Pinghu fifth section is SⅢ1, Pinghu fourth and third sections compose SⅢ2, and the Pinghu second and first sections are divided into SⅢ3. The envelope curve(equal to 3rd sequence) of the short-cycle sea level(4th sequence)is basically consistent with the 3rd cycle curve of the global sea level changes, reflecting that the global sea level change has obvious influence on the sequence growth in this zone.