Abstract: Two sets of fault systems are found in Minfeng sub-sag. One is Chennan fault in the north, and the other is Minfeng fault belt in the middle. This paper studies these two faults by covering their original depositional thickness from formation de-compaction correction, followed by calculating the fault throw and the growth index of these two faults in different periods. The study shows the faults activities: for Chennan fault, it was active strongly from the early Es3 to the middle Es3, and active lightly from the late Es3 to the Es2; for Minfeng fault, it was not formed during the early and middle Es3 until the late Es3. Such differences of the fault activity resulted in strata thickness of the lower and middle Es3 in Minfeng sub-sag assuming wedge shape with the thick in the north and the thin in the south, while the upper Es3 to the Es2 assuming thin in north and thick in south. These features indicate it is the faults activities that control the development of depositional sequence in this area.

Key words: Minfeng sub-sag, fault activity, de-compaction correction, fault throw, control