High Frequency Sequence StackingMode of Dongying Delta-turbidite Fans and Lithological Trap

Key words: 
• delta /
• turbidite fan /
• high resolution sequence /
• base level cycle /
• lithological trap /
• Dongying Sag

Abstract: Dongying delta's sand body and its associated turbidite fans are the main reservoirs of Shahejie Three Formation in Dongying Sag. Based on the high resolution sequence stratigraphical theory, this paper analyzed the variety of base level cycles and its control on the development and evolvement ofDongying delta. Its high frequency sequence stackingmode is divided into three types. This paper also studied the variety of short term base level cycles and its effect on the form and distribution of turbidite fans which are related to Dongying delta, and indicate that the slope-moving turbidity fan which consisted of the main reservoirswere formed during rising stage of the base level. The distribution of slop-moving turbidity fan ismainly controlled by the variety of base level cycles as well depositional faults and depositional palaeogeomorphology.Vertically, slop-moving turbidity fans are located on the location where the middle term base levels transformed from rising stage to falling stage. On the plane, the slop-moving fans are distributed in the downthrow of depositional faults and the palaeogeomorphological lowlands between these faults.