A source-to-sink study of the paleogene shulu sag: Characteristics and depositional dynamics of its deposits

Abstract

The Shulu Sag is located in the southwestern corner of the Jizhong Depression, Bohai Bay Basin of East China. The lower part of the Shahejie Formation developed massive conglomerate characterized by low porosity and low permeability with carbonate fragment as its main constituent. According to the sedimentary structure and distribution characteristics, etc., the carbonate breccia may fall into two genetics: one formed by fan-delta channel sedimentation, whereas the other is formed by earthquake-induced slump fan deposition. The braided river is the main sedimentary body of the fan delta and the typical characteristics are imbricate structures with normal graded bed sequence. The latter appears along with typical seismites widely distributed in the sag, which include soft sediment deformation structures (sedimentary dikes, hydraulic shattering, etc.), and brittle deformation (synsedimentary faults).