Abstract: In response to the issues of numerous shale facies, rapid facies changes and high predictability in continental faulted basins, a comprehensive analysis was conducted on the combination types, sedimentary sequences and distribution patterns of shale facies by integrating data from cores, thin sections and geochemistry by taking the shale from the upper sub-member of the Member 4 to the lower sub-member of the Member 3 of the Shahejie Formation in Eocene series in the Jiyang Depression as an example.The results show that three major types of lithofacies combinations, namely endogenous, mixed-source and exogenous are predominantly developed in the study area. The endogenous lithofacies combination is primarily formed in a sedimentary environment of shallow to semi-deep lake settings with high salinity of water bodies and limited supply of external clastic material sources. The mixed-source lithofacies combination is mainly formed in a sedimentary environment of semi-deep to deep lake settings with relatively high salinity and relatively balanced internal and external material supply. The exogenous lithofacies combination is predominantly formed in a sedimentary environment of freshwater to brackish water with an ample supply of external material sources. Overall, the co-evolution of paleoclimate and paleowater medium controls the vertical evolution of shale lithofacies combinations, while the joint evolution of paleotopography and paleosource controls the zonal and regional distribution of shale lithofacies combinations. The annular co-evolution of the sedimentary environment controls the annular development of lithofacies combinations on the plane. As the basic unit of exploration deployment, the research findings on shale lithofacies combinations have significant guiding significance for shale oil exploration.

Key words: lithofacies combination, sedimentary environment, paleowater medium, paleotopography, paleosource, continental faulted basin, Jiyang Depression