The exploration prospects of Ediacaran shales in the Yangtze Platform, South China: Insights from the coupling of generation, storage, and preservation

•The storage space of Ediacaran Doushantuo shale was dominated by both organic matter pores and matrix pores associated with dissolution.•The Doushantuo shale reservoir quality is jointly determined by carbonate minerals and organic matter content.•Three enrichment modes were summarized for typical commercial shale gas reservoirs.•The exploration feasibility and reservoir forming scale of ancient shale were clarified.