Abstract:
The marine cratons in China are characterized by "small scale, poor tectonic stability, and strong tectonic- sedimentary differentiation." Through the basin prototype restoration and paleogeographic evolution studies of the Tarim Basin, Sichuan Basin, and Ordos Basin, this study classified the types of tectonic-sedimentary differentiation. Through the typical dissection of three types of large-scale reservoirs—the reef-shoal facies of the Sinian Dengying Formation in the Sichuan Basin, the intra-platform grain shoals of the Cambrian Longwangmiao Formation and Xixiangchi Group, and the Ordovician paleokarst in the Tarim Basin—the controlling mechanisms of tectonic- sedimentary differentiation on the development of large-scale reservoirs were summarized. The results indicated that: (1) during the extensional-convergent tectonic cycles of marine basins, the orderly superposition of rift basins, passive continental margin basins, cratonic depression basins, and foreland basins controlled the systematic development of reef-shoal facies, intra-platform grain shoal facies, and paleokarst reservoirs. (2) In strong extensional periods, intra-cratonic and marginal rifts controlled the development of reef-shoal reservoirs. In weak extensional-weak compressional periods, intra-cratonic depressions governed the formation of intra-platform grain shoal reservoirs. In strong compressional periods, the formation of paleo-uplifts controlled the development of karst reservoirs. (3) The development of high-quality reservoirs in platform-margin reef-shoals and intra-platform grain shoals was generally controlled by high-energy facies zones, early dolomitization, and early dissolution. Under strong tectonic differentiation, high-quality reservoirs exhibited zonal distribution, whereas under weak differentiation, they showed discontinuous planar distribution. (4) The development of karst reservoirs was controlled by parent rock lithology, paleoclimate, tectonic geomorphology, and exposure duration. Under tectonic differentiation, karst reservoirs showed planar or zonal distribution. In marine cratonic basins, tectonic-sedimentary differentiation not only controlled the types of carbonate reservoirs but also shaped their developmental models and distribution patterns.