Formation and evolution of the strike-slip faults in the central Sichuan Basin, SW China

Petrological, Geochemical and Chronological Characteristics of Dolomites in the Permian Maokou Formation and Constraints to the Reservoir Genesis, Central Sichuan Basin, China

“…The Neoproterozoic to Middle Triassic basin evolution was influenced by the extension-convergence cycles of the Rodinia and Pangaea continents, and it experienced four tectonic cycles [13]: the Yangtze cycle, Caledonian cycle, Hercynian cycle and Indochina cycle. Under the influence of the "Guangxi Movement" in the late Caledonian period, the Leshan-Longnusi paleo-uplift was formed, which placed the tectonic slope break belt on the periphery of the uplift depression of central and northern Sichuan in the highland of paleogeomorphology for a long time, and controlled the sedimentary pattern of the Early Permian [14,15]; and the "Dongwu Movement" in the late Middle Permian (sedimentary period of Maokou Formation) caused the tectonic differentiation of the basin [16]. It strongly promoted the maturity of the Lower Paleozoic to Lower Permian source rocks and the generation of oil and gas [17].…”

“…Early deposition of the Maokou Formation in the Hechuan area was in the inner gentle ramp of the carbonate ramp, controlled by a NW trending strike-slip fault within the carbonate platform; a localized formation of alternating uplifted and depression paleogeomorphological patterns was established and maintained until member Mao-2 [14,16]. In this geological setting, the bioclastic banks developed in the highlands of paleogeomorphology, and in the highstand stage, the sea level dropped; the beach would emerge from the water surface for a long time, and be leached by meteoric water, forming a syngenetic karstification fracture-cave system.…”

“…According to the tectonic setting of the Sichuan Basin, in the late Middle Permian, Emei taphrogenesis led to the revival of the basement fault in the basin [14], and was subjected to NW stretching, resulting in a large number of syndepositional faults [42]. At this point, tectonic faulting was active in the Hechuan area, and a number of NW trending syndepositional faults were formed; because of the brittleness of dolomite, it is easier to form fractures in dolomite than limestone, so the fractures in the Hechuan area are mainly in the dolomite.…”