ABSTRACT
Based on quantitative and synthetic study of outcrop, well sections and mapping, the sedimentary systems, sequence stratigraphy, palaeogeography of Silurian in Sichuan basin and the sedimentary evolution in sequence framework are discussed in this paper. In Longmaxi Age of early Silurian, the study area was mainly a restricted shelf. In Xiaoheba Age, it was behaved as an expansion of shallow shelf and reduction of deep shelf, and thus the sedimentary differentiation was intensified. The palaeogeographic landscape was the coexistence of carbonate platform, shallow and deep shelf. In Hanjiadian Age, it was mainly lagoon-tidal flat-shallow shelf environments. The Early Silurian in the study area had a evolutionary trend of shallowing fill-up and regression. The distribution of sedimentary systems and sedimentary evolution was controlled by the NW squeezing of foreland upheaval zone including Qianzhong upheaval of foreland basin in Late Ordovician to Early Silurian.
