The genetic relationship between paleoenvironment, mineral compositions and lithofacies in the Ordovician–Silurian Wufeng–Longmaxi sedimentary succession in the Sichuan Basin, SW China

•Five intervals (I–V) showing changes in minerals, lithofacies and paleoenvironment were identified.•High productivity and low detrital influx lead to the enrichment of nondetrital quartz in siliceous shale in Intervals I-II.•The enrichment of carbonate in calcareous shale in Interval III was due to high detrital influx.•High detrital influx and strong chemical weathering lead to an abundance of silt and clay minerals in silty–argillaceous shale and argillaceous shale in Intervals IV-V.