The palaeokarstification in the Late Palaeozoic Youjiang Basin, southwestern China

The integration of well logs, outcrops and tectonic data shows that the Youjiang Basin underwent several stages of palaeokarstification during the Late Palaeozoic. One to three karst cycles may be recognized mostly at the top of the Upper Permian strata, top of the Middle Permian Maokouan strata and top of the Carboniferous strata and subordinately at the top of the Devonian strata. The occurrence of the palaeokarstification is closely associated with the sequence boundaries and lowstand systems tract created by the Guizhou-Guangxi, Ziyun and Dongwu Movements. The genetic types include weathering, regional meteoric corrosion, regional dolomitization, regional palaeokarstification, regional dedolomitization and regional fresh-water cementation and filling.