KINK STRUCTURE IN THE WEST HUBEI AND EAST CHONGQING

The raised and steep anticline in East Sichuan fold belt including West Hubei and East Chongqing is actually a regional large-scale kink structure formed by multiple strata series under vertically buckling effect.When the Jiangnan-Xuefeng basement decoupling nappe horizontally extruded from SE to NW,the sedimentary cover of Middle-Upper Palaeozoic basin progressively (decreasingly)deformed and resulted in kink structure.The kink structure is characterized by both shear folding and bend folding.It usually occurs in crisp,thin and large viscidity difference strata series with relatively mean lithology.Kink structure in the West Hubei and East Chongqing is divided into 5 types:flexure anticline,kink anticline,box anticline,chervon anticine and parasitic anticline.Kink structure controls natural gas generation and distribution in the East Sichuan.