Geological Background--Physical Geology
the geopark is primarily sedimentary with strata of devonian, carboniferous, permian, triassic, neogene and quaternary age. the following formations (from oldest to youngest) are found within the geopark: rongxian, du’an, baping, dapu, huanglong, maping, nandan, qixia, maokou, heshan, luolou, banna, baifeng, lanmu, wanggao and guiping. in addition to these 16 formal stratigraphic units there are informal stratigraphic units composed of reef limestone. the sedimentary rocks are 2638~4875 m thick, with the devonian, carboniferous and permian forming a 2203~3395 m thick continuous carbonate depositional sequence in leye, while those in fengshan are 2663~4000 m thick.
in the geopark there are ten major rock types which can be further subdivided into 70 types， of them terrigenous clastics and carbonates account for more than 90% of the rocks in the geopark. terrigenous clastics (primarily greywacke and siltstone) are present in the middle triassic baifeng, banna and lanmu formations with minor occurrences in the neogene and quaternary strata. carbonate rocks are located throughout the geopark and dominate nearly all of the strata from the upper devonian rongxian formation to the triassic luolou formation. they are the material basis for the karst landforms.