Sedimentary facies types and models for the Neogene deposits on the northern slope of the Chengning uplift

The detailed examination of the sedimentary facies on the basis of cores,thin sections,well logs and seismic data have revealed that the Neogene Guantao Formation and Minghuazhen Formation on the northern slope of the Chengning uplift are composed of braided and meandering stream deposits,respectively.These deposits consist of the following sedimentary microfacies: riverbed lag,channel bar,point bar,natural levee,crevasse splay and flood plain microfacies.The Guantaoan and Minghuazhenian sedimentary models are proposed on the basis of the planar distribution and evolution of the sedimentary microfacies for the purpose of the exploration of the reservoir sandstones.