SEDIMENTARY MICROFACIES IN THE UPPER MEMBER OF THE EOGENE HESAN FORMATION IN THE SHUANGHE-ZHAO’AO AREA,BIYANG FAULT DEPRESSION,HENAN

Three continental sequences may be recognized for the upper member of the Eogene Hesan Formaion in the Shuanghe-Zhao'ao area of the Biyang fault depresion,where the sedimentary facies display a facies pattern of alluvial fan-fan delta-lake from south to north.A sedimentary model is thus suggested for the upper member of the Hesan Forma-tion on the basis of source area and its tectonic settings,in combination with well logs and geological data as well as the distribution of the seismic facies.The studied three continen-tal-sequences comprise thirteen parasequence sets including more than fifty parasequences, of which more than ten are sedimentary mocrofacies;thirty-three are lithologic facies.