Study on Sequence Stratigraphy of Guantao Formation in Jiyang Depression

By using drilling,logging,and seismic data,sedimentology,sequence stratigraphy methods, earthquake geology,sedimentary characteristics of Guantao formation in Jiyang depression have been studied,and the sequence stratigraphy has been divided.It is found that:Guantao formation in Jiyang Depression mainly developed fluvial facies sediments,braided river delta sediments with shallow lakes as the background existed in the lower section of Guantao formation,and lake delta sediments and shallow meandering river delta sediments developed in the upper section of Guantao foramtion.On these basis,sequence interface identification and sequence stratigraphy division have been carried out.Guantao formation can be divided into a tectonic sequence and two third-order sequences.Sequence end interfaces are typeⅠ sequence boundary.Each sequence can be divided into three systems,that is low water level system,expansion system,and domain and HST.