Study On The Sequence Stratigraphy And Depositional System Of Qinhuangdao LD20 Project

Based on the seismic data,geological data,logging data,borehole coring data and other related datum on the study area,especially the application of high precision 3D seismic data of the project,the paper has settled up the sequence framework,and has analyzed the spatial and temporal distribution characteristics of sedimentary system.The stratigraphy of palaeogene in LD20 are composed of seven three-order sequences,such as SSQk,SSQs4,SSQs3,SQs12,SQd3,SQd2 and SQd1.The SQd3 and SQd2 can be divided for highstand systems tract and low system tract.Distribution of Synsedimentary faults are different in every sequence,performing as weak(SSQk)-strong(SSQs4)-weak(SSQs3,SQs12)-strong(ESTd3,SQd2)-weak(SQd1).In SSQk,synsedimentary faults were confined in Qinna sag.In SSQs4,the area of Synsedimentary faults became more large.In SSQs3,the area of Synsedimentary faults shrank and the number of Synsedimentary faults became less.In SQs12,the area of Synsedimentary faults shrank continuity,Synsedimentary faults distribute only in the eastern of Qinnan.The fan delta,braided river delta,meandering river delta,and lacustrine sublacustrine fan sedimentary systems developed in LD20 project.In SSQk-SQs12,lacustrine sublacustrine fan and braided river delta systems are main.In SQd3-SQd1,lacustrine sublacustrine fan and braided river delta systems are main,in SQd2,sublacustrine fan can be also found,meandering river delta can be also found in HSTd2 and SQd1.The distribution of sedimentary system is successive and different,the distribution of braided river delta is most extensive,it can be found in every sequence.Figure 110;Reference 68...