The Features of Seismite in Jiyang Sub-Basin,Paleogene

By the observation of drillng cores, the seismite is recognized which mainly occurredin the upper part of Member4 and Member 3 of Shahejie Formation inthe Lower Tertiary in Jiyang sub-basin. Many kinds of soft sedimentarydeformation structures have been found in seismite, such as step micro-faults, pleatedwithin layers,liquefactionsandstone and clay veins, vibrationalliquefaction deformation structure, seismic breccias and flame structure. Seismites mainly occur in the northern steep zoneof rift lacustrine basin. There develop more seismites in Member 3 than in the upper part of Member4. Away from the basin-controlling boundary fault, the sedimentary sequence integrity of seismites gets worse. This reflects that seismites are the direct resultsof earthquake which causedby the intenseactionof basin-controlling boundary fault .The repeated emergence of seismites in stratasection showsthat themovement of boundary faultshas periodicity and episodicity. The researchprovides theoretical foundation for the tectonic evolution studies and seismite recognization in continental rift lacustrine basin.