New Recognition of Seismogenic Rocks in the Yishu Fault Zone and Its Periphery
沂沭断裂带及其近区的地震成因岩石新认识

Based on geological survey,the authors divided the seismogenic rocks in the Yishu fault zone and its periphery into four types,namely,seismite,seismic fault-tectonic rock,seismic volcanic rock and cryptoexplosive-seismic breccias.The former two types are records of tectonic earthquakes,and the latter two ones are records of volcanic earthquakes and crypotoexplosive earthquakes.Nevertheless,as the seismic fault-tectonic rocks were distributed along active faults and were mostly reformed by many strong earthquakes,geologists cannot easily define the period of their initial formation.Therefore,the authors have laid emphasis on the three types of seismogenic rocks,namely,seismite,seismic volcanic rock and crytoexplosive-seism breccia in the Yishu fault-seismic zone and its periphery.Features,time-space distribution,formation seismic mechanism and geological significance of these seismogenic rocks are discussed in detail in this paper.It is held that seismogenic rocks are records of strong seismic events and violent tectonic activities,and that a thorough study of these seismogenic rocks can be contributive to the perfection of oil accumulation or metallogeny theory for the large fault-seismic zone and its vicinity like the Tanlu fault zone.This is because a highly-permeable network consisting of different grades of faults and fissures is formed by strong earthquakes,and this network is linked up with oil or ore-forming fluids at different depths.