沂沭断裂带及其近区的地震成因岩石新认识

将沂沭断裂带及其附近地区的地震成因岩石划分为四种类型,它们是具有地震成因构造的震积岩、震断层构造岩、震火山岩及隐爆地震角砾岩.前两类是构造地震的记录,而后两类是火山地震及隐爆火山地震的记录.由于震断层构造岩沿长期活动性断层分布,大多遭受了若干期强地震活动的改造,所以不易确定其最初的形成时期.因此,笔者重点对分布于沂沭断裂地震带及附近的其它三类地震成因岩石(包括震积岩、震火山岩和隐爆地震角砾岩)作了研究,论述了三类地震成因岩石的特征、时空分布、反映的地震作用机理及意义.认为:地震成因岩石不仅是强地震事件和激烈构造活动的记录;而且,因为由强地震形成的不同等级断层和裂隙构成了一个高渗透性的能够沟通不同深度石油和成矿流体的网络,所以深入研究地震成因岩石有助于完善大断裂地震带及近区的石油聚集与成矿理论.

New Recognition of Seismogenic Rocks in the Yishu Fault Zone and Its Periphery

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.