湖北襄樊-广济断裂第四纪活动特征初步探讨

Discussion on Characteristic Activity of Xiangfan-Guangji Fault Since the Quaternary,Hubei

利用近年在襄樊-广济断裂研究中获得的有关资料,对该断裂第四纪以来的活动特征进行了初步分析,认为断裂3个几何段自第四纪以来均有不同程度的活动,断层切割地貌面、断层带物质的TL、ESR法年龄结果多集中分布在700～300ka之间(平均值约500ka),说明襄樊-广济断裂在第四纪中更新世早中期有过明显活动。历史及现今地震活动图像显示,断裂带附近地震活动呈现沿断裂走向自北西向南东逐渐增强的特点,这与断裂3个几何段的分段活动性基本一致。时间上,该断裂带上地震活动的强度、频度呈增强的趋势。

In recent years,some data have been obtained about the Quaternary activity of Xiangfan-Guangji fault belt.These data suggest that three geometric segments of the fault are characterized by various activities since Quaternary.The TL and ESR dating of fault gouge ranges from 700 ka to 300 ka（averaging 500 ka）,which suggests that the fault should have undergone intense activities during the Early and Middle Pleistocene Epoch.The historical and present seismic activity image illustrates that,seismic activity neighbouring the fault belt is gradually increased from NW toward SE,and this is favourably consistent with the activity of three fault segments themselves.In temporal,the strength and frequency of seismic activity have an increasingly enhanced trend.