广东省及邻区新生代以来构造运动与地震活动分区的研究

Division of tectonic and seismic activity in Guangdong Province and its adjacent areas since the Neozoic era

综合分析多年来地震地质调查资料,将广东省及部分邻区划分为具不同构造活动特点的6个区,分别论述、分析这些区内新生代以来的断裂构造、火山喷发、第四纪沉积及地震活动等。结果认为,由断层样品热释光测定确定的断层最近期活动年龄主要是在中更新世和晚更新世,沿海地带主要为晚更新世和全新世。新生代以来构造具继承性活动的地区是地震最活动地区,如琼雷地区。同时,由于历史上发生过强震,地震后至今具较大速率下沉地区,在今后相当长时间内可能是不易发生强震地区,如琼北东部和南澎—南澳地区;Ms6级地震将主要发生在晚更新世以来的新生盆地,如潮汕盆地和近岸海湾地区;Ms5级地震在一定条件下,几乎可能发生在省内的任何地区。

The Guangdong Province and its adjacent areas can be divided into six regions which have different tectonic activity characteristics on the base of synthesis of seismic and geologic investigate data. In this paper the authors discussed the fault structure, volcanic eruption, Quaternary sediments and earthquake activities since the Neozoic era. The result indicated that the last activity ages of the faults which are difined by thermoluminescence dating of fault gouges are in the middle and the late Pleistocene, and in the late Pleistocene and Holocene along the coast. The areas of sequential activities of structure since the Neozoic era are most active areas of the earthquakes, such as Qiong-Lei area; but some areas where the historical strong earthquakes occurred and the crust has been slowly subsiding with relative high velocity since the earthquake are areas where the strong earthquake will not occur in quite long time hereafter such as the eastern part of Qiongbei and Nanpeng-Nan'ao area. The earthquakes of magnitude 6 may occur in new basins formed since late Pleistocene e.g. Chaoshan Basin and some sea bays near coast. On a certain condition the earthquake of magnitude 5 may occur in any areas of the province.