珠江口盆地及其邻近地区的活动断裂与地震活动

The Active Faults and the Seismic Activity in the Pearl River Mouth Basin and Its Vicinity Areas

珠江口盆地位于南海北部，属于大陆地壳的陆缘张裂型盆地，其形成与地幔向上隆起和地壳拉张减薄有密切关系。自中新世纪晚期以来，珠江口盆地的坳陷为沉积区，盆地的隆起及外围为剥蚀区。盆地北缘的北东东向正断层被北北西向断裂左旋错动。盆地南缘及东沙隆起被一系列北西西－近东西向左旋走滑断裂切割。它们是本区主要的地震断裂。盆地的坳陷为地震活动较弱的地区，其北、南两侧的隆起带是近代地震频繁地区。本区地震分布继承了晚中新世以来珠江口盆地断块差异升降运动的发展。

The Pearl River mouth basin is located in the north part of the South China Sea. It is a basin type of the rifted continental margins in the crust. There are close conections between the genesis of basin and the uplift of the mantle with thinning and tension of the crust.Since the late epoch of the Miocene the fosedeep part of the basin is belonged to the deposit area. In the mean time the uplift part and the vicinity areas of the basin is the erosion zone.The normal fault zone with NEE trending are cut by some NNW faults with left-lateral dislocation in the north of the basin. There is a series of strike-slip faults with NWWEW trending in the south margin of the basin as well as in the Dongsha uplift. They are the main seismic faults in these areas.The seismic activity is very weak in thd diposit area of the basin. There are seismic activities in the uplift zones in the north and south margins of the basin, where are the active zones in the neotectonic movement.