Abstract: On April 1, 1936, an M6(3/4) earthquake occurred on the Fangcheng-lingshan Fault. This event is the biggest historical earthquake on the coastal seismic zone, South China ever. But so far, no any findings about the surface rupture of this event have been reported. This paper is the first to find several intact surface rupture zones associated with the 1936 Lingshan seismic event, in the areas of Gaotang, Jiaogengping etc. on the northeast segment of the Fangcheng-Lingshan Fault. According to the field work, the surface rupture stretches to 10km and distributes along NE direction in front of Luoyang Mountain, represented by earthquake scarp, extensional fracture, dextrally faulted gully and river system etc. The characteristics of surface ruptures and faulted landforms indicate that the surface rupture is of normal-dextral strike slip faulting. The trenching on this fault exposed that at least three seismic events have been recorded, including two historical earthquake events and the latest one is the 1936 Lingshan M6(3/4) earthquake. These surface rupture zones are the key to the detection of seismogenic structure and the re-estimate of magnitude of this event. The new finding of these surface rupture zones would be particularly significant for the detection of the seismogenic structure of Lingshan M6(3/4) earthquake.

Key words: the 1936 Lingshan M6(3/4) earthquake, surface rupture, the Fangcheng-Lingshan Fault, the Zhaixu Fault, trenching

摘要： 1936年4月1日广西灵山发生6（3/4）级地震（灵山地震），为华南沿海地震带内陆地区自有地震记载以来发生的最大地震；目前为止，未见与该地震有关的地表破裂报道和研究。在防城-灵山断裂带NE段寨圩断裂高塘-夏塘-六蒙、蕉根坪-合口等地新发现至今依然保留完好的地震地表破裂带，在华南中强震构造区尚属首次。野外调查表明，该地震地表破裂带全长约12.5km，在罗阳山前总体呈NE向展布，主要表现为地震陡坎、张裂缝、右旋错移冲沟水系等，地表破裂特征及断错地貌情况显示出该地震地表破裂性质为右旋走滑兼正断。探槽揭露该断裂至少存在3次地震事件，其中2次为古地震事件，最新1次为灵山6（3/4）级地震。这次地震地表破裂带的发现，对灵山地震发震构造的探测具有重要的科学意义。

关键词: 灵山6(3/4)级地震, 地震地表破裂, 防城-灵山断裂, 寨圩断裂, 探槽