摘要
1936年灵山63/4级地震是迄今为止有记载以来在华南陆地发生的最大地震,其产生的地震地表破裂带尚没有系统的研究.通过野外系统地质地貌调查及位错测量,发现1936年灵山63/4级地震的地表破裂带主要由东西2支组成,平面上呈斜列式展布于灵山断裂北段,全长约12.5km,走向N55°～60°E.西支在高塘—夏塘—六蒙一带断续出露,长9.4km,水平位错0.54～2.9m,垂直位错0.23～1.02m;东支出露在蕉根坪—合口一带,长3.1km,水平位错0.36～1.3m,垂直位错0.15～0.57m.最大水平位移量2.9m,最大垂直位移量1.02m.地表破裂类型主要有地震断层、地震陡坎、地震裂缝、地震崩积楔、地震滑坡、砂土液化等.
Abstract
On April 1, 1936, an M63/4 earthquake occurred on the Fangcheng-lingshan Fault. So far, the Lingshan M63/4 earthquake is the biggest one in South China. There are some reports about the Lingshan earthquake fissures, but its surface rupture hasn't been systemically studied. Based on the geological mapping and measurement of the right-lateral displacement and vertical offset, the surface rupture zone caused by the Lingshan M63/4 earthquake was found, which contains two secondary surface rupture zones in the east and west respectively, its strike varies from N55°E to N60°E with en echelon-like distribution along the north section of Lingshan Fault, and its total length is about 12. 5km. The western surface rupture zone locates intermittently along Gaotang-Xiatang-Liumeng, about 9. 4km in length, with a right-lateral displacement of 0. 54～2. 9m and a vertical offset of 0. 23～1. 02m;the other one appears between Jiaogenping and Hekou, about 3. 1km in length, with a right-lateral displacement of 0. 36～1. 3m and a vertical offset of 0. 15～0. 57m. The maximum right-lateral displacement and vertical offset are 2. 9m and 1. 02m, appearing at the east of Xiatang reservoir. The types of surface rupture mainly contain earthquake fault, earthquake scarp, earthquake fissure, earthquake colluvial wedge, earthquake caused landslide and liquefaction of sand and so on. The earthquake fault develops at the east of Xiatang and Jiaogenping, earthquake scarp appears at Xiaoyilu and Xiatang, earthquake fissure locates at Xiatang, there are multiple earthquake landslides along the surface rupture zone, and the trench LSTC03 exposes the earthquake colluvial wedge. In order to further investigate the Lingshan earthquake surface rupture zones, the author compares the parameters of Lingshan M63/4 earthquake with the similar typical earthquakes in western China, the results show that the parameters of Lingshan earthquake are similar to the typical earthquakes in western China. The length of Lingshan earthquake surface rupture is shorter, but the dislocation is bigger. The author considers that this is mainly related with the parameters of Lingshan earthquake, site condition and structural environment of surface rupture zone, the symbols of dislocation measuring, human activity and weather condition and so on. The research of surface rupture zone features and analysis of Lingshan M63/4 earthquake provides important and basic data for exploring the seismogenic structure of Lingshan M63/4 earthquake, and it has important scientific significance.
基金项目
广西科学研究与技术开发计划项目(桂科攻14251008)
NETL
NSTL
维普
万方数据