关键词: 断层活动, 年代学, 北京

Abstract: Dating the age of faulting is critical to the studies of active tectonics, paleoearthquake and neotectonics, but is sometimes difficult of access. At present, two methods are commonly used to date the age of the last faulting. The one is to date the direct products of faulting, such as fault gouge and colluvial wedge, while the other is to date the youngest sediment that was offset by faulting or the oldest sediment that was not affected by faulting. In the region from Tuoli to Yongdinghe River, western Beijing, three types of faulting can be identified along the Gaoliying fault. The first type is that the fault displaces the older loess layer, but is covered by the younger loess layer, such as the cases at Lujing and Xiaoyouying. The second type is observed at Xinkaikou, where the fault offsets the pre-Quaternary bedrocks, but does not affect the Quaternary covering layer (loess). The third type is identified at Xinzhuang village, where the fault dissects the pre-Quaternary bedrocks, resulting in fault gouge, but no Quaternary sediment covering the faults. According to the types of faulting and the characteristics of sediments, two dating methods were used to date the ages of faulting events on the Gaoliying fault in the region from Tuoli to Yongdinghe River, Beijing. Thermoluminescence dating method is suitable to dating eolian deposits, such as loess, and thus is used to date the loess samples affected by faulting or deposited after faulting. Electron Spin Resonance (ESR) dating method is currently the most reliable method to date fault gouge, and thus is used to date the ages of fault gouges collected from Xinzhuang and Dayuanshang villages, respectively. Based on the ages of faulting, it is coucluded that at least 3 faulting events had occurred on the Gaoliying fault at 270～360ka B.P., 130～140ka B.P and 1.8～4.2ka B.P, respectively.

Key words: Faulting event, Dating, Beijing