从断层泥石英颗粒的微观形貌研究八宝山断裂带的活动性

北京八宝山断裂带主要由八宝山内支、外支断裂和黄庄-高丽营断裂组成。根据野外地质资料和室内研究,认为八宝山内支断裂是燕山期的逆掩断层,已不具活动性,而外支断裂是一条规模和断距都不大的正断层,只有黄庄-高丽营断裂才是活动断层,它错断了中更新统黄土。 为了获得更多的有关八宝山断裂带活动性的资料,我们采用Kanaori提出的一种判定断层活动性的新方法,通过扫描电镜观察了八宝山断裂带的6个断层泥样品和4个有关地层中的石英颗粒表面微结构,所得结果与野外宏观地质资料相吻合

STUDY OF ACTIVITIES OF THE BABOSHAN FAULT ZONE IN TERMS OF THE MICROSCOPIC SURFACE FEATURES OF QUARTZ GRAINS IN GOUGE

The Baboshan fault zone consists of the inner branch fault,the outer branch fault and the Huangzhuang-Gaoliying fault,lying in the southwestern suburb in Beijing.Based on geological information obtained in the field and laboratory result,it is believed an overthrust of the Yenshan stage which has shown no activity at present;the outer branch,a normal fault which is small in its scale and offset;the only Huangzhuang-Goliying fault,an active fault which goes through middle Pleistocene loess.In order to gain further information in this regard,we have examined the surface features of quartz grains for 6 samples of gouge and 4 samples of relative formations obtained from the fault,using a new method to estimate activities of the fault,for which the scanning electron microscope has been used.The results coincide with the macroscopic information from the field