Abstract: The Information on the major periods of fault activities in a region is a basis for understanding the history of crustal motion or fault development.
In this paper,the major periods of faulting in Huashaoying area, Yangyuan Cornty, have been studied by means of the traditional geological methods combining with isotopic dating,quartz surface textuer observing and microstructural analysis, and the better results have been obtainde.The main periods of faulting in the area are as follows: pre-proterozoic era; Yanshan cycle;the period of 60--90rna jPliocen Early Pleistocene epoch and the last period of 0.2—0.3ma.