Discovery,study and significance of structure joints in the Late-Pleistocene in Hefei area

In this paper,by means of the chance of digging cosmically in city engineering building of the Hefei area,author made many spots probe and record to the Late-Pleistocene clay profiles,many groups structure joints were discovered.Sampled respectively the clay samples was cut by the joint,joint filling,and coating made date and analyse to age of the joints,and made microscopic observed directionally to the joint filling.The results showed that at least 3 times events of tectonic deformation had been token placed since Late Pleistocene,which is respectively 110,70-80 and 40-50 thousand years from now.The microscopic analyse show there are deformation events with stick-slip and creep-slip had been taken after the joint formed.The discovery and cognition has a signification of exploit and guidance to open out the deformation history and character since Late-Pleistocene,estimate impersonality crust stability in the area,search after the research method of tectonic activity behavior in the Middle-Eastern area.