Characteristics and formation of Qingtaishan thrust structure in northern Chaohu area

Qingtaishan thrust structure is an important part of Chuhe fault zone. Thrust nappes consist of the limestone of Sinian and Cambrian which thrusted over the shale of Silurian with NW→SE thrust direction and had a drape cline thrust surface. There are fault thrust,strike slip fault and over thrust in this thrust nappe.Thrust fault is a cataclasite zone. The dip angle of thrust faults surface is from 60° to 90°. Strike slip faults have two directions of NE and NW. The formation time of NE strike slip faults is earlier than that of NW strike slip faults.The dip angle of over thrusts is from 10° to 20° in Qingtaishan thrust nappe. The chief slip plane under Qingtaishan mountain thrust faults were formed by foreland basin deformation in early Jurassic age.Fromlate Jurassic to early Cretaceous they were sinistral fault, and showed extensibility from late Cretaceous to Eogence. Over thrust faults have moved since Neogene age.The thrust distance of Qingtaishan thrust is about 2 km.