Dating of faults and estimation of surface uplift and erosion rates in the northern margin of Dabie Mountains, China

摘要

Absolute timing of fault movement provides information about tectonic deformation history. The K-Ar dating method has been applied to determine the absolute timing of fault movement. The key to K-Ar dating of fault gouge is to verify that the illite is of authigenic origin. Here we show effective and convincing evidences for authigenic illite in fault gouge. The characteristics of the authigenic illite reveal that the host rocks were under near-surface environment during fault activities. The result indicates fault movement in Late Cretaceous in the northern margin of Dabie Mountains orogenic belt. According to the absolute timing, the uplift and erosion rates of the northern margin of Dabie Mountains are also estimated.