Tectonic evolution of the foreland basin of the SE Alborz Mountains, northern Iran

•The North Semnan Fault has thrust the SE Alborz Mountains on the foreland basin.•The reverse reactivation of the Attary Fault has disrupted the foreland basin.•A NW-oriented compression is suggested for the post-Eocene faults.•Deep-seated thrusting occurs along the flanks of the Alborz Mountains.•Motions of the South Caspian Basin relative to Iran affect the regional kinematics.