Cenozoic vertical-axis rotation of the Altyn Tagh fault system

Paleomagnetic declination data were collected from Cenozoic strata of the s outhern rim of the Tarin basin to address whether the Altyn Tagh fault has undergone significant rotation during the Indian-Asian collision. Results f rom the eastern and central Altyn Tagh fault zone suggest that it has under gone no significant rotation since the Oligocene, This implies that the bou ndary between the Tarim and Tibet has remained relatively stationary during most of the Cenozoic. In contrast, declination data from the western Kunlu n Shan on the eastern limb of the Pamir orocline, where the Karakax segment of the Altyn Tagh fault system terminates, suggest that the range has unde rgone clockwise rotations of between 19.3 degrees +/- 8.6 degrees and 27.8 degrees +/- 5.8 degrees, Such rotation is in mirror image with the document ed counterclockwise rotation of 20 degrees-50 degrees in the western Pamir orocline and implies relatively small displacements on the Karakorum fault. Our results also suggest that the Karakax fault may have formed as an acco mmodation zone between the western Kunlun Shan and the Karakorum Mountains.