Estimation of the shortening rate since late Pleistocene in the Aksu area on the southern flank of the Tianshan, China

This research focused on the Aksu area in the central part of the southern Tianshan. Along the 60 km wide Aksu fold-and-thrust belt, active thrusts re ach the surface and offset the youngest sediments. Our research was based o n the geomorphologic study that examined the advance and retreat of glacier s cut by thrusts in the Tomur area in the north of Aksu. Our fieldwork reve aled that two fault scarps were clearest across three different moraines th at represent the maximum of advance of glaciers during three glacial period s along the Tailan River in the Tomur area. The measured heights of the fau lt scarps that cut the moraines, together with the moraines-inferred age, i mply a shortening rate of 1.85 mm/a on the Aksu area since late Pleistocene . This rate, similar to that of the Korla area on its east side and of the Kaping area on its west side, but lower than that of the Kashgar area farth er west and of the Manas area in the northern margin of the belt, implies t hat the distribution of shortening across the Tianshan changed markedly alo ng the mountain.