Is the North Altyn fault part of a strike-slip duplex along the Altyn Taghfault system?

Although the Altyn Tagh fault system has played an important role in the In do-Asian collision, its geometry and tectonic evolution remain poorly known . Between 86 degrees and 92 degrees E, this system is at least 100 km wide and is bounded to the north and south by the North Altyn and Altyn Tagh fau lts, respectively. Mapping along the Jianglisai reach of the North Altyn fa ult indicates that Miocene(?) to Pliocene(?) motion was predominantly left to left-reverse slip, with transport vectors trending N45 degrees-60 degree s E. Map relationships suggest that total offset on the fault is >120 km. T hese results are inconsistent with previous models of the Altyn Tagh fault system in which oblique convergence along the northern margin of the Tibeta n Plateau is partitioned into thrusting on the North Altyn fault and left s lip on the Altyn Tagh fault. An alternative hypothesis is that the North Al tyn fault is the northern boundary of a transpressional strike-slip duplex within which the structurally elevated Altyn Mountains were created. Our mo del suggests that transpressional deformation may be restricted to this str ike-dip duplex and need not characterize the entire margin.