Abstract

A brief traverse across the Altyn Tagh and Kunlun in northern Tibet revealed abundant evidence for recent crustal deformation there. From ridges offset roughly 10 m and from fresh mole tracks 40 cm or more high along the Altyn Tagh strike-slip fault, we conclude that a large earthquake occurred in the past few hundred years. Accordingly, the rate of slip could be relatively high (30 ±20 mm/yr?). Active reverse (or thrust) faults mark the bases of several mountain ranges in the Altyn Tagh and Kunlun where the neighboring basins lie at elevations less than 4000 m. Therefore, roughly north-south crustal shortening appears to be occurring there, probably at a rate of several millimetres per year. The crustal shortening accommodated by strike-slip and reverse (or thrust) faulting appears to account for a significant part (10%–25%) of India's convergence with Eurasia. The broad zone of crustal shortening in northern Tibet indicates that the areal extent of the plateau is increasing northward by crustal thickening on its northern margin.

You do not currently have access to this article.