ROLE OF OBLIQUE CONVERGENCE IN THE ACTIVE DEFORMATION OF THE HIMALAYAS AND SOUTHERN TIBET PLATEAU

Noting similarities with subduction along curved oceanic trenches and using a simple block model, we show that radial vergence evident in ea rthquake slip vectors along the Himalayan deformation front, east-west extension on north-trending normal faults in the Himalayas and southe rn Tibet, and right-lateral strike slip on the Karakorum-Jiali fault z one can all result from basal shear caused by the Indian plate sliding obliquely beneath Tibet along a gently dipping, arcuate plate boundar y. Within the framework of this mechanism, the normal faults in the Hi malayas and southern Tibet are not proxies for the uplift history of T ibet. The distribution and style of the faults in the Himalayas and so uthern Tibet suggest that the basal drag from the underthrusting India n lithosphere extends northward beneath most of southern Tibet.