Active thrusting and the evolution of the Zagros fold belt

Abstract

Earthquake locations and fault-plane solutions reveal the spatial distribution and kinematics of strain release by faulting; information that is difficult to infer from geological evidence alone. In the Alpine-Himalayan belt, thrust faulting can be classified into one of three distinct types, each of which illustrates a particular aspect of continental deformation. Some thrusts are mechanically linked to strike-slip faults. Low angle thrusting is observed in regions where intermediate depth earthquakes and volcanism show that subduction is or was occurring. High angle reverse faulting at shallow depths is seen in the Zagros and it is suggested that this is the result of rejuvenation of old normal faults which stretched and thinned the basement of a Mesozoic continental margin.