Structure of the collision zone of Zagros orogen in northwest Iran

Two distinct collision events have occurred between Arabia and Central Iran plates، during closing of the Neo-Tethys. Structural sections along the collision zone in northwest Iran show characteristics of collision structure. The first collision occurred during obduction of the oceanic components of the Neo-Tethys over the Arabian passive margin during the Late Cretaceous. Deformation along the Arabian passive margin in radiolarite and the high Zagros zones was the result of this event. The high Zagros frontal thrust fault is the maximum limit of this collision tectonic event. The obducted oceanic components، including the ophiolites in this region، unconformably are overlain by Oligocene-Miocene sediments. By the last continent-continent collision event during Late Miocene، the hinterland of the orogen was transported over the collided zone and deformation occurred by rejuvenation of the existing thrust faults in previously collided zone and the Zagros foreland basin was formed (Zagros fold-thrust belt).