Zagros fold belt: orogenic accretion from obduction to collision

Abstract

The Zagros orogenic system comprises an exceptionally wide defor­ mation zone between Arabia and Eurasia, embracing the entire Iran, and resulting from the closure of the Neotethys Ocean through its pro­ tracted NE-dipping subduction beneath Eurasia. The ~ 2000-km long, NW-SE trending Mesopotamian basin and Zagros fold belt (deformed basement and cover of the Arabian lower plate) are at the front of this orogenic system formed by the Sanandaj-Sirjan Zone and the Urumieh­ Dokhtar Magmatic Are, parallel tectonic domains belonging to the up­ per plate. The Zagros fold belt deforms 10-12-km thick Arabian sedi­ mentary cover, which records compressive deformation since Late Cre­ taceous times. These tectonic events and their sequence have been stu­ died in great detail in the last ten years, mainly due to the profusion of dating of the syntectonic marine and non-marine sediments in the fold belt and foreland basin. Despite these new data, and taking in ac­ count that there is a general consensus that the Zagros orogeny occurred during the complete consumption of the Neotethys Ocean, tectonic in­ terpretations differ and ages of major geodynamic events remain contro­ versia!.