A tectonic window in south-western Iran

Abstract

The paper presents evidence of large-scale overthrusting during Upper Cretaceous times in part of the Zagros Mountains in south-western Iran. Thrust-sheets made up mainly of radiolarian cherts and serpentinous igneous rocks, and including fossiliferous rocks of Triassic age, are shown to have been extensively overthrust upon Cretaceous rocks, including Cenomanian limestones and marlstones probably of Senonian age. Marine Maestrichtian and younger rocks were deposited upon the thrust-sheets and were later folded, together with the sheets themselves and the underlying autochthonous rocks. Subsequent erosion of the cover has exposed the thrust-sheets over wide areas and in places has exposed the underlying autochthonous rocks in tectonic windows of which a striking example, the Dalnashin Window, is described in the paper.