Development and Folding of the NW Zagros Foreland Basin, Lurestan Povince, SW Iran

It is crucial for exploration in fold-and-thrust belts to get robust understanding of foreland basin evolution and deformation, in order to constrain the timing of hydrocarbon generation, migration and trap formation. Although it is widely accepted that the main phase of deformation in the Zagros belt occurred in the Miocene and Pliocene, recent field studies have demonstrated that folding started in the NW Zagros (Lurestan Province) as early as the Late Cretaceous and Paleocene. The objective of this work is to constrain the timing of the development and folding of the NW Zagros foreland basin, on the base of accurate dating of the Amiran, Taleh Zang and Kashkan syntectonic foreland formations at different places through Lurestan Province. A multidisciplinary approach has been used, combining benthic foraminifera biostratigraphy, calcareous nannoplankton biostratigraphy, palynostratigraphy and strontium isotope stratigraphy. Dating results show that the Amiran-Kashkan clastic wedge prograded south-eastward in the NW Zagros foreland basin between the late Cretaceous and the early Eocene. The dating of associated syn-depositional folding structures permits to establish that an early folding of the NW Zagros foreland basin progressed south-westward during the same period.