Barremian-Aptian Calcareous Nannofossil Biostratigraphy in Zagros Basin (west Iran), Tethyan Realm

The calcareous nannofossils from the upper part of Garau Formation were studied in the NW Zagros Basin, western Iran (Kabir-Kuh section). The ca. 510 m thick studied interval is mainly composed of interlayered marls, marly limestones, marly shales, laminated black shales and limestones. The succession of nannofossil bioevents defines the stratigraphic range of the studied part of section spanning the interval from the early Barremian (CC5b/NC5C) to the late Aptian (CC7b/NC7B). Six primary calcareous nannofossil bioevents and eight secondary bioevents are recorded within the studied interval. The comparison of the recorded bioevents with those referred from other parts of the Tethyan and the Boreal realms indicates some diachroneity between these localities.