Sequence stratigraphy of the Late Cretaceous–Paleocene Gurpi Formation in southwest Iran

Facies associations, microplanktonic diversity, palynofacies variations, geochemical data, and natural gamma-ray logs were analyzed from the Danial and Gurpi sections of the Campanian–Selandian Gurpi Formation in the Zagros Mountains, southwest Iran. The biostratigraphic data indicate that deposition across the Cretaceous/Paleogene boundary was continuous in the Danial Section. In contrast, a minor stratigraphic break seems to be present in the Gurpi Section, where several planktonic foraminiferal subzones are not identified. Nine depositional sequences were interpreted and correlated between the two sections. They are apparently of great lateral extent because they closely correlate to the global sea-level cycles. The Maastrichtian maximum flooding surface MFS K180 (68 Ma) of the Arabian Plate was also identified. Detailed palynofacies analysis, integrated with standard tropical/subtropical planktonic foraminifera, indicate warm Neo-Tethyan upper-bathyal to middle-shelf depositional environments for the Gurpi Formation.