Foraminifera from the Maastrichtian Garzan and Lower Germav formations of the Arabian Platform (Batman, SE Turkey)

Abstract

The Upper Cretaceous successions of the Arabian Platform in Batman and surroundings (SE Turkey) comprise the Garzan and Lower Germav formations. Shallow water limestones of the Garzan Formation contain rich benthic foraminiferal assemblages. The conformably overlying LowerGermav Formation consists mostly of marls and includes planktonic foraminifera, which suggest a relatively deeper marine environment. Benthic and planktonic foraminiferal assemblages fromboth formations were studied in 28 samples collected from a 155-m-thickmeasured section. Diverse benthic foraminiferal assemblages are mainly dominated by Orbitoides megaloformis Papp and Küpper, O. media (d’Archiac), Omphalocyclus anatoliensis Ozcan, Dicyclina schlumbergeri Munier-Chalmas, Trochospira avnimelechi Hamaoui, Nezzazata simplex Omara, Nezzazatinella picardi (Henson), Antalyna korayi Farinacci and Koyluoglu, Fleuryana adriatica (DeCastro), Biconcava bentori Hamaoui, Cuneolina pavonia d’Orbigny,C. ketini Inan, Moncharmontia apenninica (DeCastro), M. compressa (De Castro), Fissoelphidium operculiferum Smout and Vandenbroekia munieri Marie. Themajority of Late Cretaceous taxa are long-ranging. Orbitoides media and O. megaloformis within this assemblage have been documented both in the upper Campanian and Maastrichtian strata from the Tethyan Province. The age of the Garzan Formation is determined to be Maastrichtian based on the presence of Antalyna korayi, C. ketini and Fleuryana adriaticia. The abundance of opportunist planktonic foraminifera (i.e., biserial heterohelicids and rugoglobigerinids) throughout the Lower Germav Formation shows that the environmentwas not very deep during the deposition of the unit. Maastrichtian taxa such as Globotruncanita conica (White) and Globotruncanella minuta Caron and Gonzales Donoso appear in the middle part of the Lower Germav Formation, but these are absent from the lower part of the formation.