CALCAREOUS NANNOFOSSILS FROM THE EOCENE SEQUENCE OF THE NAOPURDAN GROUP, BETWAT LOCALITY, SULAIMANIYAH, KURDISTAN REGION, IRAQ

Abstract

Ten samples were collected from the Eocene sequence of the Naopurdan Group at the Betwat locality within the Thrust Zone of the Sulaimaniyah area, Kurdistan/ Iraq. The samples covered 120 meters of a succession represented by marlstone/ shale, siltstone and sandstone with limestone interlayers and slightly metamorphosed shale/ slate. This succession unconformably underlies a serpentinite rock bed, which is derived from the Mawat ophiolite complex. A biostratigraphic study is carried out for the first time for the calcareous nannofossils present in this sequence and emphasized the age of Middle Eocene. The nannofossil assemblage identified in this study comprises important species that highlights the NP15 and NP16 Zones of the Lutetian stage of the Middle Eocene in the Naopurdan Group. The Sphenolithus spp. included Sphenolithus furcatolithoides, S. cuniculus, S. spiniger, S. predistentus, S. orphanknollensis, S. kempii, S. Runus, S. perpendicularis, S. richteri, and S. moriformis. The Reticulofenestra spp. included Reticulofenestra erbae, R. westerholdii, R. bisecta, R. reticulata, R. minuta, and R. dictyoda. The Toweius spp. included Toweius gammation and T. callosus, together with species like Blackites spinosus, Blackites tenuis and Cyclicargolithus floridanus.