Early Pliocene calcareous and siliceous microfossils of the Sawai Bay Formation, Car Nicobar Island, northern Indian Ocean

The present contribution provides a study of calcareous nannofossils and siliceous microfossils from the Sawai Bay Formation on Car Nicobar Island, northern Indian Ocean. Two stratigraphically short sediment intervals near have been examined. Qualitative quantitative microfossil analyses show ‘A’ Section to be devoid microfossils, while 24 well-preserved nannofossil taxa are identified. ‘B’ yields 18 nannofossil, 33 radiolarian 25 diatom taxa. index ( Ceratolithus armatus Muller, 1974a C. cristatus  Kamptner, 1950) indicate both sections zones NN12 (CN10b) NN13 (CN10c) early Pliocene (Zanclean) age. taxa, i.e., Didymocyrtis avita Riedel, 1953, Euchitonia spp., Siphocampe lineata (Ehrenberg) Nigrini, 1977, Stichocorys peregrina Semantis spp. Stylochlamydium sp. common in Section, which is assigned Zone RN9. Most represented by representatives genera Actinocyclus Ehrenberg, 1837, Azpeitia Peragallo Tempere Peragallo, 1912, Coscinodiscus 1839a, Grammatophora 1841 Triceratium 1839b, with benthic species favus 1839b being predominant (~35% total count). Siliceous also silicoflagellates dominated Dictyocha sponge spicules astrophorids.