Upper Palaeocene Calcareous Nannoplankton from Cauvery basin, Southern India

Abstract

Phytoplankton analysis of a 240 meter deep bore hole, located in the Gopurapuram Village north-east of Vriddhachalam in Cauvery basin, revealed the presence of calcareous nannofossils and dinoflagellate cysts in the basal sample, where as the samplesb higher up in the sequence yielded only dinocysts. The nannofossil assemblage includes eight genera containing 16 recognizable species. Out of these, Discoaster is discussed to mark the Standard Nannoplankton Zone NP 9 of Upper Palaeocene. The equivalent zone marker taxa of dinocysts, foraminifera and mega-algae also support an Upper Palaeocene age for these sediments.