Nummulites (Foraminifera) from Pondicherry Area and Paleobiogeographic Implications

NThe study reports an interesting Nummulites fauna from the late Palaeocene- early Eocene sediment of Pondicherry area. The taxa Nummulites are recovered for the first time from the sediments exposed at Saidarpet and Thondaimanattam quarry sections of Pondicherry area. The biostratigraphy and paleobiogeographical implications of this Nummulites fauna are significant. The taxa was previously known only from Pakistan and now it has a broad geographical distribution, covering Europe from the Pyrenees to the North Atlantic, west and North Africa, West Africa, Oman, Pakistan, Libya and western Ireland. The fauna therefore show marked mixing of taxa from Indian subcontinent, the Mediterranean/North Atlantic and West African region as well as including a taxon previously considered endemic to the Caribbean. The occurrence of Nummulites in association with Discocylinids and trace fossils at Thondaimanattam quarry section and also in calcareous limestone in Saidarpet clearly indicate that the warm shallow water and more open marine environment. The Nummulites illustrated herein come mainly from Karasur Formation and is thus dominantly Thanetian (NP8-NP9) in age close to the Palaeocene-Eocene boundary (Nannoplankton Zone NP8 ?NP10) possibly ranging as high as top NP11.