Mid-Late Cretaceous Stratigraphy of the Cauvery Basin and the Development of the Eastern Indian Ocean

Planktonic foraminifera are widely used in Cretaceous stratigraphy and have a well-Established zonation for low latitude regions. The most recently published version includes some of the proposals for the Cretaceous stage boundaries introduced at the meeting of the International Sub-Commission on Cretaceous Stratigraphy held in Brussels in 1995.

This zonation is identified in the sediments of the Cauvery basin and correlated with the ODP boreholes on the Exmouth plateau and in Western Australia. The maximum diversity of planktonic foraminifera in the Cauvery basin can be correlated with the highest temperatures in the Cretaceous and the Mesozoic sea-Level maximum. Both of these appear to relate to enhanced rates of ocean crust production. The distribution of planktonic foraminifera in the developing eastern Indian Ocean can also be used in palaeogeographical reconstructions that confirm the predicted palaeotemperatures.