Comments on "Deccan flood basalts at the Cretaceous/Tertiary boundary?" by V. Courtillot, J. Besse, D. Vandamme, R. Montigny, J.-J. Jaeger and H. Cappetta

Abstract

The age of the flood basalts of the Deccan area and the length of the interval during which the outpourings took place are not known precisely. The authors have tried to date those basalts and estimate how long the volcanic activity lasted: on the basis of new paleomagnetic, paleontological and geochronological data of the Deccan effusives they came to the preliminary conclusion that the volcanic activity may have lasted less than 1 Ma and that the majority of the lavas poured out during chron 29R. Unfortunately, the authors were not familiar with our paper on paleomagnetism and radiomettic age determinations of Deccan Trap lavas [2]. In our paper we presented the paleomagnetic data derived from 223 individual lava flows from 16 sections all over the Deccan area and gave the K-Ar age determinations for 13 selected, unaltered lava flows. We agree that the enormous volume of Deccan extrusives poured out in a relatively short interval and that the volcanic activity was probably concerned with the spreading in the central Indian Ocean in Late Cretaceous and Early Tertiary time.