RECORD OF THE CRETACEOUS MAGNETIC QUIET ZONE - A PRECURSOR TO THE UNDERSTANDING OF EVOLUTIONARY HISTORY OF THE BAY OF BENGAL

Magnetic study along a transect joining the sites of Ocean Drilling Pr ogramme (ODP) leg 116 (1 degrees S, 81 degrees 24'E) and the vicinity of Deep Sea Drilling Project (DSDP) site 218 (7 degrees N, 87 degrees 30'E) revealed the presence of a wide magnetic smooth zone sandwiched between the known Late Cretaceous anomaly A34 (approximate to 84 Myr) and the younger magnetic anomaly sequence of Early Cretaceous crust, r epresented by MO (approximate to 118 Myr), The smooth magnetic zone se ems to have evolved during the Cretaceous long normal polarity epoch ( superchron K-T) 118-84 Ma and is usually referred to as the Cretaceous magnetic quiet zone, Identification of this zone in the distal Bengal Fan perhaps serves as a missing link between the Early Cretaceous and the Late Cretaceous evolution of the crust and establishes a continuo us, evolutionary record of the ]Bay of Bengal since India's breakup fr om the eastern Gondwanaland continents.