Late Maastrichtian-Danian nannoplankton from basal Subathu of Dharampur, Simla Himalaya, India-Palaeogeographic implications

Abstract

The discovery of Danian calcareous nannoplankton of combined NP3-NP4: Chiasmolithus danicus/Ellipsolithus macellus zones from apparently unproductive Subathu of Dharampur, offers new scope for high resolution dating; reworked nannofloral elements of Late Maastrichtian (Micula mum Zone of low-mid latitudes) demand the fixing of lower age limit of Subathu Formation straddling K/T boundary. This may signify an event permitting the entry of Assam-Arakan sea along lesser Himalayan rift via Arunachal during Late Maastrichtian.