STUDY OF FLORA AND FAUNA FROM THE CHUNABATI FORMATION, DARJEELING: A PALEOGEOGRAPHIC IMPLICATION

Abstract

Miocene is a very eventful time interval during which several tectonic, climatic and oceaonographic changes took place. Miocene witnessed closure of Tethyan seaway, the Mid- Cenozoic opening of a southern seaway around Antarctica and the closing of the Indonesian seaway. The development of the Antarctic Circumpolar Current (ACC) due to the opening of Drake Passage resulted in Thermal isolation of Antarctica causing a major increase in the Antarctic ice volume, which had major influence on the global climate and established thermal gradient between low and high latitudes. This dissertation aims to study the microfaunal population of the Chunabati formation, Darjeeling Lower Siwaliks with special focus on forarninifers. Foraminifers are the unicellular shelled marine micro-organisms which evolved in the Palcozoic times and are found till date, it is supposed that they diversified during Miocene. The present work on the Chunabati Formation is confined to the study of foraminifers of Miocene Epoch. The sediments of Chunabati Formation are supposed to have been deposited in an open marine environment. The dissertation work will focus on processing the field samples and studying them under microscope to decipher the different genus and species of foraminifera. Based on the ecological niche of different species, an attempt will be made to understand the depositional environment of the fossiliferous lithic units of the Chunabati Formation.