First report of Early Proterozoic microfossils from the Bijawar group of rocks in Harda district, Madhya Pradesh

Abstract

In the course of microscopic examination of the recrystallised quartz arenites (locally named chert breccia) from the Bijawar rocks in Harda district, M.P., a number of organic bodies, mainly filaments and solitary spheroids and polygonal bodies, were detected by the authors early in 1994. Thin sections of these rocks were re-examined and the presence of microfossils in the above rocks were confirmed. Remnants of filamentous cyanobacteria belonging to the genera Gunflintia, Archaeorestis, and solitary spherical and polygonal bodies including Eosphaera, Huroniospora and some new forms were noted in the thin sections of these rocks. The Gunflintia-Huroniospora-Archaeorestis assemblage is known from the Gunflint chert of Ontario, Canada, from Early Proterozoic horizons, and the equivalents are known from the Franceville Group of Gabon, S. Africa and in the other parts of the world. The finding of these forms in the Bijawar rocks helps in assigning the age of these horizons as Lower Proterozoic (commonly known as belonging to Lower to Middle Proterozoic).