Palaeozoic Biostratigraphy of the Tethys Himalaya in North-Eastern Kumaun

Abstract

NEW fossil finds in the Kali and Kuti valleys in north-eastern Kumaun Himalaya considerably elucidate the problems of the biostratigraphic subdivision of the Palaeozoic succession and tectonic history of the Tethys Himalaya. Northern Kumaun was explored by Griesbach^1–2 in the 1890s, and Heim and Gansser³ made this region a classical area for the study of the Tethys Zone of the Himalaya through their monumental work in the 1930s. Although mostly conforming to the general structural picture of the entire Tethys Himalaya, the area showed certain biostratigraphic features that did not agree well with the wide regional stratigraphy and tectonic history as inscribed in the lithological successions in Spiti to the north-west and in West Nepal to the south-east. To study afresh the peculiarities of the Kumaun Tethys Himalaya, an expedition was sponsored and organized by the Wadia Institute of Himalayan Geology in August and September, 1971. Many significant facts have emerged from this short expedition. The new scheme of stratigraphy—with its implication on the tectonic history—accords very well with that established in the Dhaulagiri-Nilgiri region in western Nepal^4,5. The highlights of the result of the investigation are as follows.