In the Indian subcontinent, the beginning and end of the Paleogene was marked by various events that shaped the various physiographic features of the Indian subcontinent. The subcontinent lay within the equatorial zone during the earliest part of the Paleogene. Carbonaceous shale, coal and lignite deposits of early Eocene age (~55.5–52 Ma) on the western and north-eastern margins of the Indian subcontinent are rich in fossils and provide information on climate as well as the evolution and paleobiogeography of tropical biota. Indian Paleogene deposits in the India–Asia collision zone also provide information pertaining to the paleogeography and timing of collision. Indian Paleogene rocks are exposed in the Himalayan and Arakan mountains; Assam and the shelf basins of Kutch–Saurashtra, Western Rajasthan; Tiruchirappalli–Pondicherry and Andaman and, though aerially limited, these rocks bear geological evidence of immense importance.