Himalayan Geology, Vol. 21 (1& 2), 2000, pp. 63-85, Printed in India

Correlation of Continental Eocene Vertebrate Localities of the Indian Subcontinent

KISHORE KUMAR
Wadia Institute of Himalayan Geology, 33, GMS Road, Dehra Dun 248 001, India

In the Indian subcontinent, the continental Eocene vertebrates are known from several localities in the Ghazij, Mami Khel, Kuldana (Pakistan), and Subathu (India) successions that are exposed on both sides of the Hazara-Kashmir Syntaxis. Most of these localities are situated in the Outer Himalaya along the Main Boundary Thrust (MBT) from Barbora Banda (Kohat District, North-West Frontier Province, Pakistan) in the west through Kalakot (Rajauri District, Jammu and Kashmir, India) to Subathu (Solan District, Himachal Pradesh, India) in the east. Some of the continental Eocene mammal localities of the subcontinent, viz., Sor Range-Deghari Coalfield area and Shahrig-Nakus in the Quetta District of Pakistan fall beyond the Outer Himalayan belt. A majority of the continental Eocene vertebrate localities along this long stretch indicate broadly similar depositional environment but ate lithologically dissimilar and have yielded vertebrate fauna dominated by different groups in different localities. This led several workers to suggest that from west to east these localities may be diachronous. To evaluate this suggestion, the available data on lithostratigraphy, biostratigraphy and taphonomy were analysed. This revealed that most of the continental Eocene vertebrate localities of the Indo-Pakistan subcontinent and particularly those in the northwest India and the northern Pakistan are contemporaneous and of an early Middle Eocene age. However some localities to the west particularly the Sor Range-Deghari Coalfield area Shahrig-Nakus and Barbora Banda (westernmost localities) in Pakistan are definitely older (Early Eocene) than the rest and the Jozara locality situated north of Barbora Banda in Pakistan is possibly the youngest of them all. The variations in the faunal composition of various localities that are considered contemporaneous are interpreted to be partly due to their differing taphonomy and paleoecology rather than chronology. The absence of certain forms in some of the localities may also be due to inadequate sampling.