With the passing of Khadg Singh Valdiya we have lost a Himalayan scholar and a scholar of Himalayan proportions. Born in Myanmar he returned to his native Pithoragarh and then studied at Lucknow University where he completed his Ph.D.

Valdiya was a geologist focusing on sediments and tectonics. His research interests were wide. He helped establish and grow the best geology institutions in the country and found a welcoming research abode after retirement @jncasr where he continued to be productive.

An abiding interest of his research was the origin of the Himalayas and the origin of the Himalayan rivers in general and the Ganga in particular. Here are excerpts from two of his reviews.

On the emergence of the Himalayas, he writes in 2002 ”India collided with mainland Asia at 65 Ma..As the Indian lithosphere bent down and it's upper-crust buckled up as an upwarp in the period 35-45 Ma, the southern margin of Asia became the water-divide of the Himalayan rivers

“A variety of Eurasian fauna migrated to the Indian landmass. The southern margin of the Himalayan province synchronously sagged to give rise to the foreland basin that was linked with the Indian sea.

“In this Paleocene foreland basin 48-49 Ma ago, the whales from one of the species of the immigrant terrestrial mammals evolved. The sea retreated from the Himalayan province by the early Miocene, even as the crust broke up along faults 20-22 million years ago.

“Rivers carried detritus generated bythe fast emerging Himalaya and deposited it in the foreland basin which turned fluvial around 23 Ma. Another fluvial foreland basin, the Siwalik, was formed at ~18 Ma.. the Himadri uplifted, briskly exhumed in the Late Miocene (9-7.5 Ma).

“The Himadri then became high enough to cause disruption of wind circulation, culminating in the onset of monsoon. The climate change that followed caused the migration of a variety of quadrupeds from Africa and Eurasia, bringing about faunal turnovers in Siwalik's life.

In Resonance in 1996, he pointed out that “The Sindhu, Satluj, Ganga, Karnali, Kosi, Arun, and Brahmaputra rivers, among the scores of mountain rivers, had established their drainage networks well before the Himalaya came into existence as a mountain barrier.”

Valdiya was a gentle man, understated despite his extraordinary research and scholarship. Always approachable and friendly this Pahari who made Bengaluru one of his homes will be much missed.