The Unconformity At Rathivade

My friend Pradeep Sarkar died last Tuesday June 7th. He got up that morning and complained of shortness of breath. In a few minutes it was all over. He leaves behind a shattered family, a wife and a son, and a large number of stunned friends, colleagues and students.

I met Pradeep when he joined the faculty at Fergusson College, Pune, during my second year B.Sc. He had a way with students and his enthusiasm for geology rubbed on to others. A boring summer vacation was looming ahead.  Having already decided to major in geology, Anil Lalla, Nalin Nair and myself asked him if he was going for fieldwork to the Konkan coast. As it happened he was and to our delight he invited us to go along with him.

We traveled to the little town of Malvan in the Sindhudurg district in southern Maharashtra. His research involved mapping the Precambrian geology with emphasis on understanding sedimentary structures and environments of deposition of the mid-late Proterozoic Kaladgi Group. Peninsular Gneiss, Greenstone schist belt, deformed conglomerate, trough cross bedding, fining up sequence. We had read and heard about these magical geological features in class. Pradeep made them come alive in the field in the week of our arriving at Malvan. He taught us how to read a toposheet and how to overlay the geology on it. He taught us how to measure and describe lithological sections. He taught us how to scan the horizon and see beyond.

In the evenings after fieldwork we used to go to the rocky  Malvan beach where the Kaladgi Group sediments were exposed. He used to point out to us ripple marks and bedforms made by the action of waves on a sandy sea floor more than a billion years ago. Sometimes we walked a little out of the way, outside town, to one of his favorite spots. A bridge over a small estuary; there we stood watching the rise or ebb of tides, taking in the salty breeze, waiting for the Arabian Sea sunset. Malvan would remain very close to his heart long after he finished his PhD work. He ended up marrying a local girl, the daughter of the lodge he always stayed in.

We remained good friends throughout. After I left India to pursue graduate studies we struck up a lively correspondence. I used to mail him research papers. His interests were moving toward studying calcrete, calcium carbonate deposits found as nodules and veins in the semi arid eastern Deccan plateau. On my return to India a few years back we renewed our meetings. During short chai sessions at the local tapri he used to hold court, talking excitedly of his research and teaching commitments. He wanted to see some of my PhD samples of Ordovician carbonates and maybe hold a lab session with graduate students. I agreed to meet him in his lab. Alas, that day never came. His work load was such that he just never got around organizing it.

Last week on June 10th I attended a sad but memorable condolence meeting for Pradeep. Friends and colleagues talked touchingly on the many memories they had of time spent with him. He leaves behind a legacy of 3 decades of excellence in teaching and of inspiring countless students to take up geology as a career.

When I heard the news of his passing on June 7th, my mind skipped back to that field trip and I found myself thinking about the unconformity near the village of Rathivade some distance away from Malvan. Amidst monsoon showers and sunny interludes we walked through the Konkan countryside. In a stream bed we came across something he had badly wanted us to see- The Great Eparchaean Unconformity. There scattered along were patches of Archean gneiss. Along the stream bank overlying the gneiss were mid Proterozoic Kaladgi sediments. By the time I had walked to the stream edge, Pradeep had rushed in and was already standing knee deep in water. It is an important feature of Indian geology he explained.... this unconformity. Etched on the surface of Peninsular India, it speaks of a change from a hot tectonically active Archean earth in which was formed the gneiss, to a cooler more stable Proterozoic world, where, on large cratonic basins in shallow seas, thick sequences of sandstones and limestones accumulated. This unconformity- he told us-  marks a long period of quiescence between these two phases of formation of the earth's crust, maybe a 300 -500 million year break.

With amazement we stared at him. 

Since then, at different times and places, I met and was influenced by other good teachers and mentors who kept my interest in geology alive. But it all began during that late summer in June 1986 when the generosity of a young PhD scholar opened the eyes of three geology enthusiasts to the wonders of this earth.

 Pradeep Sarkar 1960-2016