A. B. Roy, M. Sc., Ph. D. (Jadavpur University), Retired Professor of Geology, M~hanla~SukhadUian iversity, Udaipur, is working as the Senior Scientist of the Indian National Science Academy. Earlier, he was engaged in research as an Emeritus Fellow of the All India Council of Technical Education. He worked on different aspects of Geology of Rajasthan for over 3 decades. He was elected Fellow of the Indian Science Academy in 1989, and of the Indian National Science Academy in 1990. He is recipient of National Mineral Award in 1993. He was awarded a gold medal in 1998 by the Directorate of Mines and Geology, Government of Rajasthan, for his contributions to the mineral sector development in Rajasthan. Professor Roy received Bellur Rama Rao Centenary Award (2000), which is the highest award bestowed by the Geological Society of India for his lifetime contributions in the field of Precambrian geology. He has over 80 publications to his credit including research papers, book reviews and edited volumes.