Physical Research Laboratory, Ahmedabad
Jyotiranjan S Ray is a professor at the Physical Research Laboratory (PRL), Ahmedabad. He obtained M.Tech., in Applied Geology, from IIT Roorkee in 1992 and PhD from PRL in 1998. After spending four years in Canada and USA, for postdoctoral research, he returned to PRL as a research scientist in 2003. Ray is a geochemist by profession. He uses elemental and isotopic tracers to understand geological processes such as the evolution of earth’s mantle through time, subduction zone magmatism and evolution of modern and ancient sedimentary basins. His contributions to the studies on carbonatite magmatism, the evolution of Vindhyan Supergroup and Andaman Subduction Zone are noteworthy. His efforts have been rewarded with several national awards including the INSA Young Scientist Award in 2000, National Geoscience Award in 2009, PRL Award in 2013 and Shanti Swarup Bhatnagar Prize in 2015.
Session 2C: Symposium: ‘Earth Science of the North-East’
Chairperson: R Ramesh, National Institute of Science Education and Research, Bhubaneswar
Cretaceous carbonatite-alkaline-basaltic magmatism in North-eastern India and Gondwanaland breakup
Carbonate-bearing carbonatite magmas are commonly associated with alkaline silicate mag-mas. Many carbonatite–alkaline complexes are located within Large Igneous Provinces (LIPs), which often are linked to the breakup of supercontinents. While the genetic link between carbonatite and alkaline magmas is fairly well understood, the reason for their occurrence in LIPs remains elusive. The latter becomes important in the theory of (deep mantle) plume origin for LIPs with the general understanding that the former originate from the continental lithospheric mantle. The Cretaceous carbonatite–alkaline complexes of the Shillong Plateau, being associated closely with the Sylhet Traps in space and time, offer a unique opportunity to study and understand the genetic connection between the two and with the breakup of the Gondwanaland, the last known supercontinent of our planet. The speaker will discuss important results of geological, geochronological, geochemical and isotopic studies carried out during the last two decades on these complexes and shed light on the tectonic evolution of India, vis-à-vis Gondwanaland during late Early Cretaceous (120–105 million years ago).