Research Projects

Earth's geodynamic regime, distinguished by the operation of diverse plate tectonic processes, represents a unique phenomenon. Compelling geological evidence indicates the early Earth's tectonic system was fundamentally different. During the Eoarchean to early Paleoarchean periods (more than 3.6 billion years ago), elevated mantle temperatures, approximately 200–300°C above present-day conditions, precluded the establishment of modern plate tectonics. Instead, the Earth's outer layer was controlled by different processes like stagnant lid convection, heat-pipe volcanism, and mantle plume-driven magmatism. These thermally driven conditions led to the genesis of trondhjemite–tonalite–granodiorite (TTG) plutonic suites and associated greenstone belts, constituting the structural and compositional cores of Archean cratons. A critical and transformative shift towards sustained, horizontal plate tectonics occurred progressively between 3.5 and 2.5 billion years ago. This shift was primarily driven by secular mantle cooling, which led to an increase in lithospheric strength and viscosity that facilitated the formation and stabilisation of coherent, rigid tectonic plates capable of lateral movement and subduction. Investigating the precise mechanisms and chronology underlying this geodynamic transition remains one of the paramount unresolved challenges in Earth sciences. The Bastar Craton in India provides an exceptional geological record to explore this fundamental shift. Unlike most cratons, such as the Kaapvaal craton in South Africa, the Pilbara craton in Australia, and the Dharwar and Singbhum cratons in India, which mainly show signs of vertical tectonics, the southwestern Bastar Craton has a unique mix of very old Eo- to Paleoarchean TTG gneisses and younger, arc-related magmatic charnockites. This distinctive tectonic architecture offers an unparalleled natural laboratory to examine the initiation of evolutionary pathways from a vertical, plume-dominated geodynamic regime to horizontal, subduction-driven tectonics. This project will undertake a rigorous, multi-scale analytical methodology, integrating comprehensive field mapping, advanced geochemical analyses, high-precision zircon U–Pb and Hf petrochronology, and thermodynamic modelling. Such an approach promises to provide transformative insights into early crustal evolution and mantle dynamics. Moreover, this research will firmly establish the Bastar Craton as a globally significant locus for studies on early Earth processes and substantially contribute to both national and international scientific endeavours. This research is expected to provide a quantitative framework that has profound social and scientific implications. From a social science perspective, understanding the architecture of Archean cratons is fundamentally linked to resource geology; the processes that formed these ancient landmasses also controlled the localisation of strategic mineral deposits vital for economic security and technological advancement. By establishing the Bastar Craton as a global benchmark for early Earth studies, this project will enhance India's scientific leadership and foster international collaboration. This, in turn, directly supports capacity building by training a new generation of researchers in advanced analytical techniques, strengthening the nation's scientific workforce. Finally, the story of our planet's formation is a shared human heritage. Disseminating this research will promote public engagement and a deeper societal appreciation for India’s globally significant geological legacy.