Research Projects

The emergence of continental crust above sea-level is a pivotal moment in Earth's evolution, altering the composition of the atmosphere and oceans, providing climate feedback, and creating new sites for life proliferation and ore deposition. However, the exact date and how continental crust first emerged remains contentious. Isotopic evidence suggests that subaerial landmasses first appeared around 2.5 billion years ago. Plate tectonic processes have been suggested to facilitate this emergence event. However, the geological rock record reveals older paleosols, barite deposits, and terrestrial sedimentary rocks, suggesting subaerial crust was present before 2.5 billion years ago. The tectonic processes responsible for these early episodes remain elusive due to the highly contentious operation of plate tectonics before 2.5 billion years ago. This project aims to constrain the tectonic process that drove continental emergence before 3.2 billion years ago from the metamorphic rock record. The project will study the metamorphic rocks of the singhbhum Craton of India, which shows evidence of crustal emergence during 3.4-3.2 billion years ago and hosts multiple lithounits that underwent metamorphism. The project will also generate high-resolution ages from zircon/monazite to identify how many tectonothermal events may have affected the cratonic crust before 3.2 billion years ago and constrain the depositional ages of terrestrial sedimentary units that are inferred to be older than 3.2 billion years ago from stratigraphic correlation but lack robust geochronological data.