Research Projects

Characterization of the mantle & its evolution during the Archean-Proterozoic are essential to understand early earth geodynamic conditions. It has been established that the crust of Early earth formed due to the partial melting of the mantle. The Proterozoic mafic magmatism represented by voluminous dyke swarms & sills (remnants of extensively eroded Large Igneous Provinces) are short-lived magmatic events that present significant temporal & chemical constraints on the development of the lithospheric mantle. The mafic dyke swarms & sills possess such minerals as baddeleyite, which yield high-precision Pb-Pb geochronology. They also retain pristine isotopic, geochemical, & paleomagnetic signatures. Given the above characteristics, a better understanding of the Proterozoic mafic dyke swarms & sills will help us to improve our knowledge of early mantle evolution, in turn, shed light on the early earth geodynamics. The Dharwar Craton (DC) & the Bastar Craton (BC) preserve well-exposed Proterozoic dykes & sills from ~2.36 Ga to ~1.44 Ga. There is a lack of a unique geological model regarding how these cratons might have evolved during their geological histories. Thus, DC & BC are the natural laboratories to study the mantle’s nature & evolution through the Proterozoic. The defined objectives are as below: • To provide new precise age, isotopic & geochemical constraints for less known/ unstudied dyke swarms of DC, & BC & to correlate with coeval dyke swarms elsewhere during the Proterozoic. • To characterize the mafic dykes from the DC, & BC, in terms of their source, petrogenesis, & tectonic setting. • To differentiate & quantify the crust-mantle interactions in the evolution of the Proterozoic mantle. • To understand the evolution of paleotectonic conditions of dyke emplacement. Toward achieving the above objectives, we shall first conduct field studies to understand geology & field relationships and sampling. The sampled rocks will be subjected to multiple analyses like petrography, Geochronology (Pb-Pb Baddeleyite; to assign ages of mafic magmatism), & Sr-Nd isotopic analysis (to understand petrogenesis) using TIMS, major element data using WD-XRF technique (to classify rocks), & trace & REE element data using HR-ICP-MS (to classify rocks & to understand petrogenesis). This project will help us improve the nature of the mantle source of dykes, as well as the tectonic conditions that prevailed during their formation, which will help to understand the evolution of the Proterozoic mantle. Second, the shared ancestry of the DC & BC can be explored & a unique geotectonic model can be proposed to explain their evolution during the Proterozoic. The results will be published in journals of international repute, & presented at national/ international conferences, apart from being reported in the form of progress reports. The data obtained in this project will be archived according to the Institutional data policy.