New age constraints for the Proterozoic Aravalli-Delhi successions of India and their implications

The Precambrian geological history of Peninsular India covers nearly 3.0 Ga. The Peninsula is an assembly of five different cratonic nuclei known as the Aravalli–Bundelkhand, Eastern Dharwar, Western Dharwar, Bastar and Singhbhum cratons along with the Southern Granulite Province. Final amalgamation of these elements occurred either by the end of the Archaean (2.5 Ga) or by the end of the Palaeoproterozoic ( c. 1.6 Ga). Each of these nuclei contains one or more sedimentary basins (or metasedimentary basins) of Proterozoic age. This chapter provides an overview of each of the cratons and a brief description of the Precambrian sedimentary basins in India that form the focus of the remainder of this book. In our view, it appears that basin formation and subsequent closure can be grossly constrained to three separate intervals that also broadly correspond to the assembly and disaggregation of the supercontinents Columbia, Rodinia and Gondwana. The oldest Purana-I basins developed during the 2.5–1.6 Ga interval, Purana-II basins formed during the 1.6–1.0 Ga interval and the Purana-III basins formed during the Neoproterozoic–Cambrian interval.

Chapter 3 The Archaean and Proterozoic history of Peninsular India: tectonic framework for Precambrian sedimentary basins in India

Evidence for a Neoarchean LIP in the Singhbhum craton, eastern India: Implications to Vaalbara supercontinent

Evolution of the Singhbhum Craton and supracrustal provinces from age, isotopic and chemical constraints

Large Igneous Province Record Through Time and Implications for Secular Environmental Changes and Geological Time-Scale Boundaries

Depositional history of the Upper Vindhyan succession, central India: Time constraints from Pb–Pb isochron ages of its carbonate components

The Singhbhum craton in eastern India hosts a number of mafic dyke swarms popularly called 'newer dolerites'. Previous attempts to obtain emplacement ages of these rocks were limited to a few poor-precision K-Ar whole-rock and Rb-Sr isochron ages. Here, two prominent dykes from the WNW-ESE trending swarm in the south central region of the craton were dated using Pb-Pb baddeleyite thermal extraction-thermal ionization mass spectrometer method. These dykes yielded identical baddeleyite Pb-Pb ages of 1766.2 ± 1.1 Ma (SKJ-10) and 1764.5 ± 0.9 Ma (SKJ-15) respectively, which are interpreted as the time of emplacement of the WNW-ESE trending 'newer dolerite' dyke swarm. The predominantly parallel dyke trend in this swarm for over 100 km along strike indicates these dyke fractures were formed due to horizontal compressive stresses in a region that may have been associated with a palaeo compressional system. Coeval ∼1770 Ma magmatism in the Singhbhum craton and in China, Australia, Brazil and Uruguay confirms this event was globally widely dispersed. The timing of this event also coincides with orogenic activity in majority of continents that may have formed during the assembly of supercontinent Columbia.

B. Vijayagopal

Papers

Depositional history of the Upper Vindhyan succession, central India: Time constraints from Pb–Pb isochron ages of its carbonate components

Precise Pb–Pb Baddeleyite Ages of 1765 Ma for a Singhbhum 'Newer Dolerite' Dyke Swarm