U-Pb detrital zircon ages from the Dhanjori and Chaibasa Formations, Singhbhum Craton, eastern India, and its regional stratigraphic and global implications

The Singhbhum Craton, eastern India, bears supracrustal record from the Paleoarchean to Neoproterozoic and provide us a rare opportunity to infer early Earth surface processes and crust-mantle interaction. An ambiguous stratigraphic relationship and lack of adequate geochronological data from the Dhanjori and Chaibasa formations is the major impediment to inferring the geological evolution across the Archean-Proterozoic transition. Herein we present new U-Pb detrital zircon ages from the Dhanjori and Chaibasa Formations. Our data clearly indicates that the lower part of the Dhanjori succession was deposited during the Mesoarchean (∼2990 Ma). In contrast, the Chaibasa sedimentation took place during the Paleoproterozoic (∼1870-1830 Ma). Our geochronological data confirms that (1) the Dhanjori-Chaibasa succession represents a normal stratigraphic sequence, and (2) the provenance for the Dhanjori and Chaibasa Formations were distinctly different. The occurrence of much older zircon populations in the upper compared to the lower Chaibasa Member sandstones indicate progressive unroofing of older lithologies because of plume upliftment. Terrestrial sedimentation in Singhbhum initiated on a tectonically stable ∼3300 Ma granitoid basement. In contrast to other cratonic blocks like the Dharwar, Pilbara, and the Kaapvaal, the terrestrial sedimentation on the northern margin of the Singhbhum Craton probably continued throughout the Neoarchean. Precise U-Pb zircon ages from the upper Dhanjori Member will bracket the age of Dhanjori sedimentation and will help in global stratigraphic correlation during the Neoarchean-Paleoproterozoic.