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 a supracrustal record from the Paleoarchean to Neoproterozoic and provides a rare opportunity to infer early Earth surface processes and crust–mantle interactions. 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 indicate that the lower part of the Dhanjori succession was deposited during the Mesoarchean (∼2990 Ma). In contrast, Chaibasa sedimentation took place during the Paleoproterozoic (∼1870–1830 Ma). Our geochronological data confirm that (1) the Dhanjori–Chaibasa succession represents a normal stratigraphic sequence, and (2) the provenances 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 indicates progressive unroofing of older lithologies as a result of plume uplift. Terrestrial sedimentation in Singhbhum was initiated on a tectonically stable ∼3300 Ma granitoid basement. In contrast to other cratonic blocks like the Dharwar, Pilbara and Kaapvaal, 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.