Overview of the meso- to neoproterozoic evolution of the Vindhyan basin, central India

Abstract

Abstract Despite its origin in a stable intracratonic basin, the Vindhyan Supergroup, central India, embodies tectonic-driven depositional cycles of various orders. A marked change in sedimentation pattern was coupled with a transient plate-margin compression in the otherwise extensional regime. An unconformity laterally correlatable with a conformity, that divides the Supergroup in two sequences arose in consequence. Maximum flooding surfaces (MFS) within the sequences can generally be correlated with intrabasinal volcanism that drastically diminished through the initial rift to later sag stage of basin evolution. Concomitantly with the change in tectonic milieu, paleoseismic deformation structures and related deposits also became drastically reduced in scale. Nevertheless, metre- and decametre-scale depositional cycles correlate well with the subtle record of paleoseismicity. Intermittent tilting of the depositional substratum is demonstrable in systematic bed-dip changes in metre-scale fining upward depositional cycles in the rift stage. In the sag stage, it is reflected merely in consistent deflection of paleocurrent directions at the top of the decametre-scale parasequence sets. Towards the top of the Supergroup, progressive thickening and decreasing frequency of parasequences indicates a declining rate of basin subsidence. Progradation, despite punctuation, thus resulted in basin-filling.