A combined geochemical, Nd, and stable Ca isotopic investigation of provenance, paleo-depositional setting and sub-basin connectivity of the Proterozoic Vindhyan Basin, India

Geochemical and isotopic investigation of Proterozoic clastic chemical sedimentary rocks provide insights into surface conditions the early Earth. The mid-Proterozoic Vindhyan Basin central India, comprising ~5 km thick, mostly undeformed unmetamorphosed sediments, is one such archive which exposed in two sub-basins, Son Valley sub-basin east (SVV) Chambal west (CVV). Nd compositions siliciclastic from CVV are reported order to understand provenance sediments this results compared with SVV evaluate whether sub-basins had shared a common provenance. Elemental ratios, as Th/Co, La/Sc suggest that have dominantly upper crustal silicic/felsic provenances broadly similar those equivalent stratigraphic horizons SVV. Initial composition (εNd(t)) Lower Vindhyans CVV, calculated at their respective times deposition, sediment derivation Banded Gneissic Complex, Berach Granitoids, 1.82 Ga continental arc granitoids Aravalli Range Hindoli Volcanics. In contrast, εNd(t) values Upper siliciclastics Delhi Belt were primary source detritus during deposition these sediments. Paleo-depositional environment connectivity between evaluated using geochemical, radiogenic Nd, stable Ca carbonates both sub-basins. Non-redox sensitive REY anomalies Y/Ho ratios an epeiric sea limited connection open ocean. Neodymium carbonate units connected Carbonates record significant shift towards more around 1.6 Ga, possibly result Andean-type magmatism near vicinity sub-basin. δ44/40Ca typically lower than carbonates. This difference likely due greater freshwater input consistent existence paleo-gradients Basin.