An approach to provenance and tectonic setting of the Proterozoic Upper Kaimur Group sandstones, Son Valley: constraints from framework mineralogy and heavy mineral analysis

Framework mineralogy and heavy mineral analysis of Proterozoic Upper Kaimur Group Sandstones of the Vindhyan basin, Son Valley have been investigated on composition, provenance and tectonic setting. The studied sandstones are quartzarenite to sublitharenite in composition with high quartz, low feldspar, mica and low to moderate amounts of lithic fragments of metamorphic and sedimentary rocks. The detrital modal compositions of these sandstones reveal that these sandstones belong to the continental block, recycled orogen, rifted continental margin tectonic regime with maturity and stability of the source region. The characteristic heavy minerals are zircon, tourmaline, rutile, epidote, biotite, chlorite, staurolite, hornblende, hypersthene, garnet and opaques. The non-opaque heavy mineral assemblage of the sandstone is dominated by zircon, tourmaline and rutile (ZTR) suggests a recycled sedimentary source. Though heavy mineral suites of all the sandstone samples are by and large similar, but differences are seen in their frequencies of heavy minerals in a vertical succession. Mineralogical maturity coupled with characteristic heavy mineral associations is consistent with northern and northwestern palaeoflow and tectonic evolutionary history of the region that indicates Mahakoshal Group and Chhotanagpur granite gneiss present in the southern side of the study area show the source of the Upper Kaimur Group rocks.