Major Element Geochemistry Analysis of Rocks of Pur-Banera Supracrustal Belt, Aravalli Craton, North-WesternIndia

Abstract

The creation of the Indian craton was significantly affected by the Rodinian and Columbian supercontinent cycles. In the Indian Shield, there were two continental blocks at earlier stage - : a) the Southern Indian Block which included the Dharwar, Bastar, and Singhbhum cratons, & b) the Northern Indian Block which included Bundelkhand and Aravali cratons (Ozha et al, 2016). The Aravalli basin started forming by ~2.2–2.1 Ga on a basement rock with composition TTG–amphibolite and then terminated at around 1.8 to 1.9 billion years because of the downgoing of Aravalli crustal mass due west throughout the Aravalli mountain building process. Whole opening and closing followed the lucidity of the Archaean craton at ~2.5 Ga. This can be correlated with the worldwide process of accretion related with the formation of Columbia. The Pur-Banera Belt is a ~30 km lengthy North NorthEast – South SouthWest trending Paleoproterozoic sequence overlying Mangalwar Complex of Archean age in south-central Rajasthan. The Pur-Banera belt consists of metamorphosed sedimentary rocks. It lies in Bhilwara area of the Aravalli Craton, north-western India. This belt comprises supra- crustal sequence related to rift settings, of Mesoproterozoic age. Although the Pur-Banera belt contains siliceous, calcareous, and ferruginous metasediments. But this belt also contains large proportions of metapelites which bear the minerals garnet, kyanite, and staurolite. The most discerning parameters are ferric oxide + magnesium oxide percent, titanium oxide percent, aluminum oxide by silica, potassium oxide by sodium oxide, aluminum oxide by (calcium oxide + sodium oxide). In general, there is a gradual reduction in ferric oxide + magnesium oxide, titanium oxide, aluminum oxide by silica, and an rise in potassium oxide by sodium oxide, aluminum oxide by (calcium oxide + sodium oxide) in sandstones from ocean island arc - passive margins (through continent island arc and active continent margin). In this study, we analyse the rocks on the basis of their major oxides. We try to interpret and predict the protolith, provenance, and tectonic configuration of the area by geochemical analysis of major oxides.