The Oligocene Barail sedimentary sequence (Tikak Parbat Formation) of Tiru valley, Nagaland constitutes a part of the Belt of Schuppen. These sequences have been studied for the first time employing lithofacies analysis technique. A total of eleven lithofacies namely, coal facies (C), coaly shale facies (CSh), grey shale facies (Sh), shale-sand laminites facies (Ls), ripple laminated shale-sand facies (Rs), tabular cross stratified sandstones facies (Sp), trough cross stratified sandstones facies (St), compound cross stratified sandstone facies (Sc), ripple cross-stratified sandstone facies (Sr), paleosol facies (P) and mudstone facies (Mst) grouped into two lithofacies associations i.e. coal laminites facies association (CLFA) and cross stratified facies association (XSFA) have been identified using four vertical profile sections (VPS) measured and recorded along cut faces of open cast mine in parts of Tiru valley coal field, Nagaland. Presence of coal, silt-mud, very fine to medium sand, heterolithic stratifications (flaser, wavy lenticular and tidal beddings), compound, tabular and trough cross stratifications having low to tangential foresets with abundant mud drapes, bimodal bipolar cross stratification, and substantial reactivation surfaces indicate deposition in a tidal flat environment.
Miocene Tipam Sandstone Formation in parts of Cachar Fold Belt, Northeast India has been studied using petrographic and geochemical attributes to investigate the composition, paleoweathering, tectonic setting, and source rock characteristics. It comprises of coarse to medium grained false-bedded multistoried ferruginous sandstone and variegated sandy clay. Petrographically, these sandstones belong to sub-lithic and lithic arenite varieties possessing an average recalculated modal composition of Q67F13R20. Geochemically, Tipam sandstones have high SiO2, more Na2O than K2O, and relatively low Fe2O3, MgO, MnO content in accordance with the modal composition. Weathering indices like CIA, CIW, PIA and ICV suggest derivation of sediments from low to moderately weathered source terrain bearing plagioclase feldspar in the range of An10 – An55 comparable to granodiorite and granite composition. Dominantly a passive margin setup with high degree of sediment recycling has been envisaged during the deposition of Tipam Sandstone Formation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.