Lower Palar River Sediments, Southern Peninsular, India: Geochemistry, Source-Area Weathering, Provenance and Tectonic Setting

Abstract

This present study describes the geochemistry of fluvial sediments of the Palar river (lower reaches), Southern Peninsular India, with an aim to evaluate their provenance, weathering and tectonic setting. The bulk sediment chemistry is influenced by grain size. The river sediments are enriched with SiO2 and depleted in Al2O3, K2O, CaO, Na2O, MgO, P2O5, MnO, Fe2O3 as compared with UCC values. Geochemical classification indicate that the sediments are mainly arkose, wacke and shale in composition. Discriminant diagrams together with immobile element ratio plots reveal that, the Palar river sediments are mostly derived from rocks formed in an active continental margin. Additionally, the rare earth element ratios as well as chondrite-normalized REE patterns with flat HREE, LREE enrichment, and negative Eu anomalies indicate felsic rock sources. The chemical indices of alteration suggest that Palar river sediments are chemically immature and have experienced low chemical weathering effects. This is further supported by the Th/U Rb/Sr ratio and A-CN-K ternary diagram, with most of the sample data points falling close to the plagioclase-smectite line. The bivariate plot of Th/Sc versus Zr/Sc suggest a moderate recycled origin of the sediments.

Indexical and statistical approaches to investigate the integrated origins of elements in the sediment of Teesta River, Bangladesh: sediment quality and ecological risk assessment

“…In Table 3, elemental concentrations (with mean, median, SD, RSD, and analytical uncertainties) of measured elements are tabulated along with the relevant benchmark data of the upper continental crust (UCC), soil median, and sediments from national and international rivers to obtain a comparative, and regulative idea. 22,35,[44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] Relative to other studied rivers of Bangladesh, namely Buriganga, 22 Sela, 35 and Pashur, 44 elemental presence of Ti, Rb, Cs, Th, and U was elevated to some extent in the Teesta River. Specically, Rb, Cs, and U were ∼1.2-1.4 times greater in the Teesta River than in the Buriganga River.…”