LAUSR

The present study emphasizes major elemental geochemical attributes-based prediction of nature, palaeoweathering intensity, provenance, tectonic setting and palaeoclimatic condition of source area of Sabarmati alluvial sediments lying in Ahmadabad locality, Gujarat, India. The sediments successions are comprised of gravel, poorly graded sand, with dominant silty and clayey sands, silt and clay with low-to-high level of plasticity. The sediments exhibit increasing concentration of MnO followed by P 2 O 5 , TiO 2 , K 2 O, MgO, Na 2 O, CaO, Fe 2 O 3 , Al 2 O 3 and SiO 2 which supports quartz dominating sand layers in comparison with silty and clayey sequences. The values of SiO 2 /Al 2 O 3 , Na 2 O/Al 2 O 3 and K 2 O/Al 2 O 3 and higher values of ICV indicate immature sediments with low dilution of ‘Na’ and ‘K’. Lithologically, the majority of sediments belong to shale and Fe-shale varieties. The values of ICV, CIA, CIW and PIA and various bivarient and discrimination diagrams reveal the mechanical fragmentation, abrasion and low to moderate degree of chemical palaeoweathering of fragments of felsic and intermediate igneous rocks of rift basin located at island arch and active continental margin under arid/semi-arid conditions sporadically interfered by short-term humid and semi-humid climatic conditions were responsible for formation of sediments sequences of the area.