Geochemical compositions and provenance of Late Holocene core sediments from Mullipallam Creek, southeast coast of India

Abstract

Geochemical analyses of major oxides (SiO₂, Al₂O₃, Fe₂O₃, Na₂O, K₂O, CaO, MgO, P₂O₅ and TiO₂) were carried out on the Late Holocene core sediments in the Mullipallam Creek, Southeast coast of India to infer their texture, sediment classification and provenance for paleoweathering conditions. Based on their major oxides compositions, the sediments were classified as Fe-Shale. Bivariate plots of grain size parameters (mean against sorting) are distinguished between open and closed-basin conditions. Chemical Index of Alteration (C1-70.21; C2-69.02), Chemical Index of Weathering (C1-75.25; C2-74.68), Plagioclase Index of Alteration (C1-73.32; C2-72.44) indices and A-CN-K plot suggests moderate chemical weathering in the source area, which was favoured and accelerated under the existing humid conditions of the tropical climate. Al₂O₃ /TiO₂ ratio also proposes the intermediate to felsic source rocks and some of the sediments are derived from mafics. The provenance discrimination diagram explains that the plots appeared in mafic provenance fields indicating that they are derived from different environments.