Spatial dynamics of sediment mineralogy and geochemistry along the Vellar River-to-Coast Continuum, India

Abstract

This study examines the mineralogical and geochemical features of sediment samples collected from the Vellar River, its Estuary, and nearby Coastal regions. By combining X-ray diffraction with chemical assays of Organic Carbon, Calcium Carbonate, and Phosphate, the study seeks to elucidate spatial variations in sediment composition, sources, and depositional processes throughout the River–Estuary–coastal system. The results show quartz as the most common mineral throughout, with specific secondary mineral groups characterising each environment. River and Estuarine sediments contain the highest levels of Organic Carbon, while Coastal sediments are abundantly rich in Calcium Carbonate. Phosphate distribution reveals a contrasting pattern, with significant enrichment observed in specific Riverine and Estuarine pockets rather than the open coast. This pattern reflects both natural biological activity and localised human influence. These findings offer insights into sediment transport mechanisms and emphasise the environmental dynamics influencing sedimentary regimes in tropical coastal systems.