Chemical and Sediment Characteristics of the Upper Reaches of Cauvery Estuary, East Coast of India

Abstract

Major and minor element geochemistry of water and suspended and bed sediments collected from upper reaches of the estuary are studied to understand the geochemical processes in tropical estuarine systems. Suspended sediment concentrations increase downstream with chlorinity. All the major dissolved elements like Na, K, Ca, Mg and Si show conservative behaviour. Dissolved phosphate is non-conservative. The phi mean size of sediments increases downstream. Clay minerals in the suspended sediments are predominantly kaolinite, illite and montmorillonits. Si is most dominant element in the sediments followed by Na, Al, Ca, Fe, K and Mg. Heavy metals are enriched in the suspended sediments compared to the bed sediments. Major and minor elements transported along with the clay minerals due to flocculation get trapped in the estuarine bed sediments.