Sedimentological and clay mineral studies in Kakinada Bay, east coast of India

Abstract

The sediments of Kakinada Bay are predominantly silty clays, with a phi mean range between 2.9 to 7.8. Northern, central and southern parts of the bay consist of finer sediments (5.5 to 7.2 phi) while the eastern and western parts of the bay are of sandy sediments (2.9 to 3.05 phi). Interrelationships of size statistical parameters and the CM diagram of the bay sediments suggest a mechanism of slow deposition from quiet water. Montmorillonite is the predominant clay mineral followed by kaolinite and illite. Concentration of montmorillonite in the bay sediments is mainly controlled by the energy conditions of depositional environment. Kaolinite enrichment at the drainage channel entrance is due to preferential settling of kaolinite in low saline water.