Granulometric studies on the modern sediments of Ettikulam lagoon, west coast of India

Abstract

Surface sediment samples were studied to decipher the significant textural variation within the lagoonal area. Sediment distribution is affected by the river deposition and various geomorphic features such as barriers and islets in this region. Muddy sand covers a major part of the lagoon. Most of the lagoonal sediments are polymodal, positively skewed, and poorly to very poorly sorted. The platykurtic and leptokurtic nature of lagoonal sediments are due to the mixing of different size populations in varying proportion. CM pattern indicates the prevalence of low to moderate current activity in the areas adjacent to river mouths and inlet, and a quiet area in the middle part of the lagoon. The protected nature, adequate supply of sediments by rivers and the presence of small natural islands within the lagoon are responsible for the sediment distribution pattern in the lagoonal area.