Pratiksha P. Bagul, Prafull B. Kamble, Omkar Parab and Milind A. Herlekar*

Department of Geology, Savitribai Phule Pune University, Pune-411007(MS), India

(*Corresponding Author, E-mail: milindaherlekar@gmail.com)

Abstract

The seasonal variations in the textural parameters of beach sediments were studied along the Purangad-Gaonkhadi Coast of the Ratnagiri District, Maharashtra, India. During the pre-monsoon (PRM) season, the foreshore sediments comprise fines and to medium sand, while the backshore, raised beach (Berm) and foredune sediments show fine sand characteristics. The PRM foreshore, backshore, raised beach (Berm) and foredune sediments are well-sorted to moderately well-sorted. The foreshore sediments show symmetrical to strongly fine skewed whereas, backshore sediments are fine skewed to strongly fine skewed. The foreshore and backshore sediments in the post-monsoon (POM) season are comprised of coarse-grained sands, whereas raised beach and foredune sediments contain fine-grained sand. The foreshore sediments are poorly sorted to very poorly sorted, while the backshore and raised beach sediments are moderately poorly sorted. The linear discriminant analysis (LDA) plots of the sediments fall in a shallow marine environment, while few fall in a beach shallow environment. The XRF studies indicate a high concentration of ‘Fe’ in the northern part while it decreases towards the southern part along the beach. The ‘Fe’ concentration also increases cross-shore from foreshore to backshore. The ‘Ti’ concentration also shows an increasing trend from the foreshore to the backshore zone. The mudflat samples have indicated the presence of kaolinite, illite, smectite, and chlorite. The concentration of kaolinite and illite is higher than that of smectite and chlorite from north to south in the study area. The waves and currents along the Gaonkhadi Coast of the Ratnagiri District are formed under high energy conditions during the SW monsoon and affected erosion with a strong winnowing process.

Keywords: Grain Size, Linear Discriminant Functions, CM Plots, Depositional Sedimentary Environment, West Coast of India