Depositional features in tourist beaches of Chennai Metropolis, SE coast of India: Inferences from grain size studies

The present study was undertaken to examine the depositional and transportation pattern in the tourist beaches of Chennai in SE coast of India. Twenty four samples were analyzed for textural parameters, Linear discriminate function (LDF), C-M plots and heavy/light minerals from beach, berm and dune regions. Results of textural parameters indicate that they are coarse grained in the three regions. Majority of the samples indicate that they are moderately well sorted, symmetrically skewed and leptokurtic. The LDF analysis allowed in identifying areas that are characterized by: (1) beach, (2) shallow agitated environment and (3) fluvial deposits. C-M plots indicate that the sediments in the beaches were deposited from the near shore environment. Heavy mineral analysis suggests that the heavy and light minerals were in the range of 0.5 to 16.9% and 82.08 to 98.14% and the light/dark layers are controlled by the prevailing tidal conditions in the coastal region. It is observed that sand is accumulating from the shallow agitated environment, while the transportation and deposition of sediments is mainly due to the interaction of tidal activities at the same time. C-M plots suggest that the sediments fall in the graded suspension and the saltation activities in the region also facilitate to understand the hydrodynamics of the region suggesting that they are deposited by high-energy activities.