Sediment Texture and Geochemistry of Beaches between Redi-Vengurla, Sindhudurg, West Coast of India

摘要

Textural and geochemical determinations were carried out on three beaches (Vengurla, Aravali, and Redi) of the Sindhudurg district, Maharashtra, west coast of India. Seasonal sediments from the beach were collected during 200304 to understand the sediment dynamics (texture, dispersal pattern, depositional environment, etc.) and geochemical characteristics. In general, a seaward grain size fining is seen along Vengurla beach (swash-backwash phenomenon), with a coarsening seaward trend along Aravali and Redi beaches (high-energy conditions). The CM pattern studies reveal traction currents as the transport mechanism. Thus, the sediments of the study area are deposited under moderate to high-energy conditions. The geochemical study shows that the percentages of V, Cr, and Zr are greater in premonsoon; Si, Al, K, Sr, Mn, Ti, and P are greater in monsoon; and Mg, Ca, K, Mn, Na, S, Cl, and P are greater in postmonsoon at Vengurla beach. At Aravali beach, the percentages of Si and Al are more than those observed at Vengurla or Redi beaches. The percentages of Mn, Na, S, and Cl are greater premonsoon; Si, Al, Fe, K, Ti, Cr, and Zr are greater in monsoon compared with the other two seasons; and Mg, Ca, Sr, Mn, P, and V are greater in postmonsoon. At Redi, Cr and Ca are greater than at the two other beaches. Percentage of Fe is greater in all the seasons at Redi. Mn and Ti are quantitatively greater in premonsoon; Si, Al, Fe, and K are greater in monsoon; and Fe, Mg, Ca, Sr, Na, S, Cl, P, V, Cr, and Zr are greater in postmonsoon. These seasonal changes can be attributed to changing wind, wave, and current regimes prevalent in this coastal tract, which seem to be dissimilar even though the three beaches are adjacent (but separated by headlands or a creek).