ENVIRONMENTAL AND PROVINANCE STUDY OF MUDFLATS FROM SHASTRI ESTUARY, RATNAGIRI DISTRICT, MAHARASHTRA USING CLAY MINERALSS.B. Joshi and D. D. Kulkarni
Coastal environment is most active, dynamic and transitional in nature and is characterized by the interplay of continental and marine environments. Estuary represents a most complex environment, developed in the transitional ecotone environment at the confluence point of river and sea. The Konkan Coastal Belt (KCB) of Maharashtra is traversed by eighteen major and thirty-six minor west flowing perennial rivers, originate in the Western Ghats and produce remarkable mud flats along their course. Shastri is one of the most important estuaries of west coast of Maharashtra. During present investigations, sedimentological, clay mineralogical studies of mud-flats from Shastri estuary have been carried with respect to genesis, environmental and provenance using pipette analysis, X-ray diffraction and I-R studies. Representative mud samples have been analyzed. In all samples, the water-soluble salts are found to be negligible in quantity than acid soluble salts. All sediment samples contain significant number of fines with < 63 Ã¬m size. Pipette analysis shows that the sediments from mouth of estuary are of silty- sand type whereas the sediments from middle and upper reach of sandy-silt in nature. X-ray diffraction and I R studies show the presence of kaolinite, goethite, gibbsite, illite, muscovite, chlorite and montmorillonite minerals. The presence of particular clay mineral is due to chemical weathering of the host rock in humid and subtropical conditions. The process of laterization of basalt involves leaching of the most of the oxides from pyroxenes and feldspars. This leaching process is responsible for the formation of different clay minerals in the residual deposit.