Abstract
Major ion chemistry of water and elemental geochemistry of suspended and surficial sediments collected from the Cauvery Estuary were studied to understand the geochemical processes in this tropical estuarine system. Specific conductance (EC), total dissolved solids (TDS), and total suspended matter (TSM) increased conservatively with increasing chlorinity. In general, SO4 2−, Na, K, Ca, and Mg showed an increasing trend while H4SiO4 and PO4 3− showed a decreasing trend toward the sea. Additional removal mechanisms operating for these ions in the Cauvery Estuary have been identified based on observed concentrations. Factor analysis pointed out the sources contributing to the observed trends in estuarine water chemistry. POC and PON decreased toward the high chlorinity zone. TSM in the Cauvery Estuary were mostly of inorganic nature. Stable carbon isotope values showed that the carbon was equally of marine and terrestrial origin and helped to delineate the contribution of river water and seawater. The ϕ mean size (a logarithmic grain size scale commonly used by sedimentologists) indicated that the surficial sediments were primarily comprised of coarse and silt, whereas suspended sediments were principally silt and clay. Suspended sediments were enriched in clays compared to surficial sediments. Quartz and feldspar were abundant among detritals while chlorite, kaolinite, and montmorillonite were dominant among clays. Silicon was the most abundant element in the sediments followed by Al, Ca, Na, K, Fe, Mn, and P. Heavy metals were enriched in the suspended sediments compared to the surficial bottom sediments as follows: Fe = 3.5, Mn = 7.4, Pb = 1.1, Zn = 15.2, Cu = 7.4, and Cr = 4.0. The levels of Cd, Cr, Zn, and Fe increased up the middle reaches and then decreased toward the sea due to urban effluent and fertilizer input. Size fractionation studies indicated that the metal concentration in the finer fraction was 50% higher by mass than the coarse silt and fine silt fractions. Chemical fractionation studies showed that the abundance of metals were in the order of residual > organic/sulfide > carbonate > Fe/Mn oxide > exchangeable fractions.
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Literature Cited
Cai, O. L., F. C. Tan, andJ. M. Edmond. 1988. Sources and transport of particulate organic carbon in the Amazon river and estuary.Estuarine, Coastal and Shelf Science 6:1–14.
Carrol, D. 1970. Clay minerals: A guide to X-ray diffraction. Geological Society of America Special Paper 125. Boulder, Colorado. 85 p.
Census. 1981. Government of India Publication. Series I. 310 p.
Coonley, L. S., Jr.,E. B. Baker, andH. D. Holand. 1971. Iron in the Mullica River and the Great Bay, New Jersey.Chemical Geology 7:51–63.
Eisma, D. P., J. J. Boon, R. van Greiken, J. Kalf, and W. G. Mook. 1985. Loss of particulate organic matter in estuaries as exemplified by the Ems and Gironde estuaries, p. 397–421.In E. T. Degens (ed.), SCOPE/UNEP, Vol. 58. Sonderband.
Flanagan, F. J. 1976. Dispersion and analysis of eight new USGS rock standards, United States Geological Survey Professional Paper. United States Government Printing Office, Washington, D.C. 840 p.
Folk, R. L. 1974. Petrology of Sedimentary Rocks. Hemphill Publishing Co., Austin, Texas. 184 p.
Forstner, U. 1983. Assessment of metal pollution in rivers and estuaries, p. 395–419.In I. Thornton (ed.), Applied Environmental Geochemistry, Vol. I. Academic Press, New York.
Forstner, U. andG. T. W. Wittman. 1981. Metal Pollution in the Aquatic Environment, 2nd edition. Springer-Verlag, New York. 486 p.
Gibbs, R. J. 1967. Quantitative X-ray diffraction analysis using clay mineral standards extracted from the samples to be analyzed.Clay Mineral 7:79–90.
Gobeil, C., B. Sundby, andN. Silverberg. 1981. Factors influencing particulate matter geochemistry in the St. Lawrence turbidity maximum.Marine Chemistry 10:123–140.
Griffiths, J. C. 1967. Scientific Methods in the Analysis of Sediments. McGraw-Hill, New York. 508 p.
Ittekot, V., A. Spitzy, andU. Laerz. 1982. Dissolved organic matter in the Elbe Waser and Ems river and the German Bight, p. 1–52.In E. T. Degens (ed.), Transport of C and Minerals in the Major World Rivers. SCOPE/UNEP, Sonderband.
Mook, W. G. andB. K. S. Koene. 1975. Chemistry of dissolved inorganic carbon in estuarine and coastal brackish water.Estuarine and Coastal Marine Science 3:325–336.
Naidu, A. S. 1985. Organic carbon, nitrogen and C/N ratios in deltaic sediments. North Arctic Alaska.SCOPE. 56:311–321.
Ramanathan, A. L., V. Subramanian, andP. Vaithiyanathan. 1988. Chemical and sediment characteristics of the upper reaches of the Cauvery Estuary.Indian Journal of Marine Sciences 17:114–120.
Ray, S. B., M. Mohanti, andB. L. K. Somayajulu. 1984. Suspended matter, major cations and dissolved silicon in the estuarine water of the Mahandi River, India.Journal of Hydrology 69:183–196.
Sackett, W. M.. 1986. Uses of stable carbon isotope composition of organic carbon in sedimentological studies on tropical marine systems.The Science of the Total Environment 58: 397–412.
Salomons, W. andU. Forstner. 1984. Metals in the Hydrocycle. Springer-Verlag, New York. 347 p.
Seralathan, P. andA. Seetaramaswamy. 1987. Geochemistry in the modern deltaic sediments of the Cauvery River,Indian Journal of Marine Sciences 11:167–169.
Seralathan, P. andA. Seetaramaswamy. 1987. Geochemistry of the modern deltaic sediments of the Cauvery River, east coast of India.Indian Journal of Marine Sciences 16:31–38.
Shapiro, L. andW. W. Burnock. 1962. Rapid analysis of silicate, carbonate and phosphate rocks. United States Geological Survey bulletin 1144. United States Government Printing Office, Washington, D.C. 46 p.
Sholkovitz, E. R. 1976. Flocculation of dissolved organic and inorganic matter during the mixing of river water and sea water.Geochimica et Cosmochimica Acta 37:851–880.
Socher, J., U. Nagel, D. Egersglvess, andU. Forstner. 1982. Metal contents in sediments from Elbe, Weses, and Ems estuaries and from the German Bight, Grainsize effects. Mitt. Gent. Paten. Inst. Univ. Homburg.SCOPE/UNEP 52: 687–702.
Spate, O. H. K., A. T. A. Learmonth, andB. H. Farmer. 1972. India, Pakistan and Ceylon. Methuen and Co., London. 420 p.
Subramanian, V. 1983. Factors controlling the chemical composition of river water of India. Proceedings of IAHS Symposium, Hamburg 141:145–151.
Subramanian, V. andP. K. Jha. 1988. Geochemical studies on the Hooghly estuary. Mitt. Geol. Palen. Inst. SCOPE/UNEP Sonderband. Hamburg. p. 267–288.
Subramanian, V., R. van Griekan, andL. van’t Dack 1987. Heavy metals distribution in the sediments of the Ganges and Bramhaputra.Environmental Geology and Water Sciences 9:93–103.
Tan, F. C. andP. M. Strain. 1979. Organic carbon isotope ratio in the St. Lawrence Estuary and the Gulf of St. Lawrence.Estuarine and Coastal Marine Science 8:231–235.
Tan, F. C. andP. M. Strain. 1983. Sources, sinks and distribution of organic carbon in the St. Lawrence Estuary, Canada.Geochimica et Cosmochimica Acta 147:125–132.
Tandon, H. L. S. 1987. Phosphorus research and agricultural production in India. Fertilizer Development and Consultation Organization, Government of India, New Delhi. 160 p.
Tessier, A., P. F. C. Campbell, andM. Bisson. 1979. Sequential extraction procedure for the separation of particulate trace metals.Analytical Chemistry 51:844–851.
Vaithiyanathan, P., V. Subramanian, andA. L. Ramanathan. 1989. Transport and distribution of phosphorus by Indian rivers.Memoirs of the Geological Society of India 13:127–137.
Wentworth, C. K. 1922. A scale of grade and class terms for clastic sediments.Journal of Geology 30:377–392.
Wilber, W. G. andJ. V. Hunter. 1979. The impact of urbanization on distribution of heavy metals in bottom sediments in the Saddle River.Water Resources Research Bulletin 15:790–800.
Yeats, P. A. andJ. M. Bewers. 1982. Discharges of metals from the St. Lawrence River.Canadian Journal of Earth Science 19:982–992.
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Ramanathan, A.L., Vaithiyanathan, P., Subramanian, V. et al. Geochemistry of the Cauvery Estuary, East Coast of India. Estuaries 16, 459–474 (1993). https://doi.org/10.2307/1352594
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DOI: https://doi.org/10.2307/1352594