| dc.description.abstract | The coastal sediments (129 samples) of central- southwest coast of India, in and around Cochin, the second biggest industrial city along the west coast of India, were analyzed for their textural and geochemical fractions such as Fe, Co, Cr, Cu, Mn, Ni, Pb and Zn on a seasonal basis, which form a first report of this kind. Metal accumulation was found to be highest during the period just after the summer monsoon due to the flushing of previously deposited sediments from the Cochin backwaters; the weak coastal currents favoring deposition in the coastal environment. Cross-shelf transport was found to be insignificant during the other two seasons. The geochemical studies reveal two different processes regulating the regional distribution of trace elements in this environment; viz: (1) The increased monsoonal supply of materials through the Cochin backwaters causing increased metal deposition (2) Effective masking of these metals by incorporation into clay and organic association which follows immediately after the monsoon. As the season progresses, they are further impoverished in metals (normalized) through size segregation of marine sediments. The correlations between various sedimentary parameters are elucidated to interpret the coherence between metallic and carrier phases during each season. While organic associations for most of the metals with seasons are preferential, absence of any correlation for Zn and Mn with organic carbon and clay on all occasion is striking | |
