000029212 001__ 29212
000029212 041__ $$aEnglish
000029212 100__ $$aDatta, D. K.
000029212 245__ $$aDistribution and Fractionation of Heavy Metals in the Surface Sediments of the Ganges- Brahmaputra-Meghna River System in the Bengal Basin
000029212 260__ $$c1998
000029212 300__ $$a93-101
000029212 511__ $$aIndus, IndusARTICLES
000029212 520__ $$aThe lower Ganges-Brahmaputra-Meghna (G-B-M) drainage basin occupies the total Bengal Basin, which is one of the unique basins of the world because of its location and size, density of population, and catastrophic deposition of sediments. The increased heavy metal concentration in the 63 m fraction of surface sediments shows similarity among major segments of the G-B-M system in the basin, which reflects the homogenization of lithologic and chemical diversity of the greater denudation regime by the river processes. The differences in heavy metal concentation in the lower G-B-M system with that of its upper and middle counterpart is mainly related to the contrast between Himalayan rivers and the other major South Asian rivers, and may be due to the geological differences of their denudation regime. Heavy metals in the Lower G-B-M system have an affinity towards the clay fraction of the sediments. The correlation matix of heavy metals in the lower Brahmaputra and Meghna suggests the importance of Fe-Mn oxyhydroxides in their accumulations. Iron, Ti and Mn are higher in the Meghna main channel, Zn is higher in the Meghna tributaries, and Cr is higher in both the Brahmaputra and Meghna compared to the value for standard shale. The enrichment factor is ≤1 for most of the metals except Mn which is relatively higher in the Meghna and lower Ganges main channels. The geoaccumulation index (Igeo) for most of the heavy metals lies below grade zero, suggesting unpolluted sediment quality. The lower Ganges system shows relatively higher concentration in the nondetrital fraction of heavy metals, probably due to the presence of petroleum refinery, industrial and mining effluents, and agricultural runoff in the drainage basin. The relative uniformity in concentration of heavy metals in vertical profiles may be due to the uniformity in sediment grain size and catastrophic deposition of sediments, where the time period represented by the vertical sediment column is not enough to reflect the cultural accumulation of heavy metals. The Bengal basin thus represents a relatively unperturbed alluvial basin with regards to heavy metal pollution.
000029212 653__ $$aKey Wordsheavy Metals
000029212 653__ $$aFluvial Sediments
000029212 653__ $$aBengal Basin
000029212 653__ $$aGanges-Brahmaputra-Meghna River System
000029212 700__ $$aSubramanian, V.
000029212 773__ $$pEnvironmental Geology
000029212 773__ $$v36 (1-2)
000029212 773__ $$a10.1007/s002540050324
000029212 8564_ $$uhttp://dx.doi.org/10.1007/s002540050324$$yExternal link (Open access)
000029212 980__ $$aARTICLE