Levels of elements in the surficial estuarine sediments of the Hugli River, northeast India and their environmental implications.

摘要: The present paper is the first document of a detailed geochemical and mineralogical study muddy to sandy mud estuarine sediments Hugli River collected from five different sites along its course in coastal areas West Bengal, northeast India. work attempts establish status distribution environmental implications 52 elements surficial their possible sources derivation. level both metallic non-metallic shows wide range variation all estuary can be attributed differential derivation source rocks discharge untreated effluents originating industrial, agricultural, aquacultural as well domestic sewage. element contents, particularly heavy metal content sediments, are lowest upstream part at Diamond Harbor, whereas, these slightly higher intermediate stretch Haldia highest mouth Gangasagar. These changes indicate that metals carried find ultimate depositional sink delta near Gangasagar, where almost showed elevated values. majority have concentrations Canning, site within tidal channel network Hugli-Matla drainage basin away direct influence River. This severely contaminated with huge organic load sewage, aquaculture, intensive trawling activities agricultural runoff. Moreover, suffers siltation causing an moribund condition Matla this point. Equi-dimensional quartzo-feldspathic mineral grains consistent components siliciclastic composition sizes each station controlled by respective hydrodynamic conditions. Various flaky minerals (mica, chlorite, hornblende) also but show inconsistent patterns distribution. remain suspension for long time do not follow usual law settling particles depending on regime prevailing area. Presented data will serve baseline against which future anthropogenic effects may assessed. A comprehensive account regions peninsular India has been presented purpose comparison.