Abstract: Bed sediments were collected from the entire region of the Ganges basin and some parts of the Brahmaputra. In addition, selected stations were sampled for suspended sediments as well. The samples were analysed for a number of heavy metals (Fe, Mn, Ni, Cr, Cu, and Zn) by the thin-film energy dispersive X-ray fluorescence technique. There are pronounced temporal and spatial variations in the heavy metals distributions. Suspended sediments are 510 times richer than the bed sediments. None of the tributaries contribute significant heavy metal load, but around urban areas in Yamuna (tributary of Ganges), very high levels due to the distribution from the drainage network are observed. Compared to the Brahmaputra, the distribution and fractionation of heavy metals in the Ganges sediments are more erratic and highly variable. All the metals considered show high correlation among themselves. Given the high flux of suspended sediments from the Himalayan rivers (nearly 20% of the global flux), the worldwide budget for heavy metal transport may need to be suitably revised.

Abstract: Sensitive multi-element analysis techniques together with major-element and isotopic analyses were applied to spring, mine and surface waters in the vicinity of an important known zinclead deposit in a carbonate environment, in the Les Malines area (Gard, France). Both the dissolved and suspended phases were investigated, and concretions and sediments were also considered in some cases. This methodological test shows that the ore body leaves various clear fingerprints, such as the Zn, As, Sb, Pb and U levels in the dissolved phase, the sulfate increment and the δ 34S. Some of the elements in solution are controlled by slightly soluble compounds, e.g. Zn by smithsonite and hydrozincite, Ba by barite, and Pb by hydrocerussite. Mapping the saturation indices for these elements appears useful for displaying the hydrogeochemical anomaly.