Geochemistry of Iron in Fresh Groundwater of the Sredneobskoy Basin, Russia

In the central part of Western Siberia a study of the chemical composition of fresh groundwater in the upper 600 m of the Sredneobskoy basin was carried out. It was shown that groundwater generally contains high concentrations of iron. The features of the distribution of iron in groundwater and sources of its origin are investigated. The maximum iron content is confined to the waters of the Neogene-Quaternary and Paleogene sediments that form a favorable gleysol (Eh -100 to +50 mV), neutral pH (6,8 to 7,5), the geochemical environment with a high content of dissolved organic matter. Aluminum silicate rocks are a source of iron, namely, the primary mineral water-bearing rocks, which in these circumstances are extremely soluble and therefore not in equilibrium with respect to the release of iron, calcium, magnesium, sodium, and other elements.