Пространственно-временные изменения вещественного состава донных отложений и речных вод Туганского россыпного узла (Томская область)

Abstract

The changes in the chemical and mineral composition of bottom sediments and waters of the Omutnaya River (the element of the Omutnaya–Kirghizka–Tom–Ob river system) during the main phases of the water regime in 2018–2019 within the planned Tugan placer deposit (ore minerals—ilmenite and zircon) have been studied. Geochemical parameters were estimated using an inductively coupled plasma mass spectrometry method. It was obtained that the spatiotemporal changes in the gross contents of chemical elements are generally interrelated with their migration forms. General increase in the concentrations of substances in suspended form is predominant and noted in spring floods, with dissolved—in the winter low-water period. Changes in the chemical composition of bottom sediments (fraction up to 1 mm) during the year and from the source to the mouth of the river due to the influence of local geological and hydrological factors are weaker than the corresponding changes in the chemical composition of river waters. Based on the studies, it was shown that the maximum concentrations of ore elements within the halos of placer deposits are most likely under conditions of a relatively stable (geologically) decrease in the intensity of water exchange.