Some Features of the Lithogeochemistry of Surface Bottom Sediments in the Pechora River Delta
摘要
Some lithogeochemical features of surface bottom sediments (silty sands, silty pelites, and pelitic silts) in the Pechora River Delta are analyzed. It was found that their bulk chemical composition (calculated on the anhydrous basis) is similar to that of the Pechora River suspended matter. The previous assumption that the detrital material composing the surface bottom sediments are predominantly sourced from sedimentary and felsic igneous rocks of the Urals is confirmed. The preservation of a provenance signal from this distant provenance in the Pechora River Delta is probably associated with both the rather harsh climate in the drainage basin and the absence of any other clastic sources in the middle and lower reaches of the Pechora River. It is shown that the content of the overwhelming majority of trace elements in the studied samples is noticeably lower or comparable to that in the upper continental crust. Absolute concentrations of heavy metals in bottom sediments of the Pechora River and Bol’shaya Zemlya Tundra soils, sampled in different years using various methods, have a fairly high degree of convergence. The main carriers of both heavy metals and other trace elements in bottom sediments are feldspars, fine-grained/silty–clayey components, as well as iron oxides and hydroxides.