Natural Radioactive Elements as Indicators of Conditions of Formation of Sedimentary Rocks of the West Siberian Plate

Abstract

Abstract—The paper presents major tendencies in the distribution of potassium, uranium, thorium, and Th/U ratio throughout the facies profiles of the main Mesozoic sedimentation basins of the West Siberian plate. The potassium and thorium behavior is determined by the number and position of source areas and the degree of their tectonic activity. The uranium distribution is controlled by the accumulation level and the type of organic matter as well as by redox potential. Under conditions of primary sedimentation scattering of uranium, the Th/U ratio is not statistically significant indicator of sedimentation settings.