The examination of macroelements and natural radionuclides in the bottom sediments of small lakes and soils in the catchment areas of the Baikal region allows for the study of the mechanism of inflow and the source of these materials.On the basis of the results of rentgenostructural analysis lake sediments are divided into four types:terrigenous,carbonate, terrigenous-carbonate and organogenic.Through the analysis of gamma-ray spectrometry and ato-