Isotopic composition of water of salt lakes in Eastern Transbaikalia

The isotope composition of the natural waters of the Eastern Transbaikalia is studied. It is established that the water of the soda lakes is more enriched with oxygen-18, but in smaller - with deuterium. It is shown that the enrichment of the waters of salt lakes with heavy isotopes is due not only to the evaporation process, but to the interaction of water with the rock. The participation of the reactions of hydrolysis of alumosilicates in the fractionation of oxygen is confirmed by the direct dependence of the magnitude of the oxygen shift on pH, the value of which depends on the degree of such interaction.