Isotopic Composition of Waters in Salt Lakes of Eastern Transbaikal

The isotopic composition of the natural waters of Eastern Transbaikal is studied. It is established that the water of the soda lakes is more enriched in oxygen-18 than in deuterium. It is shown that the enrichment of the salt-lake waters in heavy isotopes occurs not only due to the evaporation process, but also due to water–rock interaction. The participation of the aluminosilicate hydrolysis reactions 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.