Abstract
The first regional studies related to the study of the stable isotopic composition of groundwater in the territory of Kazakhstan were carried out in the 80s of the last century. Some basic regional regularities in the zoning of deep confined waters according to their isotopic composition were identified. The results of the research revealed, in general, the similarity in the genesis of deep pressure waters of the artesian basins of South Kazakhstan with the waters of the Neogene-Quaternary age. It has been established that the formation of groundwater reserves in deep confining aquifers occurred during the last Pleistocene glaciation. The influence of pluvial epochs on the replenishment of groundwater reserves in arid regions is confirmed by isotope studies in the modern deserts of Africa, the Arabian Peninsula, and Central Asia. In recent years, additional regional studies of the stable isotopic composition of deep confined waters of sedimentary basins in South Kazakhstan have been carried out. Groundwater samples were taken in the course of expeditionary research. The ratios of the stable isotopes 2Н/1H и 18O/16O were measured on a highly sensitive LGR 912-0008 laser spectrometer. Water samples calibrated against the International Standard: Vienna Standard Mean Ocean Water (VSMOW) were used as internal standards, this standard was promulgated by the International Atomic Energy Agency (IAEA). The measurement accuracy of 2Н и 18O was ± 1 ‰ и 0,5 ‰, respectively. To assess the degree of non-uniformity of the processes of the genesis of deep confined waters, the coefficients of the deuterium kurtosis were calculated. The research results showed that the artesian waters of the sedimentary basins were formed mainly due to meteoric waters.