MINERAL WATER SUBSALT WATER-BEARING RESERVOIRS OF THE CASPIAN DEPRESSION
The article reveals the regularities of the distribution and formation of mineral waters of the subsalt floor of the Caspian basin. Sub-salt deposits in the Central part of the Caspian basin lie at great depths up to 10-11 km and are achieved by drilling only in the onboard zone. The power of the subsalt floor in the on-Board zone is 3-4 km, increasing to the Central Caspian rift to 10-16 km in the section of which there are lower Paleozoic and Vendian-Riphean formations. In the pre-salt are located the lower part of the pre-salt hydro-system. In the pre-salt floor of the Caspian basin there are three groups of mineral waters according to the classification by V.V. Ivanov and G.A. Nevraev: I - without "specific" components and properties; III - hydrogen sulfide; V is bromine, iodine, boric water and with a high content of organic substances. There is a great variety in the class of chloride waters without «specific» components and properties; hydrogen sulfide; bromine, iodine, boron waters. According to the ion-salt composition, iodine-bromine chloride sodium, sodium-calcium (calcium-sodium) brines, with mineralization up to 310 g / dm<sup>3</sup> and below to the Foundation are desalinated brines. They are analogues of the Vologda, Moscow, Ust-Kachkin types.