Geography and geology / 3. Hydrology and water resources

D.g-m.s.,professor V.L. Bocharov, Ph.D. in geography, associate professor L.N. Strogonova

Voronezh State University

Geological and geochemical indicators of mineral waters and brines genesis in Voronezh Prihopere,

(Russia)

Sodium chloride and sodium-calcium water of high mineralization levels on the genesis of the main concern in their mass to sedimentogene waters. They represent the buried seawater, in varying degrees of evaporated or diluted. The chemical composition of such water is changed as a result of its interaction with water-bearing rocks.

Study of laws of distribution of mineral waters leads to the conclusion that the formation of mineralization, chemical classes and subclasses, gas composition, spa elements obey the laws of hydrodynamic and hydrogeochemical zoning, which is manifested in the regional plan [1,2].

Features of spatial distribution of mineral waters balneological groups are the result of processes of interaction of water and mineral composition of the rocks in the existing natural and historical conditions that occur in the form of carbon dioxide, sulfuric acid leaching of carbonate and sand-clay soils, the hydrolysis of feldspars, ion exchange between water and disperse part of rocks . The most important role belongs to the same sulfate and nitrate reduction. The combined effect of these processes determines metamorphic waters in the forward direction, which is expressed in a qualitative and quantitative change in the of macro- and microcompositions.

Western edge part of the Volga-Hoper Artesian Basin is composed of clastic-carbonate sequences of Medium and Upper Devonian, Carboniferous sediments, overlying predominantly terrigenous Lower Cretaceous and Neogene-Quaternary rocks with disturbed bedding and drop them in an easterly direction, characterized by mineral waters with reservoir and reservoir-type fissure circulation.

On a plot of deep immersion (more than 250 m from the surface) aquifers (Voronezh Prihopere) highly mineralized brines formed mainly sodium chloride or sodium chloride and calcium compounds with salinity 32.3 – 135,7 g/dm³ and more, accompanied by accumulation of bromine from 100 to 306,4 dm³ and iodine from 1 to 6 dm³. Mineral water carbonates weak nitrogen and hydrocarbon gases [3].

In particular, sodium chloride in water is constantly contained an admixture of sulfate and bicarbonate, alkaline earth metals - calcium, and magnesium. Besides these elements are always present in varying amounts as rare earth metals - strontium and barium.

Water large artesian basins containing specific components in quantities exceeding standards set for healing mineral water solutions are classified as bromine, iodine or iodine-bromide. Since bromine and iodine, have undoubtedly marine origin permanently associated rare earth metals - lithium, rubidium, cesium, entering the aqueous solution upon dissolution of carbonates and sulphates. Distribution of these elements, in which the analysis of sodium chloride and sodium-calcium mineral waters not given due importance, can help in solving the issues of genetic and classification of these waters and their quality assessment for use in medical and spa purposes.

Formation of medical table and therapeutic mineral water in Voronezh Prihopere occurred under the influence of complex natural processes. All this is an extremely wide field of activity for further study of groundwater, during which can be obtained new data on the genesis of mineral waters and open new fields of mineral springs. The most valuable results can be obtained with the help of complex geological, physical and chemical methods of underground hydrosphere investigation, including the search for and evaluation of mineral water resources, their protection from pollution and depletion.

Productive at sodium chloride mineral waters and brines are lower hydrogeological zone rocks of carbonate formation in some cases complicated by the presence of sulfate-lagoonal dolomite formation. Lithology-facies conditions and geochemical environment of formation of the Devonian rocks of the complex contributes to the formation of bromine and iodine-bromine mineral waters and brines, which are confined to the middle and lower Upper Devonian. Mineralization of sodium-chloride water increases with depth, starting with the 120 m and reaches a maximum at depths of 900-950 m [3].

So, a clear dependence establishes between salinity and water content of iodine, bromine and strontium. The same connection is typical for barium, but only for certain levels of basic salts, and then the dependence is reversed. Geochemical separation of these elements is determined by their solubility in saline waters and brines.

Literature

1. Posohov E.V. Mineral water (medical, industrial, energy) / E.V. Posohov, N.I. Tolstihin. – L.: Nedra, 1977. – 240p.

2. Smirnova A.Y. Mineral waters of Russia. Textbook / A.Y. Smirnova, V.L. Bocharov - Voronezh P.h. "Manager", 2009, № 1. – 130p.

3. Bocharov V.L. Geochemistry of mineral waters and brines Voronezh Podonja / V.L. Bocharov, O.A. Babkina, A.Y. Smirnova // Geoecological evolution of the interaction of water with rocks. - Tomsk: Publishing house "NTL", 2012. - P. 303-306.