On the Hydrogeological and Hydrogeochemical Features of the Orenburg Region and Adjacent Areas

The complexity of the formation of hydrodynamics and chemical composition of natural waters of the Urals folded mountains and platform Pre-Urals is due to large differences in the geological structure and in the formation of fluids in the mountain-fold, platform, and transition zones. In addition, the properties and amount of waters in the hydrosphere in the supercritical state below the Conrad boundary are practically not investigated. Hydrogeochemical regularities are used in mapping, zoning of the territory, as well as for the interpretation of the actual material, and division of the cross-section in the drainage basins. For this purpose, concepts of hydrodynamic and hydrogeochemical floors, hydrogeochemical zones, hydrogeological and hydrogeochemical aquifer complexes and horizons are used. Each hydrogeological area is distinguished by its vertical hydrogeochemical zonation, which synthesizes the most essential features of the evolution of this structure during a particular period of history. As a result, chemical types of waters with zones of a certain thickness, successively replacing each other within adjacent areas or provinces (belts) are formed. The same type of zonation may also characterize a group of structures.