Role of salt tectonics and neotectonics in formation of hydrogeological conditions of the Baskunchak salt massif
Geological-tectonic and hydrogeological conditions of the area Baskunchak salt massif are very complex and are determined by a combination of natural and artificial factors. The geological and tectonic structure of territory led to the formation of four hydro floors: the cover (Neogene-Quaternary), post-salt (Upper-Paleogene), salt-bearing (Kungurian) and subsalt (Carboniferous-Devonian). Breakthrough salt intrusions violated hydrogeological conditions of the area, contributed to the faults of the vaults domes, in this connection, between the individual water-bearing complexes (horizons) has a hydraulic connection, caused an outbreak of discharge for which the migration of groundwater. In the area of the lake. Baskunchak allocated saline-dome structures: Baskunchak, South Baskunchak, Kubatau, Bolhunн salt domes, Baskunchak inner cavity (disjunctive trough) which is connected with salt land bridges at a depth of 1200-1500 m Baskunchaksky form hydrochloric array dissected by faults on a number of large blocks. The presence of confining beds of salt strata Kungurian and regional stage Akchagyl clays up to 400 m resulted in the presence of four structural and hydrogeological floors. Hydrogeological characteristics of each structural stage different chemistry of water, hydrodynamic and temperature conditions, the conditions of formation. These features are due to: neotectonic activity area, expressed the continuing growth of the salt structures and subsidence of the basin oz.Baskunchak; karst processes by which erosion occurs groundwater not only gypsum deposits, but the roof of salt domes. Available gullies and ravines network in combination with positive landforms create favorable conditions for the accumulation of surface waters and their entry into the rock massif. All vyscheperechislennye factors contributed to the formation of different groundwater salinity and chemical composition.