Geology, geography and global energy

Scientific and Technical Journal

Hydrogeological zoning of the caspian basin post-salt floor

2015. №4, pp. 15-24

Myazina N.G. - C. Sc. in Geology and Mineralogy, Associate Professor, Orenburg State University, 13 Pobeda ave., Orenburg, 460018, Russian Federation,

In the article the structure of post-salt pre-Caspian basin floor. Conducted and refined hydrogeological zoning by areal geophysical work (2D). In tectonic relation from the side of the ledge can be traced to the salt massifs in the inside bead area, are becoming distinct, linear, elongated along the Board outline. The width of the zone of development of salt ridges, with all their ramifications is 45-55 km non-contiguous, and parallel side ledge of salt structures can be traced for great distances from Kalmykia, Volgograd and pre-Ural trough. Vaults of ridges located throughout geological epochs close to the surface (250-500 m) and acted as a natural barrier to the migration of fluids in above-salt complex of the Caspian depression. To the East border the salt ridges observed mosaic nature of the distribution of salt bodies and mould. In the Caspian basin subsalt in the floor there are two hydrogeological basins: I - salt ridges and inter-ridge depressions of before board or transition zone, II - cellular interdome mould and typical domes (area of development of large domes isomorphic patterns, which formed salt domes, complicated cornices). Post-salt brines Caspian basin are represented by brines of Cl-Na and Cl-Ca types IIIB. A distinctive feature of the hydrogeological basin of the salt ridges and inter-ridge depressions of the troughs is lower salinity brines from 50 to 200 g / dm , poverty iodine (1-6 mg / dm ), bromine (113-547 mg / dm ). In the hydrogeological basin of cellular interdome mould and typical of the domes are derived and tested brines with a higher salinity of up to 344 g / dm , with a high content of iodine, bromine, and a presence in some areas B O (13-17 mg / dm ). This is an indicator of freer migration biological elements, hydrocarbon fluids through conductive faults from the pre-salt post-salt complex in the mould. In brines and is present Br and J in balneological and industrial concentrations. The high content of iodine priurochte to areas of hydrocarbon deposits of the Caspian depression. The study of the composition, structure of intersalt mould of post-salt floor with bearing brines contributes detection of subsoil with the hydrocarbon deposits.

Key words: Прикаспийская впадина, надсолевой этаж, районирование, гидрогеологический бассейн, химический состав и минерализация, хлоридные рассолы, Cl-Ca тип, гидроминеральное сырье, Caspian basin, suprasalt floor, zoning, hydro pool, chemical composition and salini