New genetic type of leaching zones in the salts of the verkhnekamskoe salt deposit: hydrochemical, mineralogical and structural indicators

The brine-saturated leaching zone first encountered in the salt rocks of the Verkhnekamskoe Salt Deposit is characterized in detail. It consists of a cavernous nucleus (40×70 m), composed of an aposilvinite syngenite-halite rock with gypsum and kalistroncite, and a recrystallization halo 60–80 m wide, not containing secondary sulfates. Above the leaching zone is a linear zone of weathering and decarbonization of marls above the salt layer. This zone is controlled by the anticlinal crest of the sublatitudinal strike, extending parallel to the Durinsky Trough of the sedimentary-fault nature. The penetration of supra-salt waters into a salt deposit is associated with the manifestation of deformations in the salt mass at its hinge inflection during the formation of the Durinsky deflection in the Early Permian time. The connection of the brines of the investigated leaching zone with infiltration over-salt sulfate-calcium waters was revealed and their place was determined in the general scheme of genetic typification of natural brines and waters circulating in the salt deposit of the Verkhnekamskoe Salt Deposit.