A New Genetic Type of Leaching Zone in Salts of the Verkhnyaya Kama Potassium Salt Deposit: Hydrochemical, Mineralogical, and Structural Indicators

The brine-saturated leaching zone discovered in the Verkhnyaya Kama salt deposit is scrutinized. It comprises a cavernous core (40 × 70 m) composed of aposylvinite syngenite (halite rock with gypsum and kalistrontite) and a recrystallization aureole (60–80 m wide) without secondary sulfates. The leaching zone is overlain by a linear zone of the weathering and decarbonatizaton of marls in the suprasalt sequence. This zone is controlled by a nearly latitudinal anticlinal ridge extending parallel to the Durinsky trough related to synsedimentary normal faulting. Injection of suprasalt waters into the salt body is attributed to deformations of the salt sequence as a result of its articulated bending during the formation of the Durinsky trough in the Early Permian. Brines in the studied leaching zone are linked with the infiltrational suprasalt calcium sulfate waters. Their position in the general genetic typification of natural brines and waters circulating in the salt body of the Verkhnyaya Kama deposit is defined.