Modern minerals formation at the site of brine discharge from the Lyudmilinskaya well (Solikamsk, Perm region)

The minerals formed from cold (4C) sodium chloride solutions discharged between 1923 and 2019 from the Lyudmilinskaya brine-producing well were studied. During this time, the mineralization dropped from 260 to 9 g/dc3, and, at the wellhead area, an ecosystem presented by invertebrate animals, diatoms, iron and sulfur bacteria has been formed. Minerals, such as calcite and pyrite, and micron precipitates of native phases (sulfur, copper, silver, nickel, bronze), sulphides (series chalcocite- covelline, marcasite, argentopentlandite, acantite, millerite, chalcopyrite), sulfochlorides ((Ag,Cu,Ni)3(Cl,S)), chlorides (Ag3Cl), iron hydroxides, barite and sahamalit-(Ce), were deposited both on the surface of pebbles and in clay-sand alluvial sediments. The studied brines are enriched with respect to sea water by siderophilic (Co, Ni), chalcophilic (Zn, Ge, As, Se, Sn, Sb, Bi, Pb, Tl (Cu?), and lithophilic elements (Be, Al, Ti, Cr, Mn, Y, Zr, Nb, W, Th). The increased concentration of these elements is explained by the hydrolysis and metal leaching the suprasalt clayey rocks with chlorides and sulfates. It is shown that the deposition of minerals occurs both chemically and biochemically.