Authigenic minerals of titanium and zirconium of the Verkhnekamskoye salt deposit
Newly formed titanium oxides and zircons have been identified in the salt and suprasalt of the Verkhnekamskoye Salt Deposit. These features have been associated with the hydrolysis of clay material and the release of colloidal titanium and zirconium hydroxide during diagenesis, catagenesis, and hypergenesis. This is made possible by sulfate reduction and the acidic environment, which are caused by the radiation-oxidation of Fe2+ from sylvite and carnallite. Anatase is formed both in the suprasalt and salt measures and, only in the lower part of the salt measures, in the rutile. Such a distribution can be associated both with an increase in the degree of catagenetic transformation of salt rocks with depth and with the composition of coexisting sulfate or chloride brines. A typical form of anatase crystals is pinacoid, but this is replaced by a dipyramidal structure in the carnallite zone, which is the location of the most acidic brine. Three types of twins were recorded for rutile, the formation of which is attributable to the growth of a dehydrated colloid of titanium hydroxide on a finely dispersed aggregate. The impurities V, Cr, and Zr (Al, Si, and Fe) established in the titanium oxides reflect the geochemical specialization of the aluminosilicate terrigenous material sources.