Radical distinction near-ore halmyrolysis from backgraund one is presence of acid hypergene solutions, appearing under oxidation sulphide admixtures. There are established following halmyrolysis types: 1) highly acid, if sulfide-hyaloclastite mixture contaits many pyrite; 2) slight acid, if sulfide-hyaloclastite mixture contains pyrite. sphalerite, and organic matter; 3) «subneutral» halmyrolysis taking place at the end of sulfide oxidation processes. Possibility for deposition of goethite, hematite, magnetite, and Mn minerals is determined by availability of reaction between solution and non-metalliferous minerals of sedimentary substratum. In the paper, guantitative substantiation of the results of lithologo-mineralogical researches are given.