PHYSICAL AND CHEMICAL CONDITIONS OF FORMATION OF THE MASSIVE SULFIDE ORE-DEPOSITS OF THE VERKHNEURALSKY ORE AREA, SOUTHERN URALS

Fluid inclusion studies of the minerals of ores and altered country rocks of the Verhne-uralsky ore area showed the following mineral formation parameters: homogenisation temperature range of 370-110-degrees-C, the pressure of 1-0,5 kbar and the salinity in the interval of 0,8-11,2 (rarely up to 22,8) wt.% NaCl equiv. Four solution types are distingushed by the temperature eutectic melting. Lateral temperature zoning in the altered rocks was established including the maximal temperatures in zones of ore transport and temperature decrease at the flanks. Evidences of hydrothermal solution boiling were revealed in the underlying rocks. The observed homogenisation temperatures in the ores are not connected with the composition but reflect the diagenetic and epigenetic transformation of ores. The differences of the hydrothermal solutions of studied deposits in relation to modern hydrothermal sulfide bearing solutions at the sea bottom are shown.