THE FEATURES OF FLUID REGIME AND POSSIBLE MECHANISMS OF GOLD ORES FORMATION IN VOLCANIC BELTS (ISOTOPE DATA)

Transport mathematic model describing oxygen isotopes fractionation be tween water and rocks has been used to interpret the data on oxygen is otope composition of carbonates of gold deposits of Siberia and Far Ea st volcanic belts. It has been found that gold ores formation occurred as a result of convective movement of meteoritic water close to the h eated magmatic bodies. Isotope data show the gold bodies formed in the most altered zones of hydrothermal systems discharge areas where the ratio water/rock had a maximum for the system considered. Additional d ata on carbon isotope composition in carbonates and chemical compositi on of organic matter show that the most probable mechanism of gold dep osition in the deposits considered was gold redeposition at the redox barrier forming during the movement of oxidizing meteoritic water thro ugh the rocks having properties as a result of organic matter enrichme nt at the different stages of the system evolution.