Литосфера (Dec 2015)
Mineral assemblages and behavior of ore-forming elements at rock-seawater interaction in hydrothermal conditions
Abstract
A hydrothermal interaction of oceanic rocks with seawater was simulated in the Selektor program at 350°C and 25 MPa. It was found that the maximum extraction of major ore-forming elements of massive sulfide deposits from basalts occurs under reducing conditions: 2.9 Ч 10-3 mol Fe at ξ = -lg(rock/seawater) of 2.1, 3.3 Ч Ч 10-4 mol Zn at ξ = 0.625 and 5.02 Ч 10-5 mol Cu at ξ = 1.4. The major transport complexes of these elements in hydrothermal fluids are FeCl20 > FeCl+ > Fe2+, ZnCl+ > ZnCl20 > ZnCl3-, CuCl32- > CuCl2-. According to recycling model, the mafic rocks (gabbro, basalts) are the most likely source of metals for hydrothermal sulfide systems.
