Fig. 5: Metal content of the sulphide melt.
From: The critical role of magma degassing in sulphide melt mobility and metal enrichment
a Theoretical scheme showing how sulphide consumption at equilibrium conditions increases the metal content of the sulphide melt, following the black line, which is calculated after ref. 9: Csulph=C° D (R + 1)/(R + D), where Csulph is the metal concentration in the sulphide melt, C° is the metal content of the silicate melt before sulphide segregation, D is the metal partition coefficient between sulphide and silicate melts, and R is the silicate/sulphide mass ratio. Departure from equilibrium conditions could be due to either metal transfer to the fluid phase (red arrow), or metal enrichment in the sulphide melt due to delayed diffusion of metals (green arrow). Average Cu (b) and Ni (c) contents of the sulphide melt versus its amount in each sample determined by mass balance calculations. Error bars represent the standard deviation around the mean values. The solid and the dashed lines indicate equilibrium contents for variable silicate/sulphide mass ratios (indicated on the line), as in (a), calculated for the minimum (solid line) and the maximum (dashed line) Dsulf/sil values determined in this study.
