An experimental assessment of the chalcophile behavior of F, Cl, Br and I: Implications for the fate of halogens during planetary accretion and the formation of magmatic ore deposits

The elemental and isotopic abundances of halogens (F, Cl, Br, I) are used to constrain planetary volatile loss and volatile delivery processes, but their behavior during magmatic differentiation in general, and sulfide liquid segregation in particular, is currently not well constrained. To test whether sulfide liquid segregation could affect halogen behavior during magmatic processes, we performed high-pressure experiments to systematically quantify the sulfide liquid – silicate melt partition coefficients (Dsulliq-silmelt values, defined as the ratio between the wt.% concentration of the halogen in the sulfide liquid and silicate melt, respectively) of F, Cl, Br and I at a pressure of 1 GPa and temperatures of 1683–1883 K. Results show that dry-polishing target surfaces is crucial for obtaining representative halogen concentrations of sulfide liquids. The results also show that no appreciable amounts of F partition into sulfide liquids, whereas Cl, Br and I behave increasingly chalcophile with increasing atomic radius (i.e., DF sulliq-silmelt 1) in several experiments. In contrast to previous observations, DCl/Br sulliq-silmelt was found to be