Abundances of S, Ga, Ge, Cd, In, Tl and 32 other major to trace elements in high-temperature (350-700 °C) magmatic-hydrothermal fluids

This study reports concentration data for Li, B, Na, Mg, Al, S, CI, K, Ca, Mn, Fe, Cu, Zn, Ga, Ge, As, Br, Se, Rb, Sr, Nb, Mo, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, Ce, Ta, W, Tl, Pb, Bi, Th and U in 124 high-temperature (350-700 degrees C) magmatic-hydrothermal fluids investigated from five barren, six sub-economically Mo- or Cu-mineralized, and five economically Sn-, W-, Cu, Mo- or REE-mineralized granodioritic to granitic intrusions, based on Laser-ablation ICP-MS analysis of 304 individual fluid inclusions hosted in quartz. Most of the analyzed fluid inclusions were large and well-preserved, and careful corrections for ablated host were made for Li, Al, S, Cl, Ge, Br and Sn, assuring high-quality data. The discussion in this contribution is focused on S, Ga, Ge, Cd, in and Tl, for which elements only few data have been available for high-temperature magmatic-hydrothermal fluids so far. Sulfur concentrations are mostly in the range of 0.1 to 2 wt%, but can reach up to 13 wt% in some hypersaline brines. Gallium, Ge, Cd, In and Tl concentrations are mostly within the range of 0.6-3 mu g, 10-200 mu g/g, 2-70 mu g, 0.2-20 mu g/g, and 2-80 mu g/g, respectively. If normalized to the concentration of sodium (which has a similar effect as normalizing to a constant fluid salinity), the abundances of Ge, Cd and In show a distinct correlation with Zn, whereas Ga correlates with Ba, Tl correlates with Rb, and S correlates with Mg and Th. The observed correlations are in agreement with metal transport dominated by chloride complexes in the case of Cd and Tl, dominant hydroxy-complexes in the case of Ga and Ge, and with an incompatible behavior of In and Tl during magma differentiation.