van Hinsberg et al. Determining subduction-zone fluid composition using a tourmaline mineral probe Figure S-3 Reconstructed Ba/Th vs. La/Sm ratios for subduction-zone fluids in the Tauern eclogite zone, as determined from tourmaline compositions (see Fig. 2 for locations of these points). (a) Calculated assuming constant Dtur/fl, obtained by combining experimentally determined Dphg/fl of Green and Adam (2003) with Dphg/tur of Klemme et al. (2011). (b) Calculated from Dphg/fl of Green and Adam (2003) extrapolated to relevant P-T conditions using phengite lattice systematics at constant Dphg/tur (from Klemme et al., 2011). The impact of changing speciation on Dtur/fl is shown by the thick arrows. Reconstructing fluid compositions with extrapolated D values results in lower Ba/Th in the fluid, with only minimal impact on La/Sm. The differences in Ba/Th between core and mantle become smaller, but the predicted effect of changes in speciation would re-introduce this difference. The gray uncertainty ellipses show the 1 standard deviation uncertainty in the ratios resulting from the spread in the trace element analyses of the minerals. Figure S-3 Reconstructed Ba/Th vs. La/Sm ratios for subduction-zone fluids in the Tauern eclogite zone, as determined from tourmaline compositions (see Fig. 2 for locations of these points). (a) Calculated assuming constant Dtur/fl, obtained by combining experimentally determined Dphg/fl of Green and Adam (2003) with Dphg/tur of Klemme et al. (2011). (b) Calculated from Dphg/fl of Green and Adam (2003) extrapolated to relevant P-T conditions using phengite lattice systematics at constant Dphg/tur (from Klemme et al., 2011)… van Hinsberg et al. (2017) Geochem. Persp. Let. 3, 160-169 | doi: 10.7185/geochemlet.1719 © 2017 European Association of Geochemistry