High-resolution sulfur isotope and trace element measurements of sphalerites from the Pb-Zn deposits of the Drau Range (Eastern Alps, Austria/Slovenia)

High-resolution (partly in-situ) sulfur isotope measurements on sulfides in 17 samples from 5 different Pb-Zn deposits of the Drau range have been carried out. High-resolution sulfur isotope investigations provide knowledge on small-scale variations in the sulfur isotopic composition of coexisting sulfides and can help to interpret the mineralization processes. The sulfur isotopic composition provides evidence for different sulfur reservoirs and fluids involved in the mineralization process. Small-scale isotope heterogeneities can be related to textural aspects and this enables to recognize different sulfur reservoirs, one providing bacteriogene reduced sulfur (BSR) and another one responsible for thermochemical reduced sulfur (TSR). Both reservoirs were involved into ore formation and were able to contribute reduced sulfur during the whole mineralization process. In addition to isotopic measurements, major, minor and trace element analyses by electron microprobe (EMP) have been carried out on sphalerites in order to investigate if any relation between sulfur isotopic and chemical composition exists.