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The isotopic composition of air-borne sulphur was investigated in Saxony, Southeast Germany--a region with formerly very high atmospheric SO(2) concentrations. In addition, data from various authors were compiled for different Saxonian locations, spanning from 1992 to 2004, i.e., a time of decreasing SO(2) concentrations in the atmosphere. There were no obvious temporal changes in the mean delta(34)S value of bulk precipitation. However, the variability of monthly mean delta(34)S values decreased. The mean sulphur isotope composition of sulphate from bulk precipitation after the year 2000 converges in Saxony towards 4-5 per thousand, with similar values for different locations. Mean values of different forms of sulphur show the following enrichment order: delta(34)S of SO(2) < delta(34)S of weathering crusts < or =delta(34)S of sulphate from bulk precipitation < or =delta(34)S of dust. Judging from local differences on sulphate crusts and corresponding isotope values of sources, the delta(34)S value of SO(2) as well as for crusts mainly reflects local point sources. The mean delta(34)S value of bulk precipitation represents more regionally well-mixed SO(2) sources and is therefore an ideal tool for monitoring regional atmospheric change.

We investigated physical, chemical and isotope (S, O) parameters of sulfate from acid mine drainage from the polymetallic sulfide ore deposit Freiberg (Gennany), which was mined for more than eight hundred years. Two main groups of water were distinguished: 1. Flowing mine water with sulfate concentrations of less than 9,000 mg/l and pH values higher than 3.2, 2. Pore water in weathered low grade ores and pools with sulfate concentrations higher than 9000mg/l and pH values below 3.2. The sulfur and oxygen isotope composition of sulfate from flowing mine waters reflects mixing of sulfate from two sulfur sources: a) atmospheric sulfur from precipitation and b) sulfate formed as a result of sulfide oxidation processes. Sulfur isotope values of mine water sulfate were used to estimate the contribution of sulfate derived through oxidation of sulfides. The sulfur isotope composition of pore water sulfate and precipitated sulfate (jarosite) from weathered low grade ore samples is identical to the sulfur isotope composition of primary sulfides. The oxygen isotope composition of pore water sulfate from low grade ore samples indicates that the oxidation process proceeds relatively slowly in 02-depleted waters, probably without significant microbial catalysis.