Isotopic composition of the major contributors to atmospheric sulfur

Abstract

Only a few S isotope data from atmospheric precipitates are available. These results demonstrate the possibility to discriminate between sulfur burdens from different natural and/or anthropogenic sources. The ?34S patterns of the major suppliers of atmospheric sulfur are discussed. Their δ ranges overlap so completely that we cannot use S isotope data of atmospheric samples to calculate the net contribution rates from the individual sources at a global scale. For selected areas, however, such conclusions can frequently be drawn. The most reliable results are to be expected from areas with only two (at maximum three) major sulfur suppliers with well known S isotopic composition and large δ difference between the individual sources. Limitations are given mainly by the complex origin of atmospheric sulfur from a variety of different sources (especially in highly industrial regions) and by the broad δ ranges even in relatively “uniform” suppliers. Furthermore the fate of the sulfur compounds after emission to atmosphere may be quite complex. Additional fractionation processes efface the “fingerprint” character of the S isotope composition. In some cases these difficulties may be overcome, when the S isotope values are correlated with other geochemical data.DOI: 10.1111/j.2153-3490.1974.tb01969.x