<p>The redox sensitive element sulfur is used for reconstructing the oxygen fugacity during magmatic melt evolution applying the sulfur isotopic composition of sulfide and sulfate minerals. Especially fast ascending sulfur-rich alkaline magma from the upper mantle provides the possibility for determining the oxidation state of Earth`s mantle via a detailed investigation of the sulfur cycling. Here we present the first sulfur isotope data of sulfides, sulfates as well as carbonate associated sulfate (CAS) of carbonatite (s&#246;vite) from two well-studied locations (Orberg and Badberg) of the Kaiserstuhl volcanic complex, situated in the southern part of the Upper Rhine Graben (Germany). Based on our results, s&#246;vites are 25000 times more enriched in sulfate than in sulfide. Sulfides display a &#948;<sup>34</sup>S value of 0.6&#160;&#8240; (V-CDT), whereas water-soluble sulfate (e.g. anhydrite) show a sulfur isotopic composition between 3.8&#160;&#8240; and 6.1&#160;&#8240;. &#948;<sup>34</sup>S<sub>CAS </sub>data are at 6&#160;&#8240; at the Orberg and 9&#160;&#8240; at Badberg locality. Our sulfur isotope data are comparable to other carbonatite occurrences worldwide (e.g. Phalabora, South Africa), emplaced at similar temperatures (ca. 860&#160;&#176;C). However, the strongly elevated sulfate content recorded here for s&#246;vites formed at this high temperature is unique and indicates an enhanced oxidation state during s&#246;vite formation in the Kaiserstuhl volcanic complex.</p>
Sedimentary and diagenetic environment of mizunami Group of middle Miocene age, central Japan, deduced from sulfur isotope data