(Table 1) Microbialites from coral reefs off the volcanic islands Tahiti and Vanuatu and from the nonvolcanic sites Belize and the Maldives

Contents of CaCO3, total organic carbon (TOC), total sulfur (TS, non-carbonate = decalcified rest of sample), and chromium reducible sulfur (CRS, representing sulfide minerals in microbialite) as well as the isotopic compositions of sulfur in bulk samples, CRS, sulfur in carbonate associated sulfate (CAS), oxygen in CAS, carbon in TOC, and lipids specific for sulfate-reducing bacteria (SRB) in microbialites (all average values because lipid biomarkers were analyzed in other microbialite samples than those shown here, see Table 2) and in one coral from Tahiti (control measurement).