A multiple sulfur and organic carbon isotope record from non-conglomeratic sedimentary rocks of the Mesoarchean Witwatersrand Supergroup, South Africa

► Strong tectonic and depofacies control over pyrite distribution, pyrite type, pyrite chemistry, S/C ratios and multiple sulfur and organic carbon isotope compositions (δ13Corg, δ34S, Δ33S, Δ36S). ► Preservation of detrital pyrite and non-zero Δ33S values infers low O2 Mesoarchean atmosphere. ► Dampened Δ33S values reflect dilution by a mass-dependent crustal sulfur reservoir. ► Tectonism, weathering, microbial sulfate reduction and anaerobic methanotrophy could have triggered Mesoarchean glaciation. ► Large Δ33S values associated with diamictite may represent unique atmospheric chemistry and/or hydrological freeze-thaw cycles.