Bacterial and thermochemical sulfate reduction (BSR, TSR)
Two ways of turning sulfate into sulfide. Bacteria do it at low temperature (below about 80 °C) with strong fractionation, producing very light sulfides; abiotic thermochemical reduction occurs at about 100 to 180 °C by reaction with organic matter and fractionates less.
Composition
Sulfate-sulfide Δ34S: up to 40 to 70 ‰ for BSR, about 10 to 20 ‰ for TSR.
Sources
In the atlas
- Gisements MVT Rhénan (Bleiberg, Mechernich) Germany/Austria
- Red Dog United States
- Limei China
- Yutang China
- Coal-mine tip, site 2 (confined chalk aquifer) France