How does pyrite form (pyritisation)?
One of the most important chemical processes in organic-rich marine sediments is decomposition of organic matter in bacterial sulphate reduction. Bacterial sulphate reduction produces bisulphide. Bisulphite can be partially oxidised or can react with organic matter and reactive metal species. All these reactions may be bacterially mediated. The reaction of reduced sulphur with reactive dissolved iron and iron minerals, if available, results in the formation of iron sulphides. The most common iron sulphide in pyrite.
