Pyrite sulfur isotopes reveal glacial−interglacial environmental changes

• DOI: 10.1073/pnas.1618245114
• Publication Date: 2017-05-23T00:40:47Z
• Authors: Virgil Pasquier; Pierre Sansjofre; Marina Rabineau; Sidonie Revillon; Jennifer Houghton; David A. Fike
• Keywords: Biogeochemical Cycle; Sedimentation; Sulfur Cycle; Deposition

Significance Changes in sulfur isotope ratios ( 34 S/ 32 S) of marine phases are often attributed to global biogeochemical perturbations. Sediments collected on the shelf Gulf Lion revealed remarkable isotopic fluctuations sedimentary pyrite over last 500,000 years, ranging between −44.0‰ and 32.3‰. We suggest this pattern is related changes local environmental deposition, specifically, sedimentation modulating connectivity with overlying water column resulting microbial activity. Besides providing new understanding an important poorly constrained aspect past glacial−interglacial transitions, our results critically because they question degree which isotopes reflect processes versus depositional conditions.