The controls on sedimentary pyrite formation in Southern Ocean deep-sea sediments ...

• Main Authors: Mikler, Monika, Weber, Michael, Franz, Sven Oliver, März, Christian
• Format: Text
• Language: English
• Published: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV) 2022
• Subjects: Scotia Sea; Southern Ocean
• Online Access: https://dx.doi.org/10.48380/3dwn-bn74; https://www.dggv.de/e-publikationen/the-controls-on-sedimentary-pyrite-formation-in-southern-ocean-deep-sea-sediments

The formation of pyrite in deep-marine sediments is typically limited by organic carbon or/and reactive iron availability. The Southern Ocean generally exhibits an iron deficiency, limiting bioproductivity and thus the sequestration of CO2 from the atmosphere. Based on iron deficiency in the photic zone, it could be assumed that the formation of pyrite is iron-limited, too. To evaluate the controls on sedimentary pyrite formation, sediments from ca. 4 Ma to recent, recovered during IODP Expedition 382 (Iceberg Alley) in the Scotia Sea, were examined for their carbon, nitrogen, sulfur, major and minor element contents. The organic carbon and sulfur contents in the sediments have a mean value of c. 0.4 and 0.3 wt.%, respectively, whilst iron has a mean value of c. 4 wt.%. Organic carbon and sulfur demonstrate a good correlation and a significant increase from c. 1.25 Ma toward the stratigraphically younger. Further, the relationship between iron, sulfur, and organic carbon suggests that sulfur is fixed in ...