Age determination and pyrite framboids analysis of sediment cores from the northern continental margin of the South China Sea ...

• Main Authors: Lin, Qi, Wang, Jiasheng, Algeo, Thomas J, Sun, Fei, Lin, Rongxiao
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2017
• Subjects: Methane hydrate
• Online Access: https://dx.doi.org/10.1594/pangaea.871848; https://doi.pangaea.de/10.1594/PANGAEA.871848

Many studies have confirmed that size distributions of framboidal pyrite can be an effective indicator of bottom-water redox conditions in modern as well as ancient sedimentary environments. However, one environment in which production of framboidal pyrite has not been sufficiently studied to date is the sulfate-methane transition zone (SMTZ), in which anaerobic oxidation of methane (AOM) is coupled with microbial sulfate reduction (MSR) to enhance iron sulfide mineral precipitation (e.g., FeS2, FeS, and Fe3S4). Here, we document for the first time size distributions for pyrite framboids from the SMTZ, based on data from two sites in the methane hydrate-bearing region of the northern South China Sea. On the basis of framboid size, pyrite concentration, and sulfur isotope data, we propose new insights into the formation process of authigenic pyrite framboids within the SMTZ. We conclude that (1) Enhanced anaerobic oxidation of methane (AOM) not only plays a dominant role in the accumulation of 34S-enriched ... : Supplement to: Lin, Qi; Wang, Jiasheng; Algeo, Thomas J; Sun, Fei; Lin, Rongxiao (2016): Enhanced framboidal pyrite formation related to anaerobic oxidation of methane in the sulfate-methane transition zone of the northern South China Sea. Marine Geology, 379, 100-108 ...