The influence of coupling mode of methane leakage and debris input on anaerobic oxidation of methane

Anaerobic oxidation of methane (AOM) is an important biogeochemical process, which has important scientific significance for global climate change and atmospheric evolution. This research examined the δ34S, terrigenous clastic indices of TiO₂ and Al₂O₃, and times for formation of the Ba front at site SH1, site SH3 and site 973-4 in the South China Sea. Three different coupling mechanisms of deposition rate and methane flux were discovered. The different coupling mechanisms had different effects on the role of AOM. At site 973-4, a high deposition rate caused a rapid vertical downward migration of the sulphate–methane transition zone (SMTZ), and the higher input resulted in mineral dissolution. At site SH3, the deposition rate and methane flux were basically in balance, so the SMTZ and paleo-SMTZ were the most stable of any site, and these were in a slow process of migration. At site SH1, the methane flux dominated the coupled mode, so the movement of the SMTZ at site SH1 was consistent with the general understanding. Understanding the factors influencing the SMTZ is important for understanding the early diagenesis process.