Factors controlling the carbon isotope composition of dissolved inorganic carbon and methane in marine porewater: An evaluation by reaction-transport modelling

Carbon isotope compositions of dissolved inorganic carbon (DIC) and methane (CH4) in porewater of marine sediments at seafloor temperatures show very large variation covering a δ13C range from −100‰ to +35‰. These extreme values are the result of isotope fractionation during microbial carbon metabolism, but the combined effect of all factors controlling the isotope distributions is still not completely understood. We used a model approach to...