Well-hidden methanogenesis in deep, organic-rich sediments of Guaymas Basin.

ABSTRACT: Deep marine sediments (>1mbsf) harbor ~26% of microbial biomass and are the largest reservoir of methane on Earth. Yet, the deep subsurface biosphere and controls on its contribution to methane production remain underexplored. Here, we use a multidisciplinary approach to examine methanogenesis in sediments (down to 295 mbsf) from sites with varying degrees of thermal alteration (none, past, current) at Guaymas Basin (Gulf of California) for the first time. Traditional (¹³C/¹²C and D/H) and multiply substituted (¹³CH₃D and ¹²CH₂D₂) methane isotope measurements reveal significant proportions of microbial methane at all sites, with the largest signal at the site with past alteration. With depth, relative microbial me

SUBMITTER: Bojanova DP 

PROVIDER: S-EPMC10579335 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature