Abiotic redox reactions in hydrothermal mixing zones: Decreased energy availability for the subsurface biosphere.

ABSTRACT: Subseafloor mixing of high-temperature hot-spring fluids with cold seawater creates intermediate-temperature diffuse fluids that are replete with potential chemical energy. This energy can be harnessed by a chemosynthetic biosphere that permeates hydrothermal regions on Earth. Shifts in the abundance of redox-reactive species in diffuse fluids are often interpreted to reflect the direct influence of subseafloor microbial activity on fluid geochemical budgets. Here, we examine hydrothermal fluids venting at 44 to 149 °C at the Piccard hydrothermal field that span the canonical 122 °C limit to life, and thus provide a rare opportunity to study the transition between habitable and uninhabitable environments. In contrast with previous studies, we show that hydrocarbons are contributed by bioma

SUBMITTER: McDermott JM 

PROVIDER: S-EPMC7456078 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature