Fluid mixing and the deep biosphere of a fossil Lost City-type hydrothermal system at the Iberia Margin
Abstract
We provide biogeochemical, micropaleontological, and petrological constraints on a subseafloor habitat at the passive Iberia Margin, where mixing of reduced hydrothermal serpentinization fluids with oxic seawater provided the energy and substrates for metabolic reactions. This mixing zone was inhabited by bacteria and archaea and is comparable to the active Lost City hydrothermal field at the Mid-Atlantic Ridge. Our results highlight the potential of magma-poor passive margins to host Lost City-type hydrothermal systems that support microbial activity in subseafloor environments. Because equivalent systems have likely existed throughout most of Earth's history in a wide range of oceanic environments, fluid mixing may have provided the substrates and energy to support a unique subseafloor community of microorganisms over geological timescales.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- September 2015
- DOI:
- 10.1073/pnas.1504674112
- Bibcode:
- 2015PNAS..11212036K