Figure 5.
Bioavailable energy yields for metabolic redox reactions for each sample type. For the Snail site, the energy yields result from (A) 15–116°C natural vent, (B) 3–40°C borehole, (C) H2S-type, and (D) Fe-type fluids. For the Pika site, the energy yields result from (E) 100°C natural vent and (F) 3–50°C natural vent fluids. For the Archaean site, the energy yields result from (G) 75–117°C natural vent and (H) 30°C natural vent fluids. The bioavailable energy yields for (E) 100°C natural vent in the Pika site and for (H) 30°C natural vent in the Archaean site were calculated using the geochemical data estimated from a simple mixing model of hydrothermal fluids and seawater.