Figure 1

Sketch of idealized fluid flow within a hydrothermal system and potential catabolic reactions in different environments (chimney wall, plume, recharge zone, and subseafloor mixing zone). Upwelling hot, reducing hydrothermal fluids mix with entrained cold, oxygenated seawater in subseafloor mixing zones. For these zones, the affinities of the catabolic reactions provided in the inset are examined in this paper.