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Figure 5 | Geochemical Transactions

Figure 5

From: Microbial and hydrothermal aspects of ferric oxyhydroxides and ferrosic hydroxides: the example of Franklin Seamount, Western Woodlark Basin, Papua New Guinea

Figure 5

f(O2) vs. pH iron stability diagram at 25°C and 1 bar showing the natural domains of the main groups of iron oxidizing bacteria recalculated from an Eh–pH diagram in Lundgren and Dean.[21] Activities of dissolved iron, carbonate, and sulfur species are 10-6, 10° and 10-6, respectively, from Garrels and Christ.[75] The boundary between Fe3+ and Fe2+ which is missing in the Lundgren and Dean diagram, has been added here. Other thermodynamic databases suggest the presence of FeHCO+3 supplanting siderite between 6.4 and 7.0 pH and acetates supplant other phases and species below -75 logf(O2).

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