time start = 0 day, end = 20 day decouple Fe+++ temperature = 10 C swap Fe(OH)3(ppd) for Fe+++ Fe(OH)3(ppd) = 1 free ug/kg pH = 6.7 swap O2(g) for O2(aq) O2(g) = .2 fugacity Na+ = 1 mmol/kg Cl- = 1 mmol/kg Fe++ = 30 mmol/kg scope y slide pH to 7.3 fix fugacity of O2(g) scope x kinetic redox-1 rxn = "Fe++ + .25*O2(aq) + 2.5*H2O -> Fe(OH)3(ppd) + 2*H+" rate_con = 7e12 mpower(Fe++) = 1 mpower(O2(aq)) = 1 apower(OH-) = 2 fix fugacity of O2(g) suppress FeO(c) Goethite Hematite Magnetite