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15
CH3041
FOOL’S GOLD
• The deep ocean (>500m) is highly stratified
• Plankton biomass descends through the
water column and is oxidised, as this occurs
O2 depletion occurs. Sediments DO = 0%.
water column and is oxidised, as this occurs
O2 depletion occurs. Sediments DO = 0%.
• The most available electron acceptor is
SO42-. Sulphate reducing bacteria are common in the surface of sediments.
2{CH2O} + SO42- ® HS- + 2HCO3- + H+
SO42-. Sulphate reducing bacteria are common in the surface of sediments.
2{CH2O} + SO42- ® HS- + 2HCO3- + H+
10% of HS- Fe2+ + HS- ® FeS(s) + H+
FeS(s) + S2O32- ® FeS2(s) + SO32-
• Formation of pyrite slowly
removes SO42-.
