C-O-H Fluid Calculations and Granulite Genesis Academic Article uri icon


  • Pervasive flooding of CO2 into the deep crust has been proposed as the cause of granulite-facies metamorphism. One effect of CO2 infiltration would be the dilution of H2O and the stabilization of orthopyroxene-bearing assemblages. Calculations in the C-O-H system indicate that infiltration of CO2 into rocks whose fO2 are buffered to within the stability of graphite will cause graphite to precipitate. Oxygen fugacities determined from coexisting magnetite and ilmenite from three granulite-facies terrains are sufficiently low for it to be shown that most of these samples have not been flooded by sufficient CO2 to form granulites, since graphite is not reported. Instead, most of these fO2 values are consistent with either H2O rock- or vapour-absent conditions, assuming the fraction of non-C-O-H components to be relatively small. If these fO2 values are common in rocks metamorphosed under low fH2O conditions, then vapour-absent metamorphism may be common in granulites.-J.M.H.

published proceedings

  • The Deep Proterozoic Crust in the North Atlantic Provinces

author list (cited authors)

  • Lamb, W. M., & Valley, J. W.

citation count

  • 65

complete list of authors

  • Lamb, William M||Valley, John W

publication date

  • January 1985