Program Gibbs

Petrogenetic Grids and AFM Diagrams

Program Gibbs has "pre-programmed" petrogenetic grids in the KFMASH system using the thermodynamic data bases of Spear, Pattison and Cheney (2000, unpublished) and Holland and Powell (1998). A number of routines have been written that utilize these grids, including

• Display of petrogenetic grids at various scales
• Calculation of AFM diagrams
• Display of AFM assemblage stability fields
• Calculation of assemblage stability diagrams ("pseudosections")

A tutorial describing these options is available from the Gibbs download page

References

• Holland, T. J. B. and Powell, R. (1998) An internally-consistent thermodynamic dataset for phases of petrological interest. Journal of Metamorphic Geology, 16, 309-343.
• Pattison, D. M. R., Spear, F. S., DeBuhr, C. L., Cheney, J. T. and Guidotti, C. V. (submitted) Natural assemblage and thermodynamic analysis of the reaction muscovite + cordierite = Al2SiO5 + biotite + quartz + H2O: Implications for the metapelitic petrogenetic grid. Journal of Metamorphic Geology
• Pattison, D. R. M., Spear, F. S. and Cheney, J. T. (1999) Polymetamorphic origin of muscovite + cordierite + staurolite + biotite assemblages: Implications for the metapelitic petrogenetic grids and for P-T paths. Journal of Metamorphic Geology, 17, 685-703.
• Spear, F. S. (1999) Real-time AFM diagrams on your Macintosh. Geological Materials Research, 1, 1-18.

Gibbs Home Page