Figure 6.08a. AFM Diagram relationship to Garnet-Biotite Exchange Diagram. Move the slider to see the Grt-Bt tie lines on the Thompson AFM diagram repositioned onto the equilibrium composition tie lines of a Grt-Bt exchange diagram (Figure 6.08). The AFM diagram was selected from the KFMASH Grid w/AFM Topologies diagram at 702°C and 1.0 GPa. Notice that in the AFM system, Mg-rich garnet is not stable with biotite. Also note that biotite in equilibrium with garnet on the AFM diagram has more Al than on the Mg-Fe exchange diagram. Tie lines on the exchange diagram are based on the Ferry and Spear (1978) experiments.
