1. Continuous Reactions

2. Compositional Changes in the Biotite Zone
Increasing Grade
Compositions of muscovite, chlorite and biotite, but particularly, muscovite and chlorite change continuously with increasing metamorphic grade

3. Continuous Reaction Discontinuous Reaction
H2O + Chloritoid + Biotite = Chlorite B A C
Discontinuous Reaction
H2O + Chloritoid + Biotite = Chlorite + Garnet

4. Continuous Changes Across the Staurolite-Biotite-in Reaction
Chlorite + Staurolite = Garnet + H2O
Chlorite = Garnet + Biotite + H2O
Chlorite = Staurolite+ Biotite + H2O
Staurolite+ Biotite = Garnet + H2O

5. The T-XMg Relationships
Staurolite-Biotite-in Reaction
Mg-enrichment typically in the order: cordierite > chlorite > biotite > chloritoid > staurolite > garnet

6. Calibration of the Staurolite-biotite-in Reaction

7. Staurolite-out Reaction

8. The Amphibolite Facies in Continuous Reaction Space

9. P-XMg Sections F M

10. T-XMg and P-XMg Sections