Mineral abbreviations are from Kretz (1983). The main stable mineralogical assemblages are given, the others are listed in the Appendix Table A6. A: Calculated P–T pseudosection for a meta-rhyodacite sample (BT9-01) with H₂O saturation and 5% Fe³⁺ (of total iron). The rock composition, given as mol.% oxide. Fields are colored with respect to their variances, darker colours indicate lower-variance assemblages. The stability fields written in red and bold correspond to the closest observed assemblage. 4 = ab ilm chl ms pg ep rieb qtz wrk H₂O; 5 = ab ilm chl ms pg ep ttn qtz wrk H₂O; 6 = ab ilm chl ms pg ep ttn rieb qtz H₂O; 7 = ab ilm chl ms pg czo ep ttn qtz H₂O; 8 = ab ilm chl ms pg czo ep qtz H₂O and 12 = ab ilm chl ms pg ep qtz wrk H₂O; B: Calculated P–T pseudosection for a meta-rhyodacite sample (BT9-01) with H₂O saturation and total iron as Fe²⁺. Rock composition is given as mol.% oxide. Fields are colored with respect to their variances, darker colours indicate lower-variance assemblages. The stability field written in red and bold correspond to the closest observed assemblage. 28 = ab ilm chl ms czo ttn qtz wrk H₂O; C: P-X(H₂O) equilibrium phase diagram calculated at 280 °C, using the same base composition of Figure 13A. The stability fields colored in grey correspond to the closest observed assemblage. 41 = ab ilm chl ms pg ep qtz wrk; 45 = ab ilm chl ms pg ep ttn qtz wrk; 46 = ab ilm chl ms pg ep ttn rieb qtz; D: P-X(H₂O) equilibrium phase diagram calculated at 280 °C, using the same base composition of Figure 13B. The stability field colored in grey corresponds to the observed assemblage. 51 = ab ilm chl ms czo ttn qtz wrk; 52 = ab ilm chl ms czo mc qtz; 53 = ab ilm chl ms czo ttn mc qtz.