Fig. S1. Permian–Triassic felsic tuffs in South Island, New Zealand: significance for oceanic and active continental margin subduction

Major-element oxide variation plots for the Brook Street Terrane. (a) Fe2O3 v. SiO2; (b) MnO v. SiO2; (c) MgO v. SiO2; (d) TiO2 v. Al2O3; (e) TiO2 v. MgO; (f) Fe2O3 v. MgO; (g) MnO v. MgO; (h) CaO v. MgO; (i) K2O v. MgO. See text and the Supplementary field and petrographic information for explanation.