1. Fig. 7. Major element compositions of the HAOT melt inclusions (a) and BA melt inclusions (b). Data have been recalculated as CMAS components (O’Hara, 1968) using the following procedure: C = (CaO – 10/3 P₂O₅ + 2 Na₂O + 2 K₂O); M = (MgO + FeO* + MnO); A = (Al₂O₃ + Na₂O + K₂O); S = (SiO₂ – 2 Na₂O – 2 K₂O); then projected from olivine (M₂S) onto the Di–Ne–Qz (CMS₂–CA–S) face of the ‘basalt tetrahedron’ (Falloon & Green, 1988). Whole-rock compositions are from Baker et al. (1994) and Grove et al. (2002). Diagonally shaded area indicates experimental data for dry lherzolite melts at 10 and 15 kbar (MM3 from Baker & Stolper, 1994; Baker et al., 1995; PHN1611 from Kushiro, 1996; HK66 from Hirose & Kushiro, 1993; Depma from Laporte et al., 2004). The arrow represents an increase in the degree of melting. The HAOT melt inclusions (a) plot in the tholeiite field and fall in the compositional range of lherzolite melts. The BA melt inclusions (b) span a wider range of compositions, ranging from tholeiitic compositions close to the HAOT and BA lava compositions to alkali basalt-like compositions that are very different from the BA lava compositions.
Two Contrasting H2O-rich Components in Primary Melt Inclusions from Mount Shasta
J Petrology. 2010;51(7): doi: /petrology/egq030
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