Fig. 5

Volatile and K₂O contents of the melt inclusions and groundmass in the scoria. a H₂O and K₂O contents, b CO₂ and K₂O contents, c S and K₂O contents, and d Cl and K₂O contents of the melt inclusions and groundmass. The large symbols indicate H₂O and CO₂ contents measured by SIMS. Error bars indicate the analytical errors of H₂O and CO₂ by SIMS and those of S, Cl, and K₂O by EPMA. The EPMA analytical error of H₂O is ± 1 wt%. Chemical compositions of the melt calculated from the whole-rock composition of I141129S01 at 1079 °C using the MELTS program (Table 5; Additional file 3: Table S2) are also shown. Curves with cross symbols show the compositional change associated with a decrease in pressure from 600 to 10 MPa