Skip to main content

Table 4 Chemical composition of glass in groundmass and groundmass bulk in the scoria and the ash particles from the 1979, 1989, 2003, and 2014 eruptions (wt%)

From: Petrological characteristics and volatile content of magma of the 1979, 1989, and 2014 eruptions of Nakadake, Aso volcano, Japan

Sample ID 1979.6.16 scoria 1989.10.15 scoria 1989.11.24 scoria 2003.7.10 ash particlesb
AS790616S mts10120608−2−p1mg1 AS89101501 AS891124  
Glass in groundmass Glass in groundmass Glass in groundmass Glass in groundmass Glass in groundmass
Av (n = 30, 1 s) Av (n = 40, 1 s) Av (n = 20, 1 s) Av (n = 13, 1 s)
SiO2 59.19 (0.67) 53.70 58.16 (0.52) 58.00 (1.14) 58.09 (0.71)
TiO2 1.42 (0.05) 1.23 1.37 (0.03) 1.34 (0.06) 1.38 (0.05)
Al2O3 14.10 (0.22) 14.87 14.35 (0.15) 14.49 (0.22) 14.40 (0.27)
FeOt 9.71 (0.29) 9.25 9.51 (0.20) 9.62 (0.33) 9.73 (0.27)
MnO 0.20 (0.02) 0.16 0.20 (0.03) 0.19 (0.02) 0.19 (0.03)
MgO 2.55 (0.10) 2.75 2.85 (0.10) 3.10 (0.25) 2.89 (0.18)
CaO 5.86 (0.14) 5.77 6.15 (0.13) 6.53 (0.35) 6.24 (0.30)
Na2O 3.31 (0.19) 3.38 3.36 (0.15) 3.35 (0.17) 3.29 (0.14)
K2O 3.73 (0.10) 3.31 3.48 (0.08) 3.30 (0.17) 3.48 (0.19)
P2O5 0.50 (0.01) 0.18 0.47 (0.02) 0.45 (0.02) 0.48 (0.03)
S 0.002 (0.002) 0.025 0.006 (0.003) 0.012 (0.009) 0.005 (0.002)
Cl 0.064 (0.009) 0.081 0.066 (0.005) 0.071 (0.006) 0.071 (0.005)
H2O (SIMS/EPMA) na/na 0.6/1.8 na/na na/na na/na
CO2 (SIMS) na 0.003 na na na
Temperature (°C)a      
Sample ID 2014.11.26–27 scoria
I141129S01 I141129S02 I141129S03 I141129S
Groundmass bulk Glass in groundmass Glass in groundmass Groundmass bulk Glass in groundmass Groundmass bulk Glass in groundmass
Av (n = 20, 1 s) Av (n = 20, 1 s) Av (n = 30, 1 s) Av (n = 20, 1 s) Av (n = 30, 1 s)
SiO2 57.36 (0.57) 58.41 57.57 (0.47) 57.89 (2.25) 57.64 (0.67) 57.80 (0.87) 59.63
TiO2 1.31 (0.04) 1.33 1.32 (0.02) 1.19 (0.33) 1.38 (0.03) 1.31 (0.13) 1.36
Al2O3 14.25 (0.34) 14.61 14.06 (0.11) 15.16 (2.49) 13.68 (0.23) 14.77 (0.93) 14.07
FeOt 9.35 (0.26) 9.40 9.15 (0.24) 8.74 (1.90) 9.42 (0.23) 9.25 (1.04) 10.06
MnO 0.19 (0.03) 0.18 0.18 (0.03) 0.17 (0.06) 0.19 (0.03) 0.18 (0.03) 0.22
MgO 2.79 (0.16) 2.84 2.78 (0.08) 2.76 (1.22) 2.48 (0.16) 2.63 (0.46) 2.56
CaO 6.00 (0.23) 6.00 5.89 (0.15) 6.08 (0.89) 5.62 (0.21) 6.11 (0.51) 6.07
Na2O 3.11 (0.19) 3.34 3.01 (0.18) 3.32 (0.34) 2.85 (0.15) 3.20 (0.21) 3.43
K2O 3.29 (0.14) 3.35 3.31 (0.09) 3.11 (0.56) 3.58 (0.16) 3.22 (0.29) 3.39
P2O5 0.22 (0.03) 0.47 0.24 (0.02) 0.20 (0.10) 0.26 (0.03) 0.22 (0.04) 0.50
S 0.006 (0.003) 0.001 0.006 (0.004) 0.005 (0.006) 0.003 (0.003) 0.006 (0.003) 0.006
Cl 0.062 (0.004) 0.054 0.060 (0.007) 0.029 (0.014) 0.067 (0.007) 0.064 (0.008) 0.068
H2O (SIMS/EPMA) na/na 0.1/nd na/0.1 na/(0.1) na/na na/0.2 na/(0.2) na/na 0.3/nd
CO2 (SIMS) na nd na na na na nd
Temperature (°C)a 1092    1069   1077  
  1. FeOt, total FeO; nd, not detected; na, not analyzed
  2. aEstimated from the chemical composition of the groundmass by glass (liquid) thermometer (Putirka 2008, Eq. (16)). This thermometer can apply to liquid in equilibrium with olivine + plagioclase  + clinopyroxene + spinel (or oxides) and yields a standard error of estimate (SEE) of 26 °C. Pressure of 100 MPa was assumed
  3. bChemcial composition of glass in groundmass of ash particles erupted on July 10, 2003, is after GSJ et al. (2004)