Table 1.
Analysed compositions of immiscible liquids in melt inclusions and model compositions for parent andesite at El Laco
| Oxide | High-SiO2 dacitea | Fe-cpxa | Fe-rich meltb | Low-SiO2 andesitec |
|---|---|---|---|---|
| SiO2 | 67.94 (1.40) | 40.48 (2.46) | 32.47 | 57.50 |
| TiO2 | *0.25 (0.02) | 5.59 (2.18) | 4.97 | 0.86 |
| Al2O3 | 18.05 (0.76) | 1.89 (0.53) | 2.01 | 16.31 |
| FeOtot | 4.32 (0.22) | 24.35 (4.39) | 36.16 | 6.73 |
| MgO | *0.06 (0.01) | 13.48 (2.33) | 11.16 | 4.43 |
| CaO | 0.80 (0.60) | 12.10 (4.51) | 9.71 | 6.78 |
| Na2O | 4.80 (1.26) | 0.68 (0.35) | 0.55 | 3.45 |
| K2O | 8.99 (2.63) | 0.34 (0.11) | 0.27 | 1.95 |
| P2O5 | *0.20 (0.02) | 2.26 (1.29) | 1.81 | 0.22 |
| H2O | – | – | – | 1.54 |
| Sum | 104.90 | 101.17 | 100.00 | 99.78 |
aAnalyses of melt inclusions in El Laco andesite from ref. 16; shown are mean (standard deviation), values marked * are at detection limit.
bReconstructed composition from 80% of mean Fe-cpx from ref. 16 + 20% mean Type 2a magnetite from ref. 15 normalised to 100%.
cAverage of five lowest SiO2 host andesite samples analysed by ref. 9.