Table 3.
Summary of Published Whole Rock Composition of Etna's 1967–1989 Lavas Emplaced During Summit and Flank Eruptions, With Water Content Where Availablea
| Eruption | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1967 | 1971 | 1973 | 1974 | 1975 | 1978 | 1979 | 1980 | 1989 | |
| Locationb | summit | flank | summit | flank | summit | flank | flank | summit | flank |
| Source reference | 1 | 1, 2 | 3 | 3 | 3 | 4 | 4 | 4 | 5 |
| Number of analyses | 1 | 15 | 2 | 16 | 2 | 6 | 3 | 5 | 19 |
| SiO2 | 47.4 | 47.5 | 48.9 | 47.1 | 48.8 | 47.6 | 47.8 | 48.1 | 47.7 |
| TiO2 | 1.7 | 1.7 | 1.6 | 1.6 | 1.7 | 1.7 | 1.7 | 1.7 | 1.8 |
| Al2O3 | 17.1 | 16.7 | 17.6 | 18.2 | 17.7 | 17.2 | 17.3 | 17.7 | 17.8 |
| Fe2O3 | 3.2 | 4.4 | – | – | – | 4.1 | 3.9 | 3.5 | 3.4 |
| FeO | 7.6 | 6.7 | 9.8 | 9.7 | 10.0 | 6.6 | 6.7 | 6.7 | 7.0 |
| MnO | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 |
| MgO | 5.5 | 5.2 | 5.4 | 6.8 | 4.8 | 5.6 | 5.4 | 5.3 | 5.5 |
| CaO | 10.3 | 11.0 | 10.2 | 10.4 | 10.0 | 10.6 | 10.5 | 10.3 | 10.3 |
| Na2O | 4.0 | 3.8 | 3.9 | 3.7 | 4.3 | 3.9 | 3.9 | 4.0 | 3.5 |
| K2O | 1.8 | 1.7 | 1.8 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 |
| P2O5 | 0.4 | 0.5 | 0.6 | 0.4 | 0.6 | 0.5 | 0.5 | 0.6 | 0.4 |
| H2O | 0.1 | 0.4 | – | – | – | – | – | – | – |
| Total | 99.1 | 99.8 | 100 | 100 | 100 | 100 | 100 | 100 | 99.5 |
| Viscosity at Tliquid [Bottinga and Weill, 1972] | 16 | 17 | 27 | 22 | 26 | 17 | 17 | 19 | 21 |
| Viscosity at Tliquid [Shaw, 1972]c | 34 | 27 | 53 | 20 | 57 | 25 | 26 | 40 | 30 |
| Viscosity at Tliquid (equation (2)) | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 |
| Viscosity at Terupt (method 1, Bottinga and Weill [1972]) | 389 | 419 | 662 | 540 | 638 | 419 | 419 | 466 | 515 |
| Viscosity at Terupt (method 2, Shaw [1972])c | 86 | 66 | 137 | 47 | 149 | 63 | 63 | 103 | 73 |
| Viscosity at Terupt (method 3, equation (3)) | 305 | 305 | 305 | 305 | 305 | 305 | 305 | 305 | 305 |
Averages are given from the referenced sources. Fluid viscosities for each average composition are given at liquidus (Tliquid = 1160°C) and eruption temperatures (Terupt = 1080°C). To assess fluid viscosity at liquidus and upon eruption (subliquidus) temperature, we apply the same methods as followed in Table 2, with the input parameters set appropriate to Etna. Source references: 1, Tanguy [1973]; 2, Downes [1973]; 3, Armienti et al. [1984]; 4, Tanguy and Clocchiatti [1984]; and 5, Tonarini et al. [1995].
For exact eruption location and details, see Tanguy [1981].
For cases where H2O is not available, H2O of 0.1 wt % is used for summit eruptions and 0.4 wt % is used for flank eruptions.