Western Senegal | Cape Verde Islands | ||||||
Elements (wt%) | Tertiary lavas (n = 34) | Quaternary lavas (n = 9) | Quaternary | Tertiary | |||
Fogo (active Volcan) [n = 6] | Sal (50 Ma) [n = 3] | Sao Nicolau (n = 7) | Sao Vicente (n = 7) | Santiago (n = 5) | |||
SiO2 | 39.9 - 51.7 | 40.1 - 53.6 | 40.65 - 42.47 | 35.67 - 38.89 | 39.97 - 44.47 | 38.54 - 44.47 | 38.08 - 42.96 |
Al2O3 | 10.75 - 16.05 | 9.31 - 14.8 | 13.31 - 15.71 | 8.25 - 10.93 | 11.88 - 13.87 | 8.38 - 13.34 | 10.22 - 15.49 |
Fe2O3 | 10.1 - 13.9 | 10.3 - 11.63 | 13.06 - 14.19 | 12.20 - 13.37 | 11.59 - 13.36 | 12.12 - 13.52 | 11.02 - 12.49 |
CaO | 8.57 - 15.10 | 7.69 - 14.2 | 11.07 - 12.81 | 12.48 - 16.42 | 10.81 - 14.02 | 9.71 - 14.17 | 11.19 - 14.54 |
MgO | 4.62 - 14.80 | 5.67 - 9.81 | 5.81 - 9.21 | 12.90 - 19.97 | 10.16 - 14.20 | 10.10 - 18.96 | 5.82 - 13.19 |
Na2O | 2.23 - 6.05 | 1.42 - 4.87 | 3.08 - 4.41 | 1.80 - 3.07 | 1.98 - 3.93 | 1.19 - 3.27 | 1.89 - 3.16 |
K2O | 0.23 - 1.88 | 0.08 - 1.72 | 1.92 - 2.77 | 0.93 - 1.34 | 0.56 - 1.13 | 0.35 - 1.25 | 1.23 - 2.91 |
TiO2 | 1.57 - 2.61 | 1.46 - 2.24 | 3.53 - 4.40 | 3.31 - 3.40 | 2.71 - 3.47 | 2.25 - 4.42 | 2.66 - 3.91 |
P2O5 | 0.34 - 1.34 | 0.28 - 0.74 | 0.60 - 0.91 | 0.48 - 1.44 | 0.40 - 0.79 | 0.30 - 0.65 | 0.48 - 1.20 |
Total | 99.13 - 101.9 | 99.9 - 101.4 | 99.86 - 100.88 | 97.10 - 99.76 | 98.82 - 100.68 | 96.51 - 100.85 | 95.76 - 99.02 |