Chemical analyses of Nyiragongo lavas | |||||||
Geodynamic context: | Rift | ||||||
Rift zone: | East African Rift System | ||||||
Rift zone target: | Western Branch (WB) | ||||||
Locality: | Goma (North Kivu)/DRC | ||||||
Volcano: | Nyiragongo | ||||||
Volcano type: | Stratovolcano | ||||||
Samples | DM 14UM -Nyira. 2002-1 | DM 14UM -Nyira. 1977-1 | DM 14UM -Nyira. 2002-2 | DM 14UM -Nyira. 1977-2 | DM 14UM -Nyira. 2002-3 | DM 14UM -Nyira. 1977-3 | DM 14UM -Nyira. 2002-4 |
Major elements |
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SiO2 (wt%) | 38.4 | 38.6 | 39 | 38.5 | 38.7 | 38.4 | 39.5 |
Al2O3 (wt%) | 16.5 | 16.2 | 16.2 | 16.5 | 16.2 | 16.2 | 15 |
FeOt (wt%) | 14.1 | 14 | 14 | 14.1 | 13.8 | 14.1 | 13.8 |
MnO (wt%) | 0.2 | 0.2 | 0.2 | 0.1 | 0.2 | 0.1 | 0.3 |
MgO (wt%) | 3.1 | 3 | 3.2 | 3 | 3 | 3 | 4 |
K2O (wt%) | 5.5 | 5.5 | 5.2 | 5.4 | 5.6 | 5.8 | 5.3 |
CaO (wt%) | 11.1 | 11 | 11.2 | 11.1 | 11 | 11.7 | 12.3 |
TiO2 (wt%) | 2.1 | 2 | 1.6 | 1.8 | 2.1 | 1.8 | 1.9 |
Na2O (wt%) | 6 | 6 | 6 | 6.1 | 6 | 6.1 | 5 |
P2O5 (wt%) | 1.5 | 1.6 | 1.6 | 1.6 | 1.6 | 1.5 | 1.7 |
H2O (wt%) | 1.5 | 1.5 | 1.4 | 1.4 | 1.6 | 1 | 1 |
Total (wt%) | 100.0 | 99.6 | 99.6 | 99.6 | 99.8 | 99.7 | 99.8 |
Na2O + K2O (wt%) | 11.5 | 11.5 | 11.2 | 11.5 | 11.6 | 11.9 | 10.3 |
Na2O/K2O | 1.1 | 1.1 | 1.2 | 1.1 | 1.1 | 1.1 | 0.9 |
Mg# [Mg/(Mg + Fe)] | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 |
Minor elements |
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Ni (ppm) | 40 | 42 | 48 | 45 | 42 | 50 | 40 |
Sn (ppm) | 1 | 2 | 2 | 1 | 2 | 2 | 1 |
Sc (ppm) | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
Be (ppm) | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
V (ppm) | 450 | 402 | 355 | 303 | 505 | 313 | 309 |
Ba (ppm) | 2002 | 1989 | 2120 | 2049 | 1999 | 2103 | 2157 |
Sr (ppm) | 2615 | 2357 | 2500 | 2480 | 2090 | 2398 | 2502 |
Cr (ppm) | 20 | 15 | 17 | 16 | 19 | 21 | 20 |
Zr (ppm) | 351 | 340 | 339 | 401 | 299 | 322 | 345 |
Co (ppm) | 22 | 38 | 33 | 45 | 40 | 29 | 41 |
Cu (ppm) | 203 | 211 | 175 | 169 | 191 | 185 | 180 |
Zn (ppm) | 245 | 203 | 148 | 122 | 195 | 205 | 130 |
Ga (ppm) | 11 | 15 | 21 | 28 | 16 | 24 | 19 |
Ge (ppm) | 1 | 8 | 1 | 2 | 1 | 1 | 1 |
As (ppm) | 4 | 1 | 1 | 2 | 4 | 5 | 5 |
Rb (ppm) | 99 | 88 | 89 | 108 | 122 | 106 | 124 |
Nb (ppm) | 199 | 218 | 160 | 201 | 180 | 211 | 202 |
Mo (ppm) | 1 | 1 | 3 | 2 | 5 | 1 | 4 |
Ag (ppm) | 1 | 1 | 1 | 2 | 1 | 1 | 1 |
In (ppm) | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Sb (ppm) | 1 | 0 | 0 | 1 | 0 | 0 | 1 |
Cs (ppm) | 1 | 1 | 2 | 1 | 1 | 1 | 1 |
Hf (ppm) | 4 | 4 | 5 | 4 | 5 | 5 | 4 |
Ta (ppm) | 10 | 13 | 16 | 13 | 14 | 12 | 13 |
W (ppm) | 1 | 2 | 1 | 2 | 1 | 1 | 1 |
Tl (ppm) | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Pb (ppm) | 6 | 7 | 5 | 6 | 6 | 7 | 5 |
Bi (ppm) | 0 | 0 | 0 | 1 | 0 | 0 | 0 |
Th (ppm) | 22 | 20 | 18 | 20 | 15 | 17 | 18 |
U (ppm) | 7 | 7 | 5 | 4 | 5 | 7 | 6 |
La (ppm) | 182 | 195 | 166 | 180 | 168 | 195 | 182 |
Ce (ppm) | 355 | 361 | 341 | 401 | 323 | 399 | 344 |
Pr (ppm) | 30 | 35 | 34 | 37 | 35 | 31 | 36 |
Nd (ppm) | 128 | 133 | 121 | 122 | 128 | 125 | 125 |
Sm (ppm) | 15 | 13 | 18 | 19 | 22 | 13 | 18 |
Eu (ppm) | 6 | 7 | 5 | 6 | 6 | 6 | 5 |
Gd (ppm) | 10 | 11 | 10 | 12 | 12 | 12 | 11 |
Tb (ppm) | 1 | 1 | 1 | 1 | 2 | 2 | 2 |
Dy (ppm) | 6 | 7 | 8 | 9 | 8 | 8 | 8 |
Ho (ppm) | 1 | 1 | 2 | 2 | 1 | 2 | 1 |
Er (ppm) | 3 | 3 | 4 | 4 | 4 | 4 | 4 |
Tm (ppm) | 0 | 0 | 1 | 0 | 1 | 1 | 1 |
Yb (ppm) | 3 | 3 | 3 | 2 | 3 | 3 | 3 |
Lu (ppm) | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Y (ppm) | 19 | 22 | 45 | 39 | 32 | 40 | 36 |
∑REE (ppm) | 742 | 770 | 712 | 795 | 713 | 799 | 739 |