Table 2 Calculated endmember (Mg = 0 mM) fluid compositions from Yggdrasil vent site (Sample GeoB25037-8) and Black Smoker (GeoB25031-2) from our own data, compared to endmember compositions from the literature: Loki’s Castle, Guaymas (sediment-hosted6), and Lucky Strike (basalt-hosted;6).
Yggdrasil vent site | Black smoker | Loki’s castle | Guaymas | Lucky strike | ||
|---|---|---|---|---|---|---|
T | [°C] | 272 | 316 | 317 | 315 | 305 |
pH | @25 °C | 5.3 | 5.2 | 5.7 | 6 | 4 |
NH4 | [µM] | 9359 | 7320 | 5040 | 14,800 | 9 |
Mg | [mM] | 0 | 0 | 0 | 0 | 0 |
Cl | [mM] | 509 | 530 | 490 | 598 | 489 |
Na | [mM] | 394 | 399 | 396 | 483 | 385 |
Ca | [mM] | 37.4 | 37.3 | 27.9 | 30 | 35.7 |
Si | [mM] | 13.6 | 14.8 | 15.5 | 12.8 | 15.4 |
Fe | [µM] | 32.7 | 75 | 26 | 41.5 | 435 |
Sr | [µM] | 177 | 175 | 99 | 195 | 93 |
87Sr/86Sr | 0.7079 | 0.7080 | 0.7082 | 0.7055 | 0.7043 | |
CO2 | [mM] | 26.4 | 25.5 | 24.5 | 50 | 64 |
CH4 | [mM] | 9.5 | 8.8 | 13.9 | 59 | 0.7 |
δ13C-CH4 | [‰] | − 30.5 | − 29.7 | − 27.9 | − 47 | − 13.5 |
δ2H-CH4 | [‰] | − 107 | − 107 | − 111 | − 196 |
