Table 4: Measured gas concentration and associated stable isotopic ratios hydrothermal fluids from the Kulo Lasi and Fatu Kapa vent fields. Values of log  fH2 were calculated using SUPCRT92 with the slop98 data base.

Sample nameSiteH2SN23HeR/RaH2log fH2CH4CO2C2H6C2H4C3H8C3H6n-C4H10n-C5H12δD (H2)δD (CH4)δ13C (CO2)δ13C (CH4)δ13C (C2H6)δ13C (C3H8)δ13C (C4H10)
mMmMmMmMmMmMµMµMµMµMµMµM

Seawater0.59nmnm<LOD-<LOD2.3nmnmnmnmnmnmnmnmnmnmnmnmnm
FU-PL-05-TiG1Kulo Lasi0.12nmnm<LOQ-0.0012.6<LODnm<LODnm<LOD<LODnmnmnmnmnmnmnm
FU-PL-06-TiD4Kulo Lasi1.660.10nmnm1.14-0.0011.30.020.0050.0060.0040.0050.005−323n.m.−3.2−29−27−26nm
FU-PL-06-TiG3Kulo Lasi5.051.43nmnm19.8−3.110.0065.10.110.0420.0280.0300.0240.006−306n.m.−4.1−23−26−26−24
FU-PL-06-TiD1Kulo Lasi0.392.48nmnm6.18−3.620.0043.00.10.0170.0170.0200.0120.004−300n.m.−1.9−28−24−26−24
FU-PL-06-TiG1Kulo Lasi0.79nmnm1.04−4.400.0011.00.020.0090.0050.0070.0050.001−316n.m.−0.2−27.2−22−26−24

FU3-PL-04-TiG3Stéphanie0.910.938.60.03−1.870.11415.5<LOD<LOD<LOD<LOD<LOD1.7nmnmnmnmnmnmnm
FU3-PL-08-TiD1Stéphanie1.231.98nm0.06−1.570.23529.0<LOD<LOD<LOD<LOD<LOD3.2−676−108−5−21.7nmnmnm
FU3-PL-08-TiG1Stéphanie0.982.477.60.05−1.650.20525.7<LOD<LOD<LOD<LOD<LOD2.9nmnmnmnmnmnmnm
FU3-PL-09-TiD2Stéphanie0.230.487.00.04−1.750.0596.0<LOD<LOD<LOD<LOD<LOD0.7−436−111−5.3−22.2nmnmnm
FU3-PL-06-TiD1Carla1.340.509.60.01−2.350.0214.5<LOD<LOD<LOD<LOD<LOD0.5nmnmnmnmnmnmnm
FU3-PL-08-TiD3Carla0.193.339.80.05−1.650.06611.9<LOD<LOD<LOD<LOD<LOD1.5−410−109−4.7−21.5nmnmnm
FU3-PL-11-TiG31.130.789.80.03−1.870.08510.0<LOD<LOD<LOD<LOD<LOD1.1nmnmnmnmnmnmnm
FU3-PL-14-TiD11.001.208.70.02−2.050.06910.1<LOD<LOD<LOD<LOD<LOD1.1−417−110−4.9−23.8nmnmnm
FU3-PL-14-TiD20.851.059.80.03−1.870.1108.7<LOD<LOD<LOD<LOD<LOD1.0−407−113−5−24nmnmnm
FU3-PL-14-TiD30.540.938.40.02−2.050.1659.2<LOD<LOD<LOD<LOD<LOD1.0nmnmnmnmnmnmnm
FU3-PL-18-TiD10.980.89nmnm0.01−2.350.0679.2<LOD<LOD<LOD<LOD<LOD1.0−412−111−4.9−23.6nmnmnm
FU3-PL-17-TiG2Fati Ufu1.760.849.90.01−2.590.07021.5<LOD<LOD<LOD<LOD<LOD2.3-−93−2.3−6.1nmnmnm
FU3-PL-21-TiD2Fati Ufu0.712.079.90.03−2.110.11112.6<LOD<LOD<LOD<LOD<LOD1.5−410−109−4.4−23.3nmnmnm
FU3-PL-20-TiD1Tutafi2.361.189.20.05−1.890.15622.2<LOD<LOD<LOD<LOD<LOD2.4−396−111−4.5−23.6nmnmnm
FU3-PL-21-TiD3Tutafi0.841.67nmnm0.03−2.110.05311.7<LOD<LOD<LOD<LOD<LOD1.4−415−109−4.7−24.2nmnmnm