Organic, Gas, and Element Geochemistry of Hydrothermal Fluids of the Newly Discovered Extensive Hydrothermal Area in the Wallis and Futuna Region (SW Pacific)

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 name

Site

H2S

N2

^3He

R/Ra

H2

log fH2

CH4

CO2

C2H6

C2H4

C3H8

C3H6

n-C4H10

n-C5H12

δD (H2)

δD (CH4)

δ^13C (CO2)

δ^13C (CH4)

δ^13C (C2H6)

δ^13C (C3H8)

δ^13C (C4H10)

mM

mM

mM

mM

mM

mM

µM

µM

µM

µM

µM

µM

Seawater

0.59

nm

nm

<LOD

-

<LOD

2.3

nm

nm

nm

nm

nm

nm

nm

nm

nm

nm

nm

nm

nm

FU-PL-05-TiG1

Kulo Lasi

0.12

nm

nm

<LOQ

-

0.001

2.6

<LOD

nm

<LOD

nm

<LOD

<LOD

nm

nm

nm

nm

nm

nm

nm

FU-PL-06-TiD4

Kulo Lasi

1.66

0.10

nm

nm

1.14

-

0.001

1.3

0.02

0.005

0.006

0.004

0.005

0.005

−323

n.m.

−3.2

−29

−27

−26

nm

FU-PL-06-TiG3

Kulo Lasi

5.05

1.43

nm

nm

19.8

−3.11

0.006

5.1

0.11

0.042

0.028

0.030

0.024

0.006

−306

n.m.

−4.1

−23

−26

−26

−24

FU-PL-06-TiD1

Kulo Lasi

0.39

2.48

nm

nm

6.18

−3.62

0.004

3.0

0.1

0.017

0.017

0.020

0.012

0.004

−300

n.m.

−1.9

−28

−24

−26

−24

FU-PL-06-TiG1

Kulo Lasi

0.79

nm

nm

1.04

−4.40

0.001

1.0

0.02

0.009

0.005

0.007

0.005

0.001

−316

n.m.

−0.2

−27.2

−22

−26

−24

FU3-PL-04-TiG3

Stéphanie

0.91

0.93

8.6

0.03

−1.87

0.114

15.5

<LOD

<LOD

<LOD

<LOD

<LOD

1.7

nm

nm

nm

nm

nm

nm

nm

FU3-PL-08-TiD1

Stéphanie

1.23

1.98

nm

0.06

−1.57

0.235

29.0

<LOD

<LOD

<LOD

<LOD

<LOD

3.2

−676

−108

−5

−21.7

nm

nm

nm

FU3-PL-08-TiG1

Stéphanie

0.98

2.47

7.6

0.05

−1.65

0.205

25.7

<LOD

<LOD

<LOD

<LOD

<LOD

2.9

nm

nm

nm

nm

nm

nm

nm

FU3-PL-09-TiD2

Stéphanie

0.23

0.48

7.0

0.04

−1.75

0.059

6.0

<LOD

<LOD

<LOD

<LOD

<LOD

0.7

−436

−111

−5.3

−22.2

nm

nm

nm

FU3-PL-06-TiD1

Carla

1.34

0.50

9.6

0.01

−2.35

0.021

4.5

<LOD

<LOD

<LOD

<LOD

<LOD

0.5

nm

nm

nm

nm

nm

nm

nm

FU3-PL-08-TiD3

Carla

0.19

3.33

9.8

0.05

−1.65

0.066

11.9

<LOD

<LOD

<LOD

<LOD

<LOD

1.5

−410

−109

−4.7

−21.5

nm

nm

nm

FU3-PL-11-TiG3

1.13

0.78

9.8

0.03

−1.87

0.085

10.0

<LOD

<LOD

<LOD

<LOD

<LOD

1.1

nm

nm

nm

nm

nm

nm

nm

FU3-PL-14-TiD1

1.00

1.20

8.7

0.02

−2.05

0.069

10.1

<LOD

<LOD

<LOD

<LOD

<LOD

1.1

−417

−110

−4.9

−23.8

nm

nm

nm

FU3-PL-14-TiD2

0.85

1.05

9.8

0.03

−1.87

0.110

8.7

<LOD

<LOD

<LOD

<LOD

<LOD

1.0

−407

−113

−5

−24

nm

nm

nm

FU3-PL-14-TiD3

0.54

0.93

8.4

0.02

−2.05

0.165

9.2

<LOD

<LOD

<LOD

<LOD

<LOD

1.0

nm

nm

nm

nm

nm

nm

nm

FU3-PL-18-TiD1

0.98

0.89

nm

nm

0.01

−2.35

0.067

9.2

<LOD

<LOD

<LOD

<LOD

<LOD

1.0

−412

−111

−4.9

−23.6

nm

nm

nm

FU3-PL-17-TiG2

Fati Ufu

1.76

0.84

9.9

0.01

−2.59

0.070

21.5

<LOD

<LOD

<LOD

<LOD

<LOD

2.3

-

−93

−2.3

−6.1

nm

nm

nm

FU3-PL-21-TiD2

Fati Ufu

0.71

2.07

9.9

0.03

−2.11

0.111

12.6

<LOD

<LOD

<LOD

<LOD

<LOD

1.5

−410

−109

−4.4

−23.3

nm

nm

nm

FU3-PL-20-TiD1

Tutafi

2.36

1.18

9.2

0.05

−1.89

0.156

22.2

<LOD

<LOD

<LOD

<LOD

<LOD

2.4

−396

−111

−4.5

−23.6

nm

nm

nm

FU3-PL-21-TiD3

Tutafi

0.84

1.67

nm

nm

0.03

−2.11

0.053

11.7

<LOD

<LOD

<LOD

<LOD

<LOD

1.4

−415

−109

−4.7

−24.2

nm

nm

nm