Table 1. Oxygen isotopic composition of the water of gas hydrates from Site 994 and 997.
| No. | Hole,
core, section |
Depth (mbsf) |
 18O
of H2O (  SMOW) |
[Cl-] of H2O (mM) | [Cl-]
of pristine pore water (mM) |
18O
of pristine pore water (per mil SMOW) |
Mole
fraction of gas hydrate water |
18O
of gas hydrate water ( SMOW) |
|---|---|---|---|---|---|---|---|---|
#2A |
994C-31X-7 |
259.90 |
2.6 |
17 |
505 |
-0.4 |
0.966 |
2.7 |
#14 |
997A-42X-3 |
330.15 |
2.7 |
20 |
509 |
-0.5 |
0.961 |
2.8 |
#16A |
997A-42X-3 |
330.25 |
3.3 |
5 |
509 |
-0.5 |
0.990 |
3.3 |
#16B |
997A-42X-3 |
330.25 |
3.2 |
41 |
509 |
-0.5 |
0.919 |
3.5 |
#16C |
997A-42X-3 |
330.30 |
2.7 |
62 |
509 |
-0.5 |
0.878 |
3.2 |
Note: Measured 18O
values were corrected for contamination by the interstitial water (IW) using the
chloride concentration and 18O
of IW and observed Cl- of sample waters.