Table T8. Composition of gas from analyses of decomposed samples of gas hydrate, Holes 1249B, 1249C, 1249D, 1249E, and 1249F.
Core, section, interval (cm)
Depth (mbsf)
C1
(ppmv)
C2 (ppmv)
C3 (ppmv)
i-C4 (ppmv)
n-C4 (ppmv)
i-C5 (ppmv)
CO2 (ppmv)
O2 (ppmv)
N2 (ppmv)
C1/C2
204-1249B-










4A-1, 74-82 39.64 376,691 1,328 11.0


7,376 125,755 530,050 284
204-1249C-










1H-1, 105-120 1.05 792,216 705 25.9 6.3 4.9
2,346 52,500 202,795 1,124
1H-1, 195-200 1.95 963,698 1,170 15.2


4,001 4,557 13,006 824
2H-1, 0-5 2.00 957,415 1,944 10.0


3,585 5,682 16,729 492
3H-1, 106-131 6.06 983,641 1,657 15.0


3,962 283 764 594
4H-2, 62-72 15.95 169,544 301



1,525 151,364 628,845 563
4H-3, 57-59 16.62 939,133 3,457 28.0





272
4H-4, 70-81 17.34 616,696 1,430 14.0 3.2

4,961 76,142 296,540 431
204-1249D-










1H-CC 2.11 507,255 792 25.4


2,348 61,151 234,535 640
3H-1, 150-160 10.50 813,647 1,163



28,658 2,941 100,062 699
204-1249E-










1H-1, 0-10 0.00 502,708 673
14.5 5.4
1,277 371,203 95,665 746
3H-2, 70-80 10.70 898,742 905 30.6


6,904 4,126 59,792 993
204-1249F-










1H-1, 0-20* 0.00 924,696 1,029



2,046 1,561 45,097 898
5H-1, 64-70 16.14 510,840 849
6.8

3,600 23,439 102,073 602
6H-1, 100-110 17.50 969,616 2,754 17.1


5,144 19 1,112 352
6H-1, 100-110* 17.50 969,542 3,599 32.7





269
8H-2, 117-127 32.99 972,969 2,259 15.5 13.5

5,214 71 2,382 431

Notes: * = pure gas hydrate sample (minimal contamination from sediment). C1 = methane, C2 = ethane, C3 = propane, i-C4 = isobutane, n-C4 = normal butane, i-C5 = iso-pentane, H2S = hydrogen sulfide, CO2 = carbon dioxide, O2 = oxygen, N2 = nitrogen.