Table 14. Composition of free gas collected in syringes from sediment from Site 995. "Core, section" Depth (mbsf) O2 (ppmv) N2 (ppmv) C1 (ppmv) CO2 (ppmv) C2 (ppmv) C3 (ppmv) i-C4 (ppmv) n-C4 (ppmv) i-C5 (ppmv) n-C5 (ppmv) i-C6 (ppmv) n-C6 (ppmv) C1/C2 C1/C2+ 164-995A- 6H-6 47.7 NA NA 911300 NA 23 5 0.4 0.3 31800 8H-1 59.2 NA 18000 936400 NA 53 10.7 6 0.5 0.4 17600 13200 12H-2 89.13 0 6000 943300 25600 24 10.7 6.3 0.7 1.4 39300 21900 12H-6 95.18 0 3000 948700 22600 49 11.7 7.1 0.9 1.9 19400 13400 13H-2 99.7 186000 752000 10100 500 21 0.1 0.4 469 14H-2 109.2 0 5000 827200 24300 56 30 8.8 1.2 3.4 14700 8310 14H-3 110.7 18000 89000 980600 31500 48 13.2 9.4 1.2 3.3 20300 13000 15H-6 124.7 0 1000 942700 31800 29 15.6 12.7 1.6 6.6 0.2 0.1 32300 14300 16H-5 131.58 0 1000 956000 18100 27 27.8 12.6 1.6 7.4 0.3 0.2 35800 12500 17H-6 143.7 0 1000 942700 44700 57 14.8 9.4 1.2 3.3 16500 11000 19H-4 150.58 0 1000 940500 42400 61 19 21 2.6 19 0.5 0.3 15400 7620 31H-4 275.3 179000 711000 6400 2200 0.1 0.1 33900 33X-4 276.4 0 2000 813700 145600 223 7.5 2.9 1.5 5.3 0.8 0.3 3650 3370 41X-1 339.5 0 4000 893900 85200 191 10.2 2.8 1.2 1.3 0.5 4680 4320 42X-2 350.6 141000 564000 173800 51200 53 5.1 1.9 1 1 0.3 3260 2770 43X-1 358.7 0 8000 824900 146000 240 37.7 8.3 1.3 2.1 0.7 0.2 0.2 3440 2840 44X-2 369.9 1000 14000 794100 169800 234 44.9 6.1 2.2 3.8 0.6 0.2 0.2 3390 2720 46X-3 381.59 0 1000 862200 101100 344 12.3 3.5 11 2.8 0.6 0.1 0.1 2510 2300 53X-5 433.1 26000 97000 705700 77400 759 7.8 0.9 0.6 2.2 0.4 0.2 0.2 930 915 55X-1 445.4 0 1000 887000 94700 493 33 12.2 5.5 17.1 3.3 1.5 1.4 1800 1560 56X-1 455 0 2000 774300 202600 388 70.6 20 8.6 18.9 3.5 1.4 1.4 1990 1510 57X-2 466.2 0 1000 863500 121200 339 40.9 9.3 4 6.5 1.3 0.5 0.5 2550 2150 58X-3 476.16 0 1000 887700 95600 301 24 5 2 4 1 0.4 0.4 2950 2630 61X-3 496.57 50000 212000 617300 93000 272 12 2.3 1.4 2.2 0.6 0.4 0.4 2270 2120 62X-3 505.94 6000 35000 835600 62300 362 27.6 4 2 4 1 0.5 0.5 2310 2080 63X-3 514.75 0 1000 794400 110300 353 28 4.2 2.2 4.2 1 0.4 0.4 2250 2020 64X-4 527 56000 240000 483000 149800 263 18.6 2.7 1.6 2.8 0.7 0.2 0.3 1840 1670 65X-2 533.6 0 0 924000 66500 388 28.1 3.5 1.9 4.4 1 0.4 0.5 2380 2160 66X-4 545.36 0 1000 891100 87200 485 16.4 3.2 2 3.2 0.9 0.4 0.5 1840 1740 67X-3 554.3 0 1000 902200 75900 456 17.3 3 2.1 3.1 0.9 0.4 0.6 1980 1870 68X-5 566.9 0 1000 920800 64600 496 16.2 2.8 1.8 2.8 0.8 0.4 0.5 1860 1770 69X-4 573.5 5000 33000 829400 99100 648 53.2 7.3 5 7.2 1.8 0.7 0.9 1280 1150 71X-3 583.34 0 1000 935600 47900 576 40 4.1 2.6 3.8 1 0.4 0.6 1620 1490 73X-4 603.04 0 1000 870800 59900 647 43 4.5 3.1 3.8 1.1 0.4 0.5 1350 1240 74X-2 610.4 NA NA 773700 NA 513 30 NA NA NA NA NA NA 1510 1430 74X-2 610.4 29000 125000 767400 57400 549 38.5 3.6 3.4 3.6 1.1 0.4 0.6 1400 1280 74X-2 610.4 NA NA 893000 NA 550 30 NA NA NA NA NA NA 1620 1540 74X-2 610.4 NA NA 878400 NA 588 39.3 3.9 3 3.3 0.6 0.4 0.6 1490 1370 75X-4 623 0 1000 837100 135900 704 52.3 5.5 4.4 4.6 1.5 0.6 0.7 1190 1080 76X-3 629.6 97000 409000 318300 13500 263 15 2 1.5 1.8 0.7 0.3 1210 1120 77X-5 638.02 1000 12000 778800 126200 723 37.6 5.7 4.6 4.4 1.4 0.6 0.7 1080 1000 77X-5 638.02 NA NA 859200 NA 679 NA NA NA NA NA NA 1270 1270 78X-1 647.4 186000 754000 3500 1600 3 0.4 NA NA NA NA NA NA 1350 1170 79X-2 657.82 0 1000 905100 84100 682 39.7 6.4 4.9 4.6 1.5 0.6 0.6 1330 1220 80X-3 669.15 0 1000 939200 129200 656 37.9 6.6 5.2 5.4 2 0.8 0.9 1430 1310 81X-3 679.2 35000 153000 611100 130600 743 48 7.2 6.2 5.4 1.9 0.8 0.8 823 752 82X-3 687.88 0 1000 967000 32400 636 36.6 6.5 4.9 5.6 1.9 0.9 0.9 1520 1400 83X-4 699.9 0 0 940100 53000 676 34 4.4 5.3 5.3 1.8 0.9 0.9 1390 1290 164-995B- 3H-5 106.5 NA NA 999600 NA 38 17.1 NA NA NA NA NA NA 26400 18200 3H-5 106.5 0 7000 954900 30400 52 13.6 9.9 1.2 3.5 18360 11910 6H-1 245.1 0 1000 898800 108100 236 5.4 3 1.3 5.2 0.7 3800 3570 8H-3 312.88 0 1000 902300 98900 217 20.6 3 1.8 3 0.7 0.1 4160 3670 12H-2 419.8 0 1000 850700 130300 694 15.9 4.8 2.1 4.9 0.8 0.2 1230 1180 13H-3 430.9 47000 204000 520700 202100 401 55 19.9 7.3 12.8 2.1 0.7 0.6 1300 1040 15H-3 450.1 0 1000 832100 143700 408 27.3 8.9 4 12.1 2.3 1.1 1.1 2040 1790 "Notes: Oxygen (O2) and nitrogen (N2) concentrations are included as a guide to the amount of air contamination in each sample. C1 through C6 = the alkanes: methane, ethane, propane, butane, pentane, and hexane. " "Iso- and normal configurations of butane, pentane, and hexane are designated with i- and n- prefixes. C1/C2 = the methane/ethane ratio, and C1/C2+ = the ratio of methane/the sum of (C2 through C6). NA = not analyzed."