Table 15. Composition of gases from Site 995 collected in gas-collection chambers. "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- 7H-6 51.2 131000 535000 248000 7400 12 3 1.5 20700 14800 10H-1 71.2 160000 650000 114900 4500 5 2 0.8 23900 15700 11H-2 80.7 137000 570000 229100 9200 9 3 2 0.7 0.5 24400 14400 13H-3 99.7 109000 460000 370100 18700 14 6 3.8 0.4 1.2 0.1 27400 14800 14H-5 109.2 1000 5000 104100 33200 56 26 1.2 1860 1250 14H-6 110.7 118000 494000 323500 22800 11 5 3.5 0.4 1.5 29100 15000 16H-2 127.15 117000 493000 326100 23200 12 6 4.9 0.7 2.8 26700 12300 16H-2 127.15 50000 228000 562500 39700 24 10 8.6 0.8 23200 12900 16H-4 130.15 125000 523000 293000 20600 11 5 4.3 0.5 2.4 26200 12500 19H-6 147.58 1000 519000 199800 19600 10 5 5 0.5 8.2 0.2 19400 6800 21H-4 168.7 144000 671000 118000 16500 6 4 4.6 0.7 3.4 0.5 18700 5960 31X-4 255.8 154000 708000 70300 25400 7 4 0.7 2.5 0.3 10300 4820 54X-4 440.2 175000 720000 37600 10100 20 2 0.4 0.4 0.7 0.2 1870 1590 68X-1 566.9 157000 665000 93800 40400 86 6 1.2 0.7 1.3 0.2 0.1 0.1 1100 990 68X-4 571.4 158000 666000 92700 39100 88 5 1.1 0.5 1 0.3 0.1 1050 963 71X-1 583.34 NA NA 18900 NA 12 1570 1570 71X-3 586.34 160000 702000 80000 23400 90 5 1.6 0.9 1.8 0.6 889 798 73X-3 601.54 162000 676000 80600 20300 119 5 1.5 0.7 1.8 0.8 675 623 73X-5 604.54 162000 675000 100300 20100 130 8 1.6 1 1.4 0.7 770 701 81X-1 677.7 168000 697000 81300 12000 43 4 1.6 0.4 0.4 0.8 0.3 1900 1610 83X-1 696.9 161828 701000 73600 22200 124 7 1.3 1 0.8 0.3 595 549 164-995B- 3H-1 100 158000 673000 113100 13500 65 4 1.9 0.4 0.7 0.2 1750 1570 3H-1 100 155000 654000 149000 10200 11 3 2.5 0.4 1 0.7 0.2 13500 7760 3H-1 100 159000 676000 109100 12200 61 4 1.7 0.7 0.9 1780 1590 3H-2 101.5 51000 232000 670600 29600 34 10 7.6 1 2.5 19900 12200 3H-2 101.5 53000 236000 660300 28300 35 9 0.7 0.7 2.2 0.7 0.3 18900 13600 3H-2 101.5 51000 232000 670600 29600 36 19 7.6 1 2.5 18700 10200 3H-2 101.5 149000 623000 186300 12900 25 4 2.3 1 0.8 0.7 0.2 7420 5460 3H-2 101.5 75000 316000 565700 22600 28 8 6.4 0.8 2 20400 12600 3H-2 101.5 75000 315000 561600 22400 26 7 6.2 0.7 1.9 22000 13500 3H-2 101.5 87000 374000 491400 22800 23 7 5.5 0.5 1.7 0.4 21500 12800 3H-3 103 113000 476000 338100 26900 26 6 4 0.5 1.5 1.5 0.5 13300 8560 3H-3 103 96000 408000 437400 30400 21 8 5.9 0.7 1.8 1.7 20700 11200 3H-3 103 79000 356000 505300 32600 32 10 7.9 1 2.7 0.3 15700 9340 3H-3 103 114000 481000 338300 26700 28 6 4.1 0.4 1.5 1.7 0.5 12000 7960 3H-4 104.5 72000 308000 567200 23800 26 9 6.1 0.8 2.1 0.2 21700 12800 3H-4 104.5 113000 473000 357300 20600 5 14 0.8 0.5 1.3 0.4 67400 16000 3H-4 104.5 78000 357000 515400 25400 32 9 10 1 2.3 0.2 16100 9390 3H-4 104.5 79000 334000 494400 30200 30 20 9.8 5 14 11 14 11.5 16500 4280 3H-4 104.5 116000 479000 345300 18600 12 4 3.2 0.3 1 1 28800 16100 3H-4 104.5 78000 320000 549100 NA 25 7 5.2 0.5 1.3 1.2 22300 13800 3H-5 106 125000 519000 296100 20400 36 5 3.3 0.5 0.9 0.3 8160 6470 3H-5 106 128000 527000 288300 18800 39 4 3.3 0.5 0.8 0.7 0.2 7410 5930 "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."