Table 10. Composition of gas collected in gas collection chambers at Site 996.																

"Core, section"	Sample	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+

164-996A-																
1H-3		2.29	NA	NA	8500	NA	8	1.5	 	 	 			 	1020	863
1H-3		2.3	183000	748000	8300	1000	 	1.5	 	 	 			 		5540
8H-4	1	50.93	149000	613000	238800	3100	124	3.9	1.4	0.4	1	0.4	0.1	 	1930	1820
8H-4	2	50.93	62000	259000	671000		287	9.4	3.1	0.7	2.4	0.6	0.2	0.1	2340	2210
8H-4	3	50.93	56000	228000	661400	8000	271	8.8	3	0.7	3	 	 	 	2440	2310
8H-4	3	50.93	65000	254000	6712000	7500	263	7	2.5	0.5	1.4	1	0.3	 	2550	2440
9H-3		61.26	76000	314000	5975000	6300	433	9.2	3.3	0.8	3.4	0.8	0.3	 	1380	1330

164-996D-																
4H-1	1	23.18	152000	661000	170500	5000	119	2.4	1.6	0.4	1.3	0.7	0.2	 	1430	1360
4H-1	2	23.18	66000	275000	647200	6800	462	10.8	4.1	1	4	1	0.4	 	1400	1340
6H-1		42.28	126000	519000	345200		262	8.6	2.1	0.6	2.2	0.5	0.2	 	1320	1250
6H-2		43.05	88000	365000	535300	5700	397	8	2.8	0.8	2.9	1	0.3	 	1350	1300
9H-4		46.05	177000	734000	73800	2200	51	1.8	1.1	 	1.2	1.1	0.3	 	1450	1300
9H-6		49.05	147000	616000	221300	5100	158	4.5	2.5	0.3	2.5	1.2	0.6	0.4	1400	1300

"Notes: Oxygen (O2) and nitrogen (N2) concentrations are included as a guide to the amount of air contamination in each sample. C1 through C7 = the alkanes: methane, ethane, propane, butane, pentane, hexane, and heptane. "																
"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 methane/the sume of (C2 through C6). NA = not analyzed."