Table 8. Composition of headspace gas in sediment from Site 996. 																	

"Core, section"	Depth (mbsf)	CO2 (ppmv)	C1 (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+	CO2 (uL/kg wet sediment)	C1 (uL/kg wet sediment)	C2 (uL/kg wet sediment)	C3 (uL/kg wet sediment)

164-996A-																	
1H-2	0.9	NA	8540	8.4	1.5	NA	NA	NA	NA	NA	NA	1020	863	NA	6300	6	1
2H-1	8.5	NA	6810	6		NA	NA	NA	NA	NA	NA	1140	1140	NA	8000	7	0
3X-1	10.06	NA	4510	4		NA	NA	NA	NA	NA	NA	1130	1130	NA	6200	6	0
4X-CC	19	11400	3440	0.8	1	1.7		0.5			0.2	4240	822	39400	11900	3	3
8H-3	49.83	NA	820	0.7	0.7	0.6	0.4	0.7	0.1	0.1	0.1	1230	301	NA	2900	0	2
9H-2	59.43	NA	10980	9.4	4.3	3.3	1.4	7.6	1.3	0.8	0.7	1170	381	NA	44800	38	18

164-996C-																	
1H-2	1.14	NA	2060	1.2	1.6	1.4	0.2	3			0.1	1720	276	NA	15600	9	12

164-996D-																	
1H-1	0	NA	4840	3.6		NA	NA	NA	NA	NA	NA	1350	1350	NA	2700	2	
4H-6	27.24	NA	3880	2.1		NA	NA	NA	NA	NA	NA	1850	1850	NA	12500	7	
6H-2	42.47	29000	2760	2.3	1.6	1.6	0.9	5.4	0.8	0.6	0.4	1200	203	137400	13100	11	8

164-996E-																	
1H-2	1.5	4500	30.7	 										13600	100		
2H-2	5.6	5100	27200	3.9	2.4							6980	4320	10400	55400	8	5
2H-4	8.6	NA	30800	26.1		NA	NA	NA	NA	NA	NA	1180	1180	NA	26400	22	
2H-6	11.27	NA	190	 		NA	NA	NA	NA	NA	NA			NA	200		
4H-3	25.4	17600	6550	3.1	1	0.2	0.2	0.1	0.1	0.1	0.2	2110	1330	37300	13900	7	2
5H-3	34.29	32000	6650	3.5	0.9	0.3	0.1	0.3	0.1	 	0.1	1900	1260	67900	14100	7	2
6X-4	42.2	NA	13300	13.2	 	NA	NA	NA	NA	NA	NA	1000	1010	NA	28200	28	
7H-4	51.8	NA	9220	9.4		NA	NA	NA	NA	NA	980	980	980	NA	33700	34	

"Notes: 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+ = ratio of methane/the sum of (C2 through C6). NA = not analyzed."