Table 1.

Table 1. Concentration and isotopic composition of pore-water methane at Site 995B.

Core,
section Interval
(cm) Depth
(mbsf) CH₄ conc.
(µM)* CH₄ conc.
(µM) ¹³CH₄
( vs. PDB)* ¹³CH₄
( vs. PDB)

164-995B-

1H-3
66-76
3.685
7.5
8.2
-62.4
-64.1

2H-1
122-132
17.245
6.0
6.3
-79.3
-80.6

2H-3
100-110
20.025
16.2
15.9
-93.3
-92.9

2H-3
120-130
20.225
17.2
17.7
-93.9
-93.4

2H-4
10-20
20.625
18.6
17.0
-95.4
-95.5

2H-4
30-40
20.825
16.2
19.5
-80.1
-89.4

2H-4
72-82
21.245
52.8
56.0
-98.5
-99.8

2H-4
92-102
21.445
103.2
105.3
-101.1
-101.3

2H-4
122-132
21.745
180.4
173.9
-97.5
-98.0

2H-5
10-20
22.125
281.2
267.6
-93.4
-93.4

2H-5
30-40
22.325
372.8
362.0
-92.3
-92.4

2H-5
60-70
22.625
428.5
413.9
-90.3
-90.8

2H-5
80-90
22.825
453.2
431.7
-90.7
-90.6

Core, section	Interval (cm)	Depth (mbsf)	CH₄ conc. (µM)*	CH₄ conc. (µM)	¹³CH₄ ( vs. PDB)*	¹³CH₄ ( vs. PDB)
164-995B-
1H-3	66-76	3.685	7.5	8.2	-62.4	-64.1
2H-1	122-132	17.245	6.0	6.3	-79.3	-80.6
2H-3	100-110	20.025	16.2	15.9	-93.3	-92.9
2H-3	120-130	20.225	17.2	17.7	-93.9	-93.4
2H-4	10-20	20.625	18.6	17.0	-95.4	-95.5
2H-4	30-40	20.825	16.2	19.5	-80.1	-89.4
2H-4	72-82	21.245	52.8	56.0	-98.5	-99.8
2H-4	92-102	21.445	103.2	105.3	-101.1	-101.3
2H-4	122-132	21.745	180.4	173.9	-97.5	-98.0
2H-5	10-20	22.125	281.2	267.6	-93.4	-93.4
2H-5	30-40	22.325	372.8	362.0	-92.3	-92.4
2H-5	60-70	22.625	428.5	413.9	-90.3	-90.8
2H-5	80-90	22.825	453.2	431.7	-90.7	-90.6

Notes: Conc. = concentration. * and represent two different samples from the same depth interval.