Table 1.

Table 1. ¹³C composition of methane and carbon dioxide in gas samples collected from Leg 164 cores.

Core,
section Depth
(mbsf) ¹³C (CH₄)
(PDF) ¹³C (CO₂)
(PDB) Type

164-991A-

5H-3
40.60
-72.4
-25.8
GT

164-993A-

4X-4
27.50
-77.4
-30.3
GT

164-994C-

6H-3
45.10
-81.9
-18.2
GT

6H-3
45.10
-81.8
-20.2
GT

7H-3
54.90
-81.7
-10.7
GT

8H-3
64.40
-76.2
-8.9
GT

8H-5
67.40
-75.9
-8.2
GT

10H-1
71.90
-76.6

GT

11H-3
84.40
-75.2
-7.1
GT

12H-3
93.90
-76.8

GT

13H-2
101.90
-74.5
-7.6
GT

14H-4
114.40
-72.7
-6.6
GT

15H-2
120.26
-72.4
-4.2
GT

16H-3
131.90
-73.1
-5.3
GT

17H-4
142.90
-72.2
-2.0
GT

22X-2
176.40
-71.2
-4.4

30X-5
246.83
-68.1
-5.3
GT

31X-7
260.75
-63.5
-5.7
GH

52X-1
424.50
-63.8
-9.2
GT

68X-4
554.10
-63.3

FG

69X-4
564.51
-63.0
-13.4
FG

71X-2
575.10
-63.3
-13.4
FG

72X-2
580.80
-64.7
-12.0
FG

79X-2
646.88
-62.7
-15.5
GT

79X-4
650.68
-63.9
-16.5
FG

80X-5
661.21
-63.5
-15.2
FG

81X-5
670.64
-63.7
-16.5
FG

84X-3
697.60
-65.0
-18.2
FG

164-994D-

1H-1
100.00
-71.1

GT

1H-1
100.00
-73.2

GT

1H-2
101.50
-71.9

GT

1H-2
101.50
-71.6

GT

1H-3
103.00
-73.4

GT

1H-3
103.00
-74.1

GT

1H-3
103.00
-74.9

GT

1H-4
104.50
-73.2

GT

1H-4
104.50
-73.6

GT

1H-5
106.00
-73.1

GT

1H-5
106.00
-71.5

GT

1H-5
106.00
-72.6

GT

1H-5
106.00
-72.9

GT

164-995A-

12H-2
89.13
-74.6
-5.2
FG

12H-6
95.18
-74.1
-4.9
FG

14H-2
109.20
-73.9
-4.8
FG

14H-3
110.70

-5.3
FG

15H-6
124.70
-71.8
-2.5
FG

16H-5
131.58
-70.6
-4.1
FG

19H-4
150.58
-69.1
-1.1
FG

41X-1
339.50
-64.8
-7.5
FG

42X-2
350.60
-64.8
-6.6
FG

43X-1
358.70
-64.5
-7.7
FG

44X-2
369.90
-64.0
-6.5
FG

53X5
433.10
-63.6
-10.0
FG

55X-1
445.40
-64.5
-11.0
FG

57X-2
466.20
-63.2
-10.3
FG

65X-2
533.60
-62.7
-12.2
FG

67X-3
554.30
-62.2
-13.6
FG

68X-5
566.90
-62.3
-11.6
FG

69X-4
573.50
-63.2
-14.9
FG

71X-3
583.34
-62.4
-15.1
FG

78X-1
647.40
-63.9

FG

79X-2
657.82
-62.8
-15.9
FG

80X-3
669.15
-63.5
-15.9
FG

81X-3
679.20
-63.6
-16.1
FG

82X-3
687.88
-63.6
-18.1
FG

83X-4
699.90
-63.8
-17.4
FG

164-995B-

6X-1
245.10
-67.0
-5.0
FG

8X-3
312.88
-66.5
-6.7
FG

12X-2
419.80
-63.9
-8.8
FG

13X-3
430.90
-63.7
-8.0
FG

15X-3
450.10
-63.3
-9.8
FG

2H
17.20
-79.6

PW

2H
20.02
-93.3

PW

2H
20.23
-93.9

PW

2H
20.63
-95.4

PW

2H
21.25
-98.5

PW

2H
21.44
-101.3

PW

2H
21.75
-97.5

PW

2H
22.13
-93.6

PW

2H
22.33
-92.3

PW

2H
22.63
-90.3

PW

2H
22.83
-90.7

PW

164-996A-

8H-4 (1)
50.93
-62.5
-14.5
GT

8H-4 (2)
50.93
-67.3
-8.9
GT

8H-4
50.93
-69.1
-21.9
GT

8H-4
52.50
-69.3
-23.2
FG

9H-CC
63.00
-67.4
-19.9
FG

9H-CC
63.00
-67.8
-18.5
FG

164-996D-

1H-1
1.14
-66.6
-22.3
FG

1H-2
0.02
-65.8
-26.9
FG

4H-1
23.18
-72.1
-11.4
GT

6H-1
42.28
-68.0
-14.6
GT

6H-2
43.05
-69.5
-5.3
GT

9H-6
49.05
-67.3
-14.7
GT

164-996E-

7H-CC
52.90
-70.7
-21.9
FG

164-997A-

7H-1
50.50
-76.6
-8.2
FG

8H-2
54.50
-77.8
-17.5
FG

9H-1
61.50
-79.3
-12.7
FG

10H-7
79.85
-74.7
-5.1
FG

11H-3
83.50
-74.1
-5.7
FG

12H-6
97.42
-73.4
-5.2
FG

13H-7
107.58
-72.3
-1.6
FG

22X-4
176.82
-68.3
-3.4
FG

26X-5
209.50
-66.2
-2.0
FG

27X-4
216.60
-67.7
-2.1
FG

28X-2
223.20
-66.5
-2.8
FG

30X-3
235.40
-66.6
-2.3
FG

41X-3
321.80
-65.0
-4.4
FG

42X-3
330.50
-65.8
-21.1
FG

43X-1
337.10
-65.0
-6.5
FG

44X-4
351.30
-64.9
-7.0
FG

46X-4
370.25
-64.9

FG

48X-2
386.90
-64.6
-8.3
FG

52X-5
413.10
-63.8
-6.7
FG

54X-4
427.98
-65.4
-8.6
FG

164-997B-

1X-2
320.10
-65.6
-5.4
FG

2X-2
329.70
-66.1
-5.3
FG

4X-1
414.30
-65.5

FG

5X-2
425.66
-65.0
-8.3
FG

8X-5
449.00
-64.3
-11.4
FG

11X-3
446.30
-64.5
-9.0
FG

12X-3
474.21
-64.8
-11.3
FG

13X-3
484.60
-63.9
-11.5
FG

14X-2
492.70
-64.2
-10.4
FG

16X-3
504.90
-63.6
-12.3
FG

17X-1
510.50
-63.9
-11.6
FG

18X-2
521.60
-63.9
-11.1
FG

19X-3
532.70
-63.6
-11.7
FG

20X-1
539.30
-63.1
-12.2
FG

22X-4
554.40
-63.2
-13.1
FG

23X-6
566.00
-63.6
-13.5
FG

24X-4
572.60
-64.0
-17.2
FG

26X-4
583.20
-63.3
-17.2
FG

27X-5
593.20
-63.4
-15.9
FG

28X-4
600.70
-63.8
-16.0
FG

29X-3
609.60
-63.6
-14.2
FG

30X-3
619.20
-64.3
-17.0
FG

31X-4
630.23
-63.9
-15.7
FG

33X-4
640.07
-63.8
-16.5
FG

34X-1
645.00
-62.4

FG

35X-5
658.80
-64.3
-17.0
FG

37X-5
671.20
-63.7
-16.8
FG

38X-5
679.90
-64.1
-16.6
FG

42X-3
704.77
-64.4
-18.8
FG

43X-4
716.80
-64.3
-17.5
FG

45X-4
727.26
-64.1
-16.2
FG

46X-4
734.84
-64.3
-17.1
FG

47X-4
745.70
-64.4
-17.9
FG

164-997A-

4H-3
34.90
-84.0
-20.6
GT

5H-3
34.90
-82.4
-19.3
GT

6H-3
44.40
-80.8
-15.6
GT

10H-3
74.30
-75.2
-7.4
GT

14H-4
112.73
-71.2
-1.2
GT

15H-3
121.90
-71.1
-1.1
GT

16H-3
131.40
-70.9
0.8
GT

16H-3
131.40
-71.3
1.1
GT

22X-3
176.00
-69.2
-0.9
GT

35X-3
272.95
-69.0
-2.2
GT

Core, section	Depth (mbsf)	¹³C (CH₄) (PDF)	¹³C (CO₂) (PDB)	Type
164-991A-
5H-3	40.60	-72.4	-25.8	GT
164-993A-
4X-4	27.50	-77.4	-30.3	GT
164-994C-
6H-3	45.10	-81.9	-18.2	GT
6H-3	45.10	-81.8	-20.2	GT
7H-3	54.90	-81.7	-10.7	GT
8H-3	64.40	-76.2	-8.9	GT
8H-5	67.40	-75.9	-8.2	GT
10H-1	71.90	-76.6		GT
11H-3	84.40	-75.2	-7.1	GT
12H-3	93.90	-76.8		GT
13H-2	101.90	-74.5	-7.6	GT
14H-4	114.40	-72.7	-6.6	GT
15H-2	120.26	-72.4	-4.2	GT
16H-3	131.90	-73.1	-5.3	GT
17H-4	142.90	-72.2	-2.0	GT
22X-2	176.40	-71.2	-4.4
30X-5	246.83	-68.1	-5.3	GT
31X-7	260.75	-63.5	-5.7	GH
52X-1	424.50	-63.8	-9.2	GT
68X-4	554.10	-63.3		FG
69X-4	564.51	-63.0	-13.4	FG
71X-2	575.10	-63.3	-13.4	FG
72X-2	580.80	-64.7	-12.0	FG
79X-2	646.88	-62.7	-15.5	GT
79X-4	650.68	-63.9	-16.5	FG
80X-5	661.21	-63.5	-15.2	FG
81X-5	670.64	-63.7	-16.5	FG
84X-3	697.60	-65.0	-18.2	FG
164-994D-
1H-1	100.00	-71.1		GT
1H-1	100.00	-73.2		GT
1H-2	101.50	-71.9		GT
1H-2	101.50	-71.6		GT
1H-3	103.00	-73.4		GT
1H-3	103.00	-74.1		GT
1H-3	103.00	-74.9		GT
1H-4	104.50	-73.2		GT
1H-4	104.50	-73.6		GT
1H-5	106.00	-73.1		GT
1H-5	106.00	-71.5		GT
1H-5	106.00	-72.6		GT
1H-5	106.00	-72.9		GT
164-995A-
12H-2	89.13	-74.6	-5.2	FG
12H-6	95.18	-74.1	-4.9	FG
14H-2	109.20	-73.9	-4.8	FG
14H-3	110.70		-5.3	FG
15H-6	124.70	-71.8	-2.5	FG
16H-5	131.58	-70.6	-4.1	FG
19H-4	150.58	-69.1	-1.1	FG
41X-1	339.50	-64.8	-7.5	FG
42X-2	350.60	-64.8	-6.6	FG
43X-1	358.70	-64.5	-7.7	FG
44X-2	369.90	-64.0	-6.5	FG
53X5	433.10	-63.6	-10.0	FG
55X-1	445.40	-64.5	-11.0	FG
57X-2	466.20	-63.2	-10.3	FG
65X-2	533.60	-62.7	-12.2	FG
67X-3	554.30	-62.2	-13.6	FG
68X-5	566.90	-62.3	-11.6	FG
69X-4	573.50	-63.2	-14.9	FG
71X-3	583.34	-62.4	-15.1	FG
78X-1	647.40	-63.9		FG
79X-2	657.82	-62.8	-15.9	FG
80X-3	669.15	-63.5	-15.9	FG
81X-3	679.20	-63.6	-16.1	FG
82X-3	687.88	-63.6	-18.1	FG
83X-4	699.90	-63.8	-17.4	FG
164-995B-
6X-1	245.10	-67.0	-5.0	FG
8X-3	312.88	-66.5	-6.7	FG
12X-2	419.80	-63.9	-8.8	FG
13X-3	430.90	-63.7	-8.0	FG
15X-3	450.10	-63.3	-9.8	FG
2H	17.20	-79.6		PW
2H	20.02	-93.3		PW
2H	20.23	-93.9		PW
2H	20.63	-95.4		PW
2H	21.25	-98.5		PW
2H	21.44	-101.3		PW
2H	21.75	-97.5		PW
2H	22.13	-93.6		PW
2H	22.33	-92.3		PW
2H	22.63	-90.3		PW
2H	22.83	-90.7		PW
164-996A-
8H-4 (1)	50.93	-62.5	-14.5	GT
8H-4 (2)	50.93	-67.3	-8.9	GT
8H-4	50.93	-69.1	-21.9	GT
8H-4	52.50	-69.3	-23.2	FG
9H-CC	63.00	-67.4	-19.9	FG
9H-CC	63.00	-67.8	-18.5	FG
164-996D-
1H-1	1.14	-66.6	-22.3	FG
1H-2	0.02	-65.8	-26.9	FG
4H-1	23.18	-72.1	-11.4	GT
6H-1	42.28	-68.0	-14.6	GT
6H-2	43.05	-69.5	-5.3	GT
9H-6	49.05	-67.3	-14.7	GT
164-996E-
7H-CC	52.90	-70.7	-21.9	FG
164-997A-
7H-1	50.50	-76.6	-8.2	FG
8H-2	54.50	-77.8	-17.5	FG
9H-1	61.50	-79.3	-12.7	FG
10H-7	79.85	-74.7	-5.1	FG
11H-3	83.50	-74.1	-5.7	FG
12H-6	97.42	-73.4	-5.2	FG
13H-7	107.58	-72.3	-1.6	FG
22X-4	176.82	-68.3	-3.4	FG
26X-5	209.50	-66.2	-2.0	FG
27X-4	216.60	-67.7	-2.1	FG
28X-2	223.20	-66.5	-2.8	FG
30X-3	235.40	-66.6	-2.3	FG
41X-3	321.80	-65.0	-4.4	FG
42X-3	330.50	-65.8	-21.1	FG
43X-1	337.10	-65.0	-6.5	FG
44X-4	351.30	-64.9	-7.0	FG
46X-4	370.25	-64.9		FG
48X-2	386.90	-64.6	-8.3	FG
52X-5	413.10	-63.8	-6.7	FG
54X-4	427.98	-65.4	-8.6	FG
164-997B-
1X-2	320.10	-65.6	-5.4	FG
2X-2	329.70	-66.1	-5.3	FG
4X-1	414.30	-65.5		FG
5X-2	425.66	-65.0	-8.3	FG
8X-5	449.00	-64.3	-11.4	FG
11X-3	446.30	-64.5	-9.0	FG
12X-3	474.21	-64.8	-11.3	FG
13X-3	484.60	-63.9	-11.5	FG
14X-2	492.70	-64.2	-10.4	FG
16X-3	504.90	-63.6	-12.3	FG
17X-1	510.50	-63.9	-11.6	FG
18X-2	521.60	-63.9	-11.1	FG
19X-3	532.70	-63.6	-11.7	FG
20X-1	539.30	-63.1	-12.2	FG
22X-4	554.40	-63.2	-13.1	FG
23X-6	566.00	-63.6	-13.5	FG
24X-4	572.60	-64.0	-17.2	FG
26X-4	583.20	-63.3	-17.2	FG
27X-5	593.20	-63.4	-15.9	FG
28X-4	600.70	-63.8	-16.0	FG
29X-3	609.60	-63.6	-14.2	FG
30X-3	619.20	-64.3	-17.0	FG
31X-4	630.23	-63.9	-15.7	FG
33X-4	640.07	-63.8	-16.5	FG
34X-1	645.00	-62.4		FG
35X-5	658.80	-64.3	-17.0	FG
37X-5	671.20	-63.7	-16.8	FG
38X-5	679.90	-64.1	-16.6	FG
42X-3	704.77	-64.4	-18.8	FG
43X-4	716.80	-64.3	-17.5	FG
45X-4	727.26	-64.1	-16.2	FG
46X-4	734.84	-64.3	-17.1	FG
47X-4	745.70	-64.4	-17.9	FG
164-997A-
4H-3	34.90	-84.0	-20.6	GT
5H-3	34.90	-82.4	-19.3	GT
6H-3	44.40	-80.8	-15.6	GT
10H-3	74.30	-75.2	-7.4	GT
14H-4	112.73	-71.2	-1.2	GT
15H-3	121.90	-71.1	-1.1	GT
16H-3	131.40	-70.9	0.8	GT
16H-3	131.40	-71.3	1.1	GT
22X-3	176.00	-69.2	-0.9	GT
35X-3	272.95	-69.0	-2.2	GT

Note: GT = gas tube samples, FG = free gas samples, PW = pore water, GH = gas hydrate samples. Numbers in ( ) = the number of the analyzed gas aliquot from a given PCS core.