Table 1.

Table 1. Mineralogy and stable isotopic composition of the diagenetic carbonates from the Cape Fear Diapir (Sites 991, 992, and 993) and from Blake Ridge (Sites 994, 995, and 997).

Core, section,
interval (cm) Depth
(mbsf) In situ temperature
(ºC) Total
carbonate
(wt%) Dolomite
d (104)
(Å) ¹⁸O
calcite
(PDB) ¹³C
calcite
(PDB) ¹⁸O
dolomite
(PDB) ¹³C
dolomite
(PDB) ¹⁸O
siderite
(PDB) ¹³C
siderite
(PDB) ¹⁸O water calculated (dolomite-siderite)
(SMOW) ¹⁸O water calculated (calcite)
(SMOW)

164-991A-

6H-1, 54-55
47.64
5
42.4
2.902

6.21
-27.82

0.5

6H-1, 56-57
47.66
5

2.902

6.19
-28.21

0.54

6H-1, 58-59
47.68
5
77.1
2.902

6.58
-31.22

0.91

6H-1, 63-64
47.73
5
59.8
2.902

6.75
-30.86

1.08

6H-3, 80-81
50.9
5
41.7
2.904

6.58
-31.26

0.91

164-992A-

2H-6, 59-61
10.89
4.5
56.8
2.902

6.27
-25.69

0.6

164-993A-

2X-3, 72-74
5.62
4

2.9

7.53
-20.77

1.85

2X-3, 88-91
5.78
4

n.d.

7.44
-21.23

1.76

164-994C-

2H-1,47-48
4.87
4
24.4
2.887
1
0
-2.1
-4.6

-7.7

4H-1,89-90
24.29
4
31.3
2.891
0.24
-0.1
-0.33
-1.88

-6

6H-1, 26-27
42.66
4
27.6
2.889
0.18
0.22
-0.58
0.81

-6.2

6H-4, 68-69
47.28
5
62
2.896
-3.74
-0.5
4.05
-9.08

-1.6
-6.4

7H-7, 20-21
61.1
5.5
13.2
2.891
-1.86
-0.43
-1.24
-2.12

-6.8

10H-6, 97-98
80.37
6.5
63.8
2.898
-3.26
-0.35
4.8
-7.42

-0.57
-5.5

11H-4, 69-70
86.59
6.5
13.3
2.890
-0.47

-2.68
0.43

-7.8

17H-1, 28-29
138.68
8.6
35.3
2.886
-4.56
-0.77
-2.23
1.66

-6.9
-6.2

20X-4, 2-3
162.92
9.5
20.6

0.38
0.35

3.31
7.81
-1.96

26X-2, 75-76
215.15
11.4
10.1

0.79
-1.07

2.95
6.96
-1.83

33X-3, 54-55
273.93
13.6
17.5

0.4
-0.03

2.57
5.2
-1.63

40X-1, 82-83
329.12
15.6
16

0.3
-0.28

3.47
5.58
-0.26

47X-2, 50-51
388.1
17.7
8.3

0.44
0.34

3.35
3.22
0.2

52X-2, 86-88
426.86
19.1
27

0.55
0.29

2.65
5.37
-0.2

57X-2, 64-65
464.9
20.5
17.5

-0.09
0.36

2.05
2.71
-0.32

73X-4, 66-67
592.33
25
7.7

2.13
7.34
0.82

77X-1, 32-33
626.92
26.4
15.7

2.11
3.56
1.1

78X-1, 46-47
636.66
26.7

0.95
-0.76

3.4
5.2
2.38

78X-4, 133-134
641.55
27
13.1

0.29
0.17

2.32
1.74
1.4

83X-3, 26-27
686.94
28.6
16.7

0.88
-1.55

1.85
2.22
1.33

164-995A-

5H-4, 79-80
35.49
4.8

-1.25
-2.28
1.07
-9.48

-4.6

6H-1, 137-138
41.07
5
67.9
2.898
-2.54
-0.92
6.07
-10.21

0.39
-5.2

6H-3, 25-26
42.95
5
65
2.896
-4.38
-0.76
4.06
-7.39

-1.6
-7

81X-6, 84-85
684.04
26.5

1.61
-3.03

2.7
3.82
1.68

164-997A-

5H-CC, 21-22
41.19
5.9
67.39
2.898
-1.71
-1.3
4.14
-8.44

-1.33

7H-1, 100-101
51.4
5.3
49.06
2.898
-1.39
-0.45
0.97
-9.22

-4.57

8H-3, 17-18
56.07
5.5
69.72
2.897
-1.63
0.4
6.49
-6.74

0.92

8H-5, 45-47
59.4
5.6
25.82
2.897

3.23
-5.85

-1.45

13H-8, 72-73
109.6
8
39.9
2.896
-4.65
-0.47
-1.2
3.98

-6.2
-6.5

164-997B-

22X-1, 126-127
551.06
23.7

5.05
4.56
3.45

46X-3, 119-121
734.43
27

4.85
5.90
3.9

Core, section, interval (cm)	Depth (mbsf)	In situ temperature (ºC)	Total carbonate (wt%)	Dolomite d (104) (Å)	¹⁸O calcite (PDB)	¹³C calcite (PDB)	¹⁸O dolomite (PDB)	¹³C dolomite (PDB)	¹⁸O siderite (PDB)	¹³C siderite (PDB)	¹⁸O water calculated (dolomite-siderite) (SMOW)	¹⁸O water calculated (calcite) (SMOW)
164-991A-
6H-1, 54-55	47.64	5	42.4	2.902			6.21	-27.82			0.5
6H-1, 56-57	47.66	5		2.902			6.19	-28.21			0.54
6H-1, 58-59	47.68	5	77.1	2.902			6.58	-31.22			0.91
6H-1, 63-64	47.73	5	59.8	2.902			6.75	-30.86			1.08
6H-3, 80-81	50.9	5	41.7	2.904			6.58	-31.26			0.91
164-992A-
2H-6, 59-61	10.89	4.5	56.8	2.902			6.27	-25.69			0.6
164-993A-
2X-3, 72-74	5.62	4		2.9			7.53	-20.77			1.85
2X-3, 88-91	5.78	4		n.d.			7.44	-21.23			1.76
164-994C-
2H-1,47-48	4.87	4	24.4	2.887	1	0	-2.1	-4.6			-7.7
4H-1,89-90	24.29	4	31.3	2.891	0.24	-0.1	-0.33	-1.88			-6
6H-1, 26-27	42.66	4	27.6	2.889	0.18	0.22	-0.58	0.81			-6.2
6H-4, 68-69	47.28	5	62	2.896	-3.74	-0.5	4.05	-9.08			-1.6	-6.4
7H-7, 20-21	61.1	5.5	13.2	2.891	-1.86	-0.43	-1.24	-2.12			-6.8
10H-6, 97-98	80.37	6.5	63.8	2.898	-3.26	-0.35	4.8	-7.42			-0.57	-5.5
11H-4, 69-70	86.59	6.5	13.3	2.890	-0.47		-2.68	0.43			-7.8
17H-1, 28-29	138.68	8.6	35.3	2.886	-4.56	-0.77	-2.23	1.66			-6.9	-6.2
20X-4, 2-3	162.92	9.5	20.6		0.38	0.35			3.31	7.81	-1.96
26X-2, 75-76	215.15	11.4	10.1		0.79	-1.07			2.95	6.96	-1.83
33X-3, 54-55	273.93	13.6	17.5		0.4	-0.03			2.57	5.2	-1.63
40X-1, 82-83	329.12	15.6	16		0.3	-0.28			3.47	5.58	-0.26
47X-2, 50-51	388.1	17.7	8.3		0.44	0.34			3.35	3.22	0.2
52X-2, 86-88	426.86	19.1	27		0.55	0.29			2.65	5.37	-0.2
57X-2, 64-65	464.9	20.5	17.5		-0.09	0.36			2.05	2.71	-0.32
73X-4, 66-67	592.33	25	7.7						2.13	7.34	0.82
77X-1, 32-33	626.92	26.4	15.7						2.11	3.56	1.1
78X-1, 46-47	636.66	26.7			0.95	-0.76			3.4	5.2	2.38
78X-4, 133-134	641.55	27	13.1		0.29	0.17			2.32	1.74	1.4
83X-3, 26-27	686.94	28.6	16.7		0.88	-1.55			1.85	2.22	1.33
164-995A-
5H-4, 79-80	35.49	4.8			-1.25	-2.28	1.07	-9.48			-4.6
6H-1, 137-138	41.07	5	67.9	2.898	-2.54	-0.92	6.07	-10.21			0.39	-5.2
6H-3, 25-26	42.95	5	65	2.896	-4.38	-0.76	4.06	-7.39			-1.6	-7
81X-6, 84-85	684.04	26.5			1.61	-3.03			2.7	3.82	1.68
164-997A-
5H-CC, 21-22	41.19	5.9	67.39	2.898	-1.71	-1.3	4.14	-8.44			-1.33
7H-1, 100-101	51.4	5.3	49.06	2.898	-1.39	-0.45	0.97	-9.22			-4.57
8H-3, 17-18	56.07	5.5	69.72	2.897	-1.63	0.4	6.49	-6.74			0.92
8H-5, 45-47	59.4	5.6	25.82	2.897			3.23	-5.85			-1.45
13H-8, 72-73	109.6	8	39.9	2.896	-4.65	-0.47	-1.2	3.98			-6.2	-6.5
164-997B-
22X-1, 126-127	551.06	23.7							5.05	4.56	3.45
46X-3, 119-121	734.43	27							4.85	5.90	3.9

Notes: In situ temperatures have been deduced from the downhole measurements (Paull, Matsumoto, Wallace, et al., 1996). The ¹⁸O values of dolomite and siderite have been corrected for the differential phosphoric acid fractionation (Sharma and Clayton, 1965; Carothers et al., 1988). The ¹⁸O values of the diagenetic waters in equilibrium with the diagenetic dolomite, siderite, and calcite have been deduced from the ¹⁸O values of the carbonates and from the values calculated for the in situ temperatures.