Table
2. Standard opal content measured by treatment with Na2CO3,
opal content of the sieved residue measured by treatment with NaOH, and total
opal content.
Core,
section,
interval
(cm)
Opal: Na2CO3
(wt%)
Opal: NaOH
(wt%)
Total opal
(wt%)
167-1016B-
17H-1,
6-8
3.69
0.14
3.82
17H-1,
10-12
3.48
0.08
3.56
17H-1,
14-16
6.04
0.18
6.23
17H-1,
18-20
6.72
0.38
7.09
17H-1,
22-24
7.06
0.40
7.46
17H-1,
26-28
7.51
0.54
8.04
17H-1,
30-32
7.21
0.57
7.78
17H-1,
34-36
6.75
0.73
7.48
17H-1,
38-40
5.91
0.80
6.71
17H-1,
42-44
4.40
0.41
4.81
17H-1,
46-48
4.71
0.46
5.17
17H-1,
50-52
5.14
0.55
5.69
17H-1,
54-56
4.85
0.43
5.28
17H-1,
58-60
4.81
0.55
5.36
17H-1,
62-64
5.46
0.80
6.25
17H-1,
66-68
6.13
1.28
7.40
17H-1,
70-72
6.39
0.93
7.32
17H-1,
74-76
7.13
0.65
7.78
17H-1,
78-80
5.78
0.30
6.08
17H-1,
82-84
5.56
0.37
5.93
17H-1,
86-88
5.96
0.27
6.24
17H-1,
90-92
5.30
0.20
5.50
17H-1,
94-96
4.98
0.24
5.22
17H-1,
98-100
5.53
0.42
5.95
17H-1,
102-104
5.44
0.38
5.82
17H-1,
106-108
5.72
0.65
6.38
17H-1,
110-112
5.46
0.65
6.11
17H-1,
118-120
6.25
0.50
6.75
17H-1,
122-124
6.14
0.39
6.52
17H-1,
126-128
5.89
0.28
6.17
17H-1,
130-132
5.57
0.43
6.01
17H-1,
134-136
5.60
0.47
6.08
17H-1,
138-140
5.09
0.33
5.42
17H-1,
142-144
4.55
0.25
4.80
17H-1,
146-148
4.52
0.18
4.70