|
Age interval (Ma)
|
This study
|
Normative analysis*
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
Sample ID (cm)
|
SiO2 wt%
(Na2CO3 leach) |
SiO2 wt%
(KOH leach) |
CaCO3 wt%
(coulometry†) |
Percent nonbiogenic (wt%)
|
||||||
|
Using Na2CO3
SiO2 values |
Using KOH
SiO2 values |
Sample ID
|
Biogenic silica
(%) |
CaCO3
(%) |
Nonbiogenic silica (%)
|
|||||
| 30-31 | 1-1:91-92 | 8.1 | 15.1 | 51.7 |
|
|
1-1:90-92 |
|
|
|
|
|
1-2:61-62 | 9.5 | 18.4 | 46.9 |
|
|
1-2:60-62 |
|
|
|
|
|
1-3:80-81 | 7.3 | 7.8 | 60.0 |
|
|
1-3:80-82 |
|
|
|
|
|
Average: | 8.3 | 13.8 | 52.9 | 38.9 | 33.4 |
|
10.8, 14.6 | 72.0 | 17.2,13.6 |
| 35-36 | 3-2:80-81 | 8.2 | 10.9 | 72.3 |
|
|
3-2:80-82 |
|
|
|
|
|
3-3:80-81 | 6.6 | 10.3 | 67.6 |
|
|
3-3:80-82 |
|
|
|
|
|
3-4:80-81 | 6.2 | 7.3 | 77.6 |
|
|
3-4:80-82 |
|
|
|
|
|
3-5:70-71 | 5.5 | 6.5 | 57.3 |
|
|
3-5:70-72 |
|
|
|
|
|
Average: | 7.0 | 9.5 | 68.7 | 24.3 | 21.8 |
|
6.7, n/a | 70.0 | 23.3,23.3 |
| 37-38 | 4-2:80-81 | 11.6 | 24.2 | 2.9 |
|
|
4-2:80-82 |
|
|
|
|
|
4-3:79-80 | 18.0 | 43.4 | 4.0 |
|
|
4-3:80-82 |
|
|
|
|
|
4-4:80-81 | 18.1 | 45.3 | 3.6 |
|
|
4-4:80-82 |
|
|
|
|
|
4-5:77-78 | 21.2 | 48.9 | 3.1 |
|
|
4-5:76-78 |
|
|
|
|
|
4-6:60-61 | 20.3 | 54.3 | 6.0 |
|
|
4-6:20-22 |
|
|
|
|
|
Average: | 17.9 | 43.2 | 3.9 | 78.2 | 52.9 |
|
50.7, 56.0 | 3.3 | 46.0,40.5 |
| 46-47 | 14-2:80-81 | 26.6 | 52.0 | 16.0 |
|
|
14-2:80-82 |
|
|
|
|
|
14-3:81-82 | 20.8 | 42.2 | 28.7 |
|
|
14-3:80-82 |
|
|
|
|
|
14-4:80-81 | 19.2 | 37.1 | 35.3 |
|
|
14-4:80-82 |
|
|
|
|
|
Average: | 22.2 | 43.8 | 26.6 | 51.1 | 29.6 |
|
47.4, 51.6 | 22.2 | 30.3,26.2 |
| 49-50 | 17-4:125-126 | 2.4 | 3.5 | 78.7 |
|
|
17-4:124-126 |
|
|
|
|
|
Average: | 2.4 | 3.5 | 78.7 | 18.9 | 17.9 |
|
3.1, 4.0 | 68.0 | 28.9,27.9 |
Notes: * = data separated by commas from Leinen (1976, 1979), respectively. † = method described in Lyle, et al. (2000). SiO2 biogenic values resulting from the KOH treatment are in good agreement with the normative calculation, especially for samples with opal contents >10 wt%.