Table T3. Comparison of SiO2 biogenic values resulting from the two extraction procedures used in this study on Leg 199 and other samples.
Sample ID (cm)
Age approx.
SiO2 (average wt%)
Notes
2-M Na2CO3
2-M KOH
W8709A-5BC: 5-20 2 ka 5.0 10.1 Contains volcanic glass
K7905-42BC: 15-20 12 ka 2.0 2.3
ME0005A-24JC:



0-1 0.04 ka 14.0 12.7
10-11 0.94 ka 14.4 13.5
30-31 2.6 ka 13.4 13.1
200-201 17 ka 17.1 16.0
660-661 56 ka 26.7 26.1
860-861 74 ka 18.1 18.3
Ash layer D 981-982 84 ka 10.0 25.0 Opal-bearing ash layer
Ash layer D 981-982 84 ka 6.0 21.0 Opal-free ash layer
EW9709-7PC (Pat-8):



122-124 9-21 Ma 13.8 17.7 Contains volcanic glass
335-337
16.9 24.7
387-389
17.0 22.2
518-520
14.3 20.6
696-698
18.3 32.1
804-806
10.5 14.4
829-831
7.4 8.9
982-984
17.9 34.6
1163-1165
19.7 31.9
1252-1254
21.4 29.7
1317-1319
18.4 24.9
1367-1369
20.3 31.7
1436-1438
16.3 24.0
1466-1468
14.3 22.2
1518-1520
7.1 7.0
EW9709-12PC (Pat-17):



56-58 12-21 Ma 14.3 19.4
258-260
21.3 36.3
473-475
15.5 22.9
593-595
16.9 26.1
740-742
24.1 42.5
833-835
25.9 50.8
979-981
24.2 37.3
1074-1076
27.4 45.8
1261-1263
12.0 15.1
EW9709-3PC (Pat-13):



33-35 45-50 Ma 7.9 12.0
314-316
11.2 15.5
433-435
17.5 20.7
633-635
16.8 18.5
773-775
18.6 52.6
830-832
21.7 60.9
933-935
23.0 57.9
1192-1194
22.5 55.9
1337-1339
23.1 57.0

Note: Approx = approximate.