Table T6. Summary of diatom and radiolarian biostratigraphic datums recognized in Holes 1165B and 1165C and calibrated ages for each datum event.
Upper sample | Lower sample | Event | Taxon | Constraint | Calibrated age (Ma) |
|||
---|---|---|---|---|---|---|---|---|
Core,
section, interval (cm)
|
Interval
depth
(mbsf) |
Core,
section, interval (cm)
|
Interval
depth
(mbsf) |
|||||
Diatoms: | ||||||||
188-1165B-, | 188-1165B- | |||||||
1H-2, 20-21 | 1.70 | 1H-5, 20-21 | 6.20 | LO | Actinocylclus ingens | < | 0.66 | |
1H-5, 20-21 | 6.20 | 2H-2, 95-96 | 9.25 | LO | Fragilariopsis barronii | > | 1.35 | |
2H-2, 95-96 | 9.25 | 3H-1, 95-96 | 17.25 | LO | Thalassiosira kolbei | > | 1.8-2.0 | |
3H-1, 95-96 | 17.25 | 3H-2, 20-21 | 18.00 | LO | Thalassiosira vulnifica | > | 2.2-2.3 | |
3H-2, 20-21 | 18.00 | 3H-3, 20-21 | 19.50 | LO | Thalassiosira insigna | > | 2.5-2.6 | |
3H-CC | 25.01 | 4H-1, 20-21 | 26.00 | FO | Thalassiosira vulnifica | < | 2.8-3.2 | |
5H-1, 127-128 | 36.57 | 5H-2, 127-128 | 38.07 | FO | Fragilariopsis interfrigidaria | < | 3.7-3.8 | |
5H-4, 95-96 | 40.75 | 5H-5, 60-61 | 41.90 | FO | Fragilariopsis barronii | < | 4.2-4.4 | |
6H-3, 95-96 | 48.75 | 6H-4, 59-60 | 49.89 | FO | Thalassiosira inura | < | 4.8-4.9 | |
12H-CC | 101.80 | 13H-6, 70-71 | 114.50 | FO | Thalassiosira torokina | < | 8.5-10.0 | |
23X-3, 20-21 | 188.30 | 23X-CC | 194.70 | LO | Denticulopsis dimorpha | > | 11.0-11.1 | |
27X-CC | 231.69 | 28X-CC | 242.68 | FO | Denticulopsis dimorpha | < | 12.2-12.8 | |
28X-CC | 242.68 | 30X-CC | 253.71 | FO | Denticulopsis praedimorpha | < | 12.8-13.1 | |
35X-CC | 298.38 | 36X-CC | 309.52 | FCO | Denticulopsis simonsenii | < | 14.1-14.6 | |
38X-CC | 327.78 | 39X-CC | 336.89 | FO | Actinocyclus ingens v. nodus | < | 14.5-14.7 | |
50X-CC | 443.99 | 51X-CC | 449.80 | FCO | Actinocyclus ingens | < | 15.9-16.4 | |
55X-CC | 487.52 | 56X-CC | 495.81 | FO | Denticulopsis maccollumii | < | 16.7-17.0 | |
55X-CC | 487.52 | 56X-CC | 495.81 | FO | Crucidenticula kanayae | < | 17.5-17.7 | |
59X-CC | 527.92 | 60X-CC | 534.60 | LO | Thalassiosira praefraga | > | 18.3-19.1 | |
188-1165C- | 188-1165C- | |||||||
10R-3, 127-129 | 750.77 | — | — | FO | Thalassiosira praefraga | < | 19.9-20.8 | |
Radiolarians: | ||||||||
188-1165B- | 188-1165B- | |||||||
3H-CC | 25.01 | 4H-CC | 35.75 | LO | Prunopyle titan | > | 3.5 | |
4H-CC | 35.75 | 5H-CC | 44.08 | FO | Helotholus vema | < | 4.57 | |
6H-CC | 54.39 | 1R-CC | 63.60 | LCO | Lychnocanoma grande | > | 5.03 | |
11H-CC | 100.32 | 12H-CC | 101.80 | FO | Acrosphaera? labrata | < | 7.71 | |
12H-CC | 101.80 | 13H-CC | 116.02 | LO | Cycladophora spongothorax | > | 9.12 | |
15H-CC | 128.58 | 16H-CC | 135.03 | FCO | Ceratocyrtis stigi | < | 9.32 | |
21X-CC | 172.67 | 22X-CC | 185.08 | FO | Acrosphaera australis | < | 10.36 | |
21X-CC | 172.67 | 22X-CC | 185.08 | LO | Cycladophora humerus | > | 10.53 | |
23X-CC | 194.70 | 24X-CC | 199.15 | LO | Actinonomma golownini | > | 10.77 | |
38X-CC | 327.78 | 39X-CC | 336.89 | FO | Cycladophora spongothorax | < | 12.55 | |
38X-CC | 327.78 | 39X-CC | 336.89 | FO | Cycladophora humerus | < | 14.18 | |
54X-CC | 479.50 | 55X-CC | 487.52 | FO | Cycladophora golli regipileus | < | 19.11 |
Notes: Sample designations and depths in bold type represent the occurrence of each taxon, and plain type represents sample-spacing uncertainty for each datum. LO = last occurrence, FO = first occurrence, FCO = first common occurrence, LCO = last common occurrence. — = not identified due to opal-A dissolution.