Table T1. Summary of paleomagnetic evidence for the existence and age of Brunhes Chron excursions recovered during Leg 172 and its site survey cruise.
|
Excursion
|
SPECMAP
oxygen
isotope stage |
Age
(ka) |
Long-core
measurement |
U-Channel
measurement |
Discrete
sample measurement |
|---|---|---|---|---|---|
| 3a | 3 | YES | NO | NO | |
3 |
3 | 39-40* | YES | YES | YES |
| 5a | 5 | YES | NO | NO | |
| 5 |
5.5 | 119-126 | YES | YES | YES |
7 |
7.1 | ~194 | YES | YES | YES |
| 7 |
7.5 | ~236 | YES | YES | |
| 8 |
8.3 | ~258 | YES | YES | YES |
| 9 |
8.5/9.1 | ~287/~309 | YES | YES | YES |
| 9 |
9.3 | ~328 | YES | YES | YES |
| 11 |
11.3 | ~406 | YES | YES | YES |
| 13 |
13.2 | ~510 | YES | YES (PSV?) | |
| 14 |
14.2 | ~536 | YES | YES | |
| 15 |
15.1 | ~573 | YES | YES (PSV?) | |
| 15 |
15.4 | ~604 | YES | YES | |
| 17 |
17.1 | ~666 | YES | YES |
Notes: SPECMAP oxygen isotope stage and age assignments are summarized in Keigwin, Rio, Acton, et al. (1998). Excursions in bold type are those most trustworthy; these have been replicated in long-core, U-channel, and discrete sample measurements at multiple sites. Excursions in italics are no longer considered to be real excursions. * = radiocarbon age estimate from Lund et al. (in press). PSV = paleomagnetic secular variation.