Summary: References and Notes
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2. R. Muscheler et al., Earth Planet. Sci. Lett. 219, 325
3. W. S. Broecker, E. Clark, I. Hajdas, G. Bonani, Paleocean-
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Science 293, 2440 (2001).
5. Alex Wiedenhoeft of the Forest Products Laboratory
in Madison, Wisconsin, advised us that it was not pos-
sible to identify milligram-sized fragments of tropical
woods; rather, a hand-sized piece of wood would be
required. He also commented that, once waterlogged,
any wood would be dense enough to sink in seawater.
6. T. P. Guilderson, D. P. Schrag, M. A. Cane, J. Clim. 17,
7. T. Guilderson, personal communication, 2004.
8. Because conventional radiocarbon ages are calcu-
lated using the Libby half life of 5568 years, we have
used this value to calculate all age differences in this