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| Hughen, K.A.,
Overpeck, J.T., Lehman, S.J., Kashgarian, M., Southon, J. and Peterson, L.C., 1998,
Radiocarbon 39, 483-494. |
|
|
Konrad A. Hughen1
Jonathan T. Overpeck2,3
Scott J. Lehman2 |
Michaele Kashgarian4
John Southon4
Larry C. Peterson5 |
|
Please also see updated calibration in Hughen et al. (Science, 2000)
|

| Abstract Varved sediments of the tropical Cariaco Basin
provide a new 14C calibration data set for the period of deglaciation (10,000
to 14,500 years before present - 10-14.5 cal kyr BP). Cariaco Basin calendar and 14C
chronologies were both assessed for accuracy, using a comparison of Cariaco Basin varve
ages to the GISP2 ice core layer chronology, as well as comparisons of Cariaco Basin 14C
ages to terrestrial 14C dates. These assessments show that the Cariaco Basin
varve chronology agrees, within 20-50 years, with GISP2 layer ages for abrupt,
decade-to-century-scale climatic changes throughout most of the deglacial period. In
addition, comparisons with terrestrial 14C dates indicate that the Cariaco
Basin 14C reservoir age has remained stable since the late Allerød and
throughout the Younger Dryas climatic event. This evidence demonstrates that the varve and
radiocarbon chronologies together provide an accurate alternative to existing 14C
calibrations based on coral U/Th dates. The Cariaco Basin calibration generally agrees
with coral-derived calibrations but is more continuous and resolves century-scale details
of 14C change not seen in the coral records. Radiocarbon plateaus can be
identified at 9.6, 11.4, and 11.7 14C kyr BP, in addition to a large, sloping
plateau during the Younger Dryas (between 10.0 and 10.4 14C kyr BP).
Accounting for features such as these is crucial to determining the relative
timing and rates of change during abrupt global climate changes of the last deglaciation. 1Dept. of Earth and Planetary Sciences, Harvard
University, Cambridge, MA 02138
2INSTAAR and Dept. of Geological Sciences, Univ. of
Colorado, Boulder, CO 80309
3 NOAA Paleoclimatology Program, NGDC, Boulder,
CO 80303
4 CAMS, Lawrence Livermore National Laboratory,
Livermore, CA 94551
5 RSMAS, University of Miami, Miami, FL 33149 |
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