Assessment of 210Pb data from Canadian lakes using the CIC and CRS models

Autor: L. D. Delorme, L. J. Turner
Rok vydání: 1996
Předmět:
Zdroj: Environmental Geology. 28:78-87
ISSN: 1432-0495
0943-0105
DOI: 10.1007/s002540050080
Popis: Much discussion has centered around which 210Pb dating method should be used, the constant initial concentration (CIC) model or the constant rate of supply (CRS) model. In this study, the activity data from 22 lacustrine sediment cores from the Canadian prairies were used to compare the determination of sediment accumulation using the two models. Other relative and absolute dating techniques have been used to calibrate the methodology. For half of the core sites examined, the mass sedimentation rate was constant, and thus both the CIC and CRS models were found to be valid. For the other half, variability was observed in the CRS mass accumulation rate trend. The validity of the CIC model for these cores was dependent on the degree of variability of the mass sedimentation rate. Where the variability is moderate to high, the CRS model may be more satisfactory. Caution should be exercised when using chronological data determined with the CRS model, however, as the accuracy of chronology in the lower reaches of a profile is questionable.
Databáze: OpenAIRE