Evaluation of210Pb dating in lake sediments using stable Pb,Ambrosia pollen,and137Cs |
| |
| Authors: | Jules M Blais Jacob Kalff R Jack Cornett R Douglas Evans |
| |
| Institution: | (1) Dept. of Biology, McGill University, 1205 Docteur Penfield, H3A 1B1 Montreal, Que., Canada;(2) Environmental Research, Chalk River Nuclear Labs, K0J 1J0 Chalk River, Ont., Canada;(3) Environmental and Resource Science Prog., Trent University, K9J 7B8 Peterborough, Ont., Canada |
| |
| Abstract: | We used sediment chronology data from fourteen published studies of lake cores across much of North America and Scandinavia in order to make a large scale comparison of the different dating techniques. The uncertainty of210Pb derived dates was determined using common sediment event markers: the stable Pb rise, the137Cs rise, and theAmbrosia pollen rise. For all data combined, the 95% confidence intervals for the stable Pb rise and theAmbrosia rise, were approximately 30 years. These 95% confidence intervals are slightly higher than those derived by First-Order Error analysis performed by others on210Pb derived dates. When comparing the concordance of two210Pb models (CRS and CIC) against markers of known history, we found that the CRS model dates (constant rate of supply) had consistently better agreement than the CIC model dates (constant initial concentration). Major discrepancies between137Cs and210Pb were common, but were consistently more severe in sediments of soft water lakes pointing to an inability of sediments with low mineral content to  immobilize Cs.This is the ninth of a series of papers to be published by this journal following the 20
th
anniversary of the first application of210Pb dating of lake sediments, Dr. P. G. Appleby is guest editing this series. |
| |
| Keywords: | constant initial concentration constant rate of supply 210Pb dating sediments |
| 本文献已被 SpringerLink 等数据库收录！ |
|
