Sediment Accumulation Rates in an Alaskan Arctic Lake Using a Modified 210 Pb Technique

Because of high concentrations of authigenic Mn and Fe oxides in surficial sediments from Toolik Lake, Alaska, the normalization of depth and 210 Pb activity scales to the sediment Al content was used for sediment accumulation rate calculations. These results are compared with the conventional 210 P...

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Bibliographic Details
Published in:Canadian Journal of Fisheries and Aquatic Sciences
Main Author: Cornwell, Jeffrey C.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1985
Subjects:
Online Access:http://dx.doi.org/10.1139/f85-103
http://www.nrcresearchpress.com/doi/pdf/10.1139/f85-103
Description
Summary:Because of high concentrations of authigenic Mn and Fe oxides in surficial sediments from Toolik Lake, Alaska, the normalization of depth and 210 Pb activity scales to the sediment Al content was used for sediment accumulation rate calculations. These results are compared with the conventional 210 Pb dating technique. I found the flux of 210 Pb to the lake to be very low (10 dpm∙cm −2 ∙yr −1 ), and excess 210 Pb is restricted to the top 5 cm of sediment. The whole lake sediment accumulation rate is about 2.7 mg∙cm −2 ∙yr −1 and the sediments are little disturbed by physical or biological processes. Low rates of physical and chemical weathering are responsible for the low sediment accumulation rates.