Change search
ReferencesLink to record
Permanent link

Direct link
Natural lead isotope variations in the atmosphere
Stockholm University, Faculty of Science, Department of Geological Sciences.
Department of Ecology and Environmental Sciences, Umeå University .
Department of Ecology and Environmental Sciences, Umeå University.
Department of Earth Science and Engineering, Imperial College London.
2010 (English)In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 290, no 1-2, 44-53 p.Article in journal (Refereed) Published
Abstract [en]

Stable lead (Pb) isotope data from pre-contamination peat sections has the potential to contribute to our understanding of earth system processes (e.g., atmospheric circulation, erosion, volcanic activity) in the past. Key questions arise however. Can the Pb isotopes archived in peat records be used for assessing aerosol dynamics on a hemispheric scale or do they mainly reflect inputs from local soils? What natural Pb sources are important and do contributions vary over time? In order to answer these questions we have synthesized all available Pb isotope data from pre-contamination peat sections in Europe, Australia, North America and South America. We specifically examine the spatial and temporal variability of the Pb isotope records and identify regionally important trends and Pb sources.

A pooling of all available pre-contamination peat data generated an average natural 206Pb/207Pb background ratio of 1.21±0.05 (2σ, n=300)(206Pb/204Pb= 18.90±0.86, 207Pb/204Pb= 15.66±0.10 and 208Pb/204Pb= 38.74±0.57, n=207). The majority of the records showed limited temporal and compositional agreement, suggesting that the peat record receives mainly inputs from local (<10 km) and/or regional (10-500 km) sources. Three-isotope plots also support local and regional control and evidence a wide natural spread at some sites, particularly those located in radiogenic geological settings. A temporally synchronous isotope excursion to values between 1.16-1.18 at sites across Europe ca 4000-3000 B.C. was detected, however. While usually associated with anthropogenic sources, there are indeed natural aerosols having 206Pb/207Pb signatures as low as 1.16 as evidenced in several peat and ice core records globally. Three-isotope plots suggest that this unlikely to be a signal of mineral dust contributions, which tend to have 206Pb/207Pb ratios ≥1.19, but rather sourced to volcanic emissions. These results stress caution when using estimates of the upper continental crust to constrain natural Pb sources in, e.g., mixing equations. Considering the strong influence from local and regional sources on Pb-containing aerosols in the peat record, the assessment of aerosol dynamics at lower latitudes is likely best achieved using a compliment of archives rather than just polar ice cores, for example. 

Place, publisher, year, edition, pages
2010. Vol. 290, no 1-2, 44-53 p.
Keyword [en]
Pb isotopes; atmospheric deposition; mineral dust; volcano; aerosol
National Category
Natural Sciences
URN: urn:nbn:se:su:diva-47310DOI: 10.1016/j.epsl.2009.11.055ISI: 000274844700006OAI: diva2:373583
Swedish Research Council
Available from: 2010-12-07 Created: 2010-12-01 Last updated: 2010-12-29Bibliographically approved

Open Access in DiVA

fulltext(2683 kB)828 downloads
File information
File name FULLTEXT01.pdfFile size 2683 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Kylander, Malin
By organisation
Department of Geological Sciences
In the same journal
Earth and Planetary Science Letters
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 828 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 44 hits
ReferencesLink to record
Permanent link

Direct link