A 220 kyr record of Pb isotopes at Dome C Antarctica from analyses of the EPICA ice core
International audience Pb isotopic compositions and Pb and Ba concentrations are reported in EPICA Dome C ice core samples dating to 220 kyr BP, indicating that Pb isotopic compositions in Antarctic ice vary with changing climate. 206Pb/207Pb ratios decrease during glacial periods, with the lowest v...
Published in: | Geophysical Research Letters |
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Main Authors: | , , , , |
Other Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2005
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Subjects: | |
Online Access: | https://hal-insu.archives-ouvertes.fr/insu-00374946 https://hal-insu.archives-ouvertes.fr/insu-00374946/document https://hal-insu.archives-ouvertes.fr/insu-00374946/file/2004GL021449.pdf https://doi.org/10.1029/2004GL021449 |
Summary: | International audience Pb isotopic compositions and Pb and Ba concentrations are reported in EPICA Dome C ice core samples dating to 220 kyr BP, indicating that Pb isotopic compositions in Antarctic ice vary with changing climate. 206Pb/207Pb ratios decrease during glacial periods, with the lowest values occurring during colder climatic periods (stages 2, 4 and 6) and the Holocene. Low Pb concentrations (<1 pg/g) were found during the Holocene and the last interglacial (climate stage 5.5) while higher Pb concentrations (>10 pg/g) were found during cold climatic periods. Ba, a proxy for mineral dust, was used to determine that dust usually accounts for ∼70% of Pb in Dome C ice, while the remaining ∼30% was attributed to volcanic emissions. Pb isotopic compositions at Dome C differ from those reported in pre-industrial ice from other Antarctic locations, due to greater proportions of dust Pb at Dome C. |
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