Climate-related variations in lead concentrations and sources in Vostok Antarctic ice from 65,000 to 240,000 years BP

Abstract

[1] Pb has been measured in various sections of the 3,623-m Vostok deep Antarctic ice core dated from 65,000 to 240,000 years BP, i.e. back to the beginning of the penultimate ice age and the preceding interglacial (isotopic stage 7.5). Pb concentrations were highly variable during this time interval, with low values down to similar to0.5 pg/g during warm climatic stages and much higher values up to similar to20 pg/g during cold climatic stages, especially isotopic stages 4.2 and 6.2 to 6.6. Rock and soil dust accounts for virtually 100% of Pb measured in the ice during cold climatic stages, while the contribution from volcanoes might be significant during warm stages.