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.
A 220 ky record of Pb isotopes at Dome C Antarctica from analyses of the EPICA ice core.
Barbante C;
2005
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
