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Fig. 18.6
Isotopic ratios of Sr (
87
Sr/
86
Sr) and Nd ["
Nd
(0)] in Antarctic dust and potential source
areas (PSA) in the Southern Hemisphere. The blue fields in (
a
)and(
b
) show the signatures of East
Antarctic glacial dust which are offset from East Antarctic interglacial dust (
green
fields). The
arrow
in panel (
b
) indicates an additional sample from stage 5.5 for which only Nd isotopes were
measured. The volcanic dust sample (
black triangle
) was extracted from one EDC ice core section
corresponding to stage 5.5. From Delmonte et al. (
2007
)
probably in Australia (Revel-Rolland et al.
2006
; De Deckker et al.
2010
) and/or
within Antarctica.
Other techniques for identifying the provenance of Antarctic dust generally
complement the initial findings based on the Sr/Nd isotopic system, or highlight
periods of enhanced source variability. Lead isotopes can be used to identify
different emission sources, such as industrial activity and dust deflation (Vallelonga
et al.
2002b
), as well as volcanism (Hinkley
2007
). Ice from EDC and Law Dome
contain mixtures of Pb from Antarctic volcanism and dust from southern South
America (Vallelonga et al.
2005
). A recent evaluation of Pb isotopes in Dome C
ice (Vallelonga et al.
2010
) identifies a second continental dust source in Antarctic
ice, which can be attributed to Australian and/or local Antarctic sources. The
geochemical composition of dust in EDC and EDML ice (Marino et al.
2009
)
confirms a common glacial dust source for these sites, compatible with a southern
South American origin. REEs in EDC (Gabrielli et al.
2010
) and EDML (Wegner
et al.
2012
) ice also demonstrate a change from a dominant glacial signature
(southern South America) to a mixture of signatures during the deglacial and
early Holocene, including Australian and New Zealand dust sources. Magnetization
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