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Abstract

An extensive Pb isotope ratio survey of ∼100 marine sediment samples from near Casey
Station, East Antarctica has been undertaken. Sediment surface grabs and cores were
collected over nine years between 1997–2006 and, following HF total digestion, were
analysed by magnetic sector ICP-MS. Fifty-two reference samples ([Pb] range 5–26 mg kg−1)
from 6 non-impacted locations displayed a broad range of Pb isotope ratios representative of
the natural background geology of the region (208Pb/204Pb ratios of 37.5–40; 206Pb/204Pb ratios
of 17–19). Potentially impacted sediments from Brown Bay (n=27, [Pb] range 18–215 mg kg−1),
adjacent to the current and former Australian Stations at Casey (and the associated Thala
Valley tip site) showed contamination by Pb characteristic of Broken Hill and Mt Isa
Australian deposits (208Pb/204Pb and 206Pb/204Pb values of 35.5–36 and 16.0–16.1, respectively).
The nearby abandoned Wilkes Station was previously manned by both US (1957–59) and
Australian (1959–69) expeditioners. Adjacent marine sediment samples (n=24, [Pb] range 13–
40 mg kg−1) displayed Pb isotopic signatures suggesting anthropogenic input from multiple
sources. On a three-isotope diagram Wilkes sediments were found to display Pb ratios lying
intermediate between Missouri (US), Broken Hill/Mt Isa (Australia)/Idaho (US), and natural
geogenic Pb end members. Discarded Pb batteries, paint samples and fuel spills were all
considered in this work as possible point sources of Pb contamination to the local
environment. Batteries are thought to be the dominant source.

Item Type:	Article
Authors/Creators:	Townsend, AT and Snape, I
Keywords:	Casey Station Wilkes Station Antarctica Pb isotope ratios Magnetic sector ICP-MS
Journal or Publication Title:	Science of the Total Environment
ISSN:	0048-9697
DOI / ID Number:	https://doi.org/10.1016/j.scitotenv.2007.09.022
Additional Information:	The definitive version is available at http://www.sciencedirect.com
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