| Summary: | Pioneering studies of lead (Pb) concentrations in polar ice by Clair C. Patterson and co-workers (e.g. Murozumi et al., 1969; Boutron and Patterson, 1983, 1986) revealed important information on climatic changes dating many thousands of years in the past and the effect that humans have had on these pristine environments. Rosman and co-workers (e.g. Rosman et al., 1993, 1994a) extended this research utilising the isotopic composition of Pb preserved in the ice to identify the source regions of both natural and anthropogenic Pb transported to the polar regions, thereby adding significantly to the understanding of atmospheric transport mechanisms and the impact of continental anthropogenic activity on the pristine polar environments. This thesis extends this area of research by investigating seasonal and short-term variability in Pb, Ba and In concentrations and Pb isotopes through the accurate sectioning of decontaminated glacial ice cores at high spatial resolution. This improves our understanding of the processes impacting on the deep ice core records, which, in turn, expands the interpretation and application of these records.A new sample preparation technique, incorporating a mechanised circular saw blade arrangement into the lathe design, first described by Candelone et al. (1994), has been developed to sample glacial ice cores at high spatial resolution with minimal contamination. This technique was extensively tested using artificially made ice cores, prepared from ultra-pure water, to quantify and minimise the Pb, Ba and In contamination associated with the process. The residual contamination in each inner core slice from the procedure amounted to 0.2 ± 0.2 pg Pb with [superscript]206Pb/[superscript]207Pb, [superscript]208Pb/[superscript]207Pb and [superscript]206Pb/[superscript]204Pb ratios of 1.16 ± 0.12, 2.35 ± 0.16 and 15.3 ± 6.7 respectively, 1.5 ± 0.4 pg Ba and 0.6 ± 2.0 fg In. This technique was then utilised to obtain high resolution analyses of Pb, Ba and In concentrations, and Pb isotopes in ice ...
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