The Geological Survey of New South Wales (GSNSW) is to release a series of Statewide radiogenic isotope datasets. These include U–Pb, K–Ar, Rb–Sr, Sm–Nd and lead (Pb) isotope analyses that were carried out as part of numerous research and mineral exploration programs. The Pb-isotope dataset is being released in collaboration with the Commonwealth Scientific and Industry Research Organisation (CSIRO). The dataset contains approximately 3,200 Pb-isotope results from rocks and ores and will be available on request. The dataset includes data from the giant Broken Hill base-metal deposit and deposits hosted by the Macquarie Arc including the Cadia porphyry Au–Cu system. New analyses can be compared with existing data using free software (*GCDkit — Janoušek et al, 2004) that has been integrated with relevant plumbotectonic models including the model by Carr et al (1995) for the Lachlan Orogen. Lead isotope compositions can identify potential sources of Pb (and other metals) incorporated into mineral deposits and terrains. Gulson (1986) suggested that such data can be used to discriminate between prospective zones and less prospective zones. Furthermore, Carr et al (1995) developed a " plumbotectonic model " for the eastern Lachlan Orogen (Fig. 1) that can be used to identify potential source(s) of metals, metallogenic events and to develop deposit model ages. This plumbotectonic model provides a robust framework for the identification of mineralisation that may be related to a specific district-and terrain-wide metallogenic event in the Lachlan Orogen. The NSW Pb-isotope dataset will assist explorers to discriminate between deposits sourcing metals from fertile reservoirs and those that are likely to be less prospective. This will be assisted by the wider availability of high-precision " double-spike " Pb-isotope analyses (Compston & Oversby, 1969) being offered by the CSIRO Pb-isotope laboratory. Suitable material for analysis includes minerals that contain abundant Pb (e.g. galena), magmatic feldspars and carbonates formed by hydrothermal ore-forming processes. Material containing a low abundance of Pb such as Pb-poor sulfides, low-Pb carbonates and bore waters can also be analysed, but may give model ages that are too young due to the incorporation of radiogenic lead from the decay of 238U and 232Th (Fig. 1).