Whilst there are sources of copper ore in Perth and Kinross, there is no evidence for their prehistoric exploitation. The very earliest metalwork would have been imported, either as raw material or as objects that were recycled and turned into insular forms. The earliest known metalwork is concentrated around historic Kinross-shire. A flat axehead, believed to be of copper and possibly typologically early (Buchanan 1980; O’Connor 2004, 205), was found at Bishop Hill (MPK3027) near Portmoak. Three copper halberds were discovered: one from Portmoak Moss (MPK11652) and two from Backside of Aldie (MPK5580). The halberds date to the Late Chalcolithic or beginning of the Early Bronze Age (around 2300–2100 BC; Needham et al 2015). One of the Backside of Aldie halberds is possibly an early type (Pistell Dewy), occurring between 2300–2200 BC (Needham et al 2015, Appendix 2). The distribution of the three halberds is important as they conform to other halberd discoveries from along the Firth of Forth, particularly in south-west Fife (eg one from Falkland).
Based on compositional analysis, it is likely that throughout the Chalcolithic and the beginning of the Early Bronze Age, the copper ore was imported from the mine at Ross Island in County Kerry, south-west Ireland (Needham 2004). The compositional data for the Backside of Aldie halberds presents a more complicated picture. One was produced from ‘A-metal’, characteristic of Ross Island and consistent with other Scottish halberds such as one from a hoard of six found at Largizean, Argyll and Bute (Sheridan 2013). In contrast, the other one is made from ‘BB-metal’ (Bell Beaker) which indicates a Continental origin (see data in Needham et al 2015, Appendix 2.) The known evidence therefore suggests that the prehistoric communities of Perth and Kinross had access to metal originating in Ireland and the Continent.
The proximity of these findspots to the Forth estuary is indicative of how rivers and waterways served as transport routes for the movement of people and metal in and out of the region. It also highlights a potential geographically induced divide between the prehistoric communities of Perth and Kinross living south of the Ochils in Kinross-shire and those to the north. The southern communities looked towards the Firth of Forth and maintained closer associations with other communities along its shores, while those north of the Ochils utilised the River Tay and its estuary as their main conduit (see Needham 2004 for comparative work on metal flow pathways).