The first records of metalliferous mining in Scotland appear in the 13th century and relate to lead from the Leadhills-Wanlockhead area which, over the next six hundred years, easily became Scotland’s biggest nonferrous metal producer. There is no known evidence for earlier mining activities and the absence of Bronze Age mines in particular is surprising given the concentration of Bronze Age monuments in many metalliferous areas (O’Brien 1996). Leadhills-Wanlockhead is also notable as the source of the gold in the 16th century for the Scottish regalia (Gillanders 1981). During the 19th and 20th centuries substantial amounts of chromite were extracted in Unst, and of baryte and iron ore from the Midland Valley. Overall, Scotland has produced over 5 x 106 tonnes of iron ore, around 850000 tonnes of baryte, 300000 tonnes of lead, about 16 000 tonnes of chromium, 7000 tonnes of zinc, 200 tonnes of antimony, and a few tonnes of gold and silver. Some copper, nickel and manganese have also been recovered. Most of these deposits are now exhausted or uneconomic under prevailing conditions.
In the last 50 years Scotland has been widely explored by the British Geological Survey (BGS) and various mining companies. Exploration has been assisted by a comprehensive nationwide drainage geochemical survey conducted by BGS. This has led to many significant discoveries but the highlight has been the discovery of world class baryte deposits at Aberfeldy, strategically placed to supply the North Sea oil industry with drilling mud. In addition, significant but currently subeconomic deposits