Abstract The distribution of rock types in Scotland has ensured that Scotland is able to produce good quality rock aggregate almost anywhere in the country. In general all aggregate is derived from two main sources: deposits of sand and gravel, which are almost exclusively of glacial origin, and crushed rock aggregate from quarries mining solid rock. Scotland is self-sufficient in aggregate production (and, in fact, exports aggregates). The annual amount of crushed rock aggregate is more than twice that of sand and gravel, with a total annual production of about 33 x 10 6 tonnes. Figure 18.1 shows the annual production of aggregate from 1972 to 1998 (BGS 1972 et seq.) and indicates that production continued to increase (or at worst plateaued out) during the recession from 1990 to 1995, in spite of UK total production showing an overall reduction of over 20% during this period. The graph shows that the annual production of sand and gravel has fallen slightly from 12 x 10 6 to about 10 x 10 6 tonnes per annum, and that hard rock production is now more than 23 x 10 6 tonnes per annum. It should be emphasized that a crushed rock granite quarry at Glensanda on Loch Linnhe which started in 1987 accounts for more than 5 x 10 6 tonnes of the crushed rock annual production. This quarry, the first custom- designed superquarry in Scotland, sends material to southeastern England, and also to northern Europe and the United States (see below).

Abstract Permian and Triassic rocks are widely distributed beneath the seas surrounding Scotland but have only limited, mostly basin-margin, exposures on land ( Fig. 10.1 ). They occur on the coast of the Moray Firth near Elgin and Golspie, in several small basins in the south and southwest of Scotland, including Dumfriesshire, Ayrshire and the Isle of Arran, and in a series of small exposures along the western seaboard of Scotland from Kintyre, through Mull and Ardnamurchan, Skye and Raasay to the vicinity of Stornoway on the Isle of Lewis. Each of these areas will be described in the context of the adjacent, mostly offshore, basinal development. The widespread distribution of rocks of Permo-Triassic age is indicative of a former very extensive cover. The historical reasons for the offshore extent but limited onshore exposure of the Permo-Triassic sequences are outlined below. Global sea level during the Permian and Triassic was generally fairly low (Vail et al . 1977), and Scotland was located far from the coast within the former Laurussian part of the megacontinent Pangaea ( Fig. 10.2 ), thus onshore exposures of Permian and Triassic rocks are almost entirely the product of terrestrial sedimentation. Over parts of continental Europe, such conditions of deposition commenced during the Late Carboniferous. Several (4-6) Late Permian (Zechstein) marine transgressions, with intervening evaporation almost to dryness, affected the North Sea area. No route can be found for marine flooding of the time equivalent Bakevellia Sea of the Irish Sea and Antrim (Smith & Taylor 1992; Jackson