A hundred years ago, Andrew Crombie Ramsey as Director-General of the Geological Survey and Archibald Geikie as Director for Scotland, had a great prospect before them. The progress of the survey in Scotland as indicated by the publication of one-inch geological maps, had lagged considerably behind that in England, Wales and Ireland where primary one-inch publication was already half completed. In Scotland, only the sheets around the Firth of Forth, and two sheets (one mainly sea) south of the Clyde had been issued. The survey of the western part of the Midland Valley was in progress, to be extended south across the Southern Uplands; the Highlands remained virtually untouched until after 1880.
Geikie was, however, already well acquainted with the two great problems with the solution of which his name and general directorate will always be associated: the tectonic history of the North-West Highlands and the volcanic history of its west and midland regions. If these formed the major items in Geikie’s forward programme, there were a host of other major discoveries to come: the metamorphic zones in the Central Highlands (George Barrow); the unravelling of the structure of the slate and greywacke country of south Scotland, strongly influenced by Lapworth’s great work at Moffat and Girvan; the interplay of facies, structure and volcanism in the central rift valley; the cauldron subsidence and ring structures of Glencoe and the volcanic centres of Arran and the Inner Hebrides (Gunn, Maufe, Bailey, Thomas, Richey); the spectacular transcurrent shift of the Great