Abstract The Lower Palaeozoic accretionary thrust belt forming the Southern Uplands terrane lies to the northwest of the Iapetus Suture and to the southeast of the Southern Upland Fault ( Fig. 6.1 ). The former structure marks the line of closure of the Iapetus Ocean and of collision between the continental blocks of Laurentia and Avalonia; it underlies the Solway Firth and approximates to the line of the Anglo-Scottish border. The latter structure separates the Southern Uplands terrane from the mainly Upper Palaeozoic rocks of the Midland Valley terrane and in particular the Ballantrae Complex. The following sections have been contributed by B. J. Bluck (Ballantrae), P. Stone (Southern Uplands stratigraphy, and provenance) and G. J. H. Oliver (Southern Uplands structure, metamorphism, and geodynamics).

Abstract The original aim of this chapter was to present a synthesis of the geological evolution of the terranes of Scotland prior to their assembly into the current geography of the region. Given the differing hypotheses presented in the preceding four chapters, this chapter could as well concentrate on what is not known about Scotland’s geological evolution. There are too many unresolved big issues to be complacent about the progress that has been made since the third edition of this book was published in 1991. So, in attempting to synthesize the geology, pre-370Ma, perhaps the aim should also be to deconstruct the currently held views (as summarized in Chapter 1 ) in an attempt for better understanding. Chapters 3 to 6 were largely completed in 2001, but some important age dating papers have subsequently been published and these data are considered below.