Abstract Carboniferous rocks occupy much of the Midland Valley of Scotland, but are commonly obscured at surface by Quaternary deposits. The succession occupies an ENE-trending graben bounded by the complexes of the Highland Boundary Fault to the NW and the Southern Upland Fault to the SE. Onshore, the graben is about 90 km wide and extends some 150 km from the Ayrshire coast and Glasgow in the west to the Fife and East Lothian coasts in the east (Fig. 43). The basins within the graben are associated with a succession of Carboniferous rocks more than 6 km thick. The Highland Boundary and Southern Upland faults were active and helped to control sedimentation, initially during the Tournaisian as sinistral strike-oblique slip faults and subsequently in the Visean to Westphalian a regime of dextral strike-oblique slip deformation (Browne & Monro 1989; Ritchie et al. 2003; Underhill et al. 2008). Isolated exposures also occur on the Isle of Arran and at Machrihanish in Kintyre. The Midland Valley of Scotland was separated from basins to the south (Tweed and Solway Firth basins and the Northumberland Trough; see Chapter 13) by the Lower Palaeozoic rocks of the Southern Uplands Block, which formed a positive, mainly emergent area throughout the Carboniferous. However, this was breached during the Carboniferous by narrow NW-SE-trending basins, for example Stranraer and Sanquhar to Thornhill.

Abstract With a few notable exceptions (e.g. Kelling 1961, 1962; Walton 1961; Williams 1962) very little modern work on the stratigraphy of the Ordovician of the Southern Uplands had been undertaken prior to 1972 and hence the area received scant attention in Williams et al . (1972). The area has subsequently been the focus of much new work, largely sparked by the publication of the accretionary prism model of McKerrow et al . (1977, see also Leggett et al . 1979) and greatly enhanced by the British Geological Survey Mapping Programme. Floyd (1996a) has rationalized the plethora of stratigraphical terms applied to the Ordovician of the Southern Uplands and identified the type sections of all the units which he has retained. His scheme is essentially followed herein (Table 1, Figs 21, 22). The overall structure of the Southern Uplands has long been recognized to be a series of fault-bounded slices striking NE–SW with the succession in each slice mostly younging northwestwards but across the terrane multiple fault repetitions generally bring in progressively younger strata towards the SE of the region (Rushton et al . 1996a). The Southern Uplands is bounded to the north by the Southern Upland Fault except southwestwards where the Stinchar Valley Fault and, locally, the older Pyet Thrust mark the structural boundary (see Floyd 1994). Peach & Horne (1899) divided the area into the Northern, Central and Southern belts; broad divisions which still have considerable value.

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).