Northumberland Trough and Solway Basin

Carboniferous rocks within this region occupy a broadly east–west graben, referred to as the Northumberland Trough within Northumberland (Bewcastle to the North Sea coast) and the Solway Basin in the vicinity of the Solway Firth, where much of the succession is obscured by Permo-Triassic strata (Fig. 13.1). The graben is bounded to the south by the Maryport-Stublick-Ninety Fathom Fault System, which forms the northern boundary of the Lake District and Alston blocks (see Chapter 12). The Carboniferous rocks are broadly separated from the Midland Valley of Scotland (Chapter 14), to the north, by the Lower Palaeozoic rocks of the Southern Uplands, which formed an emergent upland area throughout much of the Carboniferous, with local deposition within small basins. At the eastern onshore extent of the Southern Uplands a relatively condensed Carboniferous succession was deposited upon the Cheviot Block.