Stratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen: British Geological Survey Research Report RR/01/004 / M.A.E. Browne, R.A. Smith & A.M. AitkenBooks/Monographs
The lithostratigraphy of the Old Red Sandstone of the Southern Highlands, Midland Valley of Scotland and the Southern Uplands Terrane has been reviewed. Before this there were over 100 formations and members in the Lower Old Red Sandstone. The new term Lanark Group includes all late Silurian to Devonian formations in the Lanark Basin. A framework at formation level is proposed for the Lanark Basin; in ascending sequence they are the Greywacke Conglomerate, Swanshaw Sandstone, Pentland Hills Volcanic (and equivalents) and Auchtitench Sandstone formations. Rationalisation of the largely informal lithostratigraphy of the Lower Devonian in the Southern Uplands Terrane is suggested and the terms Great Conglomerate, Auchencrow Burn Sandstone and White Hill Sandstone formations are proposed. The newly defined Reston Group includes these and other Lower Devonian formations in the geographically separated outcrops (other than the Lanark Basin) overlying the Southern Uplands Terrane. The group terminology in the northern Midland Valley of Scotland has been rationalised from six to four, recognising the recent research indicating that the Lower Old Red Sandstone lithofacies was laid down in three sedimentary basins. From oldest to youngest these are the Stonehaven (Group), Crawton (Dunnottar-Crawton Group) and Strathmore (Arbuthnott-Garvock and Strathmore groups) basins, of which the last named is by far the most extensive. Middle Devonian strata are not represented as a result of non-deposition or erosion during the Acadian Orogeny. The Upper Devonian strata all belong to the Stratheden Group. Some initial rationalisation of the formation terminology within the sandstone-dominated Stratheden Group is proposed with the Gargunnock Sandstones and Clashbenny Formation becoming redundant names. In areas where no formal stratigraphy had previously been applied especially in the Southern Uplands Terrane, provisional correlations are suggested.