The Deeper Structure of Central and Northern England

( Read, January , 1949) Current views on the relations of the Anglo-Welsh and Scandinavian Caledonides are considered and it is regarded as unlikely that a connection exists between their southeastern fronts in Norway and the Welsh Borderland. From a consideration of surface-exposures and sub-surface records it is suggested that the Anglo-Welsh Caledonides form an arc—convex northwards—which surrounds the comparatively undisturbed area of the Midlands, in which the folding of the Lower Palaeozoic rocks is Variscide. This is supported by analysis of the foldings of the Upper Palaeozoic and later sediments of England, in which a strong posthumous Caledonide element is present. It is concluded that the eastward continuation of the Anglo-Welsh Caledonides lies in Central Europe, and not in Scandinavia. In his Presidential Address to Section C of the British Association in 1928, Bailey indicated the main tectonic elements in the structure of Europe in a lucid map (1928, fig. 1), which presents a fairly generally accepted view (e.g., Holmes, 1944, p. 385) of the general relationships and distribution of the Caledonide, Variscide, and Alpide mountain ranges (fig. 1). This map suggests two important problems :— ( a ) The Caledonide ranges are represented as striking northeastwards from the British Isles across the North Sea into Scandinavia. Their southwestern boundary traverses the Welsh Borderland, somewhere about the line of the Church Stretton Fault, and this is linked with the great southeastward overthrust of the southeastern border in Scandinavia, an overthrust claimed by Tornquist to be of order of 80 miles. ( b ) …