Geological notes and local details for 1:10 000 scale Sheet SD 68 NW (Middleton) and part of Sheet SD 68 NE (Gawthorp)

The mapped area of Cumbria represented on Sheets SD 68 NW and NE includes the settlements of Killington, Middleton and Gawthrop. Larger settlements border the area: Sedbergh 2 km to the north, Dent 0.5 km to the east and Barbon 2.5 km to the south. The area is bounded to the east by the Dent Fault, and is completely traversed by two other major faults, the Barbon Fault and the Firbank Fault. These faults divide the solid geology into three major sectors and one minor sector, the stratigraphical continuity of which can only be inferred outside the area. The oldest rocks at outcrop occur as a small sliver along the Dent Fault, comprising Dent Group calcareous mudstones and volcanic rocks and Tranearth Group laminated mudstones; the two groups are also separated by a fault. The major outcrop sector between the Dent and Barbon fault zones comprises turbidite sandstones and subordinate mudstones of the uppermost Coniston Group and a lower division of the Bannisdale Formation, passing up into a mudstone-rich upper Bannisdale Formation. The distinction between the Coniston and lower Bannisdale units is difficult, and based mainly on the lamination characteristics of the their hemipelagic mudstone. The outcrop between the Barbon and Firbank faults comprises mudstones with thin sandstones assigned to the upper part of the Bannisdale Formation. This lithology is also present at the base of the succession west of the Firbank Fault, though most of the outcrop here comprises the overlying sandstone-rich Kirkby Moor Formation. Reddening of the upper parts of this formation also affects part of the upper Bannisdale Formation across the Firbank Fault: the reddening is therefore interpreted as secondary, and not diagnostic of a ‘Scout Hill Formation”. The Lower Palaeozoic rocks are deformed by a weak Acadian cleavage striking generally ESE, and by open kilometric-scale folds. These structures are cut by the major north-south Variscan faults. Till occurs in upland valleys and in the major valleys of the Lune and Dee, where it is moulded into drumlins. The River Lune has extensive spreads of post-glacial alluvium.