Geological notes for the Silurian strata and their Quaternary cover on 1:10k sheets SD48NW, SD58NE (Old Hutton) and SD58NW

The area described in this report forms part of the north-western sector of the Kirkby Lonsdale 1:50 000 sheet, England and Wales 49; it lies in the south-east of the English Lake District. Geologically, the area forms part of the south-eastern extremity of both the Lake District Lower Palaeozoic inlier as a whole, and of the main outcrop of the Windermere Supergroup. Two outcrops of Silurian rock are described, separated by Carboniferous strata belonging to the Dinantian, platform limestone succession of South Cumbria. The main geological boundaries are major faults trending broadly north to north-north-west, but in the north of the SD48NW sheet, the Carboniferous rocks are unconformable on those of Silurian age. The Silurian strata form parts of the Bannisdale and Kirkby Moor formations; these comprise the Kendal Group, the uppermost unit of the Windermere Supergroup. The Bannisdale Formation is made up of beds of fine-grained turbidite sandstone grading up to siltstone, and between about 50 cm and 1 m thick; these are interbedded with thinner units of banded siltstone and mudstone. An unusual thinly-bedded lithofacies is described from the top of the formation. The Kirkby Moor Formation is characterised by medium- to thickly bedded, generally fine-grained micaceous sandstone grading up into thin layers of mudstone or siltstone. Beds commonly range up to about 75 cm thick, more rarely to more than 1.5 m. A distinctive reddened, finer grained lithofacies appears within the Kirkby Moor Formation, and has been defined as The Helm Member at The Helm, to the south-east of Kendal. Folding and cleavage development affecting the Windermere Supergroup strata are described and assigned to the Acadian Orogeny, of Emsian (latest Early Devonian) age.