The BGS Lexicon of Named Rock Units — Result Details

Watch Hill Formation

Computer Code: WHG Preferred Map Code: WHg
Status Code: Full
Age range: Tremadoc Series (O1) — Arenig Series (OR)
Lithological Description: Interbedded lithic wackes (with subordinate lithic arenites), siltstones and mudstones. Sandstones are fine-grained to granular with abundant siltstone and mudstone intraclasts. Sedimentary structures are uncommon but include normal grading and sole structures.
Definition of Lower Boundary: Boundary with underlying Bitter Beck Formation is gradational and marked by an increase in the proportion of sandstone and a decrease in the proportion of mudstone in the succession. Base taken at the level where sandstone and siltstone predominate.
Definition of Upper Boundary: Not exposed but taken to lie between exposures of Watch Hill Formation and overlying Hope Beck Formation just north of Lorton Street Road Bridge.
Thickness: 55 to 800m
Geographical Limits: Within the northwest part of the Skiddaw inlier, not known elsewhere. Eastern margin is faulted, the western margin is defined by the edge of the inlier. It is underlain by the Bitter Beck Formation and overlain by the Hope Beck Formation.
Parent Unit: Skiddaw Group (SKG)
Previous Name(s): Grits Group (-608)
Watch Hill Grit (-2529)
Alternative Name(s): none recorded or not applicable
Type Area  Watch Hill, 3km eastnortheast of Cockermouth. Cooper et al, 1995. 
Cooper, A H, Rushton, A W A, Molyneux, S G, Hughes, R A, Moore, R M and Webb, B C. 1995. The stratigraphy,correlation, provenance and palaeogeography of the Skiddaw Group (Ordovician) in the English Lake District. Geological Magazine, Vol.132(2), 185-211. 
Webb, B C and Cooper, A H. 1988. Slump folds and gravity slide structures in a Lower Palaeozoic marginal basin sequence (the Skiddaw Group), NW England. Journal of Structural Geology, Vol.10(5), 463-472. 
Molyneux, S G and Rushton, A W A, 1988. The age of the Watch Hill Grits (Ordovician), English Lake District. Transactions of the Royal Society of Edinburgh, Earth Sciences, Vol.79 (1), p.43-69. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E023 E022 E029 E028