The BGS Lexicon of Named Rock Units — Result Details

Hangman Sandstone Formation

Computer Code: HASA Preferred Map Code: HaS
Status Code: Full
Age range: Eifelian Age (DI) — Givetian Age (DV)
Lithological Description: Mainly sandstone, purple, grey and green, commonly thick-bedded and parallel laminated, locally convolute-bedded or cross-bedded, fine- to medium-grained. Interbeds of cleaved shale, siltstone and silty very fine-grained sandstone, and some thicker units of cleaved purple mudstone interlaminated with very fine-grained sandstone. Minor local developments of conglomerate and pebbly sandstone, stratigraphical position uncertain. Divided into five units by Tunbridge (1978).
Definition of Lower Boundary: Conformable on Lynton Formation. Boundary taken where sandstones become dominant in upward succession.
Definition of Upper Boundary: Commonly faulted but probably conformable with Ilfracombe Slates.
Thickness: 1097m (Evans, 1922). 1350m (Lane, 1965). 1658m (Tuunbridge, 1978). 2000-2500m (Edmonds et al. 1985).
Geographical Limits: North Devon - west Somerset coasts (sheets 277 and 278).
Parent Unit: Not Applicable (-)
Previous Name(s): Upper Hangman Grits [Obsolete Name And Code: See HASA] (UPH)
Hangman Grits [Obsolete Name And Code: Use HASA] (HAG)
Hangman Sandstone Group [Obsolete Name And Code: See HASA] (HGMS)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Cliff sections between eastern end of Wild Pear Beach, Combe Martin and Ramsey Beach, west of Heddon's Mouth. 
Partial Type Section  Cliff sections between Lynmouth Bay, Lynmouth and Minehead. 
Reference(s):
Edmonds, E A, Whittaker, A, and Williams, B J. 1985. Geology of the country around Ilfracombe and Barnstaple. Memoir of the British Geological Survey, Sheets 277 and 293 (England and Wales). 
Tunbridge, I P. 1978. North Devon - Lower and Middle Devonian: Hangman Sandstone Group. 9-13 in Scrutton, C T (Editor), A field guide to selected areas of the Devonian of south-west England. International Symposium on the Devonian System. (PADS 78). (Palaeontological Association). 
Evans, J W. 1922. The geological structure of the country round Combe Martin. Proceedings of the Geologists' Association, Vol.33, 201-228. 
Lane, R. 1965. The Hangman Grits - an introduction and stratigraphy. Proceedings of the Ussher Society, Vol.1, 166-167. 
Etheridge, R. 1867. On the physical structure of west Somerset and north Devon and on the palaeontological value of the Devonian fossils. Quarterly Journal of the Geological Society of London, Vol. 23, p.568-698. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E277 E279