The BGS Lexicon of Named Rock Units — Result Details

Hotwells Group [Obsolete Name And Code: Within PEMB]

Computer Code: HOG Preferred Map Code: notEntered
Status Code: Index Level
Age range: Asbian Substage (CR) — Brigantian Substage (CX)
Lithological Description: Crinoidal and oolitic limestone, sandstones with shales and thin coals and thin fossiliferous limestones, decalcified reddish grits and sandstones with some sandy limestones.
Definition of Lower Boundary: Drawn at base of the Hotwells Limestone Formation where it rests conformably upon the Gully Oolite Formation.
Definition of Upper Boundary: Drawn at the conformable upward passage from the Upper Cromhall Sandstone Formation to the base of the Millstone Grit.
Thickness: Not known.
Geographical Limits: Avon Gorge, Bristol, Somerset.
Parent Unit: Not Entered (?)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  The Avon Gorge, Bristol, Somerset. 
George, T N, Johnson, G A L, Mitchell, M, Prentice, J E, Ramsbottam, W H C, Sevastopulo, G D and Wilson, R B. 1976. A correlation of the Dinantian rocks of the British Isles. Special Report of the Geological Society of London, No 7. 
Kellaway, G A and Welch, F B A, 1955. The Upper Old Red Sandstone and Lower Carboniferous rocks of the Bristol and the Mendips compared with those of Chepstow and the Forest of Dean. Bulletin of the Geological Survey of Great Britain, No.9, p.1-21. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E251 E264 E265