The BGS Lexicon of Named Rock Units — Result Details

Mangotsfield Member

Computer Code: MGF Preferred Map Code: notEntered
Status Code: Full
Age range: Bolsovian Substage (CC) — Bolsovian Substage (CC)
Lithological Description: Predominantly cross-bedded, lithic arenite, "Pennant" sandstone in the lower part, and an upper part with thick grey fissile mudstone beds, interbedded with sandstone and sparse coal seams. The sandstone weathers to a distinctive red to purple colour
Definition of Lower Boundary: Base of the lower most lithic arenite "Pennant" sandstone of the Mangotsfield Member, resting sharply upon the Mangotsfield Coal, present at the top of the Downend Member
Definition of Upper Boundary: Top of member taken at the top of the Rudge Vein Coal in the Somerset Coalfield: top of the High Vein Coal in the Bristol Coalfield; top of the Avonmouth No. 2 Coal in the Severn Coalfield. Overlain by grey mudstone of the Farrington Member
Thickness: Up to c. 580m at Iron Acton [ST 67 84] to Engine Common [ST 70 84]; 450m proved in the type area
Geographical Limits: Bristol, Somerset and Severn Coalfields
Parent Unit: Pennant Sandstone Formation (PES)
Previous Name(s): Mangotsfield Formation (-1692)
Mangotsfield Group (-4793)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Winterbourne railway cutting, Avon [ST 651 799]: 200m thick succession [Cleal & Thomas, 1996] 
Type Area  Mangotsfield, Avon [ST 65 77]: Parts of the member are exposed along the River Frome and quarries between Frenchay [ST 641 772] and Hambrook [ST 645 788] [Kellaway and Welch, 1993] 
Reference(s):
Kellaway, G A. 1969. The Upper Coal Measures of South-West England compared with those of South Wales and the Southern Midlands. Compe Rendu 6e Congres Internationale Stratigraphie et Geologie Carbonifere, Sheffield, 1967, Vol. 3, 1039-1055. 
Kellaway, G A and Welch, F B A, 1993. Geology of the Bristol district. Memoir of the British Geological Survey Special Sheet [England and Wales]. 
Waters, C N, Barclay, W J, Davies, J R and Waters, R A. In press. Stratigraphical framework for Carboniferous successions of Southern Great Britain (Onshore). British Geological Survey Research Report, RR/05/06. 
Cleal, C and Thomas, B A. 1996. British Upper Carboniferous stratigraphy. Geological conservation review series No. 11. [London: Chapman and Hall]. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E250 E251 E281 E264 E280