The BGS Lexicon of Named Rock Units — Result Details

Pennine Middle Coal Measures Formation

Computer Code: PMCM Preferred Map Code: PMCM
Status Code: Full
Age range: Duckmantian Substage (CB) — Bolsovian Substage (CC)
Lithological Description: Interbedded grey mudstone, siltstone, pale grey sandstone and commonly coal seams, with a bed of mudstone containing marine fossils at the base, and several such marine fossil-bearing mudstones in the upper half of the unit.
Definition of Lower Boundary: The base of the dark grey, fissile mudstone of the Vanderbeckei Marine Band, with eponymous fauna and/or other marine fossils.
Definition of Upper Boundary: The top of the dark grey, fissile mudstone of the Cambriense Marine Band, with eponymous fauna and/or other marine fossils. This definition is extended to the Scottish Solway area, which formerly used the top of the Aegiranum (Skelton) Marine Band to define the top of the formation.
Thickness: Up to 600m thick across the North Staffordshire Coalfield; about 650m thick in Lancashire; 200m thick in northwest England and in the northwest of the Canonbie Coalfield.
Geographical Limits: Central and northern England, North Wales.
Parent Unit: Pennine Coal Measures Group (PCM)
Previous Name(s): Middle Coal Measures Formation [Obsolete Name And Code: Use PMCM, MCMS, SWMCM] (MCM)
Grey Measures Of Yorkshire And Nottingham [Obsolete Name And Code: See PLCM And PMCM] (GRM)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Top part: From 161.2m (529 ft) depth at top of Cambriense Marine Band to base of borehole at 183.3m (601 ft 6 in) in No.1 underground borehole (SJ85SW19) at Parkhouse Colliery, Stoke-on-Trent. Rees and Wilson, 1998 
Partial Type Section  Base and lower part: Duckmanton, north Derbyshire [SK 4237 7040], basal Stratotype section for the Duckmantian, includes 50m thickness of Pennine Middle Coal Measures above 75m of Pennine Lower Coal Measures. Owens et al., 1985 
Reference Section  Base and lower part: Hesketh Back Cut, Chatterley Whitfield Colliery from 1045 ft (318.5m) to top of constructed stratigraphical section (V5 British Coal, G7 BGS log). Rees and Wilson, 1998 
Type Area  Potteries (North Staffordshire) Coalfield, Stoke-on-Trent: numerous borehole and shaft sections, many no longer exposed. Rees and Wilson, 1998 
Reference Section  Base: Vanderbeckei Marine Band at Miry Wood, Apedale. To be designated a RIGS site. Rees and Wilson, 1998 
Reference Section  Upper part: Below Rowhurst Coal to top of Cambriense Marine Band in No.4 underground borehole (SJ84NW/30), from 657 ft (200.3m) to 1068 ft (325.5m) depth, Holditch Colliery, Stoke-on-Trent. Rees and Wilson, 1998 
Reference(s):
Rees, J G and Wilson, A A. 1998. Geology of the country around Stoke-on-Trent. Memoir of the British Geological Survey, Sheet 123 (England and Wales). 
Owens, B, Riley, N J and Calver, M A. 1985. Boundary stratotypes and new stage names for the Lower and Middle Westphalian sequences in Britain. Compte Rendu 10e Congrhs Strat. Giol. Carbonifhre, Madrid, 1983, Vol.4, 461-472. 
Stubblefield, C J and Trotter, F M, 1957. Divisions of the Coal Measures on Geological Survey Maps of England and Wales. Bulletin of the Geological Survey of Great Britain, No.13, p.1-5. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E010 E100 E108 E110 E112 E123 E124 E125 E126 E014 E141 E015 E152 E153 E154 E155 E167 E168 E169 E018 E019 E020 E021 E022 E023 E026 E027 E028 E031 E032 E050 E070 E077 E078 E084 E085 E087 E009 E097 E098