The BGS Lexicon of Named Rock Units — Result Details

Morridge Formation

Computer Code: MORRI Preferred Map Code: notEntered
Status Code: Full
Age range: Pendleian Substage (CE) — Marsdenian Substage (CZ)
Lithological Description: Interbedded dark grey, shaly mudstones and pale grey protoquartzitic siltstones and sandstones.
Definition of Lower Boundary: Conformable base of the first thick quartzitic sandstone of the Morridge Formation above the dark grey mudstone and siltstone of the Craven Group.
Definition of Upper Boundary: Conformable base of the lowermost thick quartz-feldspathic sandstone of the Millstone Grit Group above the quartzitic sandstone and siltstone or dark grey, shaly mudstone of the Morridge Formation.
Thickness: To 600m, thinning northwards.
Geographical Limits: Goyt Trough of North Staffordshire and the Widmerpool half-graben of the East Midlands.
Parent Unit: Millstone Grit Group [See Also MIGR] (MG)
Previous Name(s): Millstone Grit Series (-3919)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Morridge, a gritstone edge in the Minn Sandstone, 2km east of Leek, Staffordshire, with composite sections of Minn Sandstone near Hurdlow [SK 0314 6081 to 0274 6084], overlying a mudstone dominated succession at Hurdlow Farm [SK 0242 6059 to 0219 6019]. Aitkenhead et al.,1985. 
Partial Type Section  Section in Blake Brook, Staffordshire from Lower Fleetgreen to Fernyford. Aitkenhead et al., 1985. Intermittent exposure of the full thickness of the Formation. Base is taken at base of the lower leaf of the Minn Sandstone [SK 055 610], and the top at the base of the Longnor Sandstone [SK 061 611] of the Hebden Formation [Millstone Grit Group]. 
Reference(s):
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. 
Chisholm, J I, Charsley, T J and Aitkenhead, N. 1988. Geology of the country around Ashbourne and Cheadle. Memoir of the British Geological Survey, Sheet 124 (England and Wales). 
Aitkenhead, N, Chisholm, J I and Stevenson, I P. 1985. Geology of the country around Buxton, Leek and Bakewell. Memoir of the British Geological Survey, England and Wales Sheet 111. 
Carney, J N, Ambrose, K and Brandon, A. 2002. Geology of the Loughborough district. Sheet explanation of the British Geological Survey, Sheet 141 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E110 E111 E123 E124