The BGS Lexicon of Named Rock Units — Result Details

Mohuns Park Mudstone Bed

Computer Code: MPMU Preferred Map Code: MPM
Status Code: Full
Age range: Callovian Age (JC) — Callovian Age (JC)
Lithological Description: Silicate mudstone, medium grey, weakly calcareous, slightly pyritous, shelly, with sporadic beds of argillaceous limestone nodules.
Definition of Lower Boundary: Arbitary boundary drawn at the top of highest substantial sandstone or sandy mudstone of underlying Kellaways Formation, above which the succession is predominantly mudstone.
Definition of Upper Boundary: Arbitary boundary within upward transition from grey mudstone to predominantly brownish grey, generally more fissile and organic-rich ("bituminous") mudstone of overlying Peterborough Member.
Thickness: 0 - 19m
Geographical Limits: Trudoxhill (Somerset) to Holwell (Dorset).
Parent Unit: Peterborough Member (PET)
Previous Name(s): Mohuns Park Member (-406)
Alternative Name(s): Peterborough Member
Stratotypes:
Type Area  Mohuns Park Farm, 2.8km south east of Abbas Combe, near Wincanton, Dorset. Bristow et al, 1995. 
Reference Section  BGS Combe Throop Borehole (ST72SW/1), 2km eastnortheast of Abbas Combe, near Wincanton, Dorset. 29.6 to 48.7m depth. Bristow et al., 1995. 
Reference(s):
Bristow, C R, Barton, C M, Freshney, E C, Wood, C J, Evans, D J, Cox, B M, Ivimey-Cook, H C, and Taylor, R T. 1995. Geology of the country around Shaftesbury. Memoir of the British Geological Survey, Sheet 313 (England and Wales). 
Bristow, C R, Barton, C M, Freshney, E C, Wood, C J, Evans, D J, Cox, B M and Woods, M A. 1999. The Wincanton district - a concise account of the geology. Memoir of the British Geological Survey, Sheet 297 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E313 E281