The BGS Lexicon of Named Rock Units — Result Details

Redcliff Formation

Computer Code: RECF Preferred Map Code: RE
Status Code: Full
Age range: Oxfordian Age (JO) — Oxfordian Age (JO)
Lithological Description: Lower and upper units of thick-bedded fine-grained sandstone and argillaceous sandstone (respectively the Nothe Grit and Bencliffe members), locally with large calcareous concretions, separated by an interval of mudstone and sandy mudstone with interbedded limestones (Nothe Clay Member). Pervasive bioturbation is evident in the Nothe Grit, and conspicuous cross stratification in the Bencliff Grit. There are common shelly and bioclastic-rich intervals, comprising particularly bivalves and ammonites.
Definition of Lower Boundary: Base is a sharp, probably non-sequential, boundary with the underlying Oxford Clay Formation. This is marked by the upward change from the mudstone of the Oxford Clay to the sandstone of the Nothe Grit Member.
Definition of Upper Boundary: The top is a sharp, planar, burrowed erosion surface at the top of the sandstone of the Bencliff Grit Member, which marks the upward change to thin argillaceous limestones and mudstones of the basal Osmington Oolite Formation.
Thickness: 29.2m at Osmington, about 28m at Sandsfoot.
Geographical Limits: South Dorset. Equivalent to the Hazelbury Bryan and lower part of the Stour Formation of north Dorset. Probably no physical continuity due to pre-Cretaceous erosion.
Parent Unit: Corallian Group (CR)
Previous Name(s): Lower Calcareous Grit And Berkshire Oolite Series (-1139)
Nothe Formation [Obsolete Name And Code: Use RECF] (NTH)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Wave-cut platforms and cliffs from Nothe Point to Rodwell, Weymouth. Base and top no longer visible. Wright (1986); Wright and Cox (2001, pp 38-45, fig.2.18). 
Type Area  Osmington, Dorset; 6km of cliff and foreshore sections between Bowleaze Cove and Ringstead Bay, including Redcliffe Point. This is likely to include the Type Section, yet to be designated. Wright and Cox (2001) 
Reference(s):
Arkell W J, 1933. The Jurassic System in Great Britain [Oxford: Clarendon Press.] 
Blake, J F and Huddleston, W H 1877. On the Corallian rocks of England. Quarterly Journal of the Geological Society of London, Vol.33, 260-405. 
Wright J K. 2001. Discussion on fault activity and sedimentation in a marine rift basin (Upper Jurassic, Wessex basin, UK). Journal of the Geological Society, London, Vol.158, 391-392. 
Arkell, W J. 1947. Geology of the country around Weymouth, Swanage, Corfe and Lulworth. Memoir of the British Geological Survey. Sheets 341, 342, 343 and small portions of sheets 327, 328 and 329 (England and Wales). 
Wright, J K. 1986. A new look at the stratigraphy, sedimentology and ammonite fauna of the Corallian Group (Oxfordian) of south Dorset. Proceedings of the Geologists' Association, Vol. 97, 1-21. 
Wright, J K, and Cox, B M. 2001. British Upper Jurassic Stratigraphy (Oxfordian to Kimmeridgian). Geological Conservation Review Series. No. 21. (Peterborough: Joint Nature Conservation Committee/Chapman and Hall.) 
Coe, A L. 1995. A comparison of the Oxfordian successions of Dorset, Oxfordshire and Yorkshire. 151-172 in Taylor, P D (Ed.) Field Geology of the British Jurassic. [Bath: The Geological Society.] 
Newall, A J. 2000. Fault activity and sedimentation in a marine rift basin (Upper Jurassic, Wessex basin, UK). Journal of the Geological Society, London, Vol.157, 83-92. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable