The BGS Lexicon of Named Rock Units — Result Details

Redcar Mudstone Formation

Computer Code: RMU Preferred Map Code: ReM
Status Code: Full
Age range: Hettangian Age (JH) — Pliensbachian Age (JE)
Lithological Description: Grey, fossiliferous, fissile mudstones and siltstones with subordinate thin beds of shelly limestone in lower part, and fine-grained carbonate-cemented sandstone in upper part; argillaceous limestone concretions occur throughout.
Definition of Lower Boundary: Where grey, silty mudstone with thin beds of limestone and calcareous sandstone rest with sharp and irregular contact on grey-green soft mudstone with thin siltstone laminae of Penarth Group (Lilstock Formation, Cotham Member); in the British Geological Survey Felixkirk Borehole, this is at depth 288.87m.
Definition of Upper Boundary: Gradational contact with overlying sandstones and siltstones of Staithes Sandstone Formation, but defined at the base of the "Oyster Bed" (highly fossiliferous calcareous and ferruginous sandstone).
Thickness: To c.283m
Geographical Limits: Cleveland Basin, North Yorkshire and Cleveland.
Parent Unit: Lias Group (LI)
Previous Name(s): LOWER LIAS (LLI)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  North Yorkshire and Cleveland coast. 
Type Section  Robin Hood's Bay North Yorkshire (lower part of formation not exposed). 
Reference Section  British Geological Survey Felixkirk Borehole, Felixkirk, North Yorkshire (SE48NE/2) 94.85-288.87m depth. 
Reference(s):
Powell, J H, 1984. Lithostratigraphic nomenclature of the Lias Group in the Yorkshire Basin. Proceedings of the Yorkshire Geological Society, Vol.45, p.51-57. 
Bairstow, L, 1969. The Lower Lias of Robin Hood's Bay. C24-C37 in International Field Symposium on the British Jurassic. Excursion No.3 Guide for north-east Yorkshire. Hemingway, J E, Wright, J K and Torrens, H s (editors). (Keele: Geology Department, Keele University). 
Cox, B M, Sumbler, M G and Ivimey-Cook, H C, 1999. A Formational framework for the Lower Jurassic of England and Wales. British Geological Survey Research Report No. RR/99/01. 
Fox-Strangways, C and Barrow, G, 1915. The geology of the country between Whitby and Scarborough (2nd edition). Memoir of the Geological Survey of the United Kingdom. 
Hesselbo, S P and Jenkyns, H C A, 1995. A comparison of the Hettangian to Bajocian successions of Dorset and Yorkshire. 105-150 in Taylor, P D (Editor). Field geology of the British Jurassic (London Geological Society). 
Ivimey-Cook, H C and Powell, J H, 1991. Late Triassic and early Jurassic biostratigraphy of the Felixkirk Borehole, North Yorkshire. Proceedings of the Yorkshire Geological Society, Vol.48, 367-374. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E062 E043 E034 E035 E044 E042 E052 E054 E055 E065 E064 E072