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 (-124)
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). Fox-Strangways, C and Barrow, G, 1915; Bairstow, L, 1969; Hesselbo, S P and Jenkyns, H C, 1995. 
Reference Section  British Geological Survey Felixkirk Borehole, Felixkirk, North Yorkshire (SE48NE/2) 94.85-288.87m depth. Powell, J H, 1984; Ivimey-Cook, H C and Powell, J H, 1991. See also Cox, B M, et al, 1999 for additional sections. 
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. 
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. 
Cox, B M, Sumbler, M G and Ivimey-Cook, H C, 1999. A Formational framework for the Lower Jurassic of England and Wales (Onshore Area). British Geological Survey Research Report No. RR/99/01. 
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). 
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