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 [Obsolete Name and Code: Use CHAM, RMU]
(-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). |
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). |
Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. |
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
|