The BGS Lexicon of Named Rock Units — Result Details

Yedmandale Member

Computer Code: YED Preferred Map Code: Ye
Status Code: Full
Age range: Oxfordian Age (JO) — Oxfordian Age (JO)
Lithological Description: Sandstone, fine- to medium-grained, calcareous, shelly, bioturbated, passing up into limestone, shelly, sandy, variably ooidal, with abundant bivalves and serpulids, and coral debris in the upper part; locally a coral rich bed is preserved near the top (Hackness Coral-Sponge Bed).
Definition of Lower Boundary: Non-sequence: generally well-cemented calcareous fine-grained sandstone, locally spicule-rich (Lower Calcareous Grit Formation), sharply overlain by softer fine- to medium-grained calcareous sandstone of basal Yedmandale Member.
Definition of Upper Boundary: Non-sequence: shelly, sandy, variably ooidal limestone, with abundant bivalves, serpulids and coral debris, with a sharp, locally encrusted top, overlain by ooidal limestone (Hambleton Oolite Member, Coralline Oolite Formation).
Thickness: 9 to 11m in the Tabular and Hackness Hills, about 8m at Scarborough, thinning east to 2.5m at Filey.
Geographical Limits: Cleveland Basin, North Yorkshire: north of the Vale of Pickering, pinches out in the west between Kirbymoorside and Helmsley.
Parent Unit: Coralline Oolite Formation (COO)
Previous Name(s): Yellow Grits And Gervillia Beds (-2545)
Greystone Or Passage Beds (-1291)
Passage Beds Member (-3149)
Yedmandale Passage Member (-4988)
Passage Beds (-3236)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Quarries at Hackness Head, Hackness, Scalby, North Yorkshire. Together expose entire member, totalling between 6 and 9m of sandstone and highly fossiliferous limestone, including the Hackness Coral-Sponge Bed. Wilson, 1949, pp 249-252; Wright and Cox, 2001, pp 150-154. 
Reference Section  Rock platform at Filey Brigg, Filey, North Yorkshire. Exposes entire Yedmandale Member, totalling 2.5m thick, where it is very shelly and atypically moderately ooidal in parts. Coe, 1995; Rawson and Wright, 1995; Wright and Cox, 2001, pp 139-144. 
Type Section  Spikers Hill Quarry (near Yedmandale), West Ayton, North Yorkshire. Exposes upper part of member, at least 3.9m thick, comprising shelly bioclastic limestone overlain by shelly ooidal limestone (Beds 0 and 1A of Wright and Cox, 2001). Type Section proposed here, see Wright and Cox, 2001, pp 157-161. 
Reference(s):
Rawson, P F and Wright, J K. 1995. Jurassic of the Cleveland Basin, North Yorkshire. 173-208 in Taylor, P D (Ed.) Field Geology of the British Jurassic. (London: Geological Society.) 
Arkell W J, 1933. The Jurassic System in Great Britain [Oxford: Clarendon Press.] 
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.] 
Wright, J K. 1983. The Lower Oxfordian (Upper Jurassic) of North Yorkshire. Proceedings of the Yorkshire Geological Society, Vol. 44, 249-281. 
Wilson, V. 1949. The lower Corallian rocks of the Yorkshire coast and Hackness Hills. Proceedings of the Geologists' Association, Vol. 60, 235-271. 
Wright, J K. 1992. The depositional history of the Hackness Coral-Sponge Bed and its associated sediments within the Passage Beds Member of the Coralline Oolite Formation (Corallian Group: Oxfordian) of North Yorkshire. Proceedings of the Yorkshire Geological Society, Vol. 49, 155-168. 
Fox-Strangways, C. 1880. The geology of the oolitic and Cretaceous rocks south of Scarborough: (Quarter sheets 95SW and 95SE). Memoir of the Geological Survey of the United Kingdom. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E043 E044 E053 E054 E063 E064