The BGS Lexicon of Named Rock Units — Result Details

Dogger Formation

Computer Code: DGR Preferred Map Code: Dgr
Status Code: Full
Age range: Aalenian Age (JA) — Aalenian Age (JA)
Lithological Description: Highly variable and heterolithic with substantial lateral interdigitation and lithofacies changes. In the Whitby area and coastal sections to the southeast, the formation consists mainly of grey, weathering yellow-brown, sideritic sandstone, medium- to coarse-grained, with sporadic phosphatic pebbles; berthierine (chamosite) ooids may be present. In central, north and west Cleveland there is a complex interdigitation between grey, weathering yellow-brown, berthierine (chamosite) ooidal ironstone (with siderite mudstone matrix) and pale grey limestone, medium-grained, bioclastic wackestone and packstone with peloids and ooids, generally bioturbated and locally cross-bedded. In addition, partings, lenses and beds of grey, fossiliferous fissile mudstone may occur, and south-west of Malton, a distinctive iron-rich pebbly medium-grained sandstone facies is locally developed. Sandstones and ironstones are characteristically highly bioturbated and yield marine fossils including bivalves and scattered ammonites; corals, bryozoans, crinoids and brachiopods are locally present in the limestones.
Definition of Lower Boundary: Across most of the Cleveland Basin, the lower boundary is generally sharp, disconformable or unconformable on the gently folded Lower Jurassic Lias Group, marked by an abrupt change where grey fissile mudstone of the Lower Jurassic Whitby Mudstone Formation is overlain by sandstone, ironstone or limestone of the Dogger Formation. The boundary is less distinctive in the Peak Trough (Knox, 1984) (e.g. exposed at Blea Wyke; Ravenscar) [NZ 991 015] where the bioturbated sandstone of the Blea Wyke Sandstone Formation (late Toarcian in age ) is overlain by the yellow brown sandstone of the Dogger Formation (Aalenian in age), although at Blea Wyke the basal bed contains phosphate pebbles and casts of brachiopods (the Terebratula Bed) (Cox and Sumbler, 2002, pp. 357-361). In the Rosedale area, the base of the formation is generally marked by an ooidal ironstone with phosphatic pebbles sharply overlying bioturbated sandstone or ooidal ironstone of the Blea Wyke Sandstone Formation (Young, T P, 1994), although in localities where these lithologies repeat, the boundary may be difficult to place.
Definition of Upper Boundary: The upper boundary is unconformable or disconformable, sharp. Marked by an abrupt upward transition from ferruginous sandstone, ironstone or limestone at the top of the Dogger Formation to cross-stratified, non-bioturbated sandstone, siltstone and mudstone (commonly with plant fragments) of the overlying Saltwick Formation (Ravenscar Group). Where both formations are dominated by mudstone, the boundary may be somewhat cryptic – that of the Dogger Formation is dark grey, less silty and of a distinctly marine aspect, that of the Saltwick Formation is paler grey, silty and with black plant debris.
Thickness: Variable, both locally and regionally; generally about 0.75 to 2m thick on the Yorkshire Coast and in ferruginous sandstone/ironstone lithofacies; limestone and mudstone lithofacies, up to 12.2m locally preserved. Thought locally to attain 29 m in the Rosedale area [SE 729 946] (Hemingway, 1974, p. 188), although Young, T P (1994) regards much of this strata as belonging to the underlying Blea Wyke Sandstone Formation in which case the Dogger Formation here is up to about 8 m thick. May be absent, locally, due to erosion prior to deposition of the overlying Saltwick Formation (Ravenscar Group).
Geographical Limits: Cleveland Basin, North Yorkshire, including the North Yorks Moors, North Yorkshire coast (between Boulby and Gristhorpe Bay) and the Howardian Hills. Offshore, the Dogger Formation is equivalent, in part, to the Wroot Formation (Lott and Knox,1994) in the southern North Sea and in part to the Drake Formation in the Brent Province (Butler et al., 2005). The formation is locally absent in the Cleveland Basin, especially on parts of the Egton Sheet (Ingleby Greenhow) and Thirsk Sheet (Hambleton Hills), where the Dogger Formation has been removed by penecontemporaneous erosion prior to deposition of the overlying Saltwick Formation (Ravenscar Group).
Parent Unit: Not Applicable (-)
Previous Name(s): Dogger (-208)
Dogger Ironstone (-1498)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The Dogger Formation occurs as variable lithofacies across the Cleveland Basin from the Yorkshire Coast, near Whitby [NZ 480 500] to the Hambleton Hills [SE 496 827] and Howardian Hills [SE 600 600]. 
Reference Section  A crag at Yew Grain [NZ 717 018] near Great Fryup, Upper Eskdale, reported in Rastall and Hemingway (1943, p.219) is typical of the ironstone and sandstone lithofacies. This section is less accessible than the coastal Type Section, but it provides an example of the mixed ironstone and sandstone lithofacies typical of the Eskdale area. Grey fine-grained sandstone and, locally, siderite mudstone of the Whitby Mudstone Formation is overlain sharply by a thin phosphatic pebble bed that marks the base of the Dogger Formation, and which passes up to blue-grey, bioturbated sandstone (1.07m), black mudstone (0.61m) and green siltstone (0.15m) ("Danby Facies") that are, in turn, overlain by green-grey, fine-grained sandstone (0.91m) and black to grey chamosite ooidal ironstone (3.96m), with a siderite matrix ("Ajalon facies"). The base of the overlying Saltwick Formation is marked by black, carbonaceous clay, passing up to yellow sandstone. Rapid local lateral variation is illustrated by the absence of the basal pebble bed and overlying bioturbated sandstone bed at the nearby Yew Grain section [NZ 7172 0185] reported by Young, T P (1994, fig.3). 
Type Section  Exposure at the base of the cliff, west of Saltwick Bay [NZ 908 113], south-east of Whitby, North Yorkshire. Grey, fissile mudstone of the Alum Shale Member, Whitby Mudstone Formation (Lias Group) is overlain by yellow-brown, bioturbated, ferruginous sandstone with occasional berthierine (chamosite) ooids and phosphatized pebbles that comprise the Dogger Formation (0.75 to 1.5m thick). Clasts in the Dogger Formation include mudstone pebbles, and fragments of ammonites and bivalves derived from the underlying Alum Shale Member. At the lower boundary, sand-filled burrows extend downwards from the Dogger Formation to the underlying mudstone. The upper boundary is marked by the sharp change from ferruginous, bioturbated sandstone of the Dogger Formation to grey, fine- to medium-grained, locally cross-bedded sandstone with plant fragments of the overlying Saltwick Formation (Ravenscar Group). The lithofacies variation of the Dogger Formation makes selection of a type section difficult. However, the best exposed and familiar sections are those in the ferruginous sandstone and ironstone lithofacies located near Whitby on the Yorkshire coast. The type section is located between Whitby East Cliff [NZ 903 114] and Saltwick Bay [NZ 915 110] (Hemingway and Knox, 1973; Hemingway, 1974). 
Reference(s):
Hemingway, J E and Knox, R W O'B. 1973. Lithostratigraphical nomenclature of the Middle Jurassic strata of the Yorkshire Basin of north-east England. Proceedings of the Yorkshire Geological Society, Vol.39, 527-535. 
Young, G. 1817. Mineralogy. A history of Whitby and Streoneshalh Abbey. (Whitby.) 
Young, T P. 1994. The Blea Wyke Sandstone Formation (Jurassic, Toarcian) of Rosedale, North Yorkshire, UK. Proceedings of the Yorkshire Geological Society, Vol. 50, 129-142. 
Hemingway, J E. 1974. Jurassic. 161-233 in Rayner, D H and Hemingway, J E (eds), The geology and mineral resources of Yorkshire. (Leeds: Yorkshire Geological Society.) 
Rastall, R H. 1905. The Blea Wyke Beds and the Dogger in north-east Yorkshire. Quarterly Journal of the Geological Society, London, Vol.61, 441-460. 
Rastall, R H and Hemingway, J E. 1939. Black oolites in the Dogger of north-east Yorkshire. Geological Magazine, Vol.76, 225-233 (273-281). 
Rastall, R H and Hemingway, J E. 1940. The Yorkshire Dogger I. The coastal region. Geological Magazine, Vol.77, 177-197. 
Rastall, R H and Hemingway, J E. 1941. The Yorkshire Dogger II. Lower Eskdale. Geological Magazine, Vol.78, 351-370. 
Rastall, R H and Hemingway, J E. 1949. The Yorkshire Dogger IV. Rosedale and Farndale. Geological Magazine, Vol.86, 201-225, 265-278. 
Black, M. 1934. Sedimentation of the Aalenian rocks of Yorkshire. Proceedings of the Yorkshire Geological Society, Vol.22, 265-279. 
Butler, N, Charnock, M A, Hager, K O and Watkins, C A. 2005. The Ravenscar Group: a coeval analogue for the Middle Jurassic reservoirs of the North Sea and offshore Mid-Norway. 43-53 in Powell, A J and Riding, J B (eds), Recent Developments in Applied Biostratigraphy. The Micropalaeontological Society, Special Publications. 
Whyte, M A and Romano, M. 2006. Lower-Middle Jurassic sequences between Whitby and Saltwick. 158-164 in Scrutton, C T and Powell, J H (eds), Yorkshire Rocks and Landscapes - A Field Guide, 3rd Edition, Yorkshire Geological Society. 
Rawson, P F and Wright, J K (eds). 1992. The Yorkshire Coast. Geologists' Association Guide, No.34. 2nd Edition, 117pp. (Ongar: PSS Group.) 
Knox, R W O'B, Howard, A S, Powell, J H and van Buchem, F S P. 1991. Lower and Middle Jurassic sediments of the Cleveland Basin N.E. England: Shallow marine and paralic facies seen in their sequence stratigraphic context. Field Excursion Guide, No.5; 13th International Sedimentological Congress, Nottingham, UK. 1990. 66pp. 
Rastall, R H and Hemingway, J E. 1943. The Yorkshire Dogger III. Upper Eskdale. Geological Magazine, Vol.80, 209-230. 
Richards, P C, Lott, G K, Johnson, H, Knox, R W O'B. and Riding, J B. 1993. 3. Jurassic of the Central and Northern North Sea. In: Knox, R W O'B and Cordey, W G. Lithostratigraphic nomenclature of the UK North Sea. [British Geological Survey, Nottingham] 
Lott, G K and Knox, R W O'B. 1994. 7. Post-Triassic of the Southern North Sea. In: Knox, R W O'B and Cordey, W G (eds.) Lithostratigraphic nomenclature of the UK North Sea. [British Geological Survey, Nottingham]. 
Knox, R W O B. 1984. Lithostratigraphy and depositional history of the late Toarcian sequence at Ravenscar, Yorkshire. Proceedings of the Yorkshire Geological Society, Vol. 45, 99-108. 
Powell, J H, Cooper, A H C and Benfield, A C. 1992. Geology of the country around Thirsk. Memoir of the British Geological Survey, Sheet 52 (England and Wales). 
Fox-Strangways, C. 1892. The Jurassic Rocks of Britain, Vol.1. Yorkshire. Memoir of the Geological Survey of the United Kingdom. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E033 E034 E035 E042 E043 E044 E052 E053 E054 E063