The BGS Lexicon of Named Rock Units — Result Details

Helsby Sandstone Formation

Computer Code: HEY Preferred Map Code: Hey
Status Code: Full
Age range: Anisian Age (TA) — Anisian Age (TA)
Lithological Description: Fine- to medium-grained, locally micaceous, cross-bedded and flat-bedded sandstones, weathering to sand near surface. Sandstones are of fluvial (sub-angular to sub-rounded grains) and aeolian (well-rounded grains) facies. Pebbles may be common, particularly near the base of the formation, and thin units of hard intraformational conglomerate occur in the south-west. Thin lenticular beds of reddish brown siltstone and mudstone occur and may be common in fining-upward sequences; calcretes and rhizocretions occur at some horizons in the south-west (Purvis and Wright, 1991; Hounslow and McIntosh, 2003; Newell, 2006).
Definition of Lower Boundary: Rests disconformably on the Wilmslow Sandstone Formation and unconformably on the Chester Formation in different areas of the country. In the west Midlands and Lancashire, it is placed at the base of the lowest pebbly bed or conglomerate. In Cumbria, it is placed where aeolian sandstones overlie a thick fluvial sandstone sequence assigned to the Wilmslow Sandstone Formation. It is not a formational boundary with characteristic features on borehole geophysical logs.
Definition of Upper Boundary: Transitional into the overlying Tarporley Siltstone Formation or, where that is absent, the Sidmouth Mudstone Formation of the MMG.
Thickness: It is locally absent in areas that were contemporary high ground such as Charnwood Forest, Breedon Hill and Mountsorrel, and possibly the Lickey Hills. The formation is thinnest in the Warwickshire, Derbyshire and north Staffordshire areas. The thickest known development (up to 500 m) is in the Worcester Basin. It thins northwards to around 250 m in the Cheshire - Lancashire area and is 90 to over 176 m thick in Cumbria. The maximum known thickness there is 176.42 m in the Sellafield 13B borehole where the top was not proved.
Geographical Limits: The formation crops out almost continuously from the south Devon coast, northwards, to near Taunton, Somerset. There is one outcrop in north-west Gloucestershire around Newent, and extensive outcrops in north Worcestershire and in Staffordshire, up to near Stoke-on-Trent. There is continuous outcrop from Warwick to Nuneaton with outcrops elsewhere in Warwickshire and extensive but broken outcrops in south Derbyshire and north-west Leicestershire, including the north side of Charnwood Forest. Further fragmentary outcrops occur in Cheshire and south-west of Manchester, with more continuous outcrops around Merseyside and in southern Lancashire. The formation crops out very locally on the Cumbrian coast and more extensively in the Eden valley.
Parent Unit: Sherwood Sandstone Group (SSG)
Previous Name(s): Basement Beds (-3812)
Building Stones (-5112)
Bulkeley Hill Sandstone Formation [Obsolete Name And Code Use: HEY] (BHSF)
Burcot Breccia (-5132)
Grinshill Sandstone [Obsolete Name And Code Use: HEY] (GHSA)
Keuper Sandstone Formation (-5133)
Keuper Sandstone, Lower [Obsolete name and code, use HEY] (-709)
Otter Sandstone (-437)
Otter Sandstones (-3599)
Ruyton Sandstone [Obsolete name and code, use HEY] (-5134)
Upper Sandstone (-3792)
Waterstones Group (-3089)
Waterstones* (-5135)
Helsby Sandstone Formation [Obsolete Code: Use HEY] (HBSF)
Hollington Formation [Obsolete Name And Code Use: HEY] (HOL)
Keuper Sandstone Passage Beds [Obsolete name use HEY] (-56)
Ormskirk Sandstone Formation [Obsolete Name And Code Use: HEY] (OMS)
Otter Sandstone Formation [Obsolete Name And Code Use: HEY] (OS)
Bromsgrove Sandstone Formation [Obsolete Name And Code: Use HEY] (BMS)
Kirklinton Sandstone Formation [Obsolete Name And Code: Use HEY] (KIS)
Bearstone Sandstones [Obsolete Name And Code: Use HEY] (BSS)
Alternative Name(s): Smith Bank Formation
Dowsing Formation
Stratotypes:
Reference Section  Bromsgrove, north Worcestershire (Warrington, et al., 1980); basal Burcot Breccia exposures (Wills, 1976, p 37); other localities (Old, et al., 1991, p 18-30).  
Reference Section  Small outcrops in river banks north of Longtown, Cumbria (Dixon et al., 1926). 
Reference Section  Sellafield Borehole 13B, Cumbria. BGS Registered No. NY00SW/42, 35.97 to 176.42 m (Barnes et al., 1994). 
Type Section  Helsby Hill, Cheshire (Earp and Taylor, 1986, p.26; Thompson, 1970). 
Reference Section  Between Hollington and Alton, Staffordshire. 
Reference Section  Sea cliffs between Budleigh Salterton and Sidmouth,south Devon (Hounslow and McIntosh, 2003).  
Reference(s):
Warrington, G, Audley-Charles, M G, Elliott, R E, Evans, W B, Ivimey-Cook, H C, Kent, P E, Robinson, P L, Shotton, F W and Taylor, F M. 1980. A correlation of the Triassic rocks in the British Isles. Special Report of the Geological Society of London, No.13. 
Wills, L J. 1970. The Triassic succession in the central Midlands in its regional setting. Quarterly Journal of the Geological Society of London, Vol.126, 225-285. 
Wills, L J. 1976. The Trias of Worcestershire and Warwickshire. Report of the Institute of Geological Sciences, No.76/2. 
Laming, D J C, 1968. New Red Sandstone stratigraphy in Devon and West Somerset. Proceedings of the Ussher Society, Vol.2, p.23-25. 
Ussher, W A E, 1902. The Geology of the country around Exeter. Memoir of the Geological Survey of Great Britain, Sheet 325. (England and Wales). 
Ussher, W A E, 1913. Geology of the country around Newton Abbot. Memoir of the British Geological Survey, Sheet 339. (England and Wales). 
Hull, E, 1869. The Triassic and Permian rocks of the Midland Counties of England. Memoir of the Geological Survey of Great Britain. 
Johnson, H, Warrington, G and Stoker, S J. 1994. Permian and Triassic of the Southern North Sea. In Knox, R W O'B and Cordey, W G (editors), Lithostratigraphic nomenclature of the UK North Sea. [Nottingham: British Geological Survey.] 
Bachmann, G H, Geluk, M C, Warrington, G, Becker-Roman, A, Beutler, G, Hagdorn, H, Hounslow, M W, Nitsch, E, Röhling, H-G, Simon, T, and Szulc, J. 2010. Triassic. 148–173 in Petroleum Geological Atlas of the Southern Permian Basin Area. Doornenbal, J C, and Stevenson, A G (editors). (Houten: EAGE Publications b.v.) 
Henson, M R, 1970. The Triassic rocks of south Devon. Proceedings of the Ussher Society, Vol.2, p.172-177. 
Ambrose, K, Hough, E, Smith, N J P and Warrington, G. 2014. Lithostratigraphy of the Sherwood Sandstone Group of England, Wales and south-west Scotland. British Geological Survey Research Report, RR/14/01. 
Binney, E W. 1846. On the relation of the New Red Sandstone to the Carboniferous strata in Lancashire and Cheshire. Quarterly Journal of the Geological Society of London, Vol. 2, 12–26. 
Pocock, R W, and Wray, D A. 1925. The geology of the country around Wem. Memoir of the Geological Survey of Great Britain, Sheet 138 (England and Wales). 
Hull, E. 1860. On the new subdivisions of the Triassic rocks of the central counties. Transactions of the Manchester Geological Society, Vol. 2, 22–34. 
Hull, E. 1860. On the south-easterly attenuation of the lower secondary formations of England; and the probable depth of Coal Measures under Oxfordshire and Northamptonshire. Quarterly Journal of the Geological Society of London, Vol. 16, 63–81. 
Old R A, Hamblin, R J O, Ambrose, K, and Warrington G. 1991. Geology of the country around Redditch. Memoir of the British Geological Survey, Sheet 183 (England and Wales). 
Dixon, E E L, Maden J, Trotter, F M, Hollingworth, M A and Tonks, L H. 1926. The geology of the Carlisle, Longtown and Silloth District. Memoir of the Geological Survey of England and Wales. 
Barnes, R P, Ambrose, K, Holliday, D W, and Jones N S. 1994. Lithostratigraphical subdivision of the Triassic Sherwood Sandstone Group in west Cumbria. Proceedings of the Yorkshire Geological Society, Vol. 50, 51-60. 
Hounslow, M W, and McIntosh, G. 2003. Magnetostratigraphy of the Sherwood Sandstone Group (Lower and Middle Triassic), south Devon, UK: detailed correlation of the marine and nonmarine Anisian. Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 193, 325–348. 
Barton, C M, Woods, M A, Bristow, C R, Newell, A J, Westhead, R K, Evans, D J, Kirby, G A, and Warrington, G. 2011. Geology of south Dorset and south-east Devon and its World Heritage Coast. Special Memoir of the British Geological Survey, Sheets 328, 341/342, 342/343 and parts of 326/340, 327, 329 and 339. 
Mitchell, G H, Pocock, R W, and Taylor, J H. 1962. Geology of the country around Droitwich, Abberley and Kidderminster. Memoir of the Geological Survey of Great Britain, Sheet 182 (England and Wales). 
Bridge, D M and Hough E, 2002. Geology of the Wolverhampton and Telford district. Sheet Description of the BGS Sheet 153 (England and Wales). 
Benton, M J, Cook, E, and Turner, P. 2002. Permian and Triassic Red Beds and the Penarth Group of Great Britain. Geological Conservation Review Series, No. 24. (Peterborough: Joint Nature Conservation Committee). 
Thompson, D B, 1969. Dome-shaped Aeolian dunes in the Frodsham Member of the so-called 'Keuper' Sandstone Formation, (Scythian ?Anisian-Triassic) at Frodsham, Cheshire, England. Sedimentary Geology 3, 263-289. 
Old, R A, Sumbler, M G and Ambrose, K, 1987. Geology of the country around Warwick. Memoir of the British Geological Survey, Sheet 184 (England and Wales). 
Woodcock, D. 2002. The sandstone quarries of Overton Hill, Frodsham: a geological study. OUGS Journal, Vol. 23, 6–15. 
Mountney, N P, and Thompson, D B. 2002. Stratigraphic evolution and preservation of aeolian dune and damp/wet interdune strata: an example from the Triassic Helsby Sandstone Formation, Cheshire Basin, UK. Sedimentology, Vol. 49, 805–833. 
Warrington, G. 2010. Alderley Edge district, Cheshire. 182–190 in Mineralisation of England and Wales. Geological Conservation Review Series, No. 36. (Peterborough: Joint Nature Conservation Committee.) 
Purvis, K, and Wright, V P. 1991. Calcretes related to phreatophytic vegetation from the Middle Triassic Otter Sandstone of south-west England. Sedimentology, Vol. 38, 539–551. 
Newell, A J. 2006. Calcrete as a source of heterogeneity in Triassic fluvial sandstone aquifers (Otter Sandstone Formation, SW England). Geological Society of London Special Publication, No. 263, 119–127. 
Thompson, D B, 1970. The stratigraphy of the so-called Keuper Sandstone Formation (Scythian-?Anisian) in the Permo-Triassic Cheshire Basin. Quarterly Journal of the Geological Society of London, Vol.126, p.151-181. 
Earp, J R and Taylor, B J, 1986. Geology of the country around Chester and Winsford. Memoir of the British Geological Survey, Sheet 109 (England and Wales). 
Cameron, T D J. 1993. 4 Triassic and Permian of the central and northern North Sea, in Knox, R W O'B and Cordey, W G, (eds.) Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. 
Cameron, T D J, Crosby, A, Balson, P S, Jeffery, D H, Lott, G K, Bulat, J, and Harrison, D J. 1992. The geology of the southern North Sea. United Kingdom offshore regional report. (London: HMSO for the British Geological Survey.) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E109 E123 E137 E096