The BGS Lexicon of Named Rock Units — Result Details

Thurstaston Hard Sandstone Bed

Computer Code: THHB Preferred Map Code: ThHB
Status Code: Full
Age range: Early Triassic Epoch (TE) — Anisian Age (TA)
Lithological Description: Sandstone and pebbly sandstone, greyish-brown. Fine- to medium-grained, moderately- to poorly-sorted. Laterally impersistent. Very well cemented in comparison to sandstone units immediately above (Thurstaston Sandstone Member) and below (Wilmslow Sandstone Formation).
Definition of Lower Boundary: Taken at the base of a maximum 3m thick pebbly sandstone bed (the Thurstaston Hard Sandstone Bed), overlying pebble-free reddish-orange sandstone (Wilmslow Sandstone Formation).
Definition of Upper Boundary: Taken at the top of a maximum 3m thick pebbly sandstone bed (the Thurstaston Hard Sandstone Bed), underlying pebble-free reddish-orange sandstone (Thurstaston Sandstone Member).
Thickness: 0 to 3m
Geographical Limits: Wirral Peninsula, west of the Woodchurch Fault (Cheshire Basin).
Parent Unit: Thurstaston Sandstone Member (THUN)
Previous Name(s): Thin inconsistent bed of hard sandstone (-3081)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Thurstaston Common, Thurstaston, Wirral. Hough, E, 1999; Lawley, R S, In press 
Type Section  A540, Thurstaston road cutting. 300-600m north of junction with Station Road and Thurstaston Road. Thompson, D B, 1970a. 
Reference(s):
Thompson, D B, 1970B. Sedimentation of the Triassic (Scythian) Red Pebbly Sandstones in the Cheshire Basin and its margins. Geological Journal 7, Pt.1, 183-216. 
Wedd, C B, Smith, B, Simmons, W C and Wray, D A, 1923. The Geology of Liverpool, with Wirral and part of the Flinthsire Coalfield. Memoir of the Geological Survey of Great Britain, Sheet 96 (England and Wales). 
Hough, E, 1999. The geology of the north Wirral district. British Geological Survey Technical Report WA/98/66. 
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). 
Lawley, R S, in preparation. The geology of the country around Heswall. British Geological Survey Technical Report. 
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. 
Rice, R C, 1939. The Trias of north-west Wirral. Proceedings of the Liverpool Geological Society 17, 349-370. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E096