| Computer Code: |
BRCT |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Anisian Age (TA)
— Anisian Age (TA) |
| Lithological Description: |
The dominant lithology is planar and trough cross-bedded, irregularly bedded and structureless red-brown sandstones. Subordinate lithologies are conglomerates composed of subrounded to angular clasts. Extraformational clasts include quartz, quartzite, limestone, chert and tuff; intraformational clasts include mudstone, siltstone and sandstone. There are subordinate beds of grey-green mudstone and siltstone. The sequence shows repeated fining-upward cycles, from conglomerate to mudstone; the siltstone and mudstone components of these are commonly absent. Sedimentary structures include ripple marks, flute casts, slump structures and convolute bedding. Micaceous bedding planes are common. A solitary fish spine was recorded from the member (Wills, 1970). |
| Definition of Lower Boundary: |
The lower boundary is taken at the lowest conglomerate resting on soft red sandstones of the Wildmoor Sandstone Member of the Wilmslow Sandstone Formation. |
| Definition of Upper Boundary: |
The upper boundary is taken at the top of the highest bed of extraformational conglomerate, above which are sandstones and mudstones of the overlying Finstall Member. |
| Thickness: |
The thickest known sequence is 192.4 m, in the Sugarbrook No.3 Borehole, but the base has not been proved. |
| Geographical Limits: |
The member has only been mapped in the Bromsgrove area of Worcestershire but is likely to extend westwards to Little Witley [SO 78 63], Worcestershire. |
| Parent Unit: |
Helsby Sandstone Formation (HEY)
|
| Previous Name(s): |
Basement Beds [Obsolete Name and Code: Use WAR, HEY, BRCT, BABE, LFSB, LLW, DELA, FRM, PLT, FRFA, PFLD, DDC]
(-3812)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Road cutting, Burcot (Benton et al., 2002). |
| Reference Section |
Sugarbrook No. 3 Borehole BGS Registered No. SO96NE/30, 206.8-398.4 m (Old et al., 1991); the base of the member was not proved. Scattered exposures south of Kidderminster, Worcestershire. |
| Reference(s): |
| Hull, E, 1869. The Triassic and Permian rocks of the Midland Counties of England. Memoir of the Geological Survey of Great Britain. |
| 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. |
| 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). |
| 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.) |
| 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. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
