The BGS Lexicon of Named Rock Units — Result Details

Bradley Flags

Computer Code: BDLF Preferred Map Code: notEntered
Status Code: Index Level
Age range: Pendleian Substage (CE) — Pendleian Substage (CE)
Lithological Description: Fine-grained sandstone interbedded with micaceous mudstone. The sandstone is highly micaceous, flaggy, with planar bedding and lamination displaying primary current lineations, cross bedding with burrow traces in places and both wave and current ripple cross lamination.
Definition of Lower Boundary: Base of lowermost thick fine-grained and micaceous sandstone above the Bradley Coal. Note that this definition is more restricted than the definition of Stephens et al. (1953), who included all sandstones above the Bradley Coal.
Definition of Upper Boundary: Passage from the fine-grained sandstone of the Bradley Flags into the overlying dark grey mudstones containing the Cravenoceras cowlingense Marine Band.
Thickness: Maximum of 25m at Bradley.
Geographical Limits: Restricted to the northwest part of the Bradford district (Sheet 69).
Parent Unit: Millstone Grit Group [See Also MIGR] (MG)
Previous Name(s): Bradley Grits [Obsolete Name And Code: Use BDLF] (BDG)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Bradley Quarry: 18m-thick succession, the upper 4 to 5m displaying parallel or low-angle cross-bedding, the lower 12 to 13m comprising 1 to 2m-thick co-sets of cross-bedded sandstone. 
Reference(s):
Waters, C N, 2000. Geology of the Bradford district. Sheet description of the BGS. 1:50000 Series, Sheet 69 Bradford (England and Wales). 
Addison, R. 1997. Geology of the Silsden and Cononley district (SE04NW and SD94NE), BGS Technical Report, WA/97/22. 
Stephens, J V, Mitchell, G H and Edwards, W N. 1953. Geology of the country between Bradford and Skipton. Memoir of the Geological Survey of Great Britain, Sheet 69 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable