The BGS Lexicon of Named Rock Units — Result Details

Addlethorpe Grit

Computer Code: AD Preferred Map Code: AD
Status Code: Index Level
Age range: Kinderscoutian Substage (CK) — Kinderscoutian Substage (CK)
Lithological Description: A brown, medium-to-coarse-grained, thinly to thickly bedded, quartzo-feldspathic, flaggy, micaceous sandstone.
Definition of Lower Boundary: A sharp upward change in a conformable succession from predominantly grey mudstone to sandstone. The base of the first sandstone above the Reticuloceras todmordense (R1a4) Marine Band (if recognised) or the Cayton Gill Shell Bed.
Definition of Upper Boundary: A sharp upward change in a conformable succession from sandstone to predominantly mudstone. The top of the last sandstone below the Reticulatum-Vallites striolatus (R1c) Marine Band (where identified) or below the coarse-grained and pebbly Addingham Edge Grit.
Thickness: Up to 50 m thick.
Geographical Limits: The Pennine foothills, between Leeds, Bradford and Harrogate.
Parent Unit: Hebden Formation (HEBD)
Previous Name(s): none recorded or not applicable
Alternative Name(s): Caley Grags Grit
Stratotypes:
Partial Type Section  Stockeld Farm Borehole SE34NE/6, near Wetherby, North Yorkshire; between 102.1 m and 108.8 m depth. Cooper and Burgess, 1993. 
Partial Type Section  Section in Scarah Quarry, near Ripley, North Yorkshire showing uppermost 15m of unit; top not seen. Cooper and Burgess, 1993. 
Reference(s):
Edwards, W Mitchell, GH and Whitfield, TH. 1950. Geology of the district north and east of Leeds. Memoir of the British Geological Survey, sheet 70 (England and Wales). 
Cooper, A H and Burgess, I C. 1993. Geology of the country around Harrogate. Memoir for 1:50000 geological sheet 62 (England and Wales). London: HMSO for the British Geological Survey. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E069 E070 E062