The BGS Lexicon of Named Rock Units — Result Details

Abbey Shale Formation

Computer Code: ASH Preferred Map Code: ASh
Status Code: Full
Age range: St David's Series (ED) — St David's Series (ED)
Lithological Description: Dark grey, greenish or blueish black mudstones with thin beds of limestone and glauconitic sandstone. Locally with phosphate, pyrite and siderite nodules.
Definition of Lower Boundary: Not penetrated in the borehole. Base gradational with Purley Shale Formation in partial type section.
Definition of Upper Boundary: A stratigraphical discontinuity. Upper dark phosphatic mudstone bed is sharply overlain by basal pebble conglomerate of Mancetter Formation.
Thickness: 10-40 m. 109 feet (33.2m) minimum in reference section.
Geographical Limits: North-west suburbs of Nuneaton, extending north-westwards to the southern suburbs of Atherstone (SP3530 9180 - SP3063 9712).
Parent Unit: Stockingford Shale Group (SSH)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Exposure in Purley Park Lane, now much overgrown. Measured by Illing, V C, (1916). 
Reference Section  Merevale No 3 Borehole, 709' 3" to 819' 0". (Base not penetrated). (SP39NW/7). 
Reference(s):
Baldock, J W, 1991. Geology of the Hartshill and Stockingford districts, Nuneaton. British Geological Survey Technical Report, WA/91/60. 
Illing, V C, 1913. Recent discoveries in the Stockingford Shales near Nuneaton. Geological Magazine, Vol.10/5, p.452-453. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E155