| 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
|
