The BGS Lexicon of Named Rock Units — Result Details

Cadnant Shales Formation [Obsolete: use NOG]

Computer Code: CDN Preferred Map Code: CaS
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: [Obsolete: use NOG] Black mudstone and silty mudstone.
Definition of Lower Boundary: Overlies tuffs of Snowdon Volcanic Group.
Definition of Upper Boundary: Base of overlying Conwy Mudstone Formation and equivalent units of Ashgill age.
Thickness: 450m
Geographical Limits: Northern and central Snowdonia.
Parent Unit: none recorded or not applicable
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Railway cutting, Conwy. 
Reference(s):
Howells M F, Reedman A J and Leveridge B E. 1985. Geology of the country around Bangor: Explanation for 1:50 000 geological sheet 106 (England and Wales). British Geological Survey Sheet Explanation. [London: HMSO.] 34pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E119 E094