Computer Code: |
MINF |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Comley Series (EC)
— Comley Series (EC) |
Lithological Description: |
Coarse- to fine-grained epiclastic rocks intercalated with pyroclastic and mixed pyroclastic and epiclastic rocks, comprising laminated siltstones, felsic air-fall tuffs and tuffites, volcanogenic sandstones and conglomerates (particularly in the lower part) and thin ash-flow tuffs. |
Definition of Lower Boundary: |
Unconformably overlies rocks of the Padarn Tuff Formation. |
Definition of Upper Boundary: |
Unconformably overlain by rocks of the Bangor Formation. |
Thickness: |
1600m |
Geographical Limits: |
Snowdonia, North Wales. |
Parent Unit: |
Arfon Group (ARN)
|
Previous Name(s): |
none recorded or not applicable
|
Alternative Name(s): |
Minfordd Formation
|
Stratotypes: |
Partial Type Section |
Track between Pant-caerhun and Tai'r-ffynnon, near Caerhun. Howells, M F, Reedman, A J and Leveridge, B E. 1985. |
Partial Type Section |
Roadcuts on Bangor By-Pass (A55) near Caerhun. Howells, M F, Reedman, A J and Leveridge, B E. 1985. |
Reference(s): |
Reedman, A J, Leveridge, B E and Evans, R B. 1984. The Arfon Group (Arvonian?) of North Wales. Proceedings of the Geologists' Association, Vol.95, 313-321. |
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. |
Rushton, A W A and Howells, M F. 1998. Stratigraphical framework for the Ordovician of Snowdonia and the Lleyn Peninsula. British Geological Survey Research Report, RR/99/08. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E106
E118
|