Computer Code: |
DYL |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Holkerian Substage (CQ)
— Asbian Substage (CR) |
Lithological Description: |
[Obsolete: use CLWYD]
Predominantly limestones with bands of carbonaceous mudstone. Lowest beds contain cherts and dolomites and dolomitic limestone. |
Definition of Lower Boundary: |
Drawn at the base of the Dyserth Group where cyclic brown limestone conformably rests upon arenaceous limestone of the Basement Beds. |
Definition of Upper Boundary: |
Drawn at the conformable upward passage of brown grey and white limestones of the Dyserth Group unconformably overlain by darker fine-grained limestones of the Teila Formation. |
Thickness: |
500 metres approx. |
Geographical Limits: |
Confined to the north Wales coastal area of Great Orme, Little Orme, Llanddulas and Prestatyn. |
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 Area |
Great Orme. |
Reference(s): |
Warren, P T, Price, D, Nutt, M J C and Smith, E G. 1984. Geology of the country around Rhyl and Denbigh. Memoir for 1:50 000 geological sheets 95 and 107 and parts of sheets 94 and 106. |
Neaverson, E. 1930. The Carboniferous rocks around Prestatyn, Dyserth, and Newmarket (Flintshire). Proceedings of the Geological Society of Liverpool, Vol.15, 179-212. |
George, T N, Johnson, G A L, Mitchell, M, Prentice, J E, Ramsbottam, W H C, Sevastopulo, G D and Wilson, R B. 1976. A correlation of the Dinantian rocks of the British Isles. Special Report of the Geological Society of London, No 7. |
Definition not published. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E094
|