| Computer Code: |
AFR |
Preferred Map Code: |
ARF |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
Rhyolitic ash-flow tuff. |
| Definition of Lower Boundary: |
Lies unconformably on sandstones, tuffs and siltstones of Cwm Eigiau Formation and mudstones of the Nant Ffrancon Subgroup. |
| Definition of Upper Boundary: |
Underlies siltstones, sandstones and calcareous mudstones of the Dwyfach Formation. |
| Thickness: |
150m |
| Geographical Limits: |
Pwllheli area, northwest Wales. |
| Parent Unit: |
Upper Lodge Volcanic Group (ULV)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Moel Bronmiod, near Pwllheli. |
| Reference Section |
Pen-y-gaer, near Pwllheli. |
| Reference(s): |
| Young, T P, Gibbons, W and McCarroll, D. 2002. Geology of the country around Pwllheli. Memoir of the British Geological Survey, Sheet 134 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E134
|
