| Computer Code: |
CRTU |
Preferred Map Code: |
CRT |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
Rhyolitic ash-flow tuffs. |
| Definition of Lower Boundary: |
Overlies Foel Ddu Rhyodacite. |
| Definition of Upper Boundary: |
Underlies and is partly interleaved with the Yoke House Formation and (locally) Nod Glas Formation. |
| Thickness: |
370-590m |
| Geographical Limits: |
Pwllheli area, northwest Wales. |
| Parent Unit: |
Llanbedrog Volcanic Group (LIG)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Lower part of formation, Nant y Gledryd. |
| Partial Type Section |
Upper part of Formation, Bodgadle Member. Southwest of Mochras Uchaf. |
| 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
|
