| Computer Code: |
NYGD |
Preferred Map Code: |
NyG |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
Crystal-lithic tuffs with variable characteristics, locally strongly welded towards the top. |
| Definition of Lower Boundary: |
Oxidised and reddened top of the rhyodacite lavas of the Foel Ddu Rhyodacite Formtion. |
| Definition of Upper Boundary: |
Overlain by coarse crystal-lithic tuffs of the Bodgadle Member, or by volcanoclastic sediments of the Yoke House Formation. |
| Thickness: |
200m |
| Geographical Limits: |
Pwllheli area, northwest Wales. |
| Parent Unit: |
Carneddol Rhyolitic Tuff Formation (CRTU)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Nant y Gledryd. |
| 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
|
