Litostratigrafie
Silur
| Telych | Cariy formation Vargas Peña formation (Rhuddan – Telych) |
| Aeron | Vargas Peña formation (Rhuddan – Telych) |
| Rhuddan | Vargas Peña formation (Rhuddan – Telych) Eusebio Ayala formation (Hirnant – Rhuddan) |
Ordovik
| Hirnant | Eusebio Ayala formation (Hirnant – Rhuddan) |