The oldest period to be represented in the rocks of Fforest Fawr Geopark; it lasted from 488 to 443 million years ago.
The Ordovician Period
This period extended over 45 million years. It is divided into three series/epochs, which are further subdivided into various stages/ages.
- Late/upper Ordovician epoch (461Ma – 443Ma)
- Ashgillian stage (448Ma – 443Ma)
- Caradocian stage (461Ma – 448Ma)
- Middle Ordovician (Llanvirnian) epoch (472Ma – 461Ma)
- Llandeilian stage (463Ma – 461Ma)
- Abereiddian/Llanvirnian stage (472Ma – 463Ma)
- Early/lower Ordovician epoch (488Ma – 472Ma)
- Arenigian stage (478Ma – 472Ma)
- Tremadocian stage (488Ma – 478Ma)
Ma = million years (ago)