Editing Ordovician (section)

=== British stages and ages ===
The Ordovician Period in Britain was traditionally broken into Early (Tremadocian and [[Arenig]]), Middle ([[Llanvirn Series|Llanvirn]] (subdivided into Abereiddian and Llandeilian) and [[Llandeilo Group|Llandeilo]]) and Late ([[Caradoc Series|Caradoc]] and Ashgill) epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column.

The Tremadoc corresponds to the ICS's Tremadocian. The Arenig corresponds to the Floian, all of the Dapingian and the early Darriwilian. The Llanvirn corresponds to the late Darriwilian. The Caradoc covers the Sandbian and the first half of the Katian. The Ashgill represents the second half of the Katian, plus the [[Hirnantian]].

==== Ashgill ====
The Ashgill Epoch, the last epoch of the British Ordovician, is made of four ages: the Hirnantian Age, the Rawtheyan Age, the '''Cautleyan''' Age, and the Pusgillian Age. These ages make up the time period from c. 450 Ma to c. 443 Ma.

The Rawtheyan, the second last of the Ashgill ages, was from c. 449 Ma to c. 445 Ma. It is in the Katian Age of the ICS's [[Geologic Time Scale]].