This is the second of these occasional pieces and tracks the epochs which mark the succession of the Ordovician and the Silurian. Great difficulty here since there are a lot of Welsh names beginning ‘Ll’ the reason being that those two great geologists Murchison and Sedgewick established the succession of the Lower Palaeozoic while working in Wales – Murchison naming the Silurian after a local people and Sedgewick the Cambrian after the old name for Wales. As the one worked upwards and the other downwards they were destined to meet, geologically speaking, which indeed they did and which resulted in a great row since each wanted a great hunk of the strata for his own system. Lapworth solved the problem after many years with a compromise by which the disputed beds were named the Ordovician after another Welsh tribe.

N.B. There is a dispute as to whether the Ordovician should start with the Arenig and another that says the top of the Silurian should be the Downtonian which is the next bed up and in the Devonian – I just remember them as a continuous list and let the boffins argue the toss!

Free wine and cheese for anything better as before.