A name often seen in paleology. From Brewer:
Silurian Rocks A name given by Sir R. Murchison to what miners call gray-wacke, and Werner termed
transition rocks. Sir Roderick called them Silurian because it was in the region of the ancient Silures that
he investigated them.

Silures, people of ancient Britain inhabiting what today is southeastern Wales. A powerful and warlike tribe, they offered fierce resistance to the Roman force that invaded their territory in AD 48 but were finally conquered in 78, after the Romans established a legionary fortress at Isca, modern Caerleon. The chief town of the Silures was Romanized as Venta Silurum, the modern Caerwent, near the Severn estuary east of Newport.



"Silures," Microsoft(R) Encarta(R) 98 Encyclopedia. (c) 1993-1997 Microsoft Corporation. All rights reserved.

Now I've got to find out who in hell the "Silures" were and from where.Back in a flash.