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Home » Articles » Geology - the Ordovician PeriodGeology - the Ordovician Period
Rocks and fossils dating from the Ordovician Period.
Rocks and fossils dating from the Ordovician Period.
The Ordovician Period lasted from 490-443 million years ago and was named after an ancient Celtic tribe, the Ordovices. Most of the Ordovician rocks preserved today in Wales originated from sediments laid down under the Iapetus Ocean. Some of these sediments have been metamorphosed into the slates which are quarried in north Wales. The ocean was teeming with many new forms of life. This period saw the first corals, the first fish, and the rise of the nautiloids to become the biggest predators in the sea. The early part of the Ordovician was a time when there was much volcanism nearby, and many ancient lava flows and ash deposits are preserved as evidence of this.
