Here goes!
“Hanes Cymru / History of Wales” by Daf
Prologue 1.1/3 – Geological time!
The land that is now Wales hasn’t always been there. 600 million years ago (MYA), we were close to the South Pole, and a short(ish) swim from Peru! Que raro!
Over the next 100 million years (MY), we stuck around the Antarctic Circle as part of an island called Avalonia, which included Wales, England, the Low Countries, North Germany and Poland in the east,
@DafSmith_v4 This makes me curious about the Bluestone. I have a piece that I'm always wearing. I've always wondered why it's only found in Wales. Did it form before Wales moved?
@weirdfizz Great question! I hadn't thought of this.
Bluestone refers to Preseli Bluestone from the Preseli Hills in Pembrokeshire (Sir Benfro).
If your bluestone is from there, it means it formed in the time when Avalonia collided with Baltica and Cymru has volcanoes, so c.450 million years ago!
@DafSmith_v4 I didn't know that's the area the Bluestone comes from, but I do know some of my ancestors came from Pembrokeshire. I guess I may be carrying a piece of their home.
@weirdfizz Also, the really cool thing about Bluestone, is that the famous stones at Stonehenge (very near where I was born in South England) are made of Preseli Bluestone.
Special
@DafSmith_v4 That I knew! But I'm still wondering how they got moved there. And why. I'm a little unwilling to believe Merlin did it with magic when there's probably an even better story with more ancient engineering!
@weirdfizz At school, we are taught they did it by rolling the stones on tree trunks.
Of course, between 450MYA and 3000-2000BCE, there were many ice ages, and glaciers could have moved the stones a long way closer to Wiltshire than where the stones started in Wales.
Glacial movement or all by human hand, another unknown!
https://www.nationalgeographic.com/history/article/111222-stonehenge-bluestones-wales-match-glacier-ixer-ancient-science