Avalonia

Geology is fate, as a very good geological writer once put it.

Explain to me about Laurentia, I don't even know if I've got the pronunciation correct, and Avalonia.

OK, you've gone hard on the technical geology questions.

I

And it is also an act of splitting apart in the sense that there are rocks in northwest Scotland which have more in common with rocks in North America than they do with the rest of Scotland and England.

when the Atlantic split and North America headed that way and Britain this way.

But the Avalonia and Laurentia thing essentially is a kind of sideswipe collision between these plates that created an enormous range of mountains called the Caledonides, which is named, you know, for Caledonia, most of which have now gone.

which have been eroded away.