Orogenic (mountain-building) belts formed in the Ordovician wherever plates converged—at subduction zones and at collisions between continents and terranes, such as microplates (smaller fragments of continental plates), oceanic arcs (chains of volcanic islands), and oceanic plateaus.

How were the Caledonian mountains formed?

Caledonian orogenic belt, range of mountains situated in northwestern Europe, developed as a result of the opening, closure, and destruction of the Iapetus Ocean in the period from the start of the Cambrian (542 million years ago) to the end of the Silurian (about 416 million years ago).

What plates formed the Caledonian mountains?

It was caused by the closure of the Iapetus Ocean when the continents and terranes of Laurentia, Baltica and Avalonia collided. The Caledonian orogeny is named for Caledonia, the Latin name for Scotland.