Caledonian orogeny Caledonian orogeny The Caledonian orogeny was a mountain-building era recorded in the northern parts of Ireland and Britain, the Scandinavian Mountains, Svalbard, eastern Greenland and parts of north-central Europe. The Caledonian orogeny encompasses events that occurred from the Ordovician to Early Devonian, roughly 490–390 million years ago (Ma). 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. The name was first used in 1885 by Austrian geologist Eduard Suess for an episode of mountain building in
East African Orogeny East African Orogeny The East African Orogeny (EAO) is the main stage in the Neoproterozoic assembly of East and West Gondwana (Australia–India–Antarctica and Africa–South America) along the Mozambique Belt. The notion that Gondwana was assembled during the Late Precambrian from two older fragments along the Pan-African Mozambique Belt was first proposed in the early 1980s. A decade later this continental collision was named the East African Orogeny, but it was also realised that this was not the simple bringing together of two halves. Rather, it was the piecemeal assembly of several much smaller cratonic elements that once formed an earlier