Tectonic Events along East Coast of what is now North America
| Event | When | Details |
| Grenvillian Orogeny | 1.1 billion years ago | Magmatic arc Collision of Laurentia with Amazonia Supercontinent of Rodinia created High plateau like Tibet created Area affected extends to Mexico As bedrock eroded, plateau rose gradually due to isostasy In Adirondacks and Hudson Highlands, Grenville rocks at surface Grenville rocks below surface in much of eastern North America |
| Formation of Iapetus Ocean | 560 million years ago | Rifting |
| Taconian Orogeny | 450 million years ago | Subduction zone forms in Iapetus Ocean Hartland volcanic island arc forms behind subduction zone The oceanic crust between the island arc and Laurentia subducts until the island arc collides with Laurentia |
| Acadian Orogeny | 380 million years ago | Avalonia splits from Gondwana and becomes attached to Baltica Baltica included the land areas now bordering the Baltic Sea The collision of Baltica with Laurentia in the Silurian is the Caledonian Orogeny Caledonian Orogeny progresses south and becomes the Acadian Orogeny |
| Alleghanian Orogeny | 300 million years ago | Rheic Ocean crust between Avalonia and Gondwana is subducted The collision of Gondwana and Laurentia is along a transform margin Gondwana rotates clockwise causing more intense uplift in southern Appalachians |
| Formation of Atlantic Ocean | 200 million years ago | Rifting initiates as a series of triple junctions In each case, one extension of the three halts, while the others continue Failed rifts: Newark Basin, Hartford Basin Atlantic Ocean continues to widen |