| Ductile thrusts that were active during the Ordovician-Silurian Caledonian orogeny divide the Moine into a scries of major nappes. |
| Avalonia drifted rapidly northwards, opening the Rheic ocean until it collided with Laurentia in the Silurian during the Caledonian orogeny. |
| The tectonic events began with the Penobscottian orogeny in the Cambrian Period that affected northwestern to north-central Maine. |
| The two rift sequences were subsequently juxtaposed by displacement on the Sgurr Beag thrust and interfolded during the Caledonian orogeny. |
| Several allochthons were thrust onto the Western Gneiss Complex during the Caledonian orogeny. |
| Following the Columbian orogeny, the third cycle of basin fill was dominated by sediments derived from the west and filling to the east. |
