How were the atlas mountains formed?

The Atlas Mountains were formed during three different stages. The first phase was formed during the Paleozoic Era when Africa and North America collided. The second phase was formed during the Mesozoic Era when the earth's crust rifted and separated the continents. Finally, in the Paleogene and Neogene Periods, the mountains were uplifted as the land masses of Europe and Africa collided at the southern end of the Iberian peninsula.