During the Late Triassic, Pangea began to be torn apart when a three-pronged fissure grew between Africa, South America, and North America. Rifting began as magma welled up through the weakness in the crust, creating a volcanic rift zone. Volcanic eruptions spewed ash and volcanic debris across the landscape as these severed continent-sized fragments of Pangea diverged. The gash between the spreading continents gradually grew to form a new ocean basin, the Atlantic. The rift zone known as the mid-Atlantic ridge continued to provide the raw volcanic materials for the expanding ocean basin.