Central Atlantic magmatic province

The Central Atlantic magmatic province (CAMP) is the Earth's largest continental large igneous province (LIP), covering an area of roughly 11 million km2 (4.2 million sq mi). It is composed mainly of basalt that formed before Pangea broke up in the Mesozoic Era, near the end of the Triassic and the beginning of the Jurassic periods.

Source: Wikipedia — Central Atlantic magmatic province (CC BY-SA 4.0)