Matachewan dike swarm located on terrain feature Canadian Shield
The Matachewan dike swarm is a large 2,500 to 2,450 million year old Paleoproterozoic dike swarm of Northern Ontario, Canada.  It consists of basaltic dikes that were intruded in greenschist, granite-greenstone, and metamorphosed sedimentary terrains of the Superior Craton of the Canadian Shield.  With an area of 360,000 square kilometres (140,000 sq mi), the Matachewan dike swarm stands as a large igneous province.