Petrogenesis of the Mesoproterozoic (1.23 Ga) Sudbury dyke swarm and its questionable relationship to plate separation

The Mesoproterozoic (~1.23 Ga) Sudbury dyke swarm was emplaced at equatorial latitudes and cross-cuts the Grenville, Southern and Superior Provinces of the Canadian Shield. The dyke swarm has been linked to the break-up of the Mesoproterozoic supercontinent Columbia (1.8 to 1.3 Ga). The Sudbury dykes are alkaline olivine diabases that extend ~300 km to the W and NW from the Grenville Front. Major element trends and MELTS modeling indicate...