Tectonic constraints on 1.3~1.2 Ga final breakup of Columbia supercontinent from a giant radiating dyke swarm

The 1.3- 1.2 Ga fan- shaped Mackenzie dyke swarm and other similar- aged dyke swarms in the Canadian Shield constitute the subswarms of a Late Mesoproterozoic giant radiating swarm. The Late Mesoproterozoic mafic dyke swarms in Australia and East Antarctica might constitute additional subswarms of the giant radiating dyke swarm. A possible Late Mesoproterozoic mantle plume is placed at the focal area of the giant radiating dyke swarm between North America and the landmass (West Australia- East Antarctica). This mantle plume triggered the continuous extension at ca. 1.3-1.2 Ga, which extended into much of Columbia and led to the final fragmentation of the Columbia supercontinent. Crown