Configuration of Columbia, a Mesoproterozoic Supercontinent

A supercontinent, here named Columbia, may have contained nearly all of the earthʹs continental blocks at some time between 1.9 Ga and 1.5 Ga. At that time, eastern India, Australia, and attached parts of Antarctica were apparently sutured to western North America, and the eastern margin of North America, southern margin of Baltica/North China, and western margin of the Amazon shield formed a continuous zone of continental outbuilding. Fragmentation began at ∼1.6 Ga, when rifting occurred in North China. Rifting continued until about 1.4 Ga in most of Columbia, and a similar age of rifting north of the Zimbabwe craton of southern Africa suggests that an entire continental block stretching from Australia to South Africa separated from Columbia at this time. Further separation of North America from South America/Africa and rotation of the different blocks ultimately resulted in their reattachment during the Grenville orogeny to form the supercontinent Rodinia.