Kenorland

Kenorland is a supercontinent postulated to have existed between about 2.8 and 2.5 billion years ago. Zircons found in the core of the supercontinent (what is now the Canadian Shield) have been dated to be about 3.2 billion years old.

It is thought that the creation of land back in those days proceeded from a deep mantle plume rifting that caused relatively rapid circulation of materials from the hot core of the planet to the cool surface, and back again. The core of Kenorland came together around the junction of the Laurentia, Baltica, Western Australia and Kalaharia cratons and most of the Nena craton. Kenorland was draped across the equator, existing mostly in the low latitudes until the supercontinent began to break up.

The breakup of Kenorland is postulated to also have been the time of a changeover in the core of the Earth as deep mantle plume rifting gave way to the two-layer core-mantle plate-tectonics-convection theory we hold now. The breakup of Kenorland at around 2.5 billion years ago coincides with the onset of the Huronian Glaciation, a Snowball Earth scenario that lasted for about 300 million years, and the geological change from the Archean Eon to the Proterozoic.

The minor supercontinent Arctica was one of the major pieces left after the breakup of Kenorland. About 2.5 billion years ago Arctica was comprised of the North Atlantic, Slave, Superior and Wyoming cratons of Laurentia plus the Angara craton of Siberia.

A second minor supercontinent of the time was West Gondwana, composed of what is now South America and Africa. East Gondwana was composed of India, Antarctica, Australia and North China.

About 2.1 billion years ago the continental land masses of the planet were coming back together again to form the supercontinent Columbia.

The cratons of West Gondwana
The West Gondwana cratons about 1.8 billion years ago
Map modified to show relationship to modern continents