Topic summary
Grunehogna Craton
Extracted from the Wikipedia article Vaalbara.
Existence and lifespan
The Archaean–Palaeoproterozoic Grunehogna Craton in Queen Maud Land, East Antarctica, formed the eastern part of the Kalahari Craton for at least a billion years. Grunehogna collided with the rest of East Antarctica during the Mesoproterozoic assembly of the supercontinent Rodinia and the Grenville orogeny. The Neoproterozoic Pan-African orogeny and the assembly of Gondwana/Pannotia produced large shear zones between Grunehogna and Kalahari. During the Jurassic break-up of Gondwana, these shear zones finally separated Grunehogna and the rest of Antarctica from Africa. In the Annandags Peaks in Antarctica, the only exposed parts of Grunehogna, detritalzircons from several crustal sources have been dated to 3.9–3.0 Ga suggesting intracrustal recycling was an important part in the formation of the first cratons.