Ur (continent)

Ur was a supercontinent that formed 3,000 million years ago (3 billion) in the early Archean eon; perhaps the oldest continent on Earth, half a billion years older than Arctica, but it may have been preceded by one other supercontinent, Vaalbara, which is suggested to have formed about 3,600 to 3,100 million years ago.[1] Ur joined with the continents Nena and Atlantica about 1,000 million years ago (1 billion) to form the supercontinent Rodinia. Ur survived as a single unit until it was sundered when the supercontinent Pangaea broke apart into Laurasia and Gondwana.[2]

Formation and breakup

Rocks that made up Ur are now parts of Africa, Australia, and India.[2]

In the early period of Ur's existence, it was probably the only continent on Earth. Thus it is considered that Ur was a supercontinent, even though it was probably smaller than Australia is now. Current day New Zealand has a vague resemblance to Ur, but rotated 90 degrees out of phase, and is about 1000 km too far South. When Ur was the only continent on Earth, all other land was in the form of small granite islands and small land-masses like Kenorland that were not large enough to be continents.

Timeline

Notes

  1. ↑ Lerner & Lerner 2003
  2. ↑ 2.0 2.1 Zubritsky 1997

References

External links