---

Protolithic shields once close together

Near each other until the Mesozoic break-up

Younger continental assemblage

Three of a kind now far apart

Up to the Siderian era range

When Ur joins Nena and Atlantica

On early Earth's archaic tectonics

Three worlds collide

The Zimgarn hypothesis surfaces

Extensive carbonate platforms develop

Differing magmatic signatures

Primordial magnetism affected

Expanding continuing stabilisation

Intracontinental within the southern margin

Ur, the longest lived landmass

Yet it remains hopelessly obscure