Columbia assembles
Nearly all the continents gather again, in the best-documented supercontinent yet.
- When
- Known to
- ± 100 million years
- Era
- Paleoproterozoic, Proterozoic
Between roughly 2.0 and 1.8 billion years ago, a global episode of mountain building — the Trans-Hudson orogeny in North America and its counterparts elsewhere — welds the cratons into the supercontinent Columbia, also called Nuna. It is the first supercontinent whose configuration can be reconstructed with reasonable confidence from palaeomagnetism and matching orogenic belts. Much of the Canadian Shield dates from this assembly.