Earth 1 Billion Years Ago: The Supercontinent Rodinia

One billion years ago most of Earth’s land was joined in the supercontinent Rodinia. North America (Laurentia) lay near its centre, with the cores of Australia, Antarctica, Siberia, Baltica and South America around it. The Grenville mountains, whose worn roots run from Texas to Labrador and Scotland, record the collisions that built it.

The land was bare rock: no plants grew on it. In the sea, life was mostly microscopic, though simple multicellular algae had appeared; the red alga Bangiomorpha, about 1.05 billion years old, is one of the oldest known.

A day lasted about 19 hours. The globe carries the continents of 540 million years ago back to this time with the PALEOMAP plate model, so the positions follow the model but the coastlines are approximate.