Supercontinent Rodinia

Rodinia was a supercontinent that came together about 1.1 billion years ago, when most of Earth's continental crust crowded into one landmass. Its core was Laurentia, the ancient heart of North America, with other continents attached around it, and the collisions that welded them raised mountain ranges called the Grenville belt. Traces of those mountains still run through eastern North America, from Canada down to the Appalachian region. The name, coined by Mark and Dianna McMenamin in 1990, comes from a Russian word meaning motherland or to beget.

Rodinia formed as plate tectonics swept continents together, and it did not last. From about 750 million years ago, hot rock rising beneath it stretched the crust and split the supercontinent into fragments. New coastlines and shallow seas appeared, and the weathering of fresh volcanic rock pulled carbon dioxide out of the air, which may have helped tip Earth toward the Snowball Earth glaciations. Exactly how Rodinia was arranged is uncertain, because rocks that old are scarce and scientists reconstruct it from magnetic signatures and matching geology. Some of its pieces later reassembled as Gondwana.