The seas flood the continents
A worldwide rise in sea level buries the continents in shallow water and lays the Great Unconformity.
- When
- Known to
- ± 15 million years
- Era
- Cambrian, Paleozoic
The Sauk transgression floods continental interiors, depositing sheets of clean quartz sand directly onto ancient crystalline basement across North America and elsewhere. The surface between them — the Great Unconformity — represents hundreds of millions of years of missing rock, and its erosion may have flushed enough nutrients into the sea to help fuel the Cambrian radiation itself.