The oldest wind-blown sand
Dunes drift across a barren Archean shore, leaving the first record of weather on land.
- When
- Known to
- ± 10 million years
- Era
- Paleoarchean, Archean
Eolian deposits in the Moodies Group are the oldest known sandstones laid down by wind rather than water. With no plants to bind it, sand moved freely, and these beds capture an entirely lifeless land surface being shaped by the atmosphere. They also imply extensive dry land beside the tidal flats.