The first continental crust
Buoyant rock begins to float above the ocean, the first hint of land.
- When
- Known to
- ± 100 million years
- Era
- Hadean
Chemical signatures in Hadean zircons indicate granite-like continental crust was being produced well before four billion years ago, though almost none of it survives — plate tectonics and bombardment recycled it. Whether it formed permanent landmasses or transient rafts on a mostly molten surface is unresolved. What is clear is that the process that eventually built the continents had already started.