Tectonic plates began forming approximately 4 billion years ago.
The formation of tectonic plates and continents appears to have initiated around 4 billion years ago, a timeline supported by the age of some of the oldest igneous rocks. This process continued for roughly a billion years, gradually slowing down until modern plate tectonics became established.
Essentially, the reference suggests:
- Early Earth (around 4 billion years ago): Initial formation of continents and the beginnings of tectonic plate activity.
- Subsequent Billion Years: Continual development and evolution of these early tectonic structures.
- Later Stages: A gradual deceleration of the formation process, leading to the plate tectonics we observe today.
This timeline aligns with geological evidence indicating that Earth's early crust was significantly different from what we see now. Over time, through processes like mantle convection and subduction, the crust evolved into the mosaic of plates that characterize modern plate tectonics.
