How did land first form on Earth?
1 Answer
Rock recycling
Explanation:
A bit different to your personal recycling but not so different at the same time!
Rocks on earth are created at divergent plate margins (one example), but if we keep doing this we need to take the rock from somewhere in order to melt it. We can't just keep melting rock if there is no rock to melt. So some rocks are subducted back into the mantle. These subducted rock can then melt again and subduct and melt and subduct and melt and so on. This process is recycling the rocks on earth and was essential when our continental crust formed quite a few billion years ago.
Another factor is the refinement of melts that are created from melting rock. When the melt is created sometimes that melt crystallised and then the melt is extracted, the remaining melt can keep crystallising and this refinement of melt also lead to our continental crust today.
