H2O(l)-> H2(l)+O(g)
as the trees transpire releasing gaseous water. Water would decomposed to release O.
Answer:
4600-4500 million years ago, the Earth formed and its crust cooled to become solid. 4500-4400 million years ago, the oldest known thing to have formed on Earth, zircon, formed along with solid crust and oceans. 4200-4100 million years ago, the close of the Hadean Period (there are no surviving rocks).