A geological event, such as a glacier or sink hole, can create a pond. Ponds are nothing more than shallow holes where water collects. Yet, if left alone, ponds will fill in with dirt and debris until they become land.
It often takes hundreds of years for a pond to be transformed from a body of clear water into soil.
The Four Stages of Pond Succession
2) As more creatures arrive the
debris on the bottom increases. Pondweed, and other submergent vegetation,
appears and soon grow all along the bottom.
4) After some time, the pond floor is close enough to the bottom that emergents can grow all the way across the floor. When this happens, the ponds becomes a marsh. Many interesting creatures can reside in the shallow muddy waters of marshes. (Marshes can be created in other ways also.)
The marsh continues to fill in with dirt and debris. Eventually trees grow in the water. It is now a swamp. Over time, the swamp may dry out. Land that was once a pond, may become a forest or grassland.