What is deposition?

Deposition is when something moves from one place to another and leaves behind a trace, like a clue it left on its way out.

Imagine you have a cookie jar full of your favorite chocolate chip cookies. One day, you take one cookie and eat it. The cookie is gone, but there's still a little crumb left on the table where you sat. That crumb is like a deposition, it’s what was left behind when something moved.

Think of deposition like a detective leaving a clue at the scene of a crime. The detective (like the cookie) goes somewhere else, but leaves behind a little bit of themselves (like the crumb). Scientists use this idea to figure out what happened in places they can't see, like deep under the ocean or inside a rock.

When snow melts and turns into water, it flows down a hill and carries tiny bits of soil with it. When the water reaches a lake, those bits of soil settle at the bottom. That’s deposition in action, the water carried something from one place to another, and left it behind like a little gift.