Alluvium

Alluvium is like a family of rocks, sand, soil, and other things that have been moved by water. You know how when you play in the mud or sand at the beach, and the water makes it all squishy and moves it around? That's what happens to alluvium too!

Sometimes when it rains really hard, you can see water rushing down the street or in a river. That water can pick up all sorts of things and carry them away. It can take rocks, dirt, or sand and move them around. And when the water finally stops moving, all the stuff it was carrying gets left behind in a new place. That stuff is called alluvium!

So when you see a riverbank or the shore of a lake, you might see different layers of rocks and dirt. Those are all made of alluvium that was brought there by the water. Sometimes people even find gold, diamonds, and other treasures in alluvium because they got picked up by the water and ended up in a new spot!