Okay kiddo, imagine you are playing with your toy boats in the bathtub. You fill up the water to the top and then start splashing around. See how the water comes out of the bathtub and spills onto the floor? That's kinda like what happened a long, long time ago on Earth.
Before humans were around, there was a big flood, but not like the ones that happen today. This flood was so huge that it covered entire continents and washed away everything in its path. The water kept rising and rising until it reached the highest mountains.
This flood was so strong that it carried rocks, soil, sand, and even living things like plants and animals along with it. As the floodwaters receded, all these things were left behind in a big mess. This mess of rocks, soil, sand, and debris that was left behind by the flood is called diluvium.
Scientists study diluvium to learn more about the history of Earth and the creatures that lived here a long time ago. It helps them piece together the story of how the Earth has changed over time and how life on our planet has adapted to those changes. Cool, huh?