Let's imagine there was a really big rock that was made a long, long time ago, and it was called the Animikie Group. This rock is made up of lots of different layers, kind of like a sandwich, except instead of bread and meat, there are layers of different kinds of rock.
The Animikie Group rock is really interesting because it was formed a really, really long time ago, back when there were even dinosaurs. The rock formed in a place that used to be really wet, like a big swamp, but over millions and millions of years, the water dried up and the dirt and sand and mud that was under the water turned into rock.
Now, many years later, scientists study the Animikie Group rock to learn about what life was like a long time ago, and what the earth was like back then. It helps them learn about the past and how things have changed over time.