Glacial Erratic Rock

99 Counties | FIND Iowa
Jul 24, 2024 | 00:02:18

What evidence of glaciers can we see today?

Waldo's Rock Park in Marion, Iowa is home to a large rock that doesn't match any others around it. Instead, it matches rocks found in Minnesota. This rock is an example of a glacial erratic, moved and left behind by a glacier.


Abby Brown:

This huge boulder is called Waldo's Rock and it actually hitched a ride here with the glacier a long long time ago.

Here in Marion, Iowa in Linn County Waldo's Rock sits in a beautiful Park called--you guessed it--Waldo's Rock Park. So what makes a rock the main attraction at a park? Well, this rock is special. It's called a glacial erratic, which means it was brought here by a glacier and, when the glacier melted, it was left behind. Experts say that the material that makes up this rock is different from the rest of the native rock in this area. It's more like the rocks found in central Minnesota. So, a glacier pushed this rock all the way down from Minnesota! But it wasn't a quick journey, nope! It took thousands of years to be pushed down here. Now that's a long trip. Glacial erratics are pretty common in Iowa. When farmers pick rocks from their fields, they may actually be gathering glacial erratics. What makes this glacial erratic unique is its size. You can even see where some of it was underground and recently excavated, or dug up. So the next time you find a rock and admire its shape or skip a rock across the pond, think about how it got here. Maybe it was dropped off by a glacier.

Every county in Iowa has a rock solid story to tell. Thanks for discovering Linn County with me.