Landforms: Where Did They Come From, What Was the Ice Age, and Where Can We Find It’s Remnants in Indiana?

Have you ever stood with looking up at the sky, wondering how everything got to be here? The land masses on our Earth literally keep us grounded …without them we would live on a vast and infinite ocean! But how did such large land masses form and have they always looked the way they do now? 

Scientists can’t travel back in time, so they must instead come up with theories as to why the land masses on Earth are in their current locations and how they formed. Most scientists believe that landmasses formed on Earth billions of years ago. It was a process that began with thousands of quick volcanic eruptions one after another, causing a buildup of what we call the crust of the Earth. At the same time, clouds had formed that were sending down rain to fill the Earth’s oceans. 

About 70-80% of the Earth’s crust is made up of granite, which scientists believe is made by these quick eruptions and subsequent cooling. These giant slabs of rock that formed did not stay in place, but instead shifted in relation to one another, something scientists have named Plate Tectonic Theory. 

Imagine what the globe looks like today. It appears that all the land masses and continents are in one steady location, yet they are shifting slightly each year. Plate tectonics are responsible for earthquakes and what caused the formation of a giant landmass, named Pangea, millions of years ago, as well as its separation into all the different land masses we see on a globe today. If you want to see it for yourself, check out this video that concentrates a billion years of continental movement into 40 seconds! 

Earth hasn’t always looked the way it does now. When landmasses first formed, Earth’s climate was overall warmer, creating a literal hotbed for all sorts of plant and animal species to emerge. But, because climate naturally changes over time, our Earth eventually began to cool and what we now know as the Ice Age began. This is when glaciers, or giant landmasses made of ice, covered large portions of the globe.  

But the “Ice Age” doesn’t mean the whole earth was cold the entire time. Instead, the climate flip flopped between glacial and interglacial periods of time. When glaciers were more prominent, they would move around the Northern latitudes of the Earth, creating different land masses such as valleys, giant rock formations and moraines. During the interglacial periods, on the other hand, the climate of Earth was like our climate today. In fact, some scientists hypothesize that we are still experiencing the Ice Age and that today we are simply in an interglacial period! 

The Ice Age’s last glacial period ended in Indiana a mere 15,000 years ago. As glaciers formed and moved, they shaped Indiana’s landscape in significant ways, flattening hills, burying rivers, digging out new lakes and forming piles of rock called moraines. Northeastern Indiana was particularly changed by glacial movement and formation.  

Chain O’Lakes and Pokagon State Parks are great places to see remnants of the Ice Age in land formations such as kettle hole lakes (when chunks of glaciers melted into giant puddles), kettle depressions, glacial kames, eskers, and glacial erratics. Check out this activity including maps of each state park and keys to where you can find some awesome evidence of Ice Age glaciers! 

Keep reading to learn more about our Earth’s climate and how humans are changing things up in big ways!