Indiana has Geology Too

Ok, it's no Colorado or Arizona There are no mountains or giant canyons. But Indiana does have a lot of landscape features that even many Hoosiers are not aware of. These include cliffs, tree-covered hills, giant sand dunes, and tons of glacial features.

First of all, let me point out that the landscape of the northern two-thirds of Indiana is a legacy of the Ice Age. Vast ice sheets covered much of Indiana from about 70,000 years ago until about 10,000 years ago. Actually, there were three other periods of glaciation prior to that, dating back about two million years.

Some of the most striking features of the ice sheets are the Great Lakes. The basins were dug out by the ice, and then filled with water when the ice melted. A great place to see one of the five Great Lakes is from Indiana Dunes National Lakeshore. Lake Michigan has formed giant sand dunes on its southern and eastern flanks. The sand has piled to an impressive 123 feet at Mount Baldy near Michigan City. Indiana Dunes State Park also offers some imposing dunes to climb or just photograph. It also has a fantastic beach that you can drive right up to.

While on your way to Lake Michigan, traveling up Interstate-65, you might take note of the large flat expanse of land near the Kankakee River. This in an outwash plain that was formed as ice melted from the glacier as it retreated northward about 11,000 years ago. And just before you get to Lake County, the land starts to rise with a gradual slope. This is the Valparaiso Moraine. A moraine is a large ridge of debris that was left behind at the edge of the ice sheet. Glaciers carry all kinds of debris, scratched loose from the bedrock of places in Canada and the northern U.S. on their way southward during their initial advance.

Sometimes, water flowing off the side of a glacier deposits mounds of sediment in small mounds. These hills are called kames, and these hills dot the central part of the state.

Northern and central Indiana are covered with glacial till, a thick layer of sediment deposited by the ice. Southern Indiana, however, has bedrock close to the surface. One of the few remnants of the Ice Age in southern Indiana is the drainage pattern. The Ohio River, for example, was not always where it is today. It was created by the glaciers.

The Ohio River eroded deep into the bedrock and left small creeks, such as Clifty Creek, high above, resulting in deep valleys and water falls. These can be explored at Clifty Creek State Park near Madison.

Another feature of southern Indiana, not related to the glaciers, is the karst topography. And by that, I mean caves, sink holes, and Indiana’s Lost River. Caves are carved into limestone by slightly acidic groundwater. At Spring Mill State Park, you can take a boat tour through one of the caves. Through Orange County flows the Lost River. Now you see it; now you don’t. It flows part of its way above ground, then disappears into the porous limestone, only to reappear several miles downstream from underneath a road bed.

Indiana really does have some nice geological features for those who are into geology. And if you’re not, they still make nice places to hike and take photos. And wandering Indiana is much cheaper than traveling cross-country.