Matt's opinion

Monday, October 20, 2014

Visit to Bluff Springs

I feel compelled by the beautiful fall season to discuss another field location. This visit is more of a low key scouting adventure for potential field trips at the Bluff Spring Fen in Elgin, IL. I must warn you, This park is a bit of a chore to locate. The entrance is hidden within the back of the Bluff City Cemetary off of US Route 20. I'll be the first to admit that this park is well worth the trip. 

What makes this place special is that it is a Fen, which is where artesian springs discharge from shallow bedrock (in this case dolomite). In northern Illinois Fens are not very common due to the thick glacial sediment deposits left behind from the last ice age. Local Fens have evolved into very special places based on the presence of nearly year round running water supply, the unique chemistry of that water, the soils developed as the bedrock surface weathers and the flora/fauna that call the Fen home. 

I found myself drawn to find local Fens to satisfy my search for places where bedrock is present at or near the surface. Too often, the search for great rock outcrops (exposure of rock at the surface) leads geologists west of the Mississippi River where arid climates limit the growth of vegetation. I'll grant that this Fen doesn't match the spectacular vistas or specimen collecting possibilities of those out west, but it demonstrates the interconnection between rock and life. One quick example of this interconnection is the Hines Emerald Dragonfly. This dragonfly is an endangered species that only lives in fens like Bluff Springs due to the specific blend of flora that live in the unique geochemical environment. You can read more about the Hines Emerald Dragonfly here:

What got me hooked in Bluff Springs is the added presence of kames. Kames are a specific feature left over after glacial ice melts away. As glaciers are melting, some of the the sediment they carry is washed into crevasses, cracks in the ice, and deposited in the empty space there. After the ice has completely melted the sediment (ice contact unstratified drift/diamicton) remains in the shape of a hill or mound. There are at least two kames in the park. One of them is rather small (about 15-20 ft high and ~50 ft diameter) and one is much larger (about 50 ft high and a couple hundred feet diameter). The large kame has a lookout at the top with a beautiful view of the fen. I've posted some pictures of the park here:

Hope you are able to find this park and enjoy all that it has to offer. The parks website is here:


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