Field Trip: Driftless Area of Wisconsin
For this year’s geology trip, students traveled to the southwestern part of the state of Wisconsin for 7 days directly after graduation. The southwestern part of the state is known as the Driftless Area for its lack of glacial drift (sediments deposited by glaciers). While glaciers covered much of Wisconsin during the most recent glacial period, the Driftless Area was never covered by ice and is therefore remarkably different from the rest of the state. The focus of the trip was on the bedrock geology, environmental geology, and natural history of the region and students gained a new appreciation for their home state!
The Leopold Center
On day 1 of the trip, the group drove down to visit the Leopold Center, the site where Aldo Leopold’s land ethic was first developed. The photo above shows the famous Leopold shack, where Leopold and his family spent time practicing conservation of their land.
The next day, Duke Welter (Trout Unlimited) took us to streams in various stages of restoration. Duke talked about the geology behind the streams and the poor land management in the early 1900’s that led to their unfavorable condition. It was an excellent tie-in to yesterday’s lesson on land ethic! Throughout the morning, Duke showed us how these streams are gradually being restored to conditions that are much healthier for different species in the area.
Driftless Area Geology
Later in the day, we stopped at a particularly enticing road cut. Students learned how to do an outcrop description and practiced interpreting depositional environment. We recognized indicators for a shallow marine environment, including some pretty cool stromatolites!
The following day, Eric Carson (Wisconsin Geological Survey), took us to several locations around southwestern Wisconsin, illustrating relatively recent processes and sediments that have dominated the appearance of the landscape.
Our lunch spot gave us a spectacular view of the confluence between the Wisconsin and Mississippi Rivers. Eric pointed out a terrace from when the level of the Wisconsin River was higher. He also discussed some of the latest ideas about the evolution of the Wisconsin River over the past few thousand years.
The next day we traveled to Parfrey’s Glen, a narrow canyon with outcrops of Cambrian sandstone and conglomerate.
Students took their time hiking through the canyon, making observations and taking notes in their field books along the way. At the end of the canyon, we discussed how these deposits could have formed. Our observations matched the current interpretation, which is that these are storm deposits from a shallow sea that covered Wisconsin over 400 million years ago!
Cave of the Mounds
A trip to the Driftless Area just wouldn’t be complete without a tour of the Cave of the Mounds! Here is the entire group (students and faculty) inside the cave. We learned how and when the cave formed, and how the various formations in the cave are deposited.
After the cave tour, students practiced their hand at panning for fossils!
Some of the fossils they found include brachiopods, gastropods, shark teeth, and petrified wood!
Governor Dodge State Park
After the cave, a stop at Governor Dodge State Park proved worthwhile for students to get a look at a huge outcrop of eolian sandstone! This large thickness of sand was deposited as part of a large dune field during the Cambrian.
At Governor Dodge State Park, students examine some fabulous dune cross-beds up-close!
Kickapoo Valley Reserve
Next, we were off to the Kickapoo Valley Reserve to learn about the La Farge Dam – a dam that was designed in the effort of flood control but was never completed. Here you see the complete intake tower, which ultimately never saw the flow of water.
The Kickapoo Valley Reserve also has some interesting outcrops. Here are the students at the base of an interesting sandstone.
Roche-a-Cri State Park
On the final stop of the trip, we climbed a high lookout tour at Roche-a-Cri State Park to gaze upon the flat landscape which was covered by Glacial Lake Wisconsin during the last glacial period.
Students learned a lot about Wisconsin on this trip and enjoyed practicing some of the techniques and concepts from the classroom in a field setting. Practice in the field makes for better geologists!