(This is the third in a series of field reports and tinned fish reviews, forming a component of Frida and Alex’s Fossil Summer 2026. The first of these is here.)
Today we explored a third of the area’s best parks, Fonfarek Glen County Park, which opened to the public in 1991. The park has two major points of interest, a 30′ tall waterfall that can be beautiful (today, it was a mere trickle), and a natural arch. Here are some photos from previous visits:
We’re planning on going further afield next week, so Fonfarek Glen felt like a good, nearby location to go fossil hunting in the interim. We weren’t mistaken. Like most of Northeastern Wisconsin’s geological features, the glen is formed from the Niagara Escarpment, out of dolomitic limestone from the Silurian Era. This is the same stone you’ll find in Door County, the Bruce Peninsula in Canada, and in Upstate New York. Though here, there appear to be layers of something else, something we did not recognize. Take a look:
Being annoyingly ignorant, we don’t know how to describe this portion of the formation adjacent to the waterfall’s catch basin. But we were able to discern fossils in the lighter portions, like so:
Ancient sea creatures? Yes! Looks like more brachiopods… Their traces are everywhere, and the more you look, the more you see. By the way, brachiopods are still among us—a creature so perfect they’ve changed very little in over 400 million years.
Frida had read that there was a section of exposed mudstone shale, part of the Maquoketa Formation. And indeed, a trek down the creek, past the arch, yielded this:
This is the same mudstone shale that we saw at Wequiock Falls. The photo above does not capture the true color, which is a cool slate blue/green. Evidently, these particular colors are derived from deposits of volcanic ash that drifted here from the birth of the Appalachian Mountains. Crazy. This formation yielded quite a few finds for the day:
We have yet to fully identify all of these.
The Alvar
There is a very rare ecosystem called an alvar. You’ll pretty much only find them on top of limestone rock formations in Sweden, Estonia, the UK, and around the Great Lakes. These are essentially exposed limestone bedrock with very thin soil in places. There are some exceedingly rare species that live on them. In all of North America, there are only 43 square miles of Alvar landscape! Though we’d often been to Fonfarek Glen, we had not realized that there was an Alvar that ran adjacent. So, we were happy to stumble upon it. Lucky!
So, we were not just fossil hunters today. We were also alvanauts.
Tinned Fish Review: Spiced Sardines in Olive Oil, Nuri (Portugal)
Unlike last week’s sardines, which failed to live up to the promise of having a bit of heat, Nuri’s spiced sardines were properly spicy. Not very spicy, mind you, but enough to be enjoyable. These were much larger sardines than we’ve seen before; very firm in texture with a delectable spine and good flake. They were meatier in a way that Frida didn’t enjoy as much as the more delicate sardines we’ve been eating. I, however, like meaty. The can contained a single clove, a single cucumber, a single slice of carrot, and a single chili pepper. All four discernibly contributed to the flavor profile. In all, an excellent tin of fish.