Saturday was my extra day in Minneapolis before the start of the GSA Annual Meeting. I had signed up for a day trip exploring the wonders of Pierce County, Wisconsin an hour's drive east of the Twin Cities.
What's in that nondescript, unsung tract of cows and corn? Quite a bit. We started with a custom tour of Crystal Cave, the state's longest show cave and the only cave I know that's owned and run by a geologist. It was also a nifty place to use my new UV flashlight.
We next visited a former iron mining district, where an iron rush based on an odd shallow occurrence of Cretaceous bog ore transformed the county in the latest 1800s. There we could gather hand samples, which I will show you when I get back.
The bulk of the afternoon was devoted to the Rock Elm Disturbance, an impact feature of Ordovician age. It has its own EarthCache, but we got a tour in depth led by Bill Cordua, who documented and named this feature starting almost 30 years ago, when impacts were unfashionable.
One of his lessons was that no matter where you live, it has mysteries awaiting discovery.