Photos by Tim Vick, Susan Schnur '07 and Clara Tsang '08
We headed off east across the plains into Wisconsin on Saturday morning, and stopped for lunch at the "Geological Marker" purported to be at 90 W 45 N. It was a fun place to stop, but when Cam put his GPS on the benchmark it turned out to be several hundred feet away from the GPS location of 90W45N. Even when he rechecked his datum and made sure it was the correct one. The benchmark was emplaced by the county.
The first stop where we saw actual rocks was in a sandstone quarry near Mosinee, where we saw wonderful trace fossils of jellyfish which had been stranded on a beach. This one didn't photograph as well as it looked on the ground, but it was over a foot wide.
There were also great ripple marks.
Here Callen shows off some ripple marks.
Next stop was near Wisconsin Rapids for a mapping exercise in the bed of
the Wisconsin River below a dam. Don used a Brunton compass to figure out
the orientation of a dike.
Qing helped people get started taking data.
Sunday we started off at the famous Van Hise Rock, northwest of Baraboo. This picture shows
clearly the different layers of quartzite (on the right) and phyllite (on the left), which
have been tipped up into vertical orientation.
And Qing led the discussion about how you can use the fabric in
the phyllite to tell which part of the fold you are in.
Clint found a piece of dickite (a clay mineral) at the contact of the
quartzite and the Mt. Simon Sandstone near Van Hise Rock.
Across the road from Van Hise Rock there's a quarry with vertical bedding.
Here Sarah checks out the ripple marks on the bedding plane.
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