Rock Elm disturbance

Just FYI, I discovered that clicking the photos in the blog bring up full sized images. 

 Not gonna be a dazzling group of photos in this post, just continuing my travelogue  from the Pepin trip. I took a circuitous route home from Pepin and ended up driving through Rock Elm, Wisconsin on the way back home. The surface of the hills and bluffs around Rock Elm look similar to the bluffs along the Mississippi, but if you dig just a bit deeper you'll start to uncover some major differences. One of those is the presence of a rock type known as Reidite which is a rare zircon based mineral formed only under great heat and pressure. Another difference is that the local quartzite rocks contain multiple shock fractures inside the rock. 

Rock Elm Wisconsin is in fact, the site of a major meteor impact that happened far in Earth's past. The crater from the impact is roughly 4 miles in diameter and has (mostly)  been filled in with glacial crushed rocks and  topsoil. But , if you know where to look you sometimes find hints...

In any event, the meteor is estimated to have been almost 600 ft in diameter and traveling at 67,000 miles per hour when it struck. For more detail, there are numerous sites on the web that discuss the disturbance. The hills in the background of this farm are part of the wall structure that was blasted out around the  crater area. 

There's no defined blast crater area left in the center, just an uplifted area typical of impact craters, where the existing sandstone bounced back upwards after the impact.A small sample of the sandstone is shown below.If you look inside the hole on the bottom right, you'll see a shed snake skin laying inside...just another reminder to be careful where you put your hands when you're hiking in this part of the country.