Digging in the Dirt

Geology was never my favorite subject in school but I've always had an interest in the subject and maintained a healthy respect for folks who like hanging out atop active volcanoes and have the patience to delineate layers of sedimentary rock. With my interest and M., the nine-year old, in tow, I headed down to the UW Geology Museum a couple weekends ago to meet up with my friends Dogger, Mel, and Miss Regan.

Walking into the lobby, we were greeted by a rather large and familiar looking blue ball. Here's a close-up of the Sunda Trench with an X marking the spot of the supposed crash site of Flight 815.



Being a geology museum, there was a panoply of rocks. This is a chunk of red granite which is the official rock of Wisconsin.



The museum is also home to a nice bit of the Canyon Diablo meteorite.



This fragment weighs in at 320 pounds and is but a small portion of the 150 foot meteorite which crashed into the Earth 20,000-40,000 years ago in what is now northern Arizona leaving a crater about 4,000 feet in diameter. That's what tons and tons of iron will do when it hits something traveling very quickly.

In addition to rocks, there were plenty of fossils, including dinosaurs.





Directly above is Edmontosaurus annectens, a duck-billed dinosaur whose remains were found in the Hell Creek Formation in South Dakota. (What is with all these references to Hell and the Devil? Hell Creek, Crater Diablo…?) The beast roamed the Earth in the Late Cretaceous Period about 65 million years ago.

The museum's Prep Lab has a window through which visitors can watch as technicians carefully wipe the dust off of the precious fossils. The gentleman there that day looked familiar and I discovered that he was a friend of a former dinosaur-loving co-worker. He also proved to be very informative as there wasn't a question that he wouldn't field. Indeed, he took great joy in sharing his knowledge with us.

Now here's an eldritch looking creature that lived strange aeons ago. A spawn of Cthulhu?



This one was in the cephalopoda display case and I couldn't help but think of fellow heathen blogger P.Z. Myers when I saw it.



Miss R. and M. got a big kick out of the black light room where minerals provide a chthonic light show. Personally, I really enjoyed all the maps illuminating the Madison area.

For instance, he's a nice cut-away of the Madison area illustrating its hydrogeology:



All the grey matter is glacial deposits. That little white spot on the isthmus is the Capitol and the line beneath it is one of Madison's wells. Tunnel City and Wonewoc are layers of sandstone while the Eau Claire layer (cutoff) is shale. Further down and out of the frame is a Precambrian foundation which is, as we say, older than dirt. The rock down there is measured in Carl Sagan units – billions and billions of years.

Here's a section of another map that I'd love to have hanging on my wall:



That's Dane County in the middle. The bluish green area shows just how far the ice of the last Ice Age extended. I believe the sheet in question here is called The Green Bay Lobe. It carried rocks from the size of pebbles to large boulders along with it. As the ice advanced, the detritus frozen within carved the land. Sometimes it produced elongated hills or drumlins, one of which has the Capitol sitting atop it.

It is quite awe-inspiring when you think about how old the ground beneath your feet is and how geological forces worked for ages and ages to produce the landscape that surrounds you. And while it is certainly chilly outside now, at least there's not a huge sheet of ice covering most of our state slowly churning away and turning your neighborhood into a drumlin.