On May 4th, a few members of the BETA Team went out to a local quarry for a side mission. There were reports of Devonian age stromatolitic structures and we were given the opportunity to look into them a little further!
The goal of the day trip was to collect samples through a section of time starting from, in the Little Cedar Formation, the Eagle Center Member and then the Hinkle Member, and then, in the Coralville Formation, the Gizzard Creek Member. These layers of rocks were deposited during the early Devonian which is a little older than the rocks we collected and analyzed from Rockford, IA.
When we set out for the trip, we were very fortunate to go out on a day when the weather was absolutely gorgeous. It was sunny with a nice breeze- a perfect spring day. It was similar to the last collection expedition I went on in fall 2015, but, as Emma explained, it was much sunnier than when she and Dr. Sedlacek collected from Rockford in November 2016. There were some other differences between this collection and Rockford as well. For starters, we all wore hard hats and protective eye wear. Rockford has been closed down for a long time, but the quarry we were at was still active and we are required by law to take a few more safety precautions! We all wore the hard hats and eye wear, but no one ended up actually needing them thankfully! Further, Rockford is pretty much a steep pit lacking vegetation. This quarry had plenty of vegetation to go around so we spent the day fighting trees to get close enough to the rock layers for collection!
Besides the differences, the collection process was similar to previous expeditions the BETA Team has gone on. Like good scientists, one of the most, if not the most, important part of the process was good measuring and note-taking. In order to draw any worthy conclusions, our results must be repeatable. Since the Hinkle Member has been well documented, we wanted to take samples below and above to use the Hinkle Member as the "zero" point so other researchers could come back and retrace our steps relative to the clearly defined Hinkle Member layer.
One of the goofiest parts of the day happened when we were slowly working our way through the rock layers, keeping an eye out for any features that looked like stromatolitic layers when Dr. Sedlacek took a step back from the outcrop and started laughing. She told us to all take a step back and we realized that there were huge bands of stromatolitic layers right above where we were, but we were too close to recognize them! It was very exciting find and we made sure to carefully document and sample from the different layers!
After collecting samples through the three consecutive members, we rolled out from the quarry, covered in mud, with bags and bags of rocks for future analysis. We stopped for some celebratory ice cream before heading back to campus. It was a long day in the quarry, but it was very successful. It was the perfect way to end the semester (and an especially good way to end finals week)!
--Jessica Wayson