Article by Jefferson County Conservation
Photo by Jefferson County Conservation: Two participants paddle for the takeout. You can see the rocks weighing down the back end of the kayaks.
Over twenty people took to the water in search of geodes along the Des Moines River. The ‘Geode Paddle’ was held on Friday, August 9th starting at 10:00am. Although the paddle was only 3.6 river miles, participants enjoyed the shorter route which allowed them to spend most of their time searching rock bars for fossils and geodes. The paddle began at Bentonsport and ended in Bonaparte. Ryan Clark, geologist with the Iowa Geological Survey, led the paddle as he discussed the geology of Iowa and why we find geodes in this stretch of river.
Clark began by sharing an overview of Iowa’s geologic history. This timeline helped for participants to have a better understanding of why the geodes are found in this area and what rock layer to be looking in. Once Clark completed his talk, Brittney Tiller, Naturalist with Jefferson County Conservation gave a brief safety talk and summary of the day. Participants began launching shortly after the talk wrapped up.
Clark explained that the geodes came from the Warsaw Formation which is a grayish shale that can easily be eroded. Participants would paddle a short distance down river before stopping at a rock bar to search for nature’s treasures. After two stops of searching for geodes, participants stopped at another rock bar. This one had more limestone present which meant geodes were not as prevalent however fossils could be found in nearly every rock. From horn coral, crinoids, and brachiopods, the fossils were in abundance. Participants were excited to have a great mix of both fossils and geodes in their boats to take home. Two more rock bars were hit before taking out at Bonaparte.
With a very long waiting list, high interest, and participants which had such a great time, this topic is clearly a participant favorite. Participants seemed to be amazed that this stretch of river had so much to offer. Overall this was an extremely successful program which should be offered again.