A year ago, water consumed many parts of Iowa. Citizens of the Iowa City/Coralville area as well as the UI community adjusted their lives around water blocking their streets, sidewalks, and inside their classrooms. Nature took its course, and the people pushed past.
When people’s homes and university buildings are lost, it’s difficult to find any bright spots. But, the Devonian Fossil Gorge, located near the Coralville Dam, provides a small light in the tragedy.
The gorge was, and still is, used as the emergency natural spillway for the dam. During the flood of 1993, as the water roared through the spillway, it eroded a campground located in its path down to the natural bedrock, revealing almost 1 million fossils from the Devonian period, 375 million years ago. At that time, what would become Iowa (and the majority of North America) was located near the Equator under a shallow, tropical ocean. Raymond Anderson, a senior research geologist at the Iowa Department of Natural Resources, said to compare it to the modern-day Caribbean.
“The seas have moved over much of the United States and Iowa many, many times geologically,” he said. “Most of the rocks you see in Iowa are a record of that sea.”
Over the 15 years following the 1993 flood, some vegetation and wetlands began to develop and cover parts of the gorge. As the 2008 flood swept through, it not only removed these developments, but widened the gorge, almost giving it a fresh start.
Tiffany Adrain, the collections manager of the paleontology repository in the geoscience department, spends a lot of time giving tours of the area.
“You can be a paleontologist for a day [at the fossil gorge],” she said. “The school kids get it really quickly. I usually take out a couple examples [of fossils] that we have in our collections, and they instantly know what they’re looking for, so they’ll point out crinoid stems, corals, pods, the rare Trilobites.”
Geologists estimate almost 1 million fossils are spread out through the gorge. Immediately following both floods, they spent time searching for significantly sized fossils and sawed them out to add to UI collections. Some of the fossils harvested include crinoids, an animal that lived attached to the sea floor by a stem, almost looking like a flower, and brachiopods — a shelled animal that also dwelled on the ocean floor.
Natural Resources geologist Brian Witzke thinks the gorge is important to the community because it attracts so much interest.
“It’s a good educational thing for the community, too — school groups really take advantage of it,” he said. “But anyone at any age is going to learn more by going out and looking at stuff, versus sitting around listening to someone talk about it.”