Devonian Fossil Gorge, Coralville Iowa
The picture above may look like a weedy, rock-strewn expanse that resembles a waste area laid bare and useless. But the interesting thing about this picture is that in June of 1993 the ground was several feet higher than pictured here, the soil and rock 17 feet thicker. Three months later, in September of ’93, it looked like it does here. The tan colored wall in the background is the spillway of central Iowa’s Coralville Dam, a retention dam built in 1958 by the Army Corps of Engineers to hold back the Coralville Reservoir, and to provide water to several cities below.
Today the pictured expanse of rock and grass is the Devonian Fossil Gorge, a veritable classroom for geologists, paleontologists, and also for those of us enduring a pandemic that looms as a potential natural catastrophe that threatens human life on earth.
The Devonian period stretched between 416 to 358 million years ago. It was named for Devon England, where rocks from that particular paleozoic era were first discovered and studied. Devonian rocks and fossils, and my afternoon at the gorge, are what brought me to write this mid-pandemic blog post. (I hope it’s mid-pandemic, we’ll see.)
Iowa’s monsoon summer of ’93 brought far more water into the Coralville Reservoir than the dam could contain. In late Spring, the spillway overflowed for the first time in the dam’s operational history. The water’s overflow rate at times exceeded 24,000 cubic feet per second. That’s 1.5 million pounds of water every second, and the deluge lasted for nearly a month. In its raging rush, the water scoured away seventeen feet of ground and rock below the spillway, opening the Devonian fossil bed buried beneath, exposing its diorama of ancient life after 358 million years.
The flood of ’93 removed 17 feet of earth & rock
When the ’93 flooding subsided, the fossil bed showed an ancient beach 350 million years after high tide. It was a snapshot of geologic history, a slice of ground embedded there fully 60 million years before dinosaurs roamed the earth. The flood of ’93 opened it to human view for the first time. It showed what scientists had long believed, that much of Iowa was once underwater, a tropical zone populated by trilobites, crinoids, and various other prehistoric sea beasties. It also proved the theory that Iowa was once situated below the earth’s equator. It would have been much warmer at that point, I can attest.
Iowa would be (roughly) at the ‘N’ in Laurentia
Iowa was once a tropical seascape
Pictured above, crinoid, brachiopod, and coral fossils are evidence of Iowa’s once warm, marine past. The buried Devonian treasure trove may have been the only good news from the great flood of ’93, but it was indeed a gift, in many ways. Geologists and paleontologists from the University of Iowa, and from several other schools, saw the exposed Devonian fossil bed as a research and pedagogical bonanza.
Favocites and corals
Long stem of a crinoid, ancient sea algae
So here’s my takeaway, and the reason behind this post. The coronavirus pandemic may not, at first glance, appear to be connected in any way with Devonian fossils, or tectonic movement, or ancient sea beasties that popped up near Devon England. But standing atop actual remains of actual creatures that actually lived, and breathed, and ate, and pooped, and reproduced 80 million years before the dinosaurs can engender a bit of reflection. These fossilized critters had little control over their environment…and neither do we. The difference is we do have some control, but we often ignore it, or use it badly.
As I took these pictures, I imagined the rainy summer of 1993. The flooding, the property damage, and the destruction caused by all that water and no place to put it was truly astonishing. The deluge was ascribed to so called 100 year flooding, the 50 inches of rain that fell on Iowa between April and August. But a portion of it was attributed to the Corps of Engineers’ creation of levees and dams, including the one in Coralville, humankind’s attempts to tame various rivers and bend them to our will and needs.
Likewise, the coronavirus has shown us what can and does happen when our interactions with nature ignore the fragile balance between us and the environment. I suspect that humankind will last another few Millenia, at most, probably less if Trump wins. Then, in that latter day far, far away, like the crinoids and brachiopods underneath my shoes as I walked the fossil gorge, we, too, will vanish, swept away by a powerful event likely of our own making. Maybe I’ve got too much time on my hands due to the pandemic, but that’s what I conjured at the fossil gorge, mankind’s fragility, and our hubristic nonchalance as extinction stares us down, and we stare back, dumbfounded, one could say fossilized in our lethargy to act.
It’s an amusing mind game picturing whatever sentient creatures follow us eons hence. This future being will no doubt sport a massive brain, with a highly evolved sense of sight, and hearing, and taste, and touch. This hyper-evolved creature will be much more aware, more intelligent, better able to project outcomes and perils, much more insightful in tending to its surroundings, a kind of Post-Anthropocene Jane Goodall, in other words.
I imagine ‘Jane’ poring over a weedy patch of ground, scanning fossils of humanoid bones from 100,000 years before, way back in 2020. She recognizes (from cranially stored texts and images) the items she sees: Remains of a so called ‘roadway’ complete with skid marks, the imprint of a discarded Domino’s pizza box, a fossilized iPhone 347, the carcass of an ancient laptop, (with error 404 intact), a well preserved Smart Car, a damaged but readable WalMart sign, an oddly granitized, tiny circular button that reads ‘MAGA’. ‘Maybe that’s what wiped them out,’ she muses.
‘Jane’ is aware of the pandemics that once ravaged humankind during the Anthropocene, various viral epidemics that, it’s alleged, wiped out the human race. She shakes her head, wondering what dangers her own species is overlooking? What peril in Jane’s natural environment must be treated with more dignity, more respect, she wonders? What barrier are we breaching, she thinks, that may eventually sweep us away to fossil beds and ancient texts? What elements in our surroundings have we lost touch with, and which may come to bite us in the tenderest of spots?
Here’s hoping Jane’s society is smarter than ours, and that by the time she posts her own blog a millenium hence, the creatures who replace us are more self aware, better caretakers of the earth, gentler with their resources and each other. Here’s hoping they understand—in their bones—that, just like us, they’re not separate from the fossils at their feet, but connected in ways no flood or virus can erase. Good luck, Jane. Here’s hoping. Thanks for reading. Comments welcome.