Having been born on the East Coast and schooled in the West, I always lived in some proximity to oceans or mountains. Once I moved to the Midwest, the nature activities I knew as a child – mainly shell collecting – seemed absent. Our region has its huge lakes and evident glacial features in the north, but little did I know that we inhabitants of the center of this continent are also standing on millions of years of accumulated marine sediments. “Shell collecting,” as I knew it, that impulse to discover, sort and identify elements of our surroundings, is actually very apparent, here, just shifted somewhat by age. And the “beaches” are less active boundaries between water and earth, rather fossil preservations of ancient aquatic landscapes.
On the evening of April 18th, Dave Dolak, ESCONI member and professor at Columbia College, delivered a fascinating lecture on the paleontological history of Northeastern Illinois. Just in the last three years, I have had the privilege to venture into some of the rock quarries of our state and collect just as I did as a child on Cape Cod. Of course, fossils become apparent to us more often in areas of disturbance: quarries, mines and road cuts. It’s somewhat ironic, actually, that a variably destructive action on the environment can bring as an indirect effect the most interesting evidence of prehistoric ecology. We fossilers are in constant lookout for the newest construction site, the next access to a giant hole in the ground, or permission to explore a gully or river bed on private property. The prizes, I suppose, are the specimens, of which there were many for show-and-tell at this gathering, but to contextualize the individual pieces in the larger environment makes it all the more rich.
Mr. Dolak did an excellent job of presenting not only compelling aerial and ground level images of the canyons and quarries themselves – the finds from these sources now in cotton-white boxes with accompanying labels – but provided chart geologic reconstructions of the sites as they once were, oh, 400 plus million years ago. My favorite of all, and I think a project that takes most people’s breath away, is the Thorton Quarry south of Chicago, bisected by highway 80. Driving over the middle of the crater, who can’t help but think of fossils, or at least the set of a science fiction movie. Having scuba dived over my lifetime on reefs and pinnacles, I was mesmerized by the scale of what had been discovered and diagramed to be an enormous, mountainous coral head, the frequency of fossils indicating exactly its orientation to rougher waters. My only thought from that point on was to imagine standing inside the place, staring at the blasted walls.
Glaciers, I’m learning, did us a favor in a way to scrape off some layers of sedimentary stone and reveal others of varying ages throughout Illinois. I have lived in the city of Chicago for some years, but never fully grasped that just below the surface is this quiet, patient ocean tomb so ancient we can hardly fathom it. We reconstruct its biology, its geology, its evolution. And, we take small treasures from its edges. Mines and quarries are like wounds in the landscape, but - like Nature herself – they deliver to our curiosity and imagination. Saturday’s meeting was a wonderful collection of specimens of the Silurian Period, rejoined after dislocation, but also a cluster of enthusiasts, a community whose members each must ponder what is, both, almost inconceivably old and right under our feet.
To see more pictures from the Paleontology meeting, click on the Group Meeting title in Photo Albums.
