This treasure may not be so much hidden as buried, mineralized, scoured, dug-up and sat-upon.
Geology professor Michael Sandy wanders into a mild winter’s fading sunlight and bends down to point at a rock in the retaining wall in Kennedy Union Plaza. On warmer days, students sit here, searching for friends or a few quiet moments before class. The rock is Springfield dolomite, and protruding out of the rock are fossilized brachiopods, bottom-dwelling creatures that thrived in ancient Paleozoic seas.
“You’re walking past the Silurian period, 420 million years ago — I like that idea,” he says, pointing out a 3-inch clam-like fossil sticking out of one chunk, a handful of half-dollar-sized ones scattered on others. “You’ve got this stuff all around us — it’s part of earth history, of our planet.”
In Dayton, that history includes an ancient, tropical sea and glaciers several hundreds of feet thick. The former created perfect conditions for the brachiopods — waving in water like clams atop stalks anchored in the sand. They died, fell to the sea floor, and were buried and infilled with sediment, their soft interiors and hard shells dissolved away leaving a fossil casting of their former selves. Fast forward 418 million years. While glaciers bulldozed up deposits that would become Woodland Cemetery just north of campus, they also revealed outcrops of Springfield dolomite and its cousin, Dayton limestone, which in the 19th century would be recognized as one of Ohio’s finest building stones.
“I’ve always enjoyed landscapes,” says Sandy who, as a child, hiked the rolling North Downs outside London. “I’ve always wondered why the land is the shape it is and, surprise surprise, geology usually has the answers.
“There is always geology to see, wherever you live. People think of the Grand Canyon; a significant record of earth history is on the doorstep.”
He means that, literally. Look at the rock used for building and you’ll find hints of an area’s geologic history.
In April, Sandy will be leading scientists from the Geological Society of America around downtown Dayton to reveal the geology behind the city’s building stones. The fieldtrip’s highlight is the Greek-Revival Old Courthouse, where Presidents Lincoln and Kennedy addressed citizens from the building’s Dayton limestone steps.
Sandy will also take scientists on a fieldtrip of Dayton’s geology, from the fossil beds of Caesar Creek to the glacial margin that carved the gorge near Clifton. His students take a similar trip each semester.
Sandy, who specializes in the relatively younger brachiopods of the Mesozoic era, appreciates the practical nature of geology. His fossils may answer questions about the chemical composition of ancient seas; the stone walls in KU Plaza can stoke a desire for more knowledge.
“If you start looking at other buildings, you start to see other fossils and geologic indicators just waiting for the eyes of the observant, inquiring student,” he says.