Rock On!



s kids, a bunch of us had cool rock collections, maybe some sparkly minerals or even an arrowhead or fossil (which took your collection into “amaze your friends/way cool” territory). Most of those specimens, safe to say, ended up whence they came, or in a landfill, as years went by.

But some kids took their cool rocks and made a career as geologists, and a couple of them live in Mt. Lebanon. Charlie Jones and Danielle Deemer have very different jobs now, but their fascination with the earth both below and around us started early.

Jones, who’s now a professor of geology at Pitt, remembers finding an interesting rock in his rural Wisconsin backyard and showing it to his geologist dad. “He said it was a volcanic lava that erupted over one billion years ago. I was pretty amazed at that number!”

Deemer, who now works in the oil and gas industry at ALPX Energy, grew up in Moon Township, and especially enjoyed her family’s camping trips. “I loved looking for fossils under the rocks.” An undergrad class at Grove City College sealed the deal.

A few fossils gathered outside, showing shells and ancient bugs.

“It was my first introduction to geology,” she recalled. “It incorporates both art and science. It’s like reading the book of nature.”

The earth’s history can read like an action page-turner, full of the crashing of continents, glacial melt and volcanic eruption. Where we live has its own dramatic history: 300 million years ago, Pennsylvania was close to the equator. “Very warm and tropical, swampy and boggy,” Deemer said. From bogs comes peat, which is made up of partially decayed vegetation and water.  Over millions of years of pressure, peat forms coal. And coal, of course, is critical to our area’s history.

Charlie Jones with his cat and a coffee smiling.
Charlie Jones

The Pittsburgh Coal Seam, the most extensive coal bed in the eastern United States, runs from Allegheny County, including the South Hills, through to West Virginia and Maryland, and extends west to Belmont County, Ohio. In fact, the seam can be viewed on the cliff behind Jim Jenkins Lawn and Garden Center. A few hundred feet away, near the corner of Painters Run and Bower Hill roads, sits a bricked-up entrance to the Beadling mine.

Local history buffs are probably aware of the mine (officially called the Harrison Mine) and the coal town of Beadling, which included parts of Upper St. Clair, Scott Township and Mt. Lebanon. According to a 2013 Tribune-Review article, the mine extended east almost to Castle Shannon and north to near what’s now St. Clair Hospital. The mine’s powerhouse and machine shop sat on the current site of the Beadling Sports Club. It was sold to the Pittsburgh Mining Company in 1912; the mine closed in 1923. (“It’s definitely worthwhile to get mine subsidence insurance,” Deemer noted.)

So there were bogs, then peat, then plenty of coal. But back to the cool rocks, specifically fossils. Where are they? The good news is that fossils are plentiful in our area. The bad news: they’re not dinosaur fossils.

“Our rocks are too old,” Deemer said. As noted, our turf was formed more than 300 million years ago. Dinosaurs came along 80 million years later.

The Benedum Hall of Geology, at the Carnegie Museum of Natural History, is a great resource, she adds. “It walks you through the geology of Pennsylvania. We’re so lucky to have a museum as wonderful as the Carnegie.”

What kinds of fossils can we find when we start digging? Calamites, says Jones, who found one in his Roycroft Avenue backyard. These are plant fossils with compressed impressions of foliage from calamite plants, which were more like trees: they could grow to 100 feet tall.  They went extinct about 250 million years ago, but their descendants, horsetail plants, can be found in the Mt. Lebanon Library fish pond, and lots of local backyards.

Look for outcrops, said Jones: places were the roads or hillsides have been cut. The cliff and rocks near the entrance to the Panhandle Trail in Collier often yield calamites. The rock ledges at Ferncliff Peninsula, in Ohiopyle State Park, are well known for their plant fossils. Closer to home, you might even find some in Bird Park, or in the hills behind The Galleria.

Spring is a great time for fossil hunting, Jones aded. “Look before all of the vegetation comes in, near the end of the freeze-thaw cycle.”

A little further east, chances of finding marine fossils increase. Trilobites, a Devonian Period ancestor of crabs and lobsters, can be found in the York County area. About three hours to the northeast, in Hamburg, New York, you can dig for your own trilobites at the Penn Dixie Fossil Park.

A fossil of a trilobite.

“The cockroaches of the ocean. I just love them,” said Deemer. She displays a fine trilobite, a gift from her husband, Chris Willan, also a geologist.

Serious fossil fans might want to visit the Ohio Valley Fossil Trail, developed by staff from 12 museums and parks in southwest Ohio, southern Indiana and northern Kentucky. It includes the Falls of the Ohio State Park in Clarksville, Indiana, site of the world’s largest Devonian-era fossil bed. Trilobites, calamites, coral and gastropods (snail fossils) abound.

Danielle Deemer holding a cup of coffee smiling.
Danielle Deemer

As for the dinosaurs: you’d have to go at least as far west as Texas to have a shot at a dino fossil. The Dakotas, Utah, Montana, Colorado and Wyoming offer good hunting grounds as well. Of course, our own Carnegie Museum of Natural History is well known for its Dinosaur Hall, where reconstructions of Tyrannosaurus Rex, Apatosaurus, and the cat-sized Dipelphodon live. (The museum website notes that their dinos are 75 percent fossil.)

Next time you’re outside, take a second look at what’s under your feet, or looming high above.

“Any place you see exposed rock, poke around. You don’t know what you’ll find,” notes Jones. “It takes patience. Once you see the first one, you’ll start seeing more.”

“Every rock tells a story,” said Deemer. “When you start building the story, that grabs people’s attention.”


Photos by John Altdorfer