Officials at Dominican University have been aware for a while that there is water some 12 or 14 feet under their campus. What they didn’t realize until recently was just how geologically significant the land under their campus is. Not only does the vestiges of an ancient and once mighty river flow under the campus, a previously unknown geologic formation also exists under their feet.
That recent discovery has led to the opportunity for Professor John Tandarich and his geology class to engage in something few geologists, let alone college students, ever get the chance to do-officially name a new “soil stratagraphic unit.”
Last week Tandarich was notified by Dr. Leon Follmer of the Illinois State Geological Survey informed Tandarich that he and his students would be doing just that.
“We’re going to [write] a professional paper in which we name the formation,” said a pleased Tandarich, who said his students are, not surprisingly, excited about the opportunity to play a small part in geologic history.
A different world: For nearly 15,000 years after the ancestral Des Plaines River disappeared, Oak Park and River Forest were at the bottom of Lake Chicago. See Oak Park Spit.
Over the years, builders excavating foundations in Oak Park and River Forest have had to contend with what they termed “ground water” at around 12 to 15 feet below the surface. As recently as this summer contractors excavating the old Bank One site in Oak Park hit water and had to cancel plans to build underground parking there.
But most have scoffed at the notion that they had uncovered a rumored ancient river, arguing that the underground water flow doesn’t look anything like a river.
Thus it wasn’t a surprise when last March, while pounding pilings into the ground around Dominican University’s planned Academic and Science Building, that workers from Pepper Construction discovered seeping water.
Jerry Sexton, construction manager, has dealt with the underground water flow before when his company built Dominican’s Centennial Hall dormitory.
“When I dug that, there was sand, then water at 10 to 12 feet,” Sexton said. “The sand was cleaner than [what you find at] the beach.”
Before starting construction last spring, Pepper Construction performed core borings to determine where they could expect to encounter water. Sure enough, excavators discovered water at about that same level adjacent to the new building.
What they discovered was a mixture of soil, sand and slippery muck. And, indeed, to the untrained eye, such as that of a reporter staring down at the 20-foot-deep ditch next to the Arts and Science Building, the wall of earth appears to be, well, dirt, sand, and a slick dark mud.
But most people don’t possess the credentials of Dominican’s Tandrich, who saw indisputable proof of an ancient river that once dominated the area. He has since spent a considerable amount of time happily traipsing about in the 20-foot-deep excavation pursuing his professional passions.
Sporting a sweatshirt that reads, “I am an environmental soil scientist, and thereby have the inalienable right to observe soils and their landscape relationships whenever and wherever I choose,” Tanderich showed up over the lunch hour in early September to give a tutorial, armed with large-type signage to identify the three geologic strata unearthed by the construction.
Three geologic strata are evident, he said, each of which is named for the Illinois town in which it was first discovered-“Equality,” the top layer; “Henry,” the middle sand layer; and “Wadsworth,” the bottom layer of pulverized dolomite rock.
Ironically, Tandrich, a Fenwick high school alum who grew up in Chicago’s Galewood neighborhood a couple miles northeast of Dominican, has traveled around the country and extensively in Missouri and Illinois, pursuing his professional passion. Now he needs only walk a few hundred yards west of his office to indulge his geologic fascination. He’s clearly delighted to have such a fine physical example of what he lectures about in class just steps from that classroom.
“That’s why this is so neat for the students,” said Tandrich. “Looking at pictures in a book is not the same as actually looking at it in reality.”
Tandarich also relishes talking about the land’s history, a history that goes far back into the mists of time. Two million years of mist, in fact.
With the happy enthusiasm of a highly educated kid playing in special dirt, Tandarich stood perched on a literally slippery slope, sticking a piece of rebar reinforcing metal into the mucky mass around him as he started an impromptu lecture on the last ice age to visit our area. Called the “Wisconsin,” it lasted some 2,000,000 years, and ended roughly 22,000 years ago. Some 20,000 years ago the vestigial river beneath Tanderich’s feet was born.
“Two million years ago, the winter snows didn’t melt over the summer,” Tandarich noted. That intense cold spell continued, he said, for up to 100,000 years at a time. The result was a massive, deep sheet of ice as one yearly snow fall after another crushed down on earlier snow falls.
At its peak, the ice mass extended from Canada down all the way through southern Illinois to Charleston.
“They built up for over 100,000 years, reaching five miles in thickness,” he said.
The growing mass started moving southward, the result of sheer astronomical weight which caused it to effectively liquefy, “like corn starch,” Tandarich noted. It continued slowly moving south over several thousand years. Then, around the area that would become Milwaukee, the warming mass of ice at the front of the glacier wall gave way, releasing astronomical quantities of water in several raging torrents in tunnels under the ice.
Amazingly, that long gradual process of freeze, move and thaw repeated itself 11 times between 2,000,000 BC and 20,000 BC.
“One of those [water] tunnels was the ancestral Des Plaines River,” Tandarich said.
“It took about 6,000 years for the ice to melt back from Charleston all the way to Milwaukee.” When the last ice age ended 20,000 to 22,000 years ago, he said, a river remained. “At least a couple miles wide,” the river dwarfed the mighty Mississippi River of today.
In the process of slowly moving south and melting, the receding glacier also released massive quantities of material-called “glacial till”-that had been scraped out of the Canadian and Wisconsin rock, and re-deposited it all along the river it was forming. Much of the rock in the path of that grinding, frozen mass was dolomite, a calcium and magnesium carbonate material that is often confused with limestone.
The ice “literally bulldozed [the dolomite], ground it to flour,” said Tandarich. Along with earth and rock, the dolomite was strewn across a wide swath of land from roughly Milwaukee to Charleston. The finely ground sand became the river bed, the pulverized dolomite lay underneath it. Over the millennia, some 8 feet of top soil developed above it all.
The old river disappeared when “Lake Chicago” developed around 12,500 BC. Deeper than today’s Lake Michigan by some 60 feet, at its greatest it lay across land from Park Ridge to the north, Tinley Park to the south, and west to Elmhurst-a far cry from the underground stream that today trickles into the Des Plaines River a quarter mile to the west.
An unexpected discovery
Even a trained professional eye can miss a detail at times. It was Dominican student Daniel Lynch, not Tandarich, who in late September spotted what proved to be a distinct soil layer within the Henry formation, the middle formation that was the river bed of the old Des Plaines River.
When Tandarich looked closer, he found that the soil had all the characteristics of “cold climate soil.”
“When it was first laid down (about 17,500 years ago) it was not covered by ice or water,” Tandarich explained. “And soil developed in the deposit.” Rain, snow, microbes and other weathering factors worked on the deposit over centuries, and a geologically distinctive soil was gradually created, one formed only in very cold climates.
“The only place you find this type of soil today is in the North Slope of Alaska and Northern Canada,” he said.
Perhaps fittingly, the academic paper Tandarich and his students are preparing is due to be finished by December, just as the weather in River Forest turns cold.
Also fittingly, the new formation’s name may be “Rosary,” after Dominican University’s original name.
“One of the students thought of [it]” said Tandarich. “That’s a possibility here. Before we finalize it, we’d want to get the President’s [Donna Carroll] OK.”
Dominican University’s newly discovered underground river was briefly overshadowed by the small lake that developed last Monday night in the basement of the school’s library during an hour-long torrential rain fall.
Thanks to the quick response from university staff, no books were lost, and damage and disruption was kept to a minimum.
“Our physical plant people and some of my staff really worked like troopers to keep books and periodicals out of harm’s way,” Dominican Librarian Inez Ringland said.
Ringland received a call from the university’s maintenance staff around 9 p.m. last Monday that water was cascading down the entrance ramp of the basement and down a loading dock ramp.
“It came down so fast that it over ran the drains outside the exits,” said Ringland. “The water was coming in pretty forcefully.”
It likely didn’t help matters that heavy ran earlier in the day had saturated the ground near the library.
Ringland said that maintenance and library staff evacuated the area, which includes the popular Cyber Café space, and disconnected all computers and electrical equipment. All the lower bookshelves were cleared of material.
As soon as the rain stopped, maintenance personnel started removing the water, a process that went on throughout the night and into the following morning. The library was still closed on Wednesday as staff used water vacuums to evacuate the remaining water and disinfected the space.
Except for the periodicals and reference section, all operations were back up and running Thursday. That included the Cyber Café, which serves sandwiches, coffee and pop to a large number of students. Ringland said workers have removed vinyl baseboards and drilled holes in the walls. Blowers are being used to force air flow behind the walls to dry inside spaves to prevent the development of mold.
According to Ringland, university Director of Building and Grounds Dan Bulow will meet soon with the school’s contractors to prevent future flooding.
Still, Ringland said she’s grateful the quick thinking of staff present Monday night helped the school “dodge a bullet.”
“Considering what we could have faced, I’m so pleased we came out as well as we did,” she said.