Thornton Quarry Problem

photo by Robert Powers -- taken on November 23, 2008

The Thornton Quarry is the largest limestone quarry in America and one of the largest limestone quarries in the world... and guess what? You've probably driven right over it and didn't even know it! It's like our own Grand Canyon!

This gargantuan hole in the ground is more than 300 feet deep, over 1½ miles long, more than a half-mile wide, and contains rocks from an ancient reef over 430 million years old. It’s been quarried on and off since the 1830’s and continues to operate today as a Material Service Corporation facility.

Millions of tons of rock are quarried from Thornton every year, and a good portion of it is used throughout the Midwest to create concrete and asphalt for roads, and ballast for railroad tracks.

You might not know, however, that there is also something very special to fossil hunters in the Thornton quarry. Scientists and amateur "rock hounds" have gone there for years to observe and collect the amazing fossils found there. Recently, it's been decided that the quarry will be used as a retention pond for the area (That means that floodwaters during big rains will be diverted away from the homes & businesses around it.). Unfortunately that also means burying the fossils beneath hundreds of feet of water. A local paleontologist has claimed that there are rare dinosaur fossils in the quarry and has demanded that the work on the retention pond be stopped. What do you think? Should the work be stopped... even if it means that people might have their houses flooded because there is no other place for the water to go?

As required by law, the Material Service Corporation is cordially inviting you, as a concerned citizen, to express any of your concerns with the proposed project at our next board meeting.

Arial view of the Thornton quarry:
Arial view of Thornton quarry during 2008 flooding period
Here are several pictures and a little background about the quarry
How were the fossils formed?
Underwater Illinois & plate tectonics
Tropical Seas in Illinois?

The Thornton Historical Society is the only organization authorized to conduct tours to the bottom of the Thornton Quarry, which it does twice a year, in June and October. Go to the Village of Thornton website’s quarrypage for more information about tours of the Thornton Quarry, the Biggest Hole in America!