There’s a city some 1,200 feet beneath Detroit, infamous for its gigantic salt deposit and incredible to see.
The Detroit mine is famous in America and still operates independently. While the mine itself is 114 years old, the deposits predate the dinosaurs. The mine spans more than 100 miles and is made up of many tunnels.
About 400 million years ago, an area known as the Michigan Basin began to sink into the ocean. The water that flooded into the area then evaporated, leaving 71 trillion tons of salt in its place.
When the mine was first opened, it was a dangerous place to work. Machinery had to be cut into pieces and lowered through the 36 square foot mine shaft into the mine itself. Even mules were lowered down by rope.
Now, miners drill holes into the salt and pack them with explosives, which yields 900 tons of salt in less than 3 seconds. Then, the crushed salt is moved via conveyor belt to the shaft to be lifted out and processed.
Though a traditional mine isn’t as efficient as evaporation pools (used by big companies like Morton), the Detroit Salt Company’s business is still strong. All of the company’s product is used for making road salt, which was in high demand during the past record-breaking winter season.
Photo Credit: Mad World News, Wayne State/Reuther Library