In ancient Roman times, prisoners were given the task of salt mining. One suspects 2000 years ago, prisoners working in salt mines did not enjoy a lengthy lifespan. More recently, the Russian authorities sent prisoners, political and otherwise, to work in the salt mines in Siberia as punishment.
When I was a kid years ago, I remember my Dad chasing us all to bed Sunday nights because “tomorrow morning its back to the salt mines for us all”. He worked in Detroit but I knew he didn’t work in a salt mine. And while I didn’t love many aspects of school and at times it seemed as a gulag, it was not Siberia
Detroit, however, has a salt mine. In fact, we have a salt city 1,200 feet below the streets of the Motor City. It is huge with over 100 miles of roads.
So how did all this salt get down there?
The Great Salt Lake in Michigan
There is a great esoteric geologic term for a large area of lower elevation than surrounding areas – it is strangely enough called a basin. Over 400 million years ago, scientists believe this area was filled with salty sea water, much like the Great Salt Lake in Salt Lake City, Utah.
This geologic basin, known as the Michigan Basin, covered much of what is now Michigan’s lower peninsula during the Devonian period
The Devonian Period, from the end of the Silurian Period, about 420 million years ago, to the beginning of the Carboniferous Period about 360 million years ago, is a subset period of the Paleozoic Era.
The Stone of Petoskey
In 1873 a city began on the eastern shore of lake Michigan, named after an Ottawa Tribal Chief, Petoskey, (anglicized from Petosegay) It is in an area famous for fossilized choral. Glaciation of fragments of coral heads, rounded and pebble sized, with a distinctive hexagon shaped pattern, are found regularly. These stones, called Petoskey Stones, were named the State Stone of Michigan in 1965 even though they are found in Canada and other states submerged under vast salt-water oceans including Iowa, Indiana, Illinois, Ohio, New York during the Devonian Period.
Salt and Coral
Climate change / global warming does not occur in straight lines; rather it tends to bumpy trend lines over time, sometimes millions of years. Through several of these climate changes, a process of layering began, leaving deposits of salt in horizontal layers as ancient salt water seas receded and evaporated.
So geologists and paleontologists tell us coral reefs grew and formed in the ocean over the US and Canada 400 million years ago and the Detroit salt layers were formed as these same oceans evaporated.
How did the oceans get there?
Obviously the water came from somewhere. Perhaps melted polar ice?
According to Live Science, (livescience.com) “Sea levels were high with much of western North America under water. Climate of the continental interior regions was very warm during the Devonian Period and generally quite dry.”
A RATIO/NAL Observer might conclude there was serious global warming over 400 million years before there were mammals, primates, or widespread usage of fossil fuels let alone a Motor City.