Today’s MI Environment story, by Kent Walters, a geologist in the Materials Management Division of the Michigan Department of Environment, Great Lakes, and Energy (EGLE), is the latest in a series of stories on rock and mineral identification.
Rocks in fields, rocks on the beach, rocks in the hole you’re trying to dig, but where do all these rocks come from in Michigan? The answer to this question begins thousands of years ago during the last glacial maximum in Michigan.
Approximately 30,000 years ago temperatures started to cool which allowed significant growth of large icesheets worldwide. One of these ice sheets known as the Laurentide Ice Sheet grew rapidly, migrating through Canada, and into the United States.