How old is Lake Superior?
What is the depth of Lake Superior? What are the Facts about Lake Superior? Questions begging for answers. Minnesota’s Sea Grant program provides us some clues to the first question. The beginnings of Lake Superior trace back a billion years! . . . when molten basalt erupted in a rift from near present day Detroit to Northern Minnesota. “Billions of tons of molten rock” from deep beneath the earth’s surface accumulated for 22 million years and some point during this time period eventually the tipping point was reached where the surface of Mother Earth could no longer support the weight . . . and the Lake Superior basin began to form. The basalt rock that formed this original basin is most apparent in the North Shore of Superior – in Minnesota and Ontario. (Learn more about Lake Superior Rocks & Agates here) Shallow seas flooded the southern portion of the basin and deposited sand and muck which eventually formed the sandstone formations found in the Bayfield Peninsula – Apostle Islands
