Where curiosity leads: Michigan’s past

I have been thinking of getting a large scale map of the Great Lakes region, and then framing it and hanging it in my living room.  This is partly because I love maps and partly because I love the Great Lakes.  I’d be happy with either a modern map or a vintage one.  To get started, I went to Google and searched for the terms USGS + Map + Great Lakes.  Among other search results was this map of aquifers in the region:

map_large

I was amazed by the existence of a circular pattern in the aquifers centered on the Lower Peninsula of Michigan.  I thought that it looked like an impact crater, like the much bigger one on the coast of the Yucatan that has been implicated in the extinction of the dinosaurs.

So I did another Google search, for “are the Great Lakes an Impact Crater,” and was amazed to learn about a geological phenomenon known as the “Carolina Bays.”  These are elliptically shaped depressions in the landscape found all over North America east of the Rocky mountains and especially in the Carolinas.**

Some scientists think they were formed by impacts of objects from the sky, specifically from a shower of large objects ejected by an impact of a bigger thing somewhere else. The long axes of the ellipses point to the Great Lakes region, as if the objects were ejected from there and then flew off on arced trajectories that would have hit the earth at an angle, producing ellipsoid craters.  There are not a lot of meteorites in the soil around the Carolina Bays, so that rules out direct or indirect hits by comets or meteors. Some people think that what rained down on the Carolinas were gigantic chunks of ice that were ejected when a comet hit the ice sheet that covered the Great Lakes region between 95,000 and 20,000 years ago.

Obviously I spent an inordinate amount of time reading about this, and now writing about it!

**By the way, this link is to the “Scientific Psychic” web site. I liked the article, but was distressed by the name of the site.  I was relieved to see this explanation on the home page, so I’m going with it.

sci·en·tif·ic  Adjective. 1) of, relating to, or exhibiting the methods or principles of science.
psy·chic   Adjective. 1) of or relating to the psyche or the mind, 2) lying outside the sphere of physical science or knowledge. Noun. 1) a person apparently sensitive to nonphysical forces.

Scientific Psychic® abides by the methodology of science. Therefore, the word “psychic” refers to adjective definition number 1; any other meaning would constitute an oxymoron. Predictions are based on the scientific method.

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About ethologist

Professor in the Zoology Department at Michigan State University
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