Strange to read old comments from a 15 year old resurrection. Nice to know some of us are still around. At any rate these Carolina Bays have lurked in the background of my mind all these years, and I have some further comments. The idea that bolide crashes in the Great Lakes area could have thrown up giant ICE CUBES also occurred to me. I read that there appeared to be 2 large craters forming Lake Michigan, but when I looked at the underwater mapping it appeared there was a third smaller depression between the 2 larger ones, kind of like an ant shape. Also, if I remember correctly and it has been a while and I can’t locate my copy of “The Book”, there were small numbers of “Bays” located in NJ and out west somewhere. All had a directional oval oriented toward the Great Lakes. So my thought is giant blocks of ice landing in various places with a directional skid. Then sitting and melting over time, with speed depending on size and weather conditions. This could affect the size, nature, and stratigraphy of depositions. Also if more than one bolide or fall location and timing, slight differences in orientation line. Remember the Jupiter S-L strikes. Minor alterations in directionality of oval bays could be related to strikes in different places at different times.
https://www.space.com/19855-shoemaker-levy-9.html [An interesting discussion of the S-L comet’s death.]
https://www.youtube.com/watch?v=gbsqWozEBBw [A 4 minute NASA video shows and discusses the impacts and science study of S-L aftermath.]
Other thoughts: Could tsunamis have affected parts of the Carolina Bays area. I seem to recall some discussion of great slides off Canary or other East Atlantic volcanic islands? What affect did the great Toba eruption (74kya) have on great rain and flooding worldwide?
My view is, the Great Lakes basin was made possible by a large impact, that whatever may have happened more recently, the entire thing started as a huge impact structure.