THE CAROLINA BAYS

The cometary theory, on the other hand, popular among earth scientists of the 1930s and 40's, is that bays are the result of an encounter between North America and a low density comet exploding above or impacting with the Laurentide Ice Sheet ~12,900 years ago.

Supporting evidence includes the failure of "wind and wave" theories to satisfactorily account for a number of the peculiar features of Carolina Bays, including the recent identification of markers suggestive of an extraterrestrial connection, the alignment of bays with points over the Great Lakes, and their tendency to overlap one another from east to west. ET markers include microspherules, magnetic grains with ET chemistry, carbon spherules suffused with nanodiamonds, and levels of Iridium sixty times background levels.

The cometary theory was out of fashion in the 50s up until the last few decades among planetary and Quaternary geologists for a number of reasons, in accordance with a general distrust into such theories after some geological features, which were believed to be of catastrophic origin, had been explained with slow changes. In part, because of the lack of any verified terminal Pleistocene crater, which an impact of such magnitude should have created, within the area formerly covered by the Laurentide Ice Sheet.

Such features are believed to be found, the proponents of an impact say, in the form of depressions in the great lakes, among other potential sites, though none of them are officially recognized in the “Earth Impact Database". Such an impact site wouldn't even be needed, though, if an explosion in the air (like Tunguska) or an impact into one to three kilometers of ice are assumed.

It has been argued that large areas of white sand are due to an immense amount of heat baking the iron, SiO2Fe -> SiO2 + Fe. according to this argument, "baking" of the sand by the impacts literally "burns" the iron straight out and redeposits it into the sand. Instead of being a set of a compound, you have pure sand and iron, which go to FeO later as iron oxide. It is argued that the iron is redeposited as magnetic iron oxides in undisturbed sand dunes near all the Carolina Bays.