Saginaw Impact hypothesis http://cintos.org/SaginawManifold/Saginaw_Bay/index.html
Good find. Interesting, well-developed hypothesis!
(Particularly since I’m working INSIDE the Saginaw Crater right now at Bay City, Saginaw, and Midland. But there are extensive oil fields right here, and across lake Huron in Canada. Would not a meteor impact that recent have destroyed those fields?)