ice and the great lakes: the plot thickens

So it seems I'm not the only skeptic of the theory that glaciers created the Great Lakes of North America.

Someone has taken quite some pains to discuss the formation of glacial till moraines and the lakes themselves in terms of great flows of water. I'm not sure that I understand exactly what he's getting at, but it seems to be that the ice pushed North America so far down that it was well below sea level when it started to rebound. The erosion of the lakes therefore coming about first by exposure to ocean currents, and then by force of the ocean pouring off of the nascant continent. Not sure I'm convinced, especially when it comes to something as sketchy as the remains of whales.

But the bathymetry of lake Huron in particular highlights the extent of the problem. There are some clearly fjord-like features in lake Huron; its whole south-western portion looks like three glacial valleys. But what's with the north? That looks like a much older and more weathered terrain with clear river valleys at points well below the current lake level.

Good to see that some people at least are talking about an alternative.