[SatinDoll]

There was an impact on one of the great lakes at that time. Came from a northerly direction and is the subject of a book, The Cycle of Cosmic Catastrophes.

[Explorer89]

Awesome book. Learned about it through the SunkenCiv ping list. This paper supports the date that book had proposed for the impact.

[djf]

There seems to be good evidence, consistent evidence, that this event is what formed the Carolina Bays.

And was the event that killed off many of the megafauna, like the mastodons.

[Mike Darancette]

Came from a northerly direction and is the subject of a book, The Cycle of Cosmic Catastrophes.

If I recall that impact was the last act in a rather complex chain of events. Remarkable concept.