I, love it! How would a meteor, hitting a glacier and causing melt wash? I mention this because ive been rock hounding in blackhawk county and have found a layer of melted limestone with a layer of glass on top dark too light shades of green teals and greys n blacks. .... Im just saying it looks like a event of chunks of glacier flowing and the bits left were the inbetweens. I say Meteor and wind fill, over time.
Younger Dryas at the end of the last glaciation had 2 episodes triggered by cosmic impacts. A lot of the formations in Iowa, particularly the Missouri and Mississippi underfit river basins, where formed by the massive outwash of glaciers melted by these impacts.
