[TN4Liberty]

Another consideration is that the stumps could have been sheared/broken off at ground level.

[lepton]

Another consideration is that the stumps could have been sheared/broken off at ground level.

Yes, but glacier ground level tends to be rather deeper than pre-glacier ground level - especially with 7,000 years of movement.

Unless...the guy is a pretty complete idiot and the stumps were churned around in the ice along with other stumps, and they are dating wood in the moraine and picking the oldest. It has happened before. I doubt it, but several things don't add up here.

[Deaf Smith]

"could have been sheared/broken off at ground level."

Glaciers ride on the ground and scrap up rock/dirt with them and pile them up elsewhere. Their full weight would not allow them to ride over a stump.

I think this is really a ice sheet.