I’m no archeologist so how do they know these are axe heads and not adzes or plows or some other implement?
I’m not either but I am a flint knapper and a collector of flint artifacts. I’ve personally found large flint biface’s on the ranch, some as long as 15 inches and about 1 inch thick. One explanation could be they’re just the result of spawling down a much larger stone so they’re easier to transport back; I do the same thing myself. Another idea, which was suggested by a friend of mine who is an archeologist, seems to think they carried large biface’s with them so they could strike off smaller and sharper flakes, as they needed them.
Would not large axes be needed to feel large trees that were later transported over water - and the boat presumably sinking taking the axes with it?