Unless it was found in a context it is nothing more than fuel for speculation. I'm not saying it isn't important, I'm just saying it doesn't mean anything in particular.

Also, I assume the axe was on the surface (unless Pete had a metal detector there) and so it could have been forced to its find location by ploughing or digging or it could have been dumped with the last load of rubbish. It could have been dropped just a few days ago by a metal detectorist, using the bank for cover, heading home from somewhere else.