No word from the OP? Hope they didn't whack it with a shovel and set it off.... If it's here in the US I doubt very much it's a mine, although some were found in Illinois near Crab Orchard lake years ago. Those were never armed and were dumped and buried there by an arms maker somewhere around WW2, and as I remember they were found when a tree fell over and they were in the roots.
My bet is on some sort of lid, or the end or a water heater tank, something along those lines, but more info like a side view and a bottom view would help....
No word from the OP? Hope they didn't whack it with a shovel and set it off....
I wonder if the OP found it in Illinois or surrounding states?More on landmines in Illinois....
"It should also be noted, that even today, an unexploded ordnance can occasionally still be found and has be to dealt with by a bomb squad for removal. Around 2006, an anti-tank mine was found during a controlled burn and exploded on the spot by a bomb squad, which suggests that landmines were in use at one time. "
Illinois Ordnance Plant, Ordill | Marion Illinois History Preservation