The former Buckeye Oil Equipment in Dayton OH made a lot of different types of tank vents. That's probably one of them. What's underneath the area? Possibility of an old tank there?
No way is it a cadastral survey pin/marker. I've seen hundreds of those and that ain't one of 'em. Too big and no specific point that was measured.
The idea to show it to an older employee at the local utilities dept is a good one if the property owner REALLY wants to know what it is. Heed Winnietrey's advice above..... he may not really want to know. Pave it over and move on.
