Well, I wish I had exciting news for everyone but I have only been left with confusion....
Me and a couple of friends went and lifted the block. I'm going to preface this by saying that I don't beleive it is a grave simply because the local cemetery nearby has the name of a person with those initials and it fits the time period. There could have been another person with the same initials, but this was a very small community and there is not another person on the census that would match.
The block was not nearly as heavy as we thought it would be, as the underside is inset and was only filled with dirt. There was nothing underneath it and I'm getting some very faint iron readings, but the ground has very high mineralization.
It looks very much like a lid to something, but I can't figure out what. I would say a concrete grave vault, but there was no concrete underneath and it would still be too small for an adult to fit in. What confuses me is the the letters were etched into it while the concrete was still wet. However, the underside of it leads me to believe it was not poured where it lays.
The question is, do I keep digging since I'm aware that a metal detector is only going to go so deep, or do you all think it's just a marker of some sort? I will be posting a picture soon.