Red oak discoloration

[Egghead]

Any idea what would have caused the black color in the wood? The tree was a standing dead red oak. When I saw the black color on one of the bucked ends I first thought it was something from the chainsaw exhaust but the color continued through the entire log. The color was in the center of the tree. Anyone ever seen this before?

 

[Egghead]

Another pic

 

[osagebow]

Iron from a nail or something. Looks dark blue in the pics.
Yard tree?

 

[Fred Wright]

Yup, there's hardware somewhere in that tree.

 

[Egghead]

That would make sense. I did find a small piece of barb wire on one piece. Thanks guys!

 

[Richie]

I notice that when I run the chainsaw, the edges of oak can sometimes turn that exact same color.