Hey everybody, longtime lurker; first post.
Today I picked up a sirloin to grind for tonight's chili, when I cut into it, I found a ring of (what looks to me like) oxidation about 1/4-1/3 of an inch below the surface of the meat. The meat was in a display case at an upscale market; wrapped in butcher paper for the ride home; and cut immediately upon arrival ~20 minutes later. The butcher says he sliced the steak yesterday.
This seems weird to me, but I ask you: are there any natural phenomena that would result in a ring like this?