:yikes: I appreciate that advice!!Looks to me like an impact with a pointy rock caused it. That shouldn't be a big deal. Stuff like that happens to tires. Keep an eye on it to see if it spreads, lengthens, deepens--probably won't.
One other thing you *could* do, if you wanted to know for sure (although I wouldn't do it). You could drill down into it, all the way into the inside of the tire to see how much rubber is left on the inside below the wound. That would make sure that you wouldn't have any chance of having it go bad on you while you're riding it. Of course that would let all the air out of the tire, but that's the insurance part that I'm talking about.
(Hope you don't take me seriously!)