The bark pattern looks like locust to me. I wouldn't burn that stuff! Put it out by the curb and we will take care of that nasty wood for you. ;-)
Seriously that is good stuff
I just finished cutting up a bit more then a cord and a half, from the local tree dump. 38-40" across the round. My Husky 350 got a work out! The rounds had to weigh a couple hundred pounds each. I have been told that when it's good and seasoned, it will burn long and very hot, not unlike coal. I don't know how reliable that is. I haven't burned any yet, and I have never burned coal, but this stuff is dense.