A shearing cut with a razor sharp chisel is even more definitive. My old eyes don't really see the pores of Northern Red/Appalachian oak especially in the 3rd picture. The small flecks seem to be consistent though. How many species of oak are there? Brings me back to my college days watching all the forestry students with their samples, magnifying glasses/loops, and going around everywhere with samples seemingly attached to their nose. They really put it to them, though I don't think they had the variety that you have on you site. They were required to KNOW them 100%Looked like beech to me but then I saw the open pores in the end grain and now I figure it's oak. Sure looks like beech on the face grain though.
A sanded-down end grain shot would likely be definitive