Hi. I know these are poor pictures so I understand if nothing comes from them. This 3' by 3' boulder looks like a big dirt clog up close but is solid. It is in central Washington County, northeastern Oklahoma, Pennsylvanian I think, on the Caney River. 99% of the ground you see it sitting on going down the river and around the bend is coral, but I see no coral in this boulder or the only other boulder (out of view). In this post, the lower middle spot in all three pics is what I am curious about. It's about a foot wide.