By: Steve Semken

Nice post, Callan! There are numerous clinker exposures in the San Juan Basin of NW New Mexico where Cretaceous coal beds crop out. Dramatically red and black like the ones you show here. Exploration geophysicists dislike it because it scatters seismic waves. I’m told that in the bituminous belt of western Pennsylvania it’s also called “red dog.” It’s so unique that when I was teaching in NW NM I would regularly be visited by folks with specimens of clinker who were certain they were meteorites!