A neighbor came over to our house one morning and handed this to me (in ~1994). She found it while looking for golf balls along a desert course. It obviously had been transported downslope from the Santa Catalina Mountains. She thought it might be a fossil bone. I ‘pronounced’ it a sheath fold, and hope that I am right. It is not often that you can hold a sheath fold, and most of its puzzling geometry, in your hand.
Age & Formation