I dig some in this particulatr area but the other day I ran across these. I can't find anything signifcant to go on in my search. The one on the right seems to be more "of" the rock, the left appears to be more "on" the rock. The left looks like leather, the right is almost like conglomerate strips. I personally haven't run into these before, any ideas? Thank you.I know the photos are a bit blurry, I can try again later with the other camera if needed.