There's another rock covered in these 'micro-cups' just here - http://www.themodernantiquarian.com/post/40644 . There's a half dozen of the same style of carved stone at this same site but it's a soft sandstone and has eroded considerably. Except for this one which I excavated and has been subsequently damaged - http://www.themodernantiquarian.com/post/36444 . The directions to this latter stone are explicit yet none have visited to upgrade this crap snap.

There's another myth of gunpowder blasters connected with Mitchell's Fold, I believe. At that stone - it sounds like a perforated stone fallen over and is on Thom's survey of the site - gunpowder was supposedly let off during wedding parties ...