tiompan wrote:
Another example you might have mentioned is the use of antural markings within genuine rock art ,look at how the man made markings are enclosed in natural markings . http://www.themodernantiquarian.com/site/6641/craig_hill.html .This is not uncommon and the questiion is did the engravers see these natural markings as convenient frames or whether they maybe perceived as earlier man made markings .
Tiompan, I think I've learnt a lot from a few of the posts here, especially with regard to natural markings. Do you mind me asking about the above example - is it possible that the natural markings occurred after the man-made carvings as sandstone can crack and split over long periods of time. 