Is there any way of teling the difference between natural and man-made circles. Is there a size or notable demarkation in the pattern (some kind of tool working!)
Yes, the patterns in the stones at Alphamstone are random - some a couple of centimetres deep. I really don't know anything about rock art and can't work out how holes like those would be created naturally; wouldn't they just get blocked up with mud up if they were outside? (the deep holes at Alphamstone are blocked up).