Good eye, Shaun. But Furry has you pointed in the right direction. I believe that there is a good article on it by Mike Diamond (a member here, but an error specialist who writes often on topics like this). Have a look for that.
The date is raised, isn't it? So it isn't "incuse doubling". It looks like the "tip ends" of the 2s are split. could it be a doubled die, or some other characteristic of modern minting processes that I don't know about (which is entirely possible!) I'd like to hear some more opinions.
National Park and ATB quarters have incused dates and lettering around the outside of the reverse. http://www.error-ref.com/incused-machine-doubling/
