Not exactly - a massive source of radon in the Eastern USA is shale and low grade coal - where there is sometimes 50 ppm of uranium which cannot be mined, economically ... but because deposits can be hundreds of feet in thickness over thousands of square miles - substantial radon seeps out - far more than from a rich but localized deposit.
-----Original Message----- From: mix...@bigpond.com >Here is a Radon map. > >http://denr.sd.gov/des/aq/images/Radonmap.gif Given that Radon is a decay product of Uranium, this is probably also a map of Uranium deposits in the US. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html