Thanks Fred. Next thing you know you’ll be telling me there are VERY old human remains and areas in the Indus Valley that are radioactive.
There are a number of causes and a variety of radioactive elements in decay. Some are dangerously radioactive while others are only mildly so. For example, it is epigenetic uranium deposits In Colorado and Wyoming that seems to produce radioactive dinosaur fossils from the Morrison Formation [1]. This issues is known by most archeologists that are active in field research, however notices are often published as reminders [2].
http://www.quora.com/Science/Why-are-some-Dinosaur-bones-covered-in-heavily-leaded-paint