Airborne Scintillation Counter Surveys
WITH THE DISCOVERY of natural radioactivity at the end of the 19th century, and the design of equipment for the detection of this phenomenon, radioactivity . surveys bad their inception. Early in the 20th century it was found that almost all rocks are radioactive to a certain degree. This radioactivity is due to the nuclear disintegration of six naturally radioactive elements : potassium, thorium, uranium, rubidium, samarium, and lutecium.