Airborne gamma radiation surveys are very useful for surface geologic mapping, and aeromagnetic surveys are equally useful for basement geologic mapping. As the essence of airborne uranium exploration is the detection of the surface expression of a fundamentally subsurface phenomenon, the problem becomes one of resolving the vagaries of uranium migration in the subsurface or of "bridging the gap" between the basement and the surface. In the data-acquisition phase of the airborne survey, the three essentials are large crystal volume gamma-ray detectors, closely spaced magnetic data (recording interval of approximately every 100 ft or 30 m of ground distance traversed, or 0.5 sec), and digital data recording. With such a magnetic data-acquisition interval, small anomalies f om sources within the section, such as mineralization in fault planes, erosional unconformities, etc, can be correlated upward with radiometric anomalies and downward with fundamental basement and structural anomalies.

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