The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K),
Radiometric (gamma spectrometry) measurements were made during walking surveys in the eastern Adirondack Highlands, New York using a GF Instruments Gamma Surveyor....
Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth...
