From introduction: Geodata International, Incorporated, conducted an airborne gamma ray and total magnetic field survey of a region of Northwest Texas which covered the Lubbock and Plainview Geologic Atlas Maps. The area shown on Figure 1 was surveyed from an aircraft using large-volume radiation detectors with computer-controlled airborne equipment. Each map line was flown in an east-west direction with an average length of 120 miles. A total of 47 map lines were surveyed spaced at 3-mile intervals beginning at latitude 33000' and ending at latitude 350