Aeromagnetic map of the Nabesna Quadrangle, Alaska

The aeromagnetic map (sheet 1) of the Nabesna quadrangle was prepared in 1971 and subsequently released by the State of Alaska as an open-file map (Alaska Div. Geol. and Geophysics, 1973). The data were collected along north-south traverses spaced at 1.6 km intervals at an altitude of 330 m (1000 ft) above the ground. Compilation was originally in the form of 30' x 15' quadrangles at a scale of 1:63,360; these quadrangles have been combined and reduced to form the present map at a scale of 1:250,000. Contour interval is 10, 20, 100, or 500 gammas, depending on the local range in the earth's magnetic field.