Total intensity of earth’s magnetic field of the Uinta and Piceance Basins and Vicinity, Utah and Colorado. 2 plates (1:500,000). Digital PDF download. MI-35D
Aeromagnetic anomalies represent variations in the strength and direction of the earth’s magnetic field that are produced by rocks containing a significant number of magnetic minerals (commonly magnetite). In the study area, only crystalline basement rocks and volcanic rocks are likely to contain enough magnetite to produce anomalies. Patterns of anomalies can reveal not only lithologic differences, but also structural features such as faults and basement rock upwarps.
Plate 1 is a composite aeromagnetic map, and Plate 2 is a merged aeromagnetic map. These black and white maps were collaboratively produced between the U.S. Geological Survey (USGS) and CGS in 1989. The USGS publication number is Map MF-2008-C. Data was compiled from 33 individual aeromagnetic surveys flown at various heights and spacing. Both magnetic contours and shading are provided on the map.