Missouri Breaks Project, Montana - Digitized aeromagnetic data
Dates
Publication Date
2016-05-24
Time Period
1981-01-01
Citation
Anderson, E.D., Parks, H.L., Jenkins, M.C., Nguyen, D.M., Hearn, B.C., Jr, and Zientek, M.L., 2016, Missouri Breaks Project, Montana - Digitized aeromagnetic data: U.S. Geological Survey data release, http://dx.doi.org/10.5066/F7TH8JTN.
Summary
From February 12 to March 8, 1981, EG and G Geometrics conducted an aeromagnetic survey in Montana for Anaconda Copper Company. A Piper Navajo aircraft was used to conducted the survey. The survey was flown along north-south flightlines spaced 660 feet at a nominal height of 450 feet above the terrain. Five uniformly spaced east-west tie-lines were also flown. During processing, the International Geomagnetic Reference Field (IGRF) of 1975 was updated to 1981 and removed from the survey observations. The resultant anomalous magnetic field was contoured at a 4.0 gamma interval and plotted to map sheets. In 2016, the map sheets were scanned, registered, and the contours were digitized. The point data released here were extracted from [...]
Summary
From February 12 to March 8, 1981, EG and G Geometrics conducted an aeromagnetic survey in Montana for Anaconda Copper Company. A Piper Navajo aircraft was used to conducted the survey. The survey was flown along north-south flightlines spaced 660 feet at a nominal height of 450 feet above the terrain. Five uniformly spaced east-west tie-lines were also flown. During processing, the International Geomagnetic Reference Field (IGRF) of 1975 was updated to 1981 and removed from the survey observations. The resultant anomalous magnetic field was contoured at a 4.0 gamma interval and plotted to map sheets. In 2016, the map sheets were scanned, registered, and the contours were digitized. The point data released here were extracted from the digitized contour lines and include: latitude, longitude, and magnetic-field value (gamma).
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MO_Breaks_Mag.xml Original FGDC Metadata
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MO_Breaks_Mag.txt
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Purpose
Aeromagnetic surveys are used for geophysical prospecting. Some variations in magnetic measurements are caused by rocks that contain significant amounts of magnetic minerals (magnetite being the most common). These anomalies reflect variations in the amount and type of magnetic material and the shape and depth of the body of rock. The features and patterns of aeromagnetic anomalies can also be used to delineate details of subsurface geology including the locations of buried faults and the thickness of surficial sedimentary rocks.
