GRIDS\USGS_GRIDS

Description of directories and files: Grids are in Geosoft Oasis Montaj format as described in the main open-file report. 

*.zon files are color scales files used to make the geotiff files. The res100k_resistivity.zon file is a color  scale for the apparent resistivity at 100,000 hertz for all of the survey areas. The .zon file in each subdirectory is the color scale for resisivity maps for each area. 

files are named:
area	_dem	digital elevation model
	_MAGrtp total magnetic field reduced to the magnetic north pole
	_MAGSP total magnetic field 
	_powerline powerline monitor in arbitrary voltage units
	_RES 	apparent resistivity at the specified nominal frequency