This cdulsmog.zip (approx. 9 MB) file contains ESRI ArcView shape files and grids used to compile Minnesota Geological Survey, Miscellanceous Map Series Map M-117 Superimposed Magnetic on Gravity Anomaly Map of the Central duluth Complex and Western Part of the Beaver Bay Complex, Lake and St. Louis Counties, Minnesota, by Val W. Chandler.  The zip file was created with WinZip 7.0 on NT4.0.  The shape files and grids are compiled in an ArcView 3.x project file entitled cdulmag_grav.apr.  Note: Although the gravity and magnetic data are shown superimposed, the grids are available in the project for viewing or use as separate themes. The publication scale of the map is 1:100,000.  It is not recommended that the data be used at larger scales.

ESRI Spatial Analyst is a required ArcView extension to open the project file.

The map plate image was created at a resolution of 144 dpi and depending upon the viewing software may not print at a 1:100,000 scale.

Metadata is provided in Acrobat Reader 3.0 and higher PDF format as cdulmeta.pdf 

The map presents derivative-enhanced aeromagnetic (gray scale) and gravity (color scale) data for the central Duluth Complex and western Beaver Bay Complex.  A presentation of this type showing two discrete data sets is called a Superimposed Magnetic on Gravity (SMOG) map.  These data are used in geologic mapping to trace density and magnetization variations in the near-surface bedrock.  Accordingly, these derivative data were used in conjunction with outcrop and drill-hole data to compile a bedrock geologic map of the area, published by the Minnesota Geological Survey as Miscellaneous Map M-101 (Miller and Chandler, 1999).


Shape file and grid naming:  All files with clp or clpd indicate locations extracted from larger file.

Project file:  cdulsmog
	View1 - SMOG map and base
	View 2 - unreclassed aeromagnetic grid, used for legend
	Layout - SMOG map layout

Shape files in directory
	amgdnew - aeromagnetic grid, part of view2, the original of the reclassed aeromagnetic grid used for the superimposition.
	bsan2 - annotation themes for base (trs, latlon, rivers, lakes cities, counties)
	ctyln - county line
	ctour2 - zero contour line from the gravity grid
	grptclpd - gravity stations within study area
	lakes - lake outlines
	major roads - major road lines
	minor roads - 	minor road lines
	papg - study area outline
	railroad lines - railroad lines
	rivers - river lines
	section lines - Township, range, section lines
	grgdclp - gravity grid used for color-fill contour map
	rclss1 - aeromagnetic grid reclassed to overlay, as a gray scale image, the gravity grid

Other files:
readme.txt - introduction to the map and digital files.
cdulmeta - metadata about the major themes in the A.V. project.
wrkmrk.tif - U of Minneosta word mark, used in layout
Location map cdc 60%.wmf - index map to study area, used in layout

Info Folder - required ArcView files for A.V. use.