The Geologic Map of North America was published in 2005 by John C. Reed, Jr. (USGS), John O. Wheeler (Geological Survey of Canada), and Brian E. Tucholke (Woods Hole Oceanographic Institution). This is an amazing piece of work that covers the entire continent of North America at a scale of 1:5,000,000. The map distinguishes 939 geologic units, including 142 that are offshore. The map also depicts many geologic features including volcanoes, calderas, impact structures, axes of submarine canyons, spreading centers, transform faults, magnetic isochrons, and subduction zones. There are several websites that make the map and associated GIS data files available online.
- Resources for the Geologic Map of North America
- Database of the Geologic Map of North America
- Geologic Map of North America
Unfortunately, none of the websites provide a truly simple way for a layperson to view the map instantly online, and I will try to bridge that gap by converting into several different formats that will make it much easier for anyone with a web browser and/or Google Earth to view the map online.
I have also created modified versions of the map that will provide a different perspective than is possible with the original map. These include two versions of the map that add 3D hill shading using elevation data from NASA. The hill shading shows the relationship between topography and geology in such a way that is not possible by looking at the flat version of the map. I also created a version based on the Winkel Tripel Projection that provides a slightly different perspective.
The various versions of the map are available below.
Google Earth Versions
There are two versions of the map which can be viewed in Google Earth. The first version is the original flat map. The second version has the 3D hill shading added. Just click on the button below to open up the maps with Google Earth.
Zoom.it is a Microsoft Labs website that makes it very simple to view huge images online and works great for displaying high resolution maps such as these. I have created three versions of the Geologic Map of North America which can be viewed with Zoom.it. Simply navigate around the maps below using your mouse. Click on the icon in the lower right corner to view the map in full screen mode.
The first version is the original map.
The next version has 3-D hill shading added.
The final version is reprojected to Winkel Tripel Projection, which shows the map in a slightly different perspective. This version also has the 3-D hill shading.
Lastly, below is the Legend.