AZGS wunderkind Ryan Clark has built a demonstration interactive geologic map of the Grand Canyon region, using the geologic maps prepared by George Billingsley of the USGS.
Run your cursor over the map and the geologic unit name and description appear in the legend at the lower left. Although the maps were published at 1:100,000 scale, the original mapping was done at 1:24,000.
Finding Nemo – Sat, Apr 22
1 hour ago