Geologic Maps are unique in that they show the distribution of geologic features on a landscape through specific symbols and colors. The United States Geological Survey's (USGS) site Geologic Maps provides visitors with a good introduction to these concepts, which include the unique features of a geologic map; the meaning of their lines, colors, and symbols; the location of faults; and more....

This rather remarkable website contains a great collection of resources for web-based instruction and demonstrations of geology concepts. The collection includes, under Classroom demonstration, the very useful SeisMac 3.0, which is an application for Mac OS X that turns a laptop computer into a " low-resolution strong-motion accelerometer," or a basic seismograph. It works by accessing the...