An official website of the United States government
Here's how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Latest Earthquakes | Chat Share
This report describes a digital geologic GIS database in an Arc/Info format for the “Geologic Map of Arizona” by Wilson and others (1983 edition).