Generalized map showing Precambrian rocks and metamorphic facies, keyed to aluminosilicate minerals in meta-shales with excess alumina, northern Park Range, Colorado
January 1, 1980
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.
