The Geologic Story of Isle Royale National Park
Huber NK. 1973. The Geologic Story of Isle Royale National Park. USGS Bulletin 1309. Washington, DC
A unpublished manuscript concerning the geologic history of Isle Royale. Includes descriptions of the types of rocks that make up Isle Royale including stratigraphy. Discusses geologic time and the effects of glaciation. Describes minerals of special interest including copper, chlorastrolite (Isle Royale greenstone), prehnite, and agate.