Abstract

A district in central Colorado is described in which coals of various ranks occur in a restricted area. Some of these coals have been altered by the intrusion of laccoliths whereas others have been affected only by minor folding. The individual effects of heat and pressure in the development of anthracite are discussed, and a theory of anthracitization is propounded utilizing shear strains and heat developed through friction.

First Page Preview

First page PDF preview
You do not currently have access to this article.