Abstract

Coals of Cretaceous and younger age occur extensively in three major regions in the Western U.S.A.: the Great Plains Region, the Rocky Mountain Region and the Pacific Coast Region. The Great Plains coals occur in Upper Cretaceous strata, but much more predominantly in Eocene and younger rocks. Only an insignificant portion of production in this region results from thin Cretaceous coal seams.

Rocky Mountain region coal development is widespread in Late Cretaceous and younger strata. Remnants of this deposition occur in 8 major areas and a few minor basins. The resource base of this region is 296 billion tons or about 23 per cent of the coal resources of the entire country. 1980 production was in excess of 85 million tons and represents 10.5 per cent of U.S. production. Of the remaining coal resources, 12 billion tons are lignite, 161 billion tons are sub-bituminous and 122 billion tons are bituminous or higher ranked. Nominal metallurgical coal reserves occur in the Uinta and Raton Mesa areas.

In the Pacific Coast region, scattered intermontagne basins of Upper Cretaceous and Tertiary Age contain mineable coal seams. These coals vary widely in rank and quality, have only a 6 billion ton resource base and represent less than 1 per cent of U.S. coal production.