The Geologic Environment of Coking Coal of Western North America with Emphasis on the Canadian Scene
VARD H. JOHNSON, Consulting Geologist, Palo Alto, California
In contrast with the well-publicized Pittsburgh coal, and the Everglades of Florida, most coal-forming swamps of Cretaceous time in western North America occupied relatively limited areas. They formed in areas of irregular subsidence, bounded by the changing levee systems of meandering streams. Coke quality is determined by the physical and chemical behaviour of the vitrain during thermal decomposition. Vitrain is at least in part a colloidal substance, originally containing large proportions of water; its formation and survival depend on maintaining a shallow cover of stagnant water up to the time of burial. Heat from swamp fires or subaerial dyhydration could destroy it or impair its quality.
Canadian, Coal, Coke, Cokes, Coking, coking, Crowsnest coal, Metamorphism, sandstone, volatile, Metamorphism, Oxygen, quality, stress