Introduction to the Volume
Many of the concepts presented in this volume evolved from work by the U.S. Geological Survey on the origin of mineral matter in coal. This work, sponsored primarily by the U.S. Environmental Protection Agency, was undertaken in response to The Clean Air Act of 1970, which was implemented, in part, to regulate emissions from coal-burning power plants. Because coal composition (coal quality) varies within and among coal reserves, there was a need for geologic models that explain and predict these variations. Using the depositional-environment models that were popular at the time, we attempted to delimit and predict the local and regional variations of mineral matter in an upper Middle Pennsylvanian coal deposit in the bituminous coal fields of the northern Appalachian Basin. According to the available depositional models, coal beds were derived from peat that formed in environments such as delta plains or fluvial systems, all of which involve movement of large amounts of siliciclastic sediment. In the broadest sense, these depositional settings were the autocyclic environments of Beerbower (1964). On the basis of depositional models, many workers believed that allochthonous processes controlled the distribution of mineral matter in coal. Consequently, aluminosilicates and quartz were thought to be mainly detrital, and the sulfur content of coal was attributed to the degree of marine influence during peat formation. Our application of these depositional models failed to explain either the local or the regional distribution of mineral matter in the initial study area, and in Pennsylvanian coal beds in the Appalachian Basin in general.