Stratigraphic Classification of Coals and Coal-Bearing Sediments
Coal beds are normal lithologic components of numerous Stratigraphic sequences of sedimentary rock and therefore should be amenable to the same basic principles of lithostratigraphic classification and terminology as other common sedimentary-rock types. However, because of the distinctive lithologic character of coal and its commercial value, the individual bed of coal is particularly important and serves to point up the role of bed as a formal lithostratigraphic unit. Sequences of several distinct but associated coal beds may constitute the basis for unification of strata into larger formally named coal-bearing lithostratigraphic units of the rank of member, formation, or group.

The general principles of lithostratigraphic classification and terminology are reviewed with particular reference to coals and coal-bearing strata, and hypothetical situations are diagrammatically illustrated to show the application of these principles.