PALYNOLOGY IN COAL SYSTEMS ANALYSIS—THE KEY TO FLORAS, CLIMATE, AND STRATIGRAPHY OF COAL-FORMING ENVIRONMENTS

Palynology has been closely and productively associated with coal geology since the early 1900’s, when spores were first observed in coal of Pennsylvanian age. Pollen and spores from coal beds of Cenozoic age have been investigated since the 1930’s. Early applications of palynology to coal geology centered on attempts to correlate coal seams, efforts that met with limited success owing to the origin of most penecontemporaneous coal palynofloras in the similar local vegetation of ancient mires. Rather than its geologic age, a coal palynoflora tends to reflect the paleoecology of the mire. The palynoflora derived from local vegetation of a mire can be an excellent indicator of the floristic composition of the plant community producing the coal-forming peat, and of the paleoclimate in which it existed.

In research on coal-depositional environments, palynology can be the key to interpretation of the nature and composition of mire floras. Understanding the kinds of plants that inhabited ancient peat mires is a basis for understanding variations in constituents of coal. Detailed studies of abundance and distribution of palynofloras within seams enhance stratigraphic analysis at the level of individual coal beds; at the level of coal zones, palynologic dating serves to place these depositional systems in their full stratigraphic context. Data for age determination can be obtained from the regional vegetation, as it is reflected by palynomorphs from clastic rocks associated with coal deposits.

As is demonstrated by recent studies of Paleocene coal in the Great Plains and Gulf Coast regions, analysis of coal-depositional environments can benefit from comprehensive investigation of the palynology of coal beds and associated rocks. Such an approach is essential in modern coal research because it provides the fundamental framework for classification of coal and associated deposits into coal systems.