Pollen, Spores, and the Dalton Coal (Upper Pennsylvanian) of Northern Texas

Judith Gennett, Robert Ravn, Anne Raymond

The Missourian Dalton coal is an extremely high-ash deposit found near Mineral Wells in northern Texas. Controversy exists as to whether the coal is an allochthonous deposit. Rooted coal balls occur in the extreme upper part of the Dalton, which yields macrofossils of plants such as Cordaites and Marattialean ferns. The lower portion of the Dalton, however, contains marine fossils including crinoid plates and brachiopod shell fragments. In addition, no rooting occurs at the base of the coal.

Palynomorphs from seven sequential samples of the Dalton coal and one overlying shale sample were examined. Common taxa include Laevigatosporites spp. (probably a sphenopsid) and Marattalian tree fern spores, Punctatosporites sp. and Cyclogranisporites orbicularis. Twenty-one other taxa were also found. Unlike most palynomorph sequences constructed for coals and modern peats, few quantitative changes occur within the Dalton. Moreover, palynomorph spectra from the coal are very similar to the spectrum from the overlying shale. This homogeneity suggests that similar processes deposited both the coal and the shale.

AAPG Search and Discovery Article #91036©1988 GCAGS and SEPM Gulf Coast Section Meeting; New Orleans, Louisiana, 19-21 October 1988.