Date of Award
Master of Arts (MA)
F.D. Holland, Jr
The Hagel bed is an economically important lignite and is the lowest named lignite in the Sentinel Butte Formation, Fort Union Group. The Hagel bed extends throughout the Knife River Basin coal-mining area of central North Dakota. Stratigraphic sections of the Hagel bed, including intercalated clastic rocks, were measured in the highwalls of the Center mine, Glenharold mine, and Falkirk mine.
Samples from the stratigraphic sections were described and analyzed, using standard palynological techniques, for their palynomorph content. Palynomorphs proved to be well preserved and abundant. Maceration of Hagel bed samples yielded a diverse collection of palynomorphs. A total of seventy-five palynomorph types consisting of thirty form genera, five extant genera, and thirty-seven morphotypes were described. Common constituents of the palynoflora include representatives of the modern classes Gymnospermae, Angiospermae, Filicineae, and Musci.
Palynologic evidence suggests that the contributing flora was dominated by swamp-forest taxa (e.g., Osmunda, Steriosporites antiguasporites, and some Taxodiaceae). Deciduous plants were dominated by riparian types (e.g., Alnus) and were consistently present but made small contributions to the palynoflora.
Palynologic percentage-frequency data were used to elucidate floral trends present. The palynomorphic associations present (based on groups of high taxonomic rank) were interpreted as a single, relatively consistent palynoflora.
A preliminary investigation of the relationship of palynologic data to present-day coal chemistry was inconclusive. A correlation of palynomorphic and geochemical data suggested that palynomorphs have a potential utility as geochemical biomarkers with further study.
Palynologic evidence and corroborating lithologic evidence suggest that the alternating deposition of clastics and coal precursors was controlled by the lateral shifting of fluvial and lacustrine environments marginal to the forest-swamp environment. The local depositional basin was broad, laterally continuous, and possessed little relief. Relatively minor changes in water level may be responsible for laterally continuous alternating clastic-to-coal depositional sequences found in the study area.
Steadman, Edward N., "Palynology of the Hagel lignite bed and associated strata, Sentinel Butte Formation (Paleocene), in central North Dakota" (1985). Theses and Dissertations. 285.