2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 246-7
Presentation Time: 2:20 PM

COMPOSITION AND INFERRED ORIGIN OF THE VANCLEVE COAL BED IN THE EASTERN KENTUCKY COALFIELD, CENTRAL APPALACHIAN BASIN


BACKUS, Jason, Kentucky Geological Survey, University of Kentucky, 228 MMRB, Lexington, KY 40506, EBLE, Cortland, Kentucky Geological Survey, University of Kentucky, 228 Mining and Mineral Resources Bldg, Lexington, KY 40506-0107 and GREB, Stephen F., Kentucky Geological Survey, University of Kentucky, 228 Mining and Mineral Resources Building, Lexington, KY 40506-0107

This study reports on the palynology, petrography and geochemistry of the Vancleve coal bed, sampled from new exposures provided by recent road construction along Kentucky Route 15 in eastern Kentucky. The Vancleve coal bed is a late Early Pennsylvanian age coal bed that occurs, and was historically mined, in the vicinity of Vancleve, Kentucky. The Vancleve coal bed has an average thickness of 0.6 m in the study area, is low in ash yield (avg. 6.6 %, dry basis), and moderate to high in total sulfur content (avg. 3.3 %, dry basis).

Palynologically, the coal bed is dominated by Lycospora, which was produced by many of the large lycopsid trees that were conspicuous elements of Early Pennsylvanian floras. Spore and pollen contribution from other plant groups, including ferns, calamites and cordaites, are minor by comparison. Vertical species variation Lycospora is evident. Bottom benches contain increased percentages of Lycospora micropapillata and L. orbicula, both of which were produced by Paralycopodites. In contrast, middle and top coal benches are dominated by Lycospora pellucida and L. pusilla, which represent Lepidophloios and Lepidodendron respectively. This species change reflects the maturing of the coal-forming mire flora. Paralycopodites is regarded as a colonizing lycopsid, while Lepidophloios and Lepidodendron represent a more mature lycopsid mire flora.

Petrographically, the Vancleve coal bed contains high percentages of vitrinite macerals (avg. 80 %, mmf), with telovitrinite occurring more frequently than detrovitrinite and gelovitrinite (avg. TV/DV + GV = 3.2). Liptinite macerals, mainly sporinite, and inertinite macerals are minor in abundance by comparison.

The Vancleve paleomire is interpreted to have been planar, with a consistently high water table. Flooded conditions would have allowed lycopsid trees to proliferate, as these plants had developed strategies for growth and reproduction in very wet areas. The same conditions also promoted the formation of coal high in vitrinite and total sulfur contents.