Development of low-ash, planar peat swamps in an alluvial-plain setting: The no. 5 Block beds (westphalian D) of southern West Virginia

Journal Article · Thu Jul 01 00:00:00 EDT 1993 · Journal of Sedimentary Petrology; (United States)

OSTI ID:6183345

Staub, J R; Richards, B K ^[1]

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1. Southern Illinois Univ., Carbondale, IL (United States). Dept. of Geology

Coals from the No. 5 Block coal beds (Westphalian D) of the central Appalachian basin are noted for their blocky, dull character and their low ash and low sulfur content. The beds are multiple benched, with rock partings separating benches. Individual benches have limited lateral extent and, where thick, are dominated by bright, high-ash coal at the base and dull, low-ash coal in the upper parts. The duller coals contain more exinite-group and inertinite-group macerals than the brighter coals. These coal beds are encased in sandstone units dominated by fining-upward sequences. The overall depositional setting is an alluvial-plain environment with northwest-flowing channels spaced approximately 20 km apart. The channels were flanked by clastic swamps about 7 km wide. Low-ash peat accumulated in areas of the flood plain most distant from the channels. These peat-accumulating swamps were about 8 km across. In a few instances low-frequency flood events introduced fine siliciclastic sediment into the peat swamps, depositing a thin layer of sediment on top of the peat. This sediment layer is thicker where the underlying coal is the thickest. These thick coal areas are topographically lower than surrounding coal areas. This relationship between coal thickness, parting thickness, and topography indicates that these peat swamps were planar at the time of deposition. Individual coal benches contain abundant preserved cellular tissue (telocollinite, semifusinite, and fusinite) at most locations, suggesting that robust vegetation was widespread in the swamps and that the morphology was planar. The high concentrations of exinite-group an inertinite-group macerals in the upper parts of benches resulted from selective decomposition and oxidation of the peat in subaerial and aquatic planar-swamp environments.

• OSTI ID: 6183345
• Journal Information: Journal of Sedimentary Petrology; (United States), Vol. 63:4; ISSN 0022-4472
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL DEPOSITS
GEOLOGY
WEST VIRGINIA
ASH CONTENT
CARBONIFEROUS PERIOD
COAL
COAL SEAMS
DEPOSITION
GEOLOGIC HISTORY
MACERALS
SULFUR CONTENT
CARBONACEOUS MATERIALS
DEVELOPED COUNTRIES
ENERGY SOURCES
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MATERIALS
MINERAL RESOURCES
NORTH AMERICA
PALEOZOIC ERA
RESOURCES
USA
011000* - Coal
Lignite
& Peat- Reserves
Geology
& Exploration