Some environments of Late Pennsylvanian coal deposition, upper Ohio Valley, eastern Ohio, northern West Virginia and western Pennsylvania, USA
- Michigan State Univ., East Lansing, MI (United States). Dept. of Geological Sciences
Diverse environments of accumulation are identified for coals and associated rocks in mines and outcrops in the upper Ohio River Valley. Some Kittanning coals are associated with thick fireclay or plastic underclay and locally, with thick deposits of evenly-laminated, dark bayfill sediments of marine or brackish origin. Freeport coals show some of the same characters. At that time, the region appears to have been one of marginally interdigitating marine and freshwater alluvial deposits with great irregularity of dimensions of prograding distributary delta lobes and intervening bays and estuaries. Conemaugh strata at mines near West Point and East Liverpool, and at roadcuts near Steubenville and Weirton are exceedingly variable locally above the Brush Creek limestone and marine shale sequences; below this they are less variable and contain commercial coals. The earliest of the red or variegated red/green shales and calcareous mudstones and other paleosols of the Conemaugh Formation first appear in this zone (Mahoning) and become predominant above the Brush Creek. Regional variation is demonstrated by comparing river bluff sections near Weirton with open-pit mine sections to the northwest. Oxidized mudstones of distal delta plains, delta plain coals and interlobate bayfill mudstones of these sections are penecontemporaneous. Lower Monongahela strata, including the important Pittsburgh coalbed, demonstrate a regional shift from lacustrine gray shales, limestones, commercial coals and alluvial sandstones westward and southward to calcareous shales, fewer sandstones and thin coals, to red/green oxidized calcareous to non-calcareous shales with occasional coaly zones. Channel-fills of various environmental origins are identified by plant and animal fossils associated with the several environments of deposition. In the classic Linton vertebrate site near Yellow Creek, sapropelic (canneloid) coal accumulation preceded the deposition of the thick Upper Freeport humic coal in a deep meandering paleochanncel. Differential compaction, slump structures, dewatering features, and joint patters are also related to different types of environments.
- OSTI ID:
- 349057
- Report Number(s):
- CONF-980985-; ISBN 1-890977-15-2; TRN: IM9924%%57
- Resource Relation:
- Conference: 15. annual international Pittsburgh coal conference, Pittsburgh, PA (United States), 14-18 Sep 1998; Other Information: PBD: 1998; Related Information: Is Part Of Fifteenth annual international Pittsburgh coal conference: Proceedings; PB: [1500] p.
- Country of Publication:
- United States
- Language:
- English
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