Composition and origin of facies of the Upper Freeport coal bed
A detailed study of the Upper Freeport coal bed, in a 120-square mile area in west-central Pennsylvania, indicates that the bed which varies from 4 to 8 feet thick, can be subdivided into at least ten facies. Peat formed within a shallow lacustrine-fluvial-swamp setting that developed on a previously subaerially-exposed carbonate-rich mud. The facies probably formed in three successive stages. In the first stage, topogenous, detritus-rich, low-lying peat formed in near-neutral pH conditions and resulted in 3 to 7 banded, vitrain-poor, coal-bed facies that are enriched in semifusinite; in the second stage, soligenous(.), detritus-poor, raised peat formed in acid pH conditions that resulted in 1 to 2 banded, vitrain-rich, coal-bed facies that are enriched in micrinite and sporinite; and in the third stage, peat islands formed that produced 1 to 2 nonbanded and 1 to 2 banded coal-bed facies of limited areal extent that are enriched in inertodetrinite. An intermediate peat facies probably developed between a contemporaneous stream and facies of the second stage resulting in a coal-bed facies that contains thick vitrain and discrete clay-rich layers. Ash and sulfur isopleths of coal-bed facies that constitute each stage show the following: in the first stage, both ash and sulfur increase toward the margins of the coal body where it intertongues with fluvially deposited rocks; in the second stage, ash distribution is random, whereas sulfur variability is correlated with roof lithology; and in the third stage, concentrations of both ash and sulfur are greatest at facies margins where the facies thin abruptly.
- Research Organization:
- Geological Survey, Reston, VA (USA)
- OSTI ID:
- 6209962
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 36; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COAL DEPOSITS
ASH CONTENT
DEPOSITION
SULFUR CONTENT
PENNSYLVANIA
CHEMICAL COMPOSITION
COAL SEAMS
COALIFICATION
GEOLOGIC HISTORY
MACERALS
ORIGIN
PEAT
PH VALUE
ENERGY SOURCES
FEDERAL REGION III
FOSSIL FUELS
FUELS
GEOLOGIC DEPOSITS
MINERAL RESOURCES
NORTH AMERICA
ORGANIC MATTER
RESOURCES
USA
010000* - Coal
Lignite
& Peat
010600 - Coal
Lignite
& Peat- Properties & Composition