Distribution and isotopic composition of sulfur in the Upper Freeport Coal of western Pennsylvania

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:5932931

Whelan, J F; Cecil, C B; Dulong, F T; Stanton, R W

The Upper Freeport Coal (UFC) of west-central Pennsylvania is separated into upper, middle, and lower facies on the basis of distinctive mineral and maceral assemblages. Microscopic examination of these facies revealed two distinct types of pyrite occurrence: (1) finely disseminated framboids and well-formed crystals; and (2) coarser, irregularly shaped pyrite (with minor marcasite) that in part replaces the coal macerals. Both pyrite concentration (wt.%) and pyrite /delta//sup 34/S values are strongly correlated with pyrite morphology. The lower facies of the UFC contains /approx/1.9% pyrite of type 1 that has /delta//sup 34/S values of /approx/1 /per thousand/. The upper facies contains /approx/4.3% pyrite (+marcasite) of type 2 that has /delta//sup 34/S values of /approx/10 /per thousand/. Both pyrite types were deposited prior to significant compaction, from H/sub 2/S produced during bacterial sulfate reduction. The difference in the /delta//sup 34/S values of the two pyrite types reflects either different sulfate sources or reduction of a greater proportion of the sulfate available during formation of the coarser pyrite. The depositional and diagenetic setting of the UFC is entirely nonmarine, yet the high pyrite content of the upper facies is equivalent to that of many high-sulfur coals that were influenced by marine waters during early diagenesis. However, marine-influenced coals that were the site of extensive bacterial sulfate reduction have organic sulfur contents of several percent, compared to uniformly low organic sulfur contents of /approx/0.6% in the UFC. The low organic sulfur content of the UFC most likely reflects the different chemistry of the fresh water diagenetic conditions.

• Research Organization: Geologic Survey, Denver, CO (USA)
• OSTI ID: 5932931
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

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CARBONACEOUS MATERIALS
CHALCOGENIDES
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FEDERAL REGION III
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IRON COMPOUNDS
IRON SULFIDES
ISOTOPE RATIO
ISOTOPES
MACERALS
MATERIALS
MINERAL RESOURCES
MINERALS
NORTH AMERICA
PENNSYLVANIA
PYRITE
QUANTITATIVE CHEMICAL ANALYSIS
RESOURCES
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
SULFUR CONTENT
SULFUR ISOTOPES
TRANSITION ELEMENT COMPOUNDS
USA