Petrology, palynology, and depositional environments of coals of the Upper Carboniferous Barachois Group (Westphalian A and C), southwestern Newfoundland
Coal samples from the Barachois Group of western Newfoudland vary in rank from high-volatile C to high-volatile A. The coals are vitrinite rich (> 70%), except some from Coal Brook that contain substantial quantities of inertinite (up to 52%). Liptinite ranges up to 18% but is a relatively minor...
| Published in: | Canadian Journal of Earth Sciences |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1991
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/e91-172 http://www.nrcresearchpress.com/doi/pdf/10.1139/e91-172 |
| Summary: | Coal samples from the Barachois Group of western Newfoudland vary in rank from high-volatile C to high-volatile A. The coals are vitrinite rich (> 70%), except some from Coal Brook that contain substantial quantities of inertinite (up to 52%). Liptinite ranges up to 18% but is a relatively minor component. The most abundant constituents amongst the three maceral groups are vitrinite – vitrinite A, inertinite–semifusinite, and liptinite–sporinite. Compositional profiles in three of the seams show no clear correlation between maceral group content and stratigraphic position. The Barachois Group coals are relatively high in ash (mean = 12.8%) and sulphur (mean = 6.9%). Spore assemblages from coal samples of the Barachois Group indicate a Westphalian A age in the Barachois Brook and Coal Brook areas and a Westphalian C age along Blanche Brook.Barachaois coals are part of a mudstone-dominated facies association that developed in an assemblage of floodplain environments. Plots of tissue preservation – gelification indices (TPI/GI) and the assemblages of spores derived from vascular plants suggest that most peats were generated in wet, forested tracts that, from the high ash content, occupied low-lying interfluves. Less wooded fen environments are also indicated, particularly in the Blanche Brook seams, by TPI/GI plots and a spore assemblage suggesting incursion of flood waters and dominance of herbaceous vegetation. Inertinite-rich samples from Coal Brook show extreme variation in paleoenvironmental conditions, which include dry forested regions. |
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