| Title | Microbial and thermochemical controlled sulfur cycle in the Early Triassic sediments of the Western Canadian Sedimentary Basin |
| Associated Data | https://doi.org/10.6084/m9.figshare.c.5272484 |
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| Author | Liseroudi, M H; Ardakani, O H ; Pedersen, P K; Stern, R A; Wood, J M; Sanei, H |
| Source | Journal of the Geological Society 2021 p. 1-20, https://doi.org/10.1144/jgs2020-175 |
| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20200695 |
| Publisher | Elsevier |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Province | Alberta; British Columbia |
| NTS | 83L/13; 83L/14; 83L/15; 83M/02; 83M/03; 83M/04; 83M/05; 83M/06; 83M/07; 83M/10; 83M/11; 83M/12; 83M/13; 83M/14; 83M/15; 93P/01; 93P/02; 93P/06; 93P/07; 93P/08; 93P/09; 93P/10; 93P/11; 93P/14; 93P/15;
93P/16 |
| Area | Dawson Creek |
| Lat/Long WENS | -121.5000 -118.5000 56.0000 54.7500 |
| Subjects | fossil fuels; geochemistry; sedimentology; mineralogy; Nature and Environment; Science and Technology; Lower Triassic; paleoenvironment; continental margins; continental shelf; sulphur geochemistry;
pyrite; hydrogen sulphide; sulphate; isotopic studies; sulphur; diagenesis; anhydrite; bitumen; microorganisms; biogeochemistry; petrographic analyses; mass spectrometer analysis; methane; thermal analyses; reservoir rocks; burial history; modelling;
Western Canada Sedimentary Basin; Montney Formation; Phanerozoic; Mesozoic; Triassic |
| Illustrations | location maps; geoscientific sketch maps; stratigraphic columns; schematic representations; models; tables; photomicrographs; geochronological charts; histograms; plots; time series |
| Program | Geoscience for New Energy Supply (GNES) Shale Reservoir Characterization |
| Released | 2021 03 08 |
| Abstract | Pyrite is one of three main sulfur reservoirs and one of the biggest fluxes in the global sulfur cycle. The sulfur isotopic signature of hydrogen sulfide, pyrite and their parent sulfate is widely used
as a proxy for tracking sulfur cycle variations in diagenetic environments. The Early Triassic Montney Formation in the Western Canadian Sedimentary Basin is characterized by distinct regional variations in pyrite abundance, type, sulfur isotopic
signature and H2S concentrations in natural gas. Two main types of framboidal and crystalline pyrite were identified to have formed during various stages of diagenesis. The wide range of delta-34Spyrite values (-34.4 to +57.8 per mille V-CDT)
demonstrates that the sulfur cycle in the Montney Formation is governed by both microbial and thermochemical processes. The comparison of delta-34S of the produced-gas H2S with pyrite, anhydrite and solid bitumen of the Montney, and underlying and
overlying formations, suggests a mixture of dominantly in situ and minor migrated H2S with thermochemical sulfate reduction origin in the Montney Formation. The large diagenetic variations in pyrite types and delta-34Spyrite values suggest a lack of
direct biogeochemical connection to the sulfur cycle and emphasize the importance of careful petrographic observations and micro-scale isotopic analysis of sedimentary units to accurately reconstruct paleoenvironmental conditions. |
| Summary | (Plain Language Summary, not published)
The Early Triassic Montney Formation in the Western Canadian Sedimentary Basin (WCSB), one of the major unconventional resources in Canada, is
characterized by distinct regional variation in H2S concentrations within natural gas-producing wells, pyrite abundance, and type, as well as sulfur isotopic signature. The current study aims to unravel the diagenetic sulfur cycle in this
unconventional gas play using H2S/HS (?H2S) and pyrite sulfur isotopic composition to better understand the origin and mechanism(s) involved in H2S generation in the Montney Formation. |
| GEOSCAN ID | 327985 |
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