The organic-rich mudrocks of the Jurassic Fernie Formation in British Columbia, Canada contain unusual silica concretions. The silica originated from dissolved volcanic ashes found in the Highwood Member. A lack of radial trends in d13C and internal zonation demonstrate that these concretions grew pervasively. Stable isotope data from calcite inter-grown within the silica matrix (d13C and d18O) indicate that the concretions formed during sulfate reduction and methanogenesis. The d34S revealed a suppressed sulfur fractionation and suggest that they formed in a system that became progressively closed. The Fernie concretions offer insight into the formation of siliceous concretions in marine environments.
| Identifer | oai:union.ndltd.org:CLAREMONT/oai:scholarship.claremont.edu:cmc_theses-3049 |
| Date | 01 January 2018 |
| Creators | Käch, Fiona |
| Publisher | Scholarship @ Claremont |
| Source Sets | Claremont Colleges |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | CMC Senior Theses |
| Rights | © 2018 Fiona M Käch, default |
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