Date of Submission
Campus Only Senior Thesis
Bachelor of Arts
© 2018 Fiona M Käch
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.
Käch, Fiona, "Unearthing the Past: Concretions of the Jurassic Fernie Formation" (2018). CMC Senior Theses. 1833.
This thesis is restricted to the Claremont Colleges current faculty, students, and staff.