Graduation Year

2018

Date of Submission

5-2018

Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts

Department

Environmental Analysis

Reader 1

Robert Gaines

Reader 2

Colin Robins

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Rights Information

© 2018 Fiona M Käch

Abstract

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.

This thesis is restricted to the Claremont Colleges current faculty, students, and staff.

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