Oxygen Isotope Dynamics of Lake Water and Dissolved Phosphate in Saline Lakes of the Cariboo Plateau of British Columbia, Canada

Simple item page
dc.contributor.advisorTutolo, Benjamin
dc.contributor.authorWalters, Liam
dc.contributor.committeememberMayer, Bernhard
dc.contributor.committeememberBarst, Benjamin
dc.contributor.committeememberTutolo, Benjamin
dc.date2025-02
dc.date.accessioned2025-01-29T23:14:26Z
dc.date.available2025-01-29T23:14:26Z
dc.date.issued2025-01-17
dc.description.abstractPhosphate availability is a critical constraint on prebiotic chemistry, yet natural environments rarely achieve concentrations compatible with origin-of-life experiments. Alkaline and saline lakes have emerged as potential solutions to this "phosphate problem," but the mechanisms controlling phosphate cycling in these extreme environments remain poorly understood. Here, I investigate phosphate dynamics in the alkaline Last Chance and Goodenough Lakes and the magnesium sulfate-rich Basque Lakes of British Columbia's Interior Plateau using oxygen isotope analysis of dissolved phosphate (δ¹⁸OPO₄) and lake waters (δ¹⁸OH₂O). I developed a modified silver phosphate precipitation protocol to enable isotopic analysis of phosphate in these chemically extreme waters. My results show that Last Chance Lake maintains phosphate concentrations up to 12 mmol/L through primarily abiotic processes, evidenced by significant deviations (up to +5.3 ‰) from oxygen isotopic equilibrium (denoted Δδ¹⁸OPO₄). However, neighboring Goodenough Lake's extensive microbial mats drive near-equilibrium signatures (Δδ¹⁸OPO₄ ≈ +2.2 ‰) while limiting phosphate accumulation. In contrast, my analysis of the Basque Lakes demonstrates how extreme brine chemistry can maintain phosphate far from equilibrium (Δδ¹⁸OPO₄ up to +10.7 ‰) through abiotic processes such as adsorption and phosphate mineral precipitation. These findings validate theoretical predictions of phosphate concentration mechanisms in alkaline environments and provide a framework for interpreting potential biosignatures in ancient Earth settings and extraterrestrial environments.
dc.identifier.citationWalters, L. (2025). Oxygen isotope dynamics of lake water and dissolved phosphate in saline lakes of the Cariboo Plateau of British Columbia, Canada (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.urihttps://hdl.handle.net/1880/120506
dc.language.isoen
dc.publisher.facultyGraduate Studies
dc.publisher.institutionUniversity of Calgary
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectPhosphate
dc.subjectIsotopes of water
dc.subjectOxygen isotopes of dissolved phosphate
dc.subjectAlkaline and saline lakes
dc.subjectAstrobiology
dc.subjectOrigin-of-life
dc.subject.classificationBiogeochemistry
dc.subject.classificationGeochemistry
dc.titleOxygen Isotope Dynamics of Lake Water and Dissolved Phosphate in Saline Lakes of the Cariboo Plateau of British Columbia, Canada
dc.typemaster thesis
thesis.degree.disciplineGeoscience
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameMaster of Science (MSc)
ucalgary.thesis.accesssetbystudentI do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
ucalgary_2025_walters_liam.pdf
Size:
1.72 MB
Format:
Adobe Portable Document Format
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
2.62 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Open Theses and Dissertations