Olivine diversity in the Leslie kimberlite, NT, Canada : implications for transport and emplacement processes
department or school: Science, Faculty of
department or school: Earth, Ocean and Atmospheric Sciences, Department of
data provider: DSpace
degree campus: UBCV
creator: Landoni, Katherine
issued: 2022-04-14T16:42:27Z
issued: 2022
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Olivine crystals are ubiquitous in kimberlites and record petrologic events through all stages of ascent and eruption. Well-preserved olivine from the Leslie kimberlite, NT, Canada elucidates the sequence of events attending kimberlite emplacement. The Leslie kimberlite mainly hosts a single phase of extrusive coherent kimberlite. We used spatially distributed samples (n = 76) from drill core to develop a 3D representation of the Leslie kimberlite. Petrographic investigation defined four distinct olivine populations: phenocrysts, macrocrysts, dunite “nodules”, and mantle xenolith-hosted olivine. SEM imagery, and major and trace element geochemistry were used to characterize and quantify chemical zonation including xenocrystic cores, mid-zones, magmatically crystallized rims, high-Mg rinds, and/or monticellite coronas. Core compositions (Fo85.7 to Fo93.8, NiO ~0.36 wt%) and other textural evidence show that cores are mantle-derived olivine xenocrysts. Mid-zones developed on cores show a sharp decrease in Fo content (~Fo90.9) across irregular, convoluted, and embayed contacts indicating disequilibrium and partial dissolution of the olivine xenocrysts combined with diffusion-driven replacement. Magmatically crystallized olivine rims can jacket xenocrystic cores and mid-zones. Rims have uniform and distinctive chemical compositions of ~Fo91.8 ± 0.7 (2σ) and NiO concentrations that decrease (~0.4 wt% to ~0.1 wt%) outward. Rinds, thin outer fringes, have a convoluted inner contact and a sawtooth contact with the groundmass. Rind compositions have high ~Fo97.1, low NiO, and elevated Mn and Ca. Rind textural relationships and compositions suggest a non-magmatic, post-emplacement origin. The four olivine populations and chemical zonation (only cores, mid-zones, and rims) are uniformly and consistently distributed throughout the Leslie kimberlite. Thus, olivine within a single phase of kimberlite predominantly records pre-emplacement processes and illustrates that magma batch…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/81194
note: OLIVINE DIVERSITY IN THE LESLIE KIMBERLITE, NT, CANADA: IMPLICATIONS FOR TRANSPORT AND EMPLACEMENT PROCESSES by Katherine Landoni B.Sc. Honors, Oregon State University, 2019 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Geological Sciences) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2022 © Katherine Landoni, 2022 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, a thesis entitled: OLIVINE DIVERSITY IN THE LESLIE KIMBERLITE, NT, CANADA: IMPLICATIONS FOR TRANSPORT AND EMPLACEMENT PROCESSES Submitted by Katherine Grace Landoni in partial fulfillment of the requirements for the degree of Master of Science in Geological Sciences. Examining Committee James K. Russell, Professor, Department of Earth, Ocean, and Atmospheric Sciences, UBC Supervisor Maya Kopylova, Professor, Department of Earth, Ocean, and Atmospheric Sciences, UBC Supervisory Committee Member Barbara Scott Smith, Adjunct Professor, Department of Earth, Ocean, and Atmospheric Sciences, UBC Supervisory Committee Member Lucy Porritt, Lecturer and Research Associate, Department of Earth, Ocean, and Atmospheric Sciences, UBC Additional Examiner iii Abstract Olivine crystals are ubiquitous in kimberlites and record petrologic events through all stages of ascent and eruption. Well-preserved olivine from the Leslie kimberlite, NT, Canada elucidates the sequence of events attending kimberlite emplacement. The Leslie kimberlite mainly hosts a single phase of extrusive coherent kimberlite. We used spatially distributed samples (n = 76) from drill core to develop a 3D representation of the Leslie kimberlite. Petrographic investigation defined four distinct olivine populations: phenocrysts, macrocrysts, dunite “nodules”, and mantle xenolith-hosted olivine. SEM imagery, and major and trace element geochemistry were used…
has type: Thesis/Dissertation
date issued: 2022-05
is shown at: 10.14288/1.0412869
language: eng
degree discipline: Geological Sciences
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Russell, J. K. (J. Kelly)
type: Text
identifier URI: http://hdl.handle.net/2429/81194