The origin of mantle xenoliths in Tertiary alkaline basalts, British Columbia, Canada

122 Pages·2017·4.47 MB·English

UUnniivveerrssiittyy ooff WWiinnddssoorr
SScchhoollaarrsshhiipp aatt UUWWiinnddssoorr
Electronic Theses and Dissertations Theses, Dissertations, and Major Papers
1-11-2016
TThhee oorriiggiinn ooff mmaannttllee xxeennoolliitthhss iinn TTeerrttiiaarryy aallkkaalliinnee bbaassaallttss,, BBrriittiisshh
CCoolluummbbiiaa,, CCaannaaddaa:: IImmpplliiccaattiioonnss ffoorr ccoonnvveerrggeenntt ppllaattee mmaarrggiinn
ggeeooddyynnaammiicc aanndd ppeettrrooggeenneettiicc pprroocceesssseess
Eyal Friedman
University of Windsor
Follow this and additional works at: https://scholar.uwindsor.ca/etd
RReeccoommmmeennddeedd CCiittaattiioonn
Friedman, Eyal, "The origin of mantle xenoliths in Tertiary alkaline basalts, British Columbia, Canada:
Implications for convergent plate margin geodynamic and petrogenetic processes" (2016). Electronic
Theses and Dissertations. 5637.
https://scholar.uwindsor.ca/etd/5637
This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor
students from 1954 forward. These documents are made available for personal study and research purposes only,
in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution,
Non-Commercial, No Derivative Works). Under this license, works must always be attributed to the copyright holder
(original author), cannot be used for any commercial purposes, and may not be altered. Any other use would
require the permission of the copyright holder. Students may inquire about withdrawing their dissertation and/or
thesis from this database. For additional inquiries, please contact the repository administrator via email
([email protected]) or by telephone at 519-253-3000ext. 3208.
The origin of mantle xenoliths in Tertiary alkaline basalts, British Columbia,
Canada: Implications for convergent plate margin geodynamic and petrogenetic
processes

By
Eyal Friedman

A Thesis
Submitted to the Faculty of Graduate Studies
through the Department of Earth and Environmental Sciences
in Partial Fulfillment of the Requirements for
the Degree of Master of Science
at the University of Windsor

Windsor, Ontario, Canada
2015
© Eyal Friedman
The origin of mantle xenoliths in Tertiary alkaline basalts, British Columbia, Canada:
Implications for convergent plate margin geodynamic and petrogenetic processes

by

Eyal Friedman

APPROVED BY:

_____________________________________________________

Dr. B. Zielinski, External Examiner
Department of Biological Sciences

_____________________________________________________

Dr. I. Samson, Internal Examiner
Department of Earth and Environmental Sciences

_____________________________________________________

Dr. A. Polat, Advisor
Department of Earth and Environmental Sciences

December 17, 2015
Declaration of Co-Authorship / Previous Publication
I. Co-Authorship Declaration
I hereby declare that this thesis incorporates material that is result of joint research,
as follows:
The collaboration occurs in Chapters 1-9 of this thesis. These chapters contain
material that has been accepted for publication. Field work was conducted with Ali Polat.
Robert Frei assisted with radiogenic isotope analyses. Ali Polat, Derek Thorkelson and
Robert Frei contributed to the manuscript by means of criticism and revision. With these
exceptions, field observations, laboratory analyses, data interpretation, key ideas and
manuscript preparation were performed by the author.
I am aware of the University of Windsor Senate Policy on Authorship and I certify
that I have properly acknowledged the contribution of other researchers to my thesis, and
have obtained written permission from each of the co-author(s) to include the above
material(s) in my thesis.
I certify that, with the above qualification, this thesis, and the research to which it
refers, is the product of my own work.

II. Declaration of Previous Publication
This thesis includes 1 original paper that has been accepted for publication in a peer
reviewed journal, as follows:

iii
Thesis Chapter Publication Title/Full Citation Publication Status*
Eyal Friedman (60%), Ali Polat
(20%), Derek Thorkelson (10%),
Robert Frei (10%), Formation of the
subcontinental lithospheric mantle Accepted for Publication
Chapters 1-9
beneath southern British Columbia, (Gondwana Research)
Canada, at a convergent plate margin:
Evidence from trace element
geochemistry of mantle xenoliths

I certify that I have obtained a written permission from the copyright owner(s) to
include the above published material(s) in my thesis. I certify that the above material
describes work completed during my registration as graduate student at the University of
Windsor.
I declare that, to the best of my knowledge, my thesis does not infringe upon
anyone’s copyright nor violate any proprietary rights and that any ideas, techniques,
quotations, or any other material from the work of other people included in my thesis,
published or otherwise, are fully acknowledged in accordance with the standard
referencing practices. Furthermore, to the extent that I have included copyrighted material
that surpasses the bounds of fair dealing within the meaning of the Canada Copyright
Act, I certify that I have obtained a written permission from the copyright owner(s) to
include such material(s) in my thesis.
I declare that this is a true copy of my thesis, including any final revisions, as
approved by my thesis committee and the Graduate Studies office, and that this thesis has
not been submitted for a higher degree to any other University or Institution.
iv
Abstract
The Tasse basalts of southeastern British Columbia, Canada, are host to a variety of
mantle xenoliths consisting predominantly of spinel lherzolite with minor dunite and
pyroxenite. On the basis of REE patterns, the xenoliths are divided into three groups
reflecting varying degrees of mantle metasomatism: (1) Group 1; concave-up LREE
patterns; (2) Group 2; flat to moderately LREE-enriched patterns; and (3) Group 3;
strongly LREE-enriched patterns. The majority of xenolith are enriched in LILE, LREE,
U, Th, Pb, and Sr, and depleted in HFSE and HREE. These geochemical characteristics
are consistent with a sub-arc mantle source. The Tasse lavas are compositionally alkaline
basalts and display OIB-like trace element patterns. They have positive εNd (+3.8 to
+5.5) values, with 338−426 Ma depleted mantle model ages, and display OIB-like Nd, Sr
and Pb isotopic compositions. The Sr−Nd−Pb isotope and trace element characteristics
suggesting that they originated from an upwelling asthenospheric mantle source.

v
This thesis is dedicated to my parents, Martin and Eva, and my
brother, Tal, for all of their love, encouragement and support through
this journey.

This thesis is also in loving memory of my best friend Andrew
Avetikov. You will forever be in my memories and in my heart.

April 2, 1986 – November 9, 2013

vi
Acknowledgements
This thesis has been a long time coming. This journey would not have been
possible without the help of Dr. Ali Polat. I would like to thank Dr. Polat for his guidance
and patience over the past few years through this process. I would also like to thank him
for giving me this wonderful opportunity.
I would also like to thank Dr. Iain Samson for sharing his expertise in petrography
and mineralogy. His insights allowed me to further develop key concepts in my research
and studies.
Special thanks go to Melissa Price and the staff at GLIER for all their help with
laboratory equipment and processes.
Thank you to Dr. Barb Zielinski for being a part of my committee and giving me
feedback and constructive criticism during my thesis proposal and defense.
A final thank you goes to all of my graduate peers who have had to put up with me
over the past few years. I appreciate all of the help you have given me and wish you the
best with your areas of research.

vii
Table of Contents
Declaration of Co-Authorship/Previous Publication..........................................................iii
Abstract................................................................................................................................v
Dedication...........................................................................................................................vi
Acknowledgements............................................................................................................vii
List of Tables.......................................................................................................................x
List of Figures.....................................................................................................................xi
Chapter 1. Introduction........................................................................................................1
Chapter 2. Regional geology................................................................................................4
Chapter 3. Geology of the study area...................................................................................7
Chapter 4. Sampling.............................................................................................................9
Chapter 5. Methodology....................................................................................................10
5.1. Major and trace element analyses........................................................................10
5.2. Strontium, neodymium and lead isotope analyses...............................................11
Chapter 6. Petrography......................................................................................................13
6.1. Mantle xenoliths...................................................................................................13
6.2. Alkaline basalts....................................................................................................14
Chapter 7. Results..............................................................................................................15
7.1. Mantle xenoliths...................................................................................................15
7.2. Alkaline basalts....................................................................................................16
7.3. Strontium, neodymium and lead isotopes of the alkaline basalts.........................16
Chapter 8. Discussion........................................................................................................18
8.1. Source characteristics of the mantle xenoliths.....................................................18
viii
8.1.1. Comparison with other Phanerozoic ultramafic rocks................................19
8.2. The petrogenetic origin of the Tasse alkaline lavas.............................................25
8.2.1. Comparison with other Cenozoic alkaline lavas........................................26
8.3. Geodynamic constraints on the origins of Cenozoic alkaline lavas in British
Columbia.....................................................................................................................29
8.4. Characteristics of the lithospheric mantle beneath southeastern British
Columbia.....................................................................................................................32
Chapter 9. Conclusions......................................................................................................38
References..........................................................................................................................40
Appendix A......................................................................................................................107
Appendix B......................................................................................................................108
Vita Auctoris....................................................................................................................109

ix