Title Page




Rheological and Geological Constraints
on the Earthquake Distribution
in the Charlevoix Seismic Zone, Québec, Canada

by

Maurice Lamontagne, B.A.Sc., M.Sc.

A thesis submitted to the faculty of Graduate Studies and Research
in partial fulfilment of the requirements for the
degree of Doctor of Philosophy

Department of Earth Sciences
Carleton University
Ottawa, Ontario, Canada

January, 1999



© Copyright

1999, Natural Resources Canada




Acceptance Form



Signed Acceptance Form

Acknowledgments

The completion of this thesis was made possible by the help and cooperation of numerous people. My gratitude goes to my supervisor, Professor Giorgio Ranalli, for his continuous support in our attempt to unveil part of the "Enigma of the Charlevoix earthquakes". His knowledge, advice and enthusiasm have been a continuous source of inspiration throughout the course of this study.

The author thanks the Seismology Program of the Geological Survey of Canada (Natural Resources Canada) , and in particular the author's supervisor R.J. Wetmiller, for their support that included a one-year educational leave at Carleton University and time for research during working hours.

My research benefitted from discussions and contributions of other scientists. I particularly thank Pierre Keating, Gervais Perron (both GSC Ottawa) and Bernard Long (UQAR Rimouski) for their work on Charlevoix data sets. I also thank, for their collaboration in various aspects of this work, Bob Wetmiller, Philip Munro, Stephen Halchuk, and Mike Andrew (GSC Seismology Section); Thierry Toutin (Canadian Centre for Remote Sensing); Roy Cooper and John Halpenny (NRCan Gravity Section); Dave Graham, formerly with the GSC); and Dave Forsyth (GSC Continental Geoscience). Ian McDonald helped converting the thesis to the CD-ROM.

I also thank the Société Québécoise d'initiatives pétrolières (SOQUIP) for providing the seismic profiles and digital data of Line 13. The gravity profiles were modelled with the program IGAO of the École Polytechnique de Montréal, while epicentral maps were prepared with the public domain GIS software Xmap8 written by J.M. Lees.

Last, but not least, I thank my spouse Sylvie for her love, patience and encouragement throughout the course of my studies, and my son Félix for cheerfully bringing me back to life's reality between long days of work.


Original Contribution

This thesis contains only the results of the research conducted by the candidate, under the guidance of his supervisor. Most of the material presented in Chapter 2 has been published in Lamontagne and Ranalli (1996); similarly, most of the description of the earthquake activity near La Malbaie (Section 4.6.1.1) has been published in Lamontagne and Ranalli (1997). In both papers, the candidate is the senior author, and the supervisor's (second author) contribution has consisted of advice and cooperation in the writing of the paper. Due to an error in the computation of the stress difference, Figure 8B of Lamontagne and Ranalli (1996) should be replaced by Figure 2.9B.

A few sections of Chapter 3 result from collaborative work with scientists of the Geological Survey of Canada. The gravity and magnetic maps, and the Euler deconvolution solutions (Section 3.2.2.1), were produced by Dr. Pierre Keating. Reprocessing of the SOQUIP seismic line 13 was done by Gervais Perron (Section 3.2.2.3). Finally, the chromo-stereoscopic image of the Charlevoix region was produced by Thierry Toutin of the Canada Centre for Remote Sensing.

In Chapter 4, the focal mechanisms of Section 4.3 are described in Lamontagne (1998) and the 1996 Summer field work in Lamontagne et al. (1997).


> > > To Table of Contents