Exploration geophysics for geologists –  Geophysical techniques, structural interpretation of geophysical data in regional exploration & new methods in borehole geophysics – SC03

Venue: Room 5413, INRS, 490 de la Couronne, Québec City

Duration : 2 days (August 18 and August 19; pre-conference short course)

Presenters: Lyal B. Harris & Bernard Giroux (INRS); Christian Dupuis (Université Laval) with case-study oral and/or poster contributions by Nathan Cleven (Université Laval) and
postgraduate students at INRS and Université Laval.

Contact person:

Number of participants: minimum 15 / maximum 30 participants

Registration deadline: May 15, 2017

•    Student: $ 200.00 CAD
•    SGA & EAG member/non-member:  $ 425.00 CAD / $ 500.00 CAD
* The reduced rate for students is available to a limited number of persons. Additional requests will be put on a waiting list.

Description:  This 2 day short course will:
– Review geophysical methods used in mineral exploration at the prospect to regional scale (Giroux).
– Show how structural geological information at different depths in the crust and upper mantle can be best extracted and interpreted from geophysical data in diverse geological environments for use in regional mineral exploration programs (Harris & Cleven).
– Provide participants with regional examples and hands-on experience in interpreting diverse geophysical images (Harris, Cleven & students).
– Present new tools and methods available for in-situ physical measurements and borehole logging and imaging (Dupuis).

Who should attend:  The short course is primarily intended for mineral exploration and survey geologists, researchers and students with a limited knowledge of geophysics. It is descriptive and practical, so if you were confused by all the maths in a geophysical course but want to know what types of geophysical treatments are available and how to use them, then this is a course for you. The structural interpretation aspects and geological applications would, however, also benefit geophysicists who wish to learn what geophysical treatments geologists require in different settings and to catch up on new borehole techniques.

Short course outline
The short course will present an overview of aeromagnetic, gravity and seismic tomographic data theory and treatment and enhancement techniques for mapping and interpreting geological structures, including:

  • Gradient filters and their combinations (ternary images, image enhancement etc.);
  • Edge detection techniques (inc. worming);
  • Spectral analysis and “depth slicing” to map structures at different depths (including applications to deep crustal to SCLM structural controls on mineralization).
  • Visualization of seismic tomographic data to map upper mantle discontinuities.
    Examples will be shown from Archaean granite-greenstone, Proterozoic high-grade gneiss, Palaeozoic volcano-sedimentary terrains and present-day subduction systems. Group exercises will provide participants with practical experience in structural interpretation of aeromagnetic and gravity data.
  • Introduction to in-hole measurements of electromagnetic properties (e.g. resistivity, magnetic susceptibility, electric permitivity):
    • nuclear logging methods (e.g. natural gamma-ray, spectral gamma-ray and neutron density)
    • borehole imaging ( e.g. optical and accoustic televiewers)
    • in-hole seismic methods (e.g. Full-waveform sonic, Vertical seismic profiling)
    • concepts of logging while drilling
    • in-situ petrophysical data integration

Important: Participants are required to bring their own laptop running either Windows or Mac OS with GIS software installed, i.e. software can both display multiple geotiff image layers and enable on-screen annotation and line drawing (bring a mouse or stylus to make this easier). If you do not already have GIS software installed or if you use an old version of QGIS:

  • Install a recent version of the free QGIS software which runs on several operating systems: (for Mac users, installation is straightforward but make sure you install software and dependency frameworks in the order given);
  • Install a QGIS line drawing plugin from the plugins menu: e.g. ‘Smart editing tools’.

Please download any required software and images to be used (a link and instructions in using QGIS will be sent to participants beforehand) and import images into a GIS before the workshop. Make sure the line drawing capabilities function and you are familiar with using them.

About the presenters

Lyal Harris is an Australian-Canadian geoscientist, professor of structural geology at INRS, an applied research, postgraduate-only university in Quebec City, Canada. His research integrates enhancement and interpretation of gravity, aeromagnetic and seismic tomographic data with field studies and analogue modelling for regional structural and tectonic syntheses, with applications to mineral exploration targeting. He is especially interested in the link between deep crustal and upper mantle structures and mineral deposits. Projects with mineral and petroleum exploration companies, and the Geological Survey of Canada (GSC) and the Quebec geological survey (MERN), include fieldwork and structural interpretation of geophysical data in Australia, Canada, France, Indonesia, India, and the USA; additional geophysics-only studies have been carried out in the Canadian arctic, New Guinea, western USA, N Africa to Middle East, Spain, Portugal, Japan, South America and the Himalayas-Tibetan Plateau. Recent research on developing non-plate tectonic models for the Archaean Earth with GSC colleague Jean Bédard has included comparative studies of the planet Venus using radar and gravity data (research that received an award as one of the top 10 scientific discoveries for 2014 by Quebec Science and the 2015 GSC team research award). He is a member of the Australian Institute of Geoscientists and the Ordre des géologues du Québec and a fellow of the Society of Economic Geologists; he is also adjunct professor at Laval University and sessional lecturer at the Université du Québec à Chicoutimi.

Bernard Giroux is a professor of applied geophysics at INRS specializing in near-surface geophysics, seismic and electromagnetic methods, and numerical modelling. His research aims at improving geophysical monitoring methods for a number of applications: mine safety and rock mass stability, CO2 storage, real-time UXO detection. He is a member of the Ordre des ingénieurs du Québec, Society of Exploration Geophysicists (SEG), Canadian Society of Exploration Geophysicists (CSEG), European Association of Geoscientists and Engineers (EAGE).

J. Christian Dupuis is Osisko Teaching Leadership Chair in Exploration Geophysics at Université Laval, Quebec City. Before joining Université Laval, he was the leader for the logging and sensing program of the Deep Exploration Technologies Cooperative Research Center and a senior research fellow at Curtin University. He is one of the inventors of the TRUPROBE autonomous sonde commercialised by Boart Longyear that enables wireline data to be acquired autonomously by drillers. His research interests are to assist the mining industry increase their exploration efficiency via petrophysical measurements. His laboratory is developing new geophysical instrumentation that will be used to assist the teams that are responsible for mineral exploration and geotechnical projects .