January 2018 – Technical Talk

BCGS Technical Talk – January 18, 2018

Speaker: Doug Schouten, PhD, CRM GeoTomography Technologies Inc.

Title: Muon Tomography Applied to a Dense Uranium Deposit at the McArthur River Mine

Date/Time: Thursday, January 18, 2018

Location: 4th Floor Conference Room, Room 451, 409 Granville St. (UK Building at Granville and Hastings), Vancouver

Abstract:

Muon Tomography Applied to a Dense Uranium Deposit at the McArthur River Mine.
Doug Schouten, PhD, CRM GeoTomography Technologies Inc.

Muon radiography is a means of inferring density by measuring the attenuation of muon (a type of elementary particle naturally abundant from cosmic ray radiation) flux through matter. Muon tomography uses tomographic methods to derive 3D density maps from multiple muon flux measurements.

Measurements of the muon flux were first used by E. P. George (1955) to measure the overburden of a railway tunnel, and by Alvarez et al (1970) in searches for hidden chambers within pyramids. More recently, muon radiography has been used in volcanology, and has also been considered for industrial and security applications. CRM Geotomography Technologies, Inc. (CRM), a spin-off from TRIUMF, is bringing muon tomography technology to bear in mineral  exploration.

In this talk, I will report on the first application of muon tomography for imaging dense uranium deposits within the Athabasca Basin in Canada, performed by CRM at Cameco and Areva’s McArthur River mine in Northern Saskatchewan. I will demonstrate the applicability of muon tomographic imaging using data acquired at a depth of about six hundred meters underground. I will show that the statistical significance of the known uranium deposit signature in the muon data is very high (larger than five standard deviations), and I will report on the very good compatibility of the corresponding 3D density inversion with drill assay data from the deposit. I will also briefly recap other recent progress by CRM in various applications of muon tomography.

BCGS Christmas Party

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Our first annual Christmas party will be held on Tuesday December 12th in conjunction with Doug Oldenburg’s 2017 SEG Distinguished Instructor Short Course on Geophysical Electromagnetics: Fundamentals and Applications.

We are pleased to invite you to mingle with fellow geophysicists around appetizers and drinks. There is no charge for this event but please let us know if you will be joining.

BCGC Christmas Party
18h30 on Tuesday, December 12th, 2017

at the Kingston Taphouse & Grille
755 Richards Street, Vancouver, BC

Annual General Meeting

Our inaugural annual general meeting (AGM) will be held:

at 18h00 on Tuesday, December 12th, 2017

at the Kingston Taphouse & Grille, 755 Richards Street, Vancouver, BC

(after Day 1 of the DISC Lecture and just before our Christmas Party)

 All of the current directors are standing for re-election and must be voted in at the AGM.

Chair

Joel Jansen, P.Eng

Anglo American Exploration Canada Ltd.

Vice-Chair

Brendan Howe

Teck Resources Ltd.

Treasurer

Ross Polutnik, P.Geo

SJ Geophysics Ltd.

Secretary

Thomas Campagne, P.Geo

Mira Geoscience Ltd.

Student Liaison

Sarah Devriese, PhD, EIT

Condor North Consulting ULC.

Scholarship Coordinator

Dennis Woods, P.Eng

Discovery International Geophysics Inc.

 We would like to remind you there are now two classes of voting members in the BCGS:

  1. General members, who will pay an annual fee of $20, that will be returned as a discount should they choose to enroll in our annual symposium; and

  2. Student members, who continue to enjoy free membership upon demonstration of enrollment in a post-secondary program at an accredited educational institution.

In order to participate in the vote, you will need to bring $20 to the AGM that will provide membership in the BCGS until December 31st, 2018. Eligible students, as defined above, are entitled to vote.

Note that the AGM is open to all members and non-members.

BCGS Fall Workshop: 2017 SEG DISC Short Course

BCGS Fall Workshop: SEG 2017 DISC Short Course

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Date: Tuesday – Wednesday, December 12-13, 2017
Time 8:00am PST to 9:00pm PST
Registration: Cost:
– Industry US$200
– Students US$50
Registration is through the SEG website. Click the button below to register.
Note: This is a 2-day event. Registration for Dec 12 includes Dec 13.
Location: UBC Robson Square, 800 Robson St, Vancouver, BC V6Z 3B7
Details: DISC 2017 website

SEG DISC 2017 course details

Coffee breaks and lunch will be provided.

Course Content:

Electromagnetics has applications in oil and gas exploration and production, mineral exploration, groundwater exploration and monitoring, geotechnical and environmental industries. Although it has widespread applications as a geophysical technique, it is not generally understood by the geoscience community. As a result it is underutilized, and in some cases, misused, as a technology.

The aim of this course is to provide over two days a fundamental understanding about EM geophysics so that practitioners can decide if an EM technique can help solve their problem, select which type of survey to employ, and set realistic expectations for what information can be gleaned. Case histories, spanning applications from many areas in the geosciences, are used as an underlying framework to bind the material together.  For more information, please see the DISC 2017 online resources at  http://disc2017.geosci.xyz.

We would like to encourage any of our members who have an EM case study at hand, and would like to contribute to the lab material, to contact the DISC 2017 lab team through their website: http://disc2017.geosci.xyz/#contribute.

Day 2: DISC Lab:

Attendees. Bring your EM problem or case study and lets discuss and analyze it as a group.

The DISC Lab days are designed for a smaller group of geoscientists. We ask participants to provide informal 5 min lightning talks about problems of local interest. We will then work as a group to break down the problems in terms of the 7-Step Framework introduced in course. If participants agree, their talks and results from discussions, will be uploaded to the web. By capturing these problems and state-of-progress onto the web, we hope to promote interaction between geoscientists worldwide.

About the Instructor:

Doug is a professor of Geophysics, director of the Geophysical Inversion Facility (GIF) and world leader in geophysical inversions. He is dedicated to making geophysics more useful for solving problems of relevance to society. Doug’s research career has focused upon the development of inversion methodologies and their application to solving applied problems in a variety of fields. Motivated to make geophysics more accessible and engaging, he has and continues to lead efforts for distributing software codes and learning resource material for students and practising geoscientists. In 2017, Doug will be on tour presenting the SEG Distinguished Instructor Short Course with the intention of promoting fundamental understanding about principles of electromagnetics and how the different surveys make use of these principles to tackle a broad spectrum of problems using EM geophysics.

Sponsorship Opportunities:

A big thank you to our sponsors!

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Sponsorship opportunities are available!

Your company sponsorship goes towards helping us put on the workshop and to keep registration costs as low as possible, especially for students. The BCGS operates on a not-for-profit basis. Any profit we make from our events goes towards the BCGS scholarship fund, administered by the KEGS Foundation.

Contact a BCGS Executive member to discuss current opportunities.

November 2017 – Technical Talk

BCGS Technical Talk – November 16, 2017

Speaker: Seogi Kang, PhD Candidate, UBC

Title: On recovering distributed induced polarization information from time domain electromagnetic data

Date/Time: Thursday November 16, 2017 @ 4:30pm

Location: 4th Floor Conference Room, Room 451, 409 Granville St. (UK Building at Granville and Hastings), Vancouver

Abstract:

The electrical conductivity of earth materials is frequency-dependent. This is due to a phenomenon known as induced polarization (IP), wherein electrical charges build-up under the application of an electric field. Macroscopically, earth rocks may be considered chargeable, as they act like electric capacitors. The goal of this thesis is to show how IP data can be extracted from geophysical data, then inverted to recover information about chargeable targets. Although both frequency and time-domain electromagnetic (EM) surveys measure IP signals, this presentation will focus solely on time-domain EM (TEM). To recover chargeability information, the following TEM-IP inversion workflow is developed. (1) Extracts a background conductivity model that is free of IP signals. (2) Decouple the TEM and IP signals by subtracting the fundamental responses estimated using the background conductivity. (3) Inverts the resultant IP data to recover pseudo-chargeabilities at multiple times for a set of 3D volumes. This is used to infer the location and dimensions of chargeable targets. (4) Carry out further analyses of pseudo-chargeabilities at multiple times to estimate intrinsic parameters such as a Cole-Cole chargeability and its associated time constant. For grounded sources, the workflow is implemented for a synthetic DC-IP example.

Results show that the early time signals, which are often discarded, can be used to estimate the background conductivity. Applying the workflow to inductive sources such as airborne EM (AEM) is more challenging, as steady-state electric fields are not produced. This was overcome by developing an IP function which (1) accurately characterizes how electric fields from inductive sources buildup in the earth and (2) allows the recovery of a 3D chargeability by solving a linear inverse problem. The efficacy of the aforementioned approach is validated using field AEM surveys over the Mt. Milligan porphyry deposit in British Columbia and Tli Kwi Cho kimberlite deposit in Northwestern Territories. For the kimberlite deposit, the recovered chargeability information is able to distinguish two distinct kimberlite units. To validate the approach, a 3D rock model is constructed using the recovered chargeability and background conductivity. This model is compared against geological models obtained through drilling and shows good agreement.