June 2020 – Technical Webinar

BCGS Technical Talk – June 18, 2020

Speaker: Dr. Richard Lynch & Dr. Charlie Beard, Sisprobe

Title: Imaging and Monitoring using Ambient Seismic Noise – Dam Wall Monitoring using Fibre Optic (Distributed Acoustic) Sensor, and Mineral Exploration using Nodes

Date/Time: Thursday, June 18, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

While active seismic methods have been used successfully for many decades in mineral and hydrocarbon exploration, passive seismic methods are still in their infancy.  In the past 10 years a popular method in the academic community has been seismic interferometry, in which ambient seismic noise – from traffic, small tremors, ocean waves, etc – is used to create virtual controlled seismic sources.  This method is inexpensive and environmentally friendly since no active seismic equipment is necessary and new ultra-portable seismic nodes can be used to collect the data.  Ambient seismic noise is now being used to construct 3D S-wave velocity images of the subsurface, typically from a few meters down to depths of a few kilometers.  It can also be used to monitor very small velocity changes in the subsurface for applications in dynamic engineered geologic environments, for example CO2 injections, hydrocarbon production and tailings dam wall stability.

This presentation will cover the basic theory of seismic interferometry and how it is used to image and monitor the subsurface.  Two case studies will be shown to illustrate the method: a dam wall in Sweden which is permanently monitored by a Distributed Acoustic Sensing fibre-optic system and a mineral exploration site in Canada where a one month deployment of 1000 seismic nodes was used to image an intrusive body that hosts Cu-Pd mineralisation.

Webinar:

A recording of the webinar will be available on Youtube after the talk.

May 2020 – Technical Webinar

BCGS Technical Talk – May 21, 2020

Speaker: Dr. Benjamin Birt, Qteq

Title: Borehole Magnetic Resonance Method and Applications

Date/Time: Thursday, May 21, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

One of the more advanced tools in oil and gas industry is the nuclear magnetic resonance tool which has been used since the 70’s to characterise reservoirs for resource estimates. The measurement allows a better understanding/characterisation of a formation with a lithology independent total porosity value. In the last 5+ years this technology has been made available to other resource sectors through decreased size and costs and can play a critical role in determining resources and information required in geotechnical application. Especially in industries where the resource is stored with in the porosity system, whether it be as simple as water or more complex in-situ recovery mines. The log can also be combined with other geophysical logs to get better understanding of dry bulk density and salinity. This presentation introduces the physics of magnetic resonance measurement and the interpretation of the tool’s output. The Borehole Magnetic Resonance measurement can be further analysed using global or core calibrated coefficients to give information about grain size distribution, moveable water (fluid), bound water (fluid), and permeability or hydraulic conductivity as the measurement is sensitive to pore size geometry. The Borehole Magnetic Resonance log can be used by multiple disciplines in the same project – utilized for in situ moisture for mine production, greenfield exploration or a mine extension, while also providing information on tailings settling and geotechnical data on dam wall and downstream ground investigation for potential seepage paths. This presentation will walk through the BMR measurement, how to interpret a basic log and give some examples from several different industries.

Webinar:

A recording of this months webinar is available on Youtube.

April 2020 – Technical Webinar

BCGS Technical Talk – April 16, 2020

Speaker: Joel Jansen, Anglo American

Title: Advances in Geophysical Inversion: From Smooth Models to Pseudo-Geology

Date/Time: Thursday, April 16, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

With respect to mineral exploration, geophysical inversion has been around since the early 1990s.  At least that’s when UBC-GIF first started.  I received my M.Sc. in 1995 and entered the workforce in 1996 right when the first codes where being released, so I’ve had a front-row seat for most of what’s happened (although that doesn’t mean I didn’t nap through a few scenes).  What I experienced exactly mimics Gartner’s technology Hype Cycle, which begins with a trigger, quickly reaches a peak of inflated expectations, then just as quickly drops into a trough of disillusionment before finally progressing up the slope of enlightenment onto the plateau of productivity.  Writer and philosopher George Santanaya wrote that “Those who don’t learn history are doomed to repeat it.”  In this presentation, with 25 years of retrospection, I take you on a personalised tour of where we’ve gone wrong and how I believe we’re now on the right track.  Hopefully it will end with a rich discussion about how the continuing development of the new tools at our disposal.

This talk was first given at this year’s DMEC (PDAC) Symposium.  Before sh*t hit the fan…

Webinar:

A recording of this months webinar is available on Youtube.

February 2020 – Technical Talk

BCGS Technical Talk – February 20, 2020

Speaker: Randy Enkin, Geological Survey of Canada – Pacific, Natural Resources Canada

Title: Linking Geology and Geophysics: Mineralogy and Lithology from Physical Properties

Date/Time: Thursday, February 20, 2020 @ 4:30pm PST

Location: 1st Floor Boardroom B (Suite 111), 409 Granville St. (UK Building at Granville and Hastings), Vancouver

Abstract:

Linking Geology and Geophysics: Mineralogy and Lithology from Physical Properties
Randy Enkin, Paleomagnetism and Petrophysics Laboratory and Section Head, Sedimentary Systems and Processes; Geological Survey of Canada – Pacific, Natural Resources Canada, Government of Canada

Effective geophysical mineral exploration requires an integrated approach to understanding the geochemistry, mineralogy, lithology, and geological processes that form deposit systems. Rock physical properties provide the link between geophysics and geology.  This presentation focuses on density and magnetic susceptibility, their distribution based on the Canadian Rock Physical Property Database (GSC Open File 8460), and the mineralogical settings of ferrous and ferric iron which explains their distribution. We move beyond simple categorization of rock types according to their physical properties, to developing a quantitative mineral mixing model based on 3 principal components:  QFC (quartz-feldspar-calcite), FM (ferromagnesian silicates), and M (magnetite). This model permits users of remote sensing data to quantify equivalent rock and mineral types, and develop a spatial view of geological processes.

Based on Enkin, Hamilton, and Morris (2020). The Henkel Petrophysical Plot: Mineralogy and Lithology from Physical Properties. Geochemistry, Geophysics, Geosystems, 20, https://doi.org/10.1029/2019GC008818

Henkle_Petrophysical_Plot

Biography:

KEGS/BCGS Roundup Breakfast 2020

KEGS/BCGS Roundup Breakfast – Tuesday, January 21, 2020

Speaker: Dr. Craig Hart, Director, Mineral Deposit Research Unit, (MDRU),
University of British Columbia

Title: Smarter Exploration Opportunities are in the gap between Geology and Geophysics

Date/Time: 2020-01-21 @ 7:30am

Location: Princess Louisa Room, The Fairmont Waterfront Hotel
900 Canada Place, Vancouver, BC V6C 3L5

Registration: Online at www.kegsonline.org (Deadline Jan 19, 2020)

Abstract:

Smarter Exploration Opportunities are in the gap between Geology and Geophysics

Craig Hart, Director MDRU (Mineral Deposit Research Unit)

Mineral exploration is a process of progressive area reduction down to the extent of an ore body. Decision-making throughout this process, including from the initial land acquisition, is strongly informed by geological maps the distribution of geological features, so a good geological map is the best exploration decision-making tool. However, most geological maps are wrong. They are representations of observations on sparse data (outcrops) assembled and subjectively interpolated with the benefit of the map maker’s accumulated experiences. Fortunately, all geological maps can be easily, and often significantly, improved with the integration of information from geophysical and physical property datasets thus providing a superior decision-making tool. These improvements can be made at all scales from regional scales to map limits of large tectonic elements like terrane boundaries, to simply improve every regional-scale (1:500k to 1:25k) geological map ever produced, to the drill target scale where the geometry of geological features can be better discerned.

The opportunity to improve geological knowledge from geophysical data is huge since the vast majority of geophysical datasets inform on regional to property scale geological frameworks, not orebodies, but most of this data is never utilized. Most geologists lack the skills to extract geological information from geophysical data other than using crayons to indiscriminately draw lines. MDRU have developed a range of tools and approaches to defining and extracting geological features from geophysical data that range from simple and pragmatic to the complex integration of derived datasets.

Understanding relationships between rocks and geophysical responses requires an understanding of rock physical properties. Although most exploration geologists are familiar with magnetic susceptibility and density data since it is routinely collected during core logging, few geologists know how to evaluate and utilize the data to interpret geological features. So although there is increasing recognition of the potential value of collecting physical property data, utilizing these data either to interpret regional geophysical datasets, to create geological models, or to constrain inversions remains an on-going challenge.

The geological information available at the surface is mostly too sparse and limiting to provide a confident base to inform smart exploration decisions, particularly in regions of cover. So ultimately geological maps should be replaced with 3D models of the geological framework of the upper crust. This effort is best done using a contiguous, data-rich environment where geological and geophysical data sets are informed by physical properties and constrained geophysical inversions that are integrated by an experienced geoscientist, probably driving a set of Machine Learning algorithms.

About the Author:

Dr. Craig Hart;
B.Sc. McMaster University (1986), M.Sc. University of BC (1995), University of Western Australia (2005).

Craig Hart is the Director of MDRU – Mineral Deposit Research Unit at the University of British Columbia (UBC) where he initiates and facilitates a wide range of mineral exploration industry-sponsored research projects that focus on gold and porphyry systems, regional metallogeny and exploration methods. Craig has degrees from McMaster University (BSc 1986), University of British Columbia (MSc 1995) and University of Western Australia (2005) spacing academic intervals over three decades separated by employment in industry and government. Craig previously worked as a Senior Research Fellow at the Centre for Exploration Targeting at the University of Western Australia (UWA) in Perth where he pursued research gold metallogeny of China and Mongolia. Most of Craig’s early career was with the Yukon Geological Survey where he undertook regional mapping and metallogenic surveys in the northern Cordillera. He played a significant role in developing intrusion-related gold models, and understanding redox controls on regional metallogeny.

Craig has considerable field and mapping experience which he integrates with geochronology, geochemistry and geophysics to develop new exploration concepts and targets. He has raised >$20M in research funding to contribute to the training of more than 40 graduate students and 20 senior researchers. He provides advanced ore deposit and mineral exploration training to students and industry, has given presentations and short courses throughout the world, and consults to a range of major and junior explorers. Dr. Hart was awarded the Geological Association of Canada Boldy Award for the best mineral deposit-related presentation in 2005, and was the SEG Distinguished Lecturer of the Society of Economic Geologists in 2010. In 2016 Craig led his team to 5th place in the Integra Gold Rush Challenge, and also took home the “Audience Choice Award” for his engaging presentation.