BCGS Technical Talk – August 27, 2020

Speaker: Jonathan Rudd, Dias Airborne

Title: Introducing two airborne systems with SQUID sensor technology

Date/Time: Thursday, August 27, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

Dias Airborne is introducing the QMAGT full tensor magnetic gradiometer (FTMG) system, and the QAMT passive EM system. These helicopter-borne systems are both built around low temperature SQUID sensor technologies that provide low-noise data acquisition. Ground-based low temperature and high temperature SQUID systems are well-established in mineral exploration industry, and their low noise advantage has brought significant benefits to many exploration programs. The QMAGT FTMG system is the product of over 20 years of research and development by the Supracon-IPHT and Anglo American – DeBeers groups. Anglo-DeBeers are operating this FTMG technology widely on their various exploration projects worldwide. The QMAGT system delivers all 9 magnetic tensors, from which the 5 independent tensors are derived for final delivery. The FTMG method brings clear advantages to exploration for kimberlites, but is also valuable in the exploration and characterization of iron ore deposits, ultramafic intrusions, and in complex structural settings – particularly where remanent magnetization is present. The QAMT system measures the Earth’s response to natural EM energy – principally lightning and solar events. The QAMT system measures all three components of the magnetic field, and uses a full-tensor MT base station, necessary for the processing, modeling and final products. The principal advantage of the QAMT system over other natural field airborne EM systems are in its ability to accurately measure all three components of the magnetic field, which significantly improves the resolution of the final imaging and modeling.

Webinar:

A recording of the webinar is available on Youtube.

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 is available on Youtube.

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.

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.

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

Biography: