KEGS May Talks - Triple Threat!
We have three KEGS talks happening this month. Two in Toronto and one in Ottawa.
Title: History of the discovery of two undercover VMS deposits near Flin-Flon
Speaker: Bob Lo
Date: Tuesday May 9th at 4:00 PM
Location: University of Toronto, Department of Earth Sciences, Room ES2093 (22 Ursula Franklin Street) and online. Register for the virtual session below:
Abstract: The exploration history of the discovery of two VMS deposits beneath the Phanerozoic cover of the Flin Flon – Snow Lake volcanogenic massive sulphide (VMS) Belt in Manitoba and Saskatchewan is presented. Due to a lack of outcrops of the host rocks, geophysical exploration techniques were key to the discoveries. Both discoveries are attributed to geophysical techniques and both used arguably the best airborne electromagnetic technology at the time to detect the sulphide mineralization for ground follow-up and then drill testing. But it took many tries or near misses over a long period of time, either by other companies or by the discoverers in the same area before the discovery hole was drilled. The exploration history of the McIlvenna Bay Deposit and of the Reed Mine Deposit are presented to show the perseverance and geophysics required to find these deposits.
Title: A Short History of HeliTEM
Speaker: Ken Witherly
Date: Tuesday May 23rd at 4:00 PM
Abstract: While helicopter-supported TEM systems are now the dominant airborne EM technology for minerals exploration, this technology was a relative late comer to the constellation of airborne EM platforms. The first functional AEM systems appeared in the early 1950s and while some ambiguity has persisted to the present as to which technology was ‘first’, the first technically ‘capable’ system was built by Hans Lundberg in 1949 and the first commercially deployed system was the INCO-McPhar system that arrived in 1951. Both of these were frequency domain systems. The first helicopter frequency domain system was built by McPhar and was commissioned in 1955. Barringer then produced the first time domain system in 1959, which was of a fixed wing configuration. The first heli-TEM system was built in the USSR, with design and testing carried out in the late 1960s, followed by over a decade of operational use for minerals and petroleum exploration. The first Canadian system was built by Questor Ltd. in the early 1980s and was called Heli INPUT in recognition that the core EM technology was drawn from the INPUT technology first designed by Barringer. Heli INPUT operated for 4-5 years before technical issues and economic headwinds at the time forced Questor to terminate the Heli INPUT program. In the mid-later part of the 1980s, Aerodat worked on a multi-component system with the nickname “Truth’. With only limited test flying, in the late 1980s, the system was scrapped due to changing company priorities. Ironically, a very similar program was re-started in 1994 at Aerodat but this time with the support of a major mining company, MIM. Following a test flight of the HeliTEM system in 1997, again corporate challenges forced the sale of Aerodat to a competitor High-Sense and the HeliTEM program was terminated. Several years later, a tsunami of acquisitions occurred when Fugro bought up the majority of the global airborne survey businesses. However, three relatively small companies avoided being ‘shallowed’ and its turned out these three groups were the source of a ‘Burgess Shale’ event where in a short period from 1997-2002, three heli-TEM systems appeared in Canada and shortly thereafter in Denmark. As well, three proprietary systems appeared as the result of efforts by Newmont, Anglo American and Normandy. Now, 25 years later, the market has matured but new systems are still coming to market offering generally minor changes/improvements. While the heli-system market is basically stable, the fixed wing technology which dominated the industry for the first sixty years, has basically vanished. What the next 25/50 years (Third Wave) will offer remains unclear. However, the expectation is that like the first two waves, a few individuals will likely be the key innovators.
Title: What lies beneath? What geophysics can contribute to the porphyry copper model
Date: Monday May 29th at 4:30pm
Location: TBD.
Abstract: Electrical methods have been applied to the search for porphyry copper and IOCG deposits since the early 1950s. While there is a generally accepted model of disseminated sulfides giving rise to a chargeability response, no clear association has been attached to what EM surveys may be responding to. Work in the early 1990s (Nickson 1993) showed the well-developed supergene blankets over a porphyry copper could be conductive; this observation was however, never applied formally to generally accepted porphyry targeting models. The presence of other conductive zones associated with porphyry copper deposits is even less well studied. On the geological side, while there is a vast body of literature describing porphyry copper deposits and how to discover them, in very few cases do these studies even speculate if anomalous concentrations of sulfides could be conductive. On the geophysical side, observations of unexpected conductivity associated with porphyry systems is sometimes noted but these observations typically stop short of suggesting that there could be a more general observation made that a new class of geophysical feature should be defined. The present study is felt to have gathered a sufficient number of case studies which show that a significant number of porphyry copper deposits possess a mineralogical character which can be identified with EM techniques. This thesis can have significant implications as to how porphyry copper are explored for, especially those at depths >500 m, a generally accepted cut-off for IP techniques. This presentation is based on a similar talk given in AEGC 2019 in Australia. The talk has been updated several times since. The abstract from the 2019 talk can be downloaded here and forms a good summary.
The KEGS Summer BBQ is back, and will be held on Tuesday, June 20th at the National Yacht Club. Details to follow.
KEGS is currently looking for speakers for the Fall 2023 meetings. If you are interested to speak at a KEGS monthly talk, please contact any of the Executive.
Find out about more geoscientific events in GTA Geoscience calendar here.
We are planning a KEGS Ottawa presentation in May and thinking about starting up regular monthly meetings again in September. We are not yet sure if we will be able to get back in to the GSC buildings for our meeting, but for now our back-up plan is to hold the May meeting at the SGL office on Hunt Club Rd.
We are starting our search for speaker suggestions and/or presentation volunteers for the 2023/2024 season. This is a great opportunity to try out or reprise a talk that you have given somewhere else. We are also always interested in student presentations. We can have either one 45 minute presentation or two 20 minute presentations per meeting.
For more information about:
please contact Luise Sander, SGL, luise@sgl.com, (613)-521-9626.
Lundin Mining is hiring a Geophysicist based out of the Corporate Head Office in Vancouver, BC.
The successful candidate will engage in all aspects of geophysical exploration in North America and Europe, while collaborating with geoscientists to ensure project success! Further details can be found here.
The Mining and Mineral Exploration technical program for the IMAGE 2023 Meeting in Houston on August 27 through September 1, 2023, has been finalized.
The MME technical program will consist of 24 MME presentations in four oral sessions, one poster session, and one special session. The four oral and one poster session are grouped as Integrated Studies for Mineral Prospectivity and Innovative Mineral Exploration Concepts and Technologies. The Special Session is focused on Use of Seismic Data for Critical Mineral Exploration.
The MME technical program will also include a workshop titled Advances in the Ground and Airborne Induced Polarization Methods for Mineral Exploration.
Finally, in addition to the above MME content, the EM and Potential Fields (EMP) technical program will consist of 24 presentations and the Near Surface (NS) technical program will consist of 40 presentations.
Key Items:
Additional details can be on the Foundation’s website.