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Friday, 19th Nov, 2021
Online
11.00AM – Cam Knight – Stand-up Comic
11.10AM – Jeffrey Hedenquist – Lithocap alteration, epithermal gold mineralization (or not), and the transition to the tops of porphyry deposits: dogma vs discovery.
11.50PM – Happy Hour – Q&A + Networking
We all are guilty of being a bit dogmatic about things at times. However, when it comes to exploring, we have to realize that the next prospect is not going to be like the last one in terms of geological characteristics. The worst thing we can do as explorers is try to squeeze a prospect into a model. We all must be open to variations that we have not seen before, and learn to think laterally (figuratively and – in the epithermal environment – literally).
Geologists became aware of the potential of enargite-gold deposits with the discovery of El Indio, Chile, in the late 1970s, and its spectacular high grades. Then came the Yanacocha district, Peru, in the mid 80s, huge but low-grade deposits, heap leachable due to supergene oxidation. Both variations fit the epithermal style of high sulfidation. However, for exploration, the important features are structural control of feeders, with highest grades, and lithologic control – lithocaps – leading to large tonnages. The deposits are all associated with a variety of advanced argillic alteration minerals that can be used during exploration, if some basic features are understood. This style was the major gold target in the 80s and 90s in the Andes, and still is. These deposits are being found in more remote areas, Onto in Sumbawa (transition to the top of a porphyry Cu deposit), as well as in less remote areas where the style is not fully appreciated.
Jeffrey Hedenquist worked with the New Zealand and Japanese governments for 10 years each on geothermal energy development and volcanic discharges, respectively, and during this time also studied the formation of epithermal and porphyry deposits. Since 1999 Dr. Hedenquist been an independent advisor to over 120 mineral industry and governmental groups on ~400 hydrothermal gold and/or copper projects in ~40 countries, including training. He is also an adjunct professor at the University of Ottawa.
Cam Knight
Cam has been an actor and stand up comedian for the past 16 years and was the co-host of a brand new show on Channel 9 called Unreal Estate alongside Kate Langbroek in 2016. He has regularly appeared on the Today show, co-hosted Studio 10 on Channel 10 and can be heard as a weekly co-host on Triple M’s Merrickville and The Weekenders with Dan Ginane in Sydney.
