Episode 12: Ore Deposit Structure - The Key to Value

07/21/20 • 58 min

Even before plate tectonic theory, economic geologists knew there was an association with ore deposits and geologic structures. Nowadays, most successful exploration companies understand the importance of understanding structural controls of an ore-forming system and incorporate structural geologists in their exploration programs.

This episode of Discovery to Recovery focuses on the regional tectonic and deposit-scale structural controls on ore deposition, specifically on volcanic-hosted massive sulfide, epithermal, and Carlin-type gold deposits. If you have ever wanted to know the answer to the following questions, have a listen!

1. What tectonic environments are most favourable not only for formation of an ore deposit, but for preservation?

2. How important is it to understand post-ore modification?

3. What are the local structural controls one can look for to vector towards and ore-forming system?

4. Can you make discoveries without a fundamental understanding of structure?

Our three speakers discuss structural controls from the regional, tectonic scale down to the prospect scale, answering these questions and more. Rodney Allen of Volcanic Resources discusses in detail how volcanic-hosted massive sulfide deposits are formed and the post-ore structural evolution that gets them to where we find them today. He also teaches us how to look for the most favourable stratigraphic horizon within a VHMS district.

Julie Rowland discusses the structural controls on epithermal deposits using examples from her home country of New Zealand, comparing and contrasting different styles of epithermal mineralization. She discusses both fossil systems and modern analogues for epithermal systems, and teaches us how to understand local structural controls when exploring for epithermal deposits.

Lastly, Moira Smith of Liberty Gold provides her expert insight into Carlin-type gold deposits, and why their structural interpretation is so important. She goes into detail on the shelf facies Carlin-type deposits outside of the main Carlin trend in Nevada, and compares and contrasts the two regions with respect to tectonic setting and local structure features.

All three speakers tell a fascinating story and all stress the importance of understanding structure and keeping an open mind.

Theme music is Confluence by East Winds. www.eastwindsmusic.com

1. What tectonic environments are most favourable not only for formation of an ore deposit, but for preservation?

2. How important is it to understand post-ore modification?

3. What are the local structural controls one can look for to vector towards and ore-forming system?

4. Can you make discoveries without a fundamental understanding of structure?

All three speakers tell a fascinating story and all stress the importance of understanding structure and keeping an open mind.

Theme music is Confluence by East Winds. www.eastwindsmusic.com

Previous Episode

11. Geoscience Technology for a Better World

What should the relationship be between geoscience technology and the communities we’re a part of? The obvious answer is that geoscience technology should be used to enrich the lives of those in our communities.
But as Paul Bauman (Technical Director, Worley) says: often the question not asked, is where should the technology come from? Should we be using bottom-up or top-down approaches to develop tech? Paul shares his thoughts on this matter, and stories from his time pioneering geophysics use for humanitarian water crisis work in the 1990s.
Another question we should ask ourselves is how should we be sharing our technology and science with non-specialists? Alan Shapiro (Science Communication Consultant & Instructor) takes us through best practices for knowledge-based communication. This field becomes increasingly important as we look to a future with growing geoscience challenges, and will need to share our data to inspire new policies and lifestyle changes.
Lastly, what are the best approaches to inspire innovation in technology? Holly Bridgwater (Unearthed Solutions) takes us through ‘open innovation’ – and how communities can be leveraged for the future of geoscience tech.
Theme music is Confluence by Eastwinds
eastwindsmusic.com

Come join us in Brisbane, Australia for SEG 2025, September 26-29th. This will be a dynamic conference with cutting edge science, new discoveries, technology and more. Opportunities for networking and learning include several workshops and field trips before and after the event, relaxed social events and of course the conference itself. See you there!

Next Episode

13. Structure - Solutions for Complex Data

Capturing structural geology data is important. Why? As Federico Arboleda (Founder and CEO, Imago) says: "There's no mine unless you can make that [geotechnical] estimation or characterization. And this is the founding data that allows you to define that."
So how can we collect this data? With the amount of technologies available, it might be easier than you think.
For example, if you already take photos of your core while logging - you’re halfway there. Often the unstructured data (images, videos, etc.) we capture in our workflows aren’t fully leveraged. Federico discusses how to best capture insights provided by imagery when it comes to structural geology.
And it was only a matter of time before phone and tablet apps crept into structural geology. Rohanna Gibson (Terrane Geoscience) shares her tips for making sure your expensive tablet survives in the field, while collecting the best data possible.
Lastly, Chris Gallagher (Rogue Geoscience) takes us through oriented drillcore logging – why, how, and when to do it. He shares the top five mistakes done in this type of logging method and advice for working with your drilling team.
Theme music is Confluence by Eastwinds
eastwindsmusic.com