An Overview of IOCG Deposits (Guest Dr. Paul Gow, Tribeca Resources)

Karl Woll: 00:00:00

Hello, and welcome to Rock Talk where we explore the world of mining through casual conversations with industry experts. I'm Karl Woll, Senior Account Executive at VRIFY Technology. And in this episode, I'm joined by Dr. Paul Gow, CEO of Tribeca Resources, a copper exploration company, operating in the Chilean Coastal IOCG belt. And this episode, Paul walks us through his background in mining as a geologist on both the research and the operational side of the industry. And then Paul gives us a mining 101 education on iron oxide copper-gold deposits. While the formation of IOCGs is not fully understood yet, Paul does a great job of walking us through the basic and the main characteristics of IOCGs. And shows us some visual examples from Tribeca's La Higuera project.

As this is a new podcast. If you have any suggestions or feedback on how to make the show better. Ideas for guests or topics. There is a link in the show notes to a form where you can submit that feedback, or you can go to rocktalkpod.com and that same form is on the website. And with that, let's jump into this week's conversation with Dr. Paul Gow. Hi, Paul. Thanks for joining me today. How are you?

Paul Gow: 00:01:16

Oh, good, thanks. Good, thanks, Karl. It's a pleasure to be here with you. Thanks.

Karl Woll: 00:01:20

And where are you joining me from?

Paul Gow: 00:01:22

I'm dialing in today from La Serena. I'm here in the north of Chile. We have one of our projects here. Just about 40 kilometers south of town and where we are at the moment is about 500 kilometers north of Santiago. So just getting up into the basically the southern reaches of the Atacama desert in northern Chile.

Karl Woll: 00:01:39

I wanted to talk to you a little bit about IOCG deposits, which you have an extensive background and knowledge base in Paul, But before we jump into IOCG deposits and you give us a bit of education on that, I wanted to learn a little bit more about you and your extensive background in the mining industry and as a geologist, so could you give us a bit of a background, how did you get into geology and into mining?

Paul Gow: 00:02:00

Yeah, sure, Karl. Probably like a lot of people, I stepped into geology at university. I wasn't particularly intending to study or work in that field, but I know when I went to university on my first year, it was, oh, more maths, more physics, et cetera, I needed to do something new.

And, at the time, I actually studied geology and meteorology and ended up plumping for geology, which is great. As you know, it's a great career and a good space to be in. You know, people talk about, you know, high tech industries. And I guess the mining industry often tends to get spun as an old industry.

But really it's incredibly high tech and it's where, where a lot of stuff is happening that's really encouraging.

Karl Woll: 00:02:40

You went on to correct me if I'm wrong, you have a PhD and you have also done some teaching as well?

Paul Gow: 00:02:45

Yes, yeah, I've been throughout my career, I guess in, in and out of the operational side of the exploration industry and also the research side of industry. So I did my PhD back in the, early 90s, working out around Olympic Dam, which is the world's largest IOCG deposit.

And that was, basically Olympic Dam and the area around it. It's quite phenomenal. It's actually under about 200 meters to 800 meters of barren cover that really is not mineralized. And so I did a lot of work looking, using geophysical data, to try and see through that cover to understand where the mineralization might be below.

And when I look back on it now, I did that in the early nineties and I see some of the stuff that's now coming out of BHP, for example, around Olympic Dam with a lot of seismic surveying and everything. And it's amazing how technology has changed and allowed us to see so much more only in about 30 years.

So It's great. Yeah, and then the other thing I also had worked until a couple of years ago as an Associate Professor at a place called the Sustainable Minerals Institute at the University of Queensland. And it's a fascinating place to be. I'm still an Adjunct Associate Professor there, but it's all about how can we do mining in a more sustainable way?

And it's quite interesting because acting sustainably is essentially what people have been trying to do for a long while. So you want to decrease your physical footprint. You want to use less fuel and lower emissions. You want to use less electricity and water and produce everything in a lot more of an economic manner.

So really being sustainable is really improving your economics. So it's a fascinating place to be.

Karl Woll: 00:04:20

Does that pertain mostly to the actual mining or other practices that we can implement in sort of the exploration phase of mining.

Paul Gow: 00:04:30

Yeah, in terms of the sustainability at the Sustainable Minerals Institute there's a great program going called Complex Ore Bodies. Which was essentially looking at ore bodies that are complex and need to overcome that complexity before they can be mined. We tend to think complexity or maybe complex metallurgy or mining methods.

But it also spans those other fields of um, there may be some sort of you know, community issues that, that the mine is not accepted or is impacting unduly on communities the environment and also the governance and political stability. So, you know, all those ESG, I guess, topics and it's quite interesting.

There was some great work done there by a guy called Rick Valenta. And he put a paper out and he was looking at all the copper deposits that we have globally. And, there's enough to last us for, 100, 200 years, but so many of them can't be accessed for some of those reasons.

So if you can overcome those hurdles, then you can start to access those complex ore bodies and produce the copper that the world needs.

Karl Woll: 00:05:29

Yeah, I think that's becoming increasingly important from what I read in the news and the literature about you know, the number of discoveries and the average grades of discoveries just declining decade over decade and year over year and conversely, the importance of copper and other materials in a decarbonizing and electrified future, going in the opposite direction. So we have decreasing, supply on ever increasing demand. It seems like that's becoming a more and more and more and more important to unlock access to those, deposits and to do things in a sustainable, friendly way. So no it sounds really interesting.

Maybe we can have another follow-up conversation at some point in the future to dig more into to that side of things.

Paul Gow: 00:06:08

Yes. Yeah, I know. It's, it's fascinating. Karl and I could talk at length about that maybe for another time.

Karl Woll: 00:06:14

Transitioning a little bit to Tribeca Resources, who you are CEO and Director of, and the La Higuera project in Chile there. Could you give us the quick background on the project and where things are at?

Paul Gow: 00:06:26

Yes. Yeah, certainly. Look, the La Higuera project is just close to where I'm at and at the moment in La Serena in northern Chile. It's a, I guess we, we'd call it a mid exploration stage project. We got into the project probably about five years ago. And then of course, COVID came along and knocked us all around a little bit.

. But since, since the end of: 2022

ines in the world back in the: 1800

Karl Woll: 00:07:19

What was it like when you took over the sort of project and started exploring again? How long had it been sort of dormant and what data did you take over from the previous operators?

Paul Gow: 00:07:29

Yeah, look, there was, there was quite an extensive arrangement of data pre, pre existing. And like most projects, it had people working on it from time to time. And it's actually quite fascinating. When you look in the exploration industry at the history of discovery, and there was a great, great book put together by Dick Sillito, maybe 20 years ago, and it was looking at all the discoveries in, around the circum pacific rim.

en mining happening since the: 1800

as another group came in late: 2000

And they're the less mature terrains in terms of exploration. So we took all the data from the La Higuera area, and followed that approach of looking under the cover. So yeah, it was a great place to come into.

Karl Woll: 00:08:47

Yeah, and I guess leading back to um, what you had said a moment ago with the Olympic Dam and just how much technological advancement there had been in the last 30 years since you originally were doing your early academic work at that project lends well to the story at La Higuera as well. Looking then at you know, these IOCG or iron oxide copper-gold deposits, could you give us an overview of what an IOCG deposit is, why they're interesting, why we should care? Give us the sort of 101 breakdown of an IOCG.

Paul Gow: 00:09:17

Yes, yeah, yeah, for sure. As you you mentioned earlier, I've been working in IOCG for a lot, a lot of my life, both from the research point of view and exploring. So I've explored um, for them both around in, in, in there are four key terrains globally. There is the Gawler Craton in South Australia. There is the Cloncurry Belt in Northern Australia the Carajas District in Northern Brazil and the Chilean IOCG Belt where we're currently working.

I'd worked in all of those terrains. So you know, Northern Chile was an obvious place to come. So when you look globally at copper production and copper, I guess is certainly flavor of the month. And as, as I read in one article, it's the most anticipated boom in a long, long while.

So it's the copper boom still anticipated, but I'm sure it's on its way. So when you look at copper production, about 80 percent of the world's copper production comes from you know, I guess what everybody, particularly in the Americas is very comfortable with, which is porphyry copper deposits.

And they're commonly up through Chile and Peru and then the western US and western Canada. So, so they produce most of the world's copper, but the other 20 percent is produced by dominantly two styles of copper. There's a thing called sediment-hosted copper deposits, which is essentially the African copper belt.

You know, the Democratic Republic of Congo and Zambia, and then there are IOCG deposits, which we'll talk about a bit more. There are a couple of other copper producers, things like VHMS, which is Volcanic Hosted Massive Sulphide Deposits, and Canada you know, the Flint Flon Belt and other belts that have some of those deposits.

So IOCG deposits are important because they're now becoming producers in a lot more places. And in fact, if you look at the largest copper resources and reserves globally, Olympic Dam, actually is the fourth largest deposit in, in the world for copper after what Escondido, the Andina complex and the Teniente complex all in Chile.

n studied basically since the: 1920

ally were only defined in the: 1980

And then the, the other, other, sorry, go on, Karl.

Karl Woll: 00:11:56

No, I'm just going to stop to summarize that probably way, way too over simplifying things, but from my understanding of a copper porphyry, would be probably closer to surface, very, very, very large deposit, however, probably relatively lower grade, whereas an IOCG would contrast to that by maybe being higher grades, but a little harder to find and maybe a little bit smaller and a little bit further at depth. Have I summarized that at a very high level accurately or where am I wrong?

Paul Gow: 00:12:25

Yeah, no, that's, that's actually pretty, pretty good summary Um, Karl. I, I have a diagram here. I can pop up if you'd like, that will, show you some of this information. So this is a plot of iron oxide copper-gold deposits throughout the world.

And you'd be familiar with these types of plots. So on the vertical axis is gold grade on the horizontal axis is copper grade. And then the size of the bubble is the, you know, the contained copper and gold in those deposits. So your first question in terms of size and grade, we can answer a little bit by looking at this plot.

So if you look at this plot that most of these deposits, I guess sort of sit between about 0.4 copper up to 1 percent copper. So probably, particularly if it's weighted towards the higher grade part of this plot, maybe a little bit slightly higher copper grades than, than the large porphyry copper deposits.

And then the gold grade you'll see they typically seem to sit around about 0.2 to 0.4 maybe Yeah, I'm probably more like 0.2 grams per tonne gold. So, not really high grade gold deposits, but that's what the grades they are. And some of these deposits actually sit off this plot.

So as, as you go up the copper plot, you'll see between 1.2 percent and 1.4%. There are some of these deposits and there are some others that actually sit off the plot, you know, up around 2 percent copper and over one gram per tonne gold so that they typically can be higher grade than the copper porphyries.

So, so the grades you're right there, the grades can typically be a little higher. They're, typically smaller. So for example, Olympic Dam, which is, is the monster is about 9 billion tons. So it's large, but these others, the next tier down that we know about are deposits called the Salobo in Brazil.

If you can see this orange sphere here, and then the other one is Candelaria here, in northern Chile and then Mantoverde, which is, is now up around about a billion tons like Candelaria and Salobo. So, you know, I guess on average, typically lower tonnage than the porphyry coppers, but grade often makes up for that.

So that's those two points. And then I think some of your other points were about, how to explore for them. Are they more difficult to find and also a depth, which is, is interesting. So they perhaps more difficult to explore for because they're not so well known. So for example, porphyry copper deposits, people have a really good idea of what they look like, particularly in terms of the minerals around them.

So that if you, if you drill some holes and you hit one set of minerals, you say, well, we think this is where we are in that system and where we need to go to get the high grade, but that's not so clear with IOCG deposits. And then your comment about depth. Part of that I guess, ties into grade.

If you have higher grade, you can mine at greater depths. But also the, some of the prime examples like Olympic Dam and others in the Olympic province in Australia, they're called Carrapateena is one of those. They are at depth. So, but, but that's not so much a function of the deposit style as just their local environment.

Although, you know, having said that I guess, some of the big porphyry coppers on the radar like Filo de Sol at the moment, are starting to get pretty deep as well. So they may be equivalent.

Karl Woll: 00:15:42

Okay. So it's not necessarily a function of the inherent geology of an IOCG versus a porphyry. It's more about the economics of mining at depth.

Paul Gow: 00:15:52

Yes. Yeah. That's a fair comment, Karl.

Karl Woll: 00:15:57

Thanks for that overview, Paul. And then looking at a way to demonstrate some of the characteristics of IOCGs. Is there anything from La Higuera and your current project in Chile that you're noticing or that you can use to help show us some of these characteristics?

Paul Gow: 00:16:13

Yes, certainly, Karl. Certainly, Karl. Yeah, no, that's great because La Higuera is really a classic IOCG deposit and displays a lot of those characteristics. IOCG deposits can be very different across the globe and in different terrains or even within the one belt. But La Higuera is a pretty stereotypical IOCG deposit.

So, this is a quick map before we get into the 3D model showing the data from our La Higuera area and what this colored image is showing is the magnetic data.

Okay, so iron oxide copper-gold deposits are dominated by iron oxide minerals and there are typically two of those minerals that are most common. One is magnetite which is a magnetic mineral and the other is hematite which is, which is non-magnetic. But what this image is showing us is that these zones that are high and here's the legend and the legend is TMI so that's Total Magnetic Intensity.

So these high pink areas are where you essentially it's a proxy for a lot of magnetite and we're looking for magnetite related mineralization so it's the place to be. So essentially that's the style of exploration that can be done in IOCG terrains for in, on a very simple basis is mapping out where that magnetite mineral occurs.

So here we have these five targets that we've been chasing up. We've drilled two of those. There's one here at Chisposo, and then the other one up here to the north at the Gaby system. So that's, that's what it all looks like in plan view, but I'll show you the 3D model here.

So this is that magnetic data that we were looking at with those same five targets marked on it. And this is the environment that we sit in. This is looking to the north. And you can see there's a couple of sort of mountain ranges here. The one on the left is called the Coastal Range.

And if we stepped another maybe three kilometres, three or four kilometres out to the west, we would actually hit the Pacific Ocean. So we're very close, close to the ocean. And then we have this valley down the middle where we're doing our work. And then as you get out to the east, you start to get up towards the sub Andean ranges and up towards the main Andes ranges.

So this is how we're exploring for iron oxide copper-gold deposits in these valleys using the magnetic data. Now, that's one property that we're looking at. And what we can do is take that from, from the surface and we, we process the magnetic data and, and it essentially then provides us with an idea of what those bodies might be looking like under the surface.

So that we can get a fair idea of where we need to be drilling. And then we put that together with, at least one other geophysical data set. and what we can see here. These east west lines are east west sections of what's called IP. It's a geophysical electrical method that tries to sense where you have sulfide, copper rich minerals in the subsurface.

So that we put these two data sets together, and you can start to see where the large bodies of magnetite are and then these other pink colors are showing us where there is potentially copper sulfide minerals as well. So that's how we're exploring under the subsurface for these IOCG deposits in the La Higuera area.

And I guess one of the things that we're trying to do in Chile is to look at this is what a typical IOCG looks like. Let's go and drill those targets. But we know there are many different varieties of iron oxide copper-gold deposits so that you may have anomalism in one data set.

But not have it in another, for example, and that may be, another target but of a different style of mineralization. So the more data sets we have, the better, but obviously how they combine, you may look for them both overlapping or you may look for them not non overlapping. It just depends on what style of mineralization you're looking for.

And the IOCG style of mineralization is so broad that, you can't afford to be overly prescriptive in what you're looking for, which is probably a good theme for all of exploration is that you want to have a model or a mineralized system that you're looking for, but you need to keep an open mind about what it may look like in detail.

So this is those magnetic bodies and we've drilled, two of those systems, one up to the north here, a thing called Gabby and another one in the center here called Chisposo, and we've had some good copper intersections of both of those. And so now we're stepping out to look at some of these, other systems.

And just, one or two more points about iron oxide copper-gold deposits. You mentioned earlier, Karl, about them being, you know, maybe more complex than porphyry deposits. And part of that is because they are very commonly in placed where they are, because they are associated with faults and shears, in the crust.

And what we see here is if you look at these bodies, they have a very common orientation through the bodies. And you can see that here. That those all associated with these faults in, the one orientation, some of them are slightly different orientations, but, those faults and in terminology, I guess we call it structurally controlled mineralization.

So these fault zones are controlling these deposits. And finally, one other, point I'd make about the IOCG style of deposit, and, we touched on it in terms of not being too prescriptive. If you were purely following this magnetic body, you would be drilling your holes down through here.

But what's been found is that these holes, had not a lot of copper, but a lot of iron in with them. And then as we stepped off the north along this fault, we started to get more copper off the end of this body. So that while these data sets can guide you into the right place, you need to be very careful and make sure that you're not too prescriptive about where you're drilling.

So that's our, a very brief overview, I guess, of our La Higuera project and, some examples of how that has some of the characteristics of an IOCG deposit.

Karl Woll: 00:21:56

Yeah, that visual makes it really interesting to see to exactly your point, Paul. So, when you look at those visuals, you think, yeah, I should be drilling a little bit to the south, but you're actually hitting better intercepts in, I'll call it the blob north of the blob there.

Paul Gow: 00:22:11

Yeah.

Karl Woll: 00:22:12

And then when you...

Paul Gow: 00:22:13

And I could go in, I could go into detail about why that is, but, you start to get into the real chemistry and then the physics of the systems, which is probably, would not be demystifying mining, I think would be, muddying mining.

But, you know, just shows you, shows you really need to keep your mind open for what these things may look like.

Karl Woll: 00:22:31

Yeah, that's super interesting. And then looking at the other, three targets or the two, Gaby and Chisposo, that have already been drilled what are the key, plans for drilling and advancement of exploration in the near term? Is there is there snow? I know it's winter in Chile right now.

Is there snow or what does the drilling season look like?

Paul Gow: 00:22:50

Well, it's, it's actually, it's quite interesting when, when people talk about working in Chile, they tend to be thinking about three or 4,000 meters of altitude. But that Gaby target I was showing you is actually at 400 meters altitude, and about 10 or 15 kilometers from the coast. And there's a lot of infrastructure and highways, et cetera, through the area.

So it's basically year round work, which, which is good. You know, it's good, it's good for junior explorers. It's a lot less I guess, capital intensive to be exploring at low altitudes near the coast with a lot of infrastructure rather than up, up in the high Andes, for example. So our, our plans are to get back drilling again later this year or maybe early next year at La Higuera. We're currently focusing on another project. We've recently acquired up up north at the moment called Chiricuto.

Karl Woll: 00:23:35

Perfect. Well thanks. Thanks for the overview. Is there anything else with respect to IOCG deposits, at a high level that you'd like to share? Or if anyone's interested in learning more and doing a bit of a deeper dive, are there any, I guess this is a two part question. Sorry, Paul, are there any resources or places you would direct listeners to learn more?

Paul Gow: 00:23:57

Yeah, look the two part question there Karl. So the first is I guess one thing we haven't discussed is the polymetallic nature of IOCG deposits and you can see that in their name, iron oxide, copper, gold. But in Australia, for example at the Olympic dam deposit copper and gold, are the primary products, but they also produce silver and uranium.

And if you look at I don't have the stats on hand, but Olympic Dam, I think would fall within the top 10 gold and uranium resources globally, on its own. So they're really polymetallic deposits. And Olympic Dam also has a lot of rare earths in it, which are not extracted currently, but I know they're looking at ways to extract them. And the difference in Chile, the polymetallic nature, there's no uranium really, and not a lot of rare earths, but cobalt is also very common. And Capstone Copper in their Mantoverde and Santo Domingo deposits they may already be, I think, producing a cobalt concentrate.

So these are polymetallic deposits, which I think is the way of the future. Mines are now becoming so, so difficult to build that why would you build a copper mine, a gold mine, a cobalt mine, and a magnetite mine when you can do it all at one place? So, in answer to your question about anything about at a high level about iron oxide copper-gold deposits is their polymetallic nature.

type and that came out in the: 1980

Karl Woll: 00:25:56

Perfect. Well, thanks so much for your time today, Paul. Really appreciate the introduction to IOCG deposits and that education. I will put some links into the show notes of this episode here where people can maybe connect with you and follow Tribeca Resources and see the progress of the projects. Anything else that you'd like to put out there for anyone to follow you or just any final parting thoughts before we jump off here, Paul?

Paul Gow: 00:26:19

Yeah, no, no. I guess my only thoughts are to stay tuned. We think we're doing some exciting work in Chile and we love it and constantly finding new and interesting projects to be working on, et cetera. So uh, yeah, if everyone just keep an eye on, on what we're doing and hopefully we'll give you some pleasant information over the next couple of years.

Karl Woll: 00:26:38

Perfect. Thanks again for your time. It was great chatting with you and I hope to talk to you again soon.

Paul Gow: 00:26:41

Yep, great Karl, thanks for having me.