Interview: Pretium’s Quartermain on the Strathcona fallout, and the road ahead

Pretium Resources (TSX: PVG; NYSE: PVG) president and CEO Robert Quartermain spoke with The Northern Miner on Oct. 29 about the controversy that’s swirled around the company since the shocking Oct. 8 resignation of highly regarded Strathcona Mineral Services as a consultant at the company’s Brucejack gold project in B.C., and plans for the company going forward. The following is an edited transcript.

The Northern Miner: Has this been the longest three weeks of your life?

Robert Quartermain: Well, I’ve been in the business now since 1975, almost 38 years, so yes, it’s certainly been a long three weeks. You know, for myself and for my fellow shareholders, I think the key thing is that we continue to drill off high-grade at the Brucejack project and continue to advance the project going forward, and we’ll be able to move beyond this.

TNM: What has happened with Pretium in the last three weeks?

RQ: As it relates to the two qualified persons (QPs), when we started the bulk-sample program — and the reason for doing the bulk sample was to look at validation of the resources which had been outlined by Snowden in November 2012 — what we wanted to do was get local data and be able to do local conditioning of the model against the broad model, and use that for the validation against the resource [estimate] and to the probable reserve, which we’ve used at the Valley of the Kings.

TNM: When was Strathcona hired?

RQ: Strathcona was hired late last year. They started their work in the spring. As part of the underground bulk sample, we also decided to employ a sample tower. If you’re doing a bulk sample, you’ll actually run some of the material through the sample tower. For every 100 tonnes of material, it takes a 1 kg sample, and you’ll get an assay for it.

We wanted to determine whether or not that was a valid methodology to help us characterize the mineralization style. Because one of the challenges that we had was that the mineralization at Brucejack is very high grade, and we know it is a heterolithic deposit — you get very high-grade values in a low-grade matrix. And both Strathcona and certainly Snowden would agree there’s a great deal of gold at the Brucejack project, and sometimes very spectacular gold that we have in the VOK zone.

We were focusing on determining the influence that each of these high-grade samples should have on the surrounding volume. In the case of using Snowden, which of course is a world-class estimator, they have been to the site, and in discussions with us, and looking at the data, felt that the multiple-indicator kriging methodology is one where you try to reduce the conditional bias that you have in the resource, and so felt that was the appropriate methodology.

And so they’ve calculated for us this resource. Strathcona, of course, are more focused on mining. They don’t do resource calculations. They were brought in to determine whether the sample tower could help our data collection and provide data for the validation.

Our plan had been with Snowden, that we would process all the material anyway through the mill, and that would be the final validation. For instance, if you take 10,000 tonnes from underground and look at the gold you recover, that would be a good validation to back the model. Bringing Strathcona in was only a part of the set along the way.

I think what occurred along the way is that perhaps Strathcona disagreed with some of the conclusions Snowden has, and Snowden continues to validate their conclusions based on their understanding of the methodology.

They have different opinions on how to best validate the resource. Strathcona took the opinion that we believe the sample tower data will do it, and Snowden was of the opinion that the sample tower was probably irrelevant, that you probably need to process the full 100 tonnes, which is largely what we did. 

And in doing that, with the first round, we showed that the actual gold we recovered was 94% higher than the sample tower would have predicted. And so, it put again into question, in a heterolithic deposit, whether a sample tower was an appropriate medium, or step within it. 

What we had hoped is that we would have the professional co-operation from two internationally recognized groups, and go through with the mandate that started in the [first half], which is the two methodologies — one of the sample tower and the other of the full milling — and looking at that reconciliation at the end of the program.

TNM: You’ve talked about bringing in a new third party?

RQ: Yes, Snowden has indicated that they would bring in another third-party independent review of the mineral resource update. And what we want to do in there is incorporate all the data that we can, insofar as Strathcona had custody of the data for the sample tower, we would be able to incorporate that into the model and be able to show its application.

The overall industry is under a bit of duress, those of us in the junior sector, and with gold prices being down, we need to get all the data we can to incorporate into the model, and speak to that with the most robust data that we can.

TNM: So the third party is going to look at the tower results, too?

RQ: To the extent that we can and they can opine on them, then yes, we will have whatever third party we have come in and look at all the data we collect. We’re still getting the final data from the sample tower — it’s taking longer to get that data because we’re doing detailed metallic screens on it. But once we have that data, yes, we would look at Snowden’s resource model to the extent that we can, and have it reviewed by a third party.

TNM: The sample tower results are almost ready?

RQ: No, those won’t be ready until well into next year. Getting the sample tower data is taking longer because it’s specific assaying that needs to be done. The metal screening on each of the samples is taking a little bit longer to get through the lab, and so that data won’t be through until early in the new year. As we had disclosed, the results of the Strathcona report wouldn’t have been available until next year’s first quarter.

TNM: The stock price fall that happened when the bulk-sample result came out (on Oct. 22, 2013), was that because people looked at the 4-gram-gold-per-tonne grade and compared it with the much higher reserve grade? 

RQ: Oh no, I don’t believe so. I think it was just from the fact that you had a qualified person just withdraw from a project partway through it. Based on the modelling we’ve done, you have to look at it holistically. 

TNM: And the stock drop on Oct. 22 — was it related to the grade of the bulk sample?

RQ: No, I think the grade would be, as we indicated to the market, with respect to the underground bulk sample, we were extracting in areas of no grade, low grade, medium grade and high grade, and the material that was to the west, in the 585, we had expected to be lower grade than the overall reserve g
rade, because in testing the model we had to look at that variation. I believe the continued movement in the share price has just been the reflection since the resignation of Strathcona, and then us discussing and getting out and talking about the project, and advancing it forward.

The fact is that there’s gold here, very high-grade gold, as evidenced by the news release we just put out. That fall happened one day . . . we put out a news release two days later, and the stock was up 20%, and more or less captured some of that downfall because we had some spectacular results out.

That’s the thing that this project continues to deliver: over the last few years, we’ve isolated the main mineral corridor where the gold is located, and can consistently go in there and hit high-grade material. 

TNM: Are you backing off the idea that there will be 4,000 oz. gold in that 10,000-tonne bulk sample?

RQ: No, not at all. We believe there will be at least 4,000 oz. there, yes. 

You can’t look at this linearly. Each of the five crosscuts is not an equal representation. It is a variable continuum. Let’s get all the material from the 10,000 tonnes, look at what those ounces are — we’re projecting 4,000 oz. — and then have a conversation around whether we recovered those materials, whether we were higher or lower in that regard. But we need to look at all the data, because you can’t look at each crosscut in isolation, you have to look at how it relates to all five crosscuts.

We’re taking a global model and are now testing it. We’re taking a lot of drilling, which will help us do the local conditioning, and the detailed drilling we can now do will tell us exactly how much gold we should have anticipated from each of these crosscuts, where there are these overall 4,000 oz. we’re expecting to get.

TNM: Your Oct. 22 press release, quoting Strathcona, says that “there are no valid gold mineral resources for the VOK zone, and without mineral resources there can be no valid mineral reserves, and without mineral reserves there can be no basis for a feasibility study.” What did they mean by “no valid”? The grade is not valid? The resource category? “No valid” seems vague.

RQ: I know, and that was a choice of Strathcona. Again, I think that relates to Snowden’s resource estimate, which Snowden validates. They take the opposite view, that the resources up here are very valid. And so it is a commentary on Snowden’s work, and that’s why we put this down as a bit of a disagreement, with respect to the QPs, on the resource.

The resource which we have published on the project has been prepared by Snowden, who are internationally recognized and have had 25 years in the business. There are many operating mines that have resources that they have prepared. So it’s their resource we’re looking at validating, and it was on their resource that Strathcona made their comments.

TNM: A broad question about high-grade deposits: how do you determine the best upper cut-off grade to use? You have an upper cut-off of 430 grams gold per tonne. Where does that number come from?

RQ: It’s not so much high-grade, it’s one where we look at and condition each value, which is greater than 400 grams per tonne. This deposit is heterolithic, i.e., it has some low-grade — a lot of material at 1 gram, 2 grams — and then very high grade, which is above 100 grams, and then into the kilo hits. You’ll see in the news release we put out that we had another 17 kg hit. You’re looking at something which is running almost 500 to 600 oz. per tonne.

What we have to do is look at, under the multiple-indicator kriging, that those values are limited in their extent. That’s part of the challenge here: how far do they carry and how much value do you put on them volumetrically?

And so if you look at and plot the population from a 5-gram cut-off, and we used a 5-gram gold-equivalent cut-off, from 5 grams up to our upper limit, where we have 42 kg, then at around I believe the ninety-fifth percentile, that comes out at around 400 grams.

So anything above that has been looked at for its location within the population, and how much weighting it should have in the model. And then anything below that has just been normally conditioned.

TNM: Back to the 10,000-tonne bulk sample, are you going to do more bulk sampling because of what’s happened? Has anything changed in your plan?

RQ: No. The 10,000 tonnes is what is legislated by the government. We can do 10,000 tonnes every five years. And so we designed this to get the most robust data that we could to go back and use it to validate the broader model. In essence that’s what we’re doing here: we’re taking the localized data that we now have and are able to take that back to the more global model, which is the November 2012 model, and look at its validation and its application.

And from that, it could tell us when we’re doing the detailed mine-plan drilling, and what kind of drill density and spacing we need to move indicated resources or probable reserves into the proven category. So that’s part of the exercise as well.

TNM: So there’s been no change in the plan.

RQ: No change at all. From what we started last March to where we are, the crosscuts are exactly where they are, the lateral drifts are where we intended, though we modified and dropped two small lateral drifts just to meet our 10,000 tonnage. And then we’d originally planned to do 15,000 metres of detailed underground fan drilling, and we’ve done 16,500 metres.

The program as we set it out is what we’re going forward with, and all the data we get from that, including sample tower data, we will incorporate into the final results, which will help us go back and validate to the original 2012 resource model.

TNM: Are you under any pressure to do more bulk sampling?

RQ: Not at this time, no. What we need to do is get all the data, look at the results, look at the validation, and from that determine if there is any more work that may need to be done.

TNM: Can you explain the constraint of the 10,000 tonnes? Is that related to provincial legislation and permitting rules?

RQ: The provincial legislation allows you to extract a 10,000-tonne bulk sample every five years for processing purposes and testing purposes.

TNM: What kind of permitting would be needed if you wanted to bring that up to 50,000 tonnes, or some number like that?

RQ: You’d have to probably get into a small mining requirement, or we could always approach the Mines Branch and see if there would be a possibility to go larger. But at this point, we designed the 10,000 tonnes to give us what we think is the appropriate data for the validation. 

The best thing for us now is to finish milling the underground material, look at what we’re going to recover and from that look at all the data and the conditioning of the local model to the global model, and from that look at
what other supportive activities we may need, with respect to the resource we’ve outlined to date.

TNM: What would be the timeline of the news from Pretium for the rest of the year and beyond?

RQ: We’re drilling underground, and so we’ll have drill results out over the next month or so, as we complete our underground drilling. We, of course, will have results from the underground milling, and we will indicate how much gold we’ve recovered from the milling. From that, we’ll have a validation of what we’ve recovered from the milling back to a local model, and validate that back to the broader model. 

We will also do an updated and revised resource for the Valley of the Kings, incorporating all of the data we’ve recovered to date. And then from that we will go back and revise and update the feasibility study which we completed last June to take into account all this new data, and make updates and modifications accordingly.

TNM: So the only change in your plan is that you may have a new third party come in to look at the resource update?

RQ: Well, yes, another third party coming in and doing essentially what Strathcona would have been doing. Snowden will do its work, and a third party will come in and review the data.

Everything is going and staying on course as we are. The key thing is that we have outlined some very high-grade gold — that’s not in question here — and so it’s a matter of: How do you determine the influence of those high-grade samples in the lower-grade material, and come up with the mine plan that we have, based on Snowden’s work? And we’re basically validating that.