It is my pleasure to provide another deep-dive with Dr. Alan Carter, President and CEO of Cabral Gold (TSXV:CBR). I have published several hours of interviews with Alan since the company went public last fall and things keep getting better. They are generating a torrent of information with two teams drilling several auger holes a day, which generates kind of subtle geological information that is not for everyone.
Listen in closely to the full interview below.
I've set the link to start playing at the 23-minute mark, where Alan goes in to explain some basic geology and ends up articulating some important points that I've never heard him say before! Read the quote in full below, which is long but worth considering closely.
"There are two types of mineralization here, Peter. We've got stockwork zones, which are up to a hundred meters wide. Certainly the Central zone is about 100 meters wide. The MG zone is a bit narrower at fifty to eighty meters. A stockwork is basically an area of rock that has basically been shot through with tiny little veins, some are only a millimeter or two wide. It's basically been shattered through with all these quartz veins so we've got that style of mineralization. Those are typically lower grade, typically averaging one to two grams a tonne.
We've also got another style of mineralization, which is a bit different. These are narrower, high-grade veins. They occur with the stockwork sometimes, sometimes without. They are much narrower, 1 to 3 metres wide and are generally single veins that basically cut the rock.We have the lower grade mineralization halos or stockworks surrounding the veins. We've got both types.
The interesting thing about this particular prospect we're talking about here called Vila Rica is that we knew there was high-grade mineralization previously. Earlier this year, we put out some results that included half a meter at 43 grams. That's a narrow zone with very high grade mineralization. You would typically mine that through an underground method. We thought that was pretty much it -- we were going to trace the narrow vein along strike before we started drilling.
What we found in the last week or so, really, is that the high-grade mineralization of Vila Rica is actually surrounded by lower grade stockwork mineralization! Lower grade stockwork mineralization suggests the possibility of a bulk tonnage deposit that we could mine, potentially, through open pit methods.Now, the significance of these two styles of mineralization together is as follows. The other four areas where we have existing deposits that have been drilled and included in our 43-101 estimates all have both styles of mineralization.
Vila Rica is the fifth one that has both styles of mineralization. Vila Rica has never been drilled, but the big difference about Vila Rica is that it was underneath all these sediments. There was no really compelling gold in soil anomaly at Vila Rica because the underlying mineral had been masked by these sediments, whereas the other four areas in our resource estimates didn't have this sediment cover masking the underlying rock. They were basically weathering in situ, so the soils were a very good indicator of what was underneath. The Vila Rica soils were not a very good indicator of what was underneath."
Thanks Alan for this brief lesson, it's not one that I will soon forget! I look forward to learning more and following how this story unfolds for Cabral at Cuiú Cuiú.
And if you're really keen then read on to hear Alan's comments in reply to my prying questions about the resource update.
"Let's just address the resource estimate for for a second. When we went public, we had resources of about 1.3 million ounces that were calculated with no artificial top-cut imposed on the results. That is to say, those were calculated by an independent engineering firm, Pincock, Allen, & Holt, based on no upper limit to those results.
For the revised resource, we used a different engineering group, Micon International, who adopted a somewhat conservative approach in our opinion when they decided a top-cut should be applied. There are some very good high-grade numbers that, in some cases, were cut to 2-5 grams a tonne depending on which zone we're talking about. Other areas were cut to 10-20 grams per tonne.We lost a lot of the high-grade material and that's why the resource is actually currently smaller now.
The interesting thing, Peter, is that if you compare apples to apples by looking at our most recent estimate without top cuts then our resource actually went up. If you reread the press release and look for the apples to apples comparison, then you will see that the historic estimate with no top-cuts was 1.3 million ounces and the current estimate with no top cuts is 1.5 million ounces.
The reason it looks like it's gone down is because there's been a different method used with statistical top-cuts applied to the actual data set that cuts the high-grade population. Most of the high-grade samples that we took have been cut way back. I want you to be aware of that."
I had arrived at the same conclusion in my article on the resource update, but hadn't heard it directly from Alan since then. I'm glad that I have some ability to understand the twists and turns of this company. Please note that I have been compensated by the company to prepare and distribute this interview.
Watch for more news from Cabral on their website at https://www.cabralgold.com/news-releases/2018/