When Anaconda Mining (TSX:ANX) reported their first results from Goldboro last summer, one hole stood out in particular with bonanza gold grades near surface: +2,500 grams per tonne over 0.5 meters starting at 33 meters. That is exciting stuff, but what is arguably more important is the sheer number of mineralized zones in that and other holes. The significance of all these mineralized intercepts is starting to become clear to me after conversations with Unknown Geologist where he has described the challenge facing Anaconda with the large number of targets at Goldboro.
Anaconda reported 10 separate mineralized zones in the bonanza hole, BR-17-04, and they seem to form 3 groups based on depth. The first group is just the single intercept of high-grade from approximately 33-36 meters. The second includes 4 mineralized intercepts from approximately 65-80 meters and the third includes 5 intercepts from 110-145 meters. These groupings are my own idea meant to reflect the stacked belt systems that are so important at Goldboro, which you can see in the company's preliminary diagram of hole BR-17-06 below.
The diagram of hole 6 is a little blurry, but it is worth squinting your eyes at because it shows quite a few interesting things. One, it twins an earlier hole. I haven't been able to figure out just which hole that is yet but am curious why they did that and how the results compare. Two, it is a deep hole. It reaches a depth of 475 meters from surface, which is probably around 650 meters downhole. Three, there are four instances of Visible Gold in the core.
Three of the VG are found on the outer limbs of belts in the East Goldbrook, which is surprising. The other is found near the nose of a belt in the Boston Richardson at depth. Just imagine if that VG on the Boston Richardson belt is part of a high-grade ore shoot that extends to surface! It may be a fairly small shoot in cross section, but there could be significant tonnage if it extends for hundreds of meters along the belt.
Keep in mind that Anaconda hasn't reported assays for hole BR-17-06 yet. What could be coming there?
There's lots more to say about all this, but I will simply point out that hole BR-17-05 had even more mineralized zones with greater grades than BR-17-04. Hole BR-17-05 had 14 mineralized zones and it is harder to separate them into groups because they are spread fairly evenly every 5-10 meters. There could be a few reasons for this. It may be that the belts spread out in the east where hole BR-17-04 was drilled, or it may be that hole BR-17-04 was collared further away from the nose of anticline than BR-17-05 and had a different angle that allowed it to hit fewer belts. The company provided a good amount of descriptive information about the holes, as in the plan map below, but I haven't seen the azimuths or dips of the holes and that leaves me grasping at straws a bit here.
A compelling feature of the geological model for Goldboro is the consistency across each individual belt system. The hallmark of that is the Boston Richardson, which was mined from surface to +200 meters. The presence of parallel belts adds to the excitement because it provides a way to start again and mine another belt from surface, but several groups have tried and failed to justify a massive open pit at Goldboro. The best potential may be in these high-grade ore shoots.
It's great that Anaconda hit one such shoot near-surface in their first holes, but there have been other similar intercepts at Goldboro in the past and they remain isolated dots of high-grade in the resource model. Watch for Anaconda to start connecting some of these dots as they trace these shoots up and down the belts to start establishing some high-grade tonnage at Goldboro -- just what they need to fill some of the spare capacity in the Pine Cove Mill.