Asiamet have released a flurry of press releases this month, they've raised money (
link) and recommenced drilling on the Beutong porphyry Cu-Au deposit (
link).
It contains a decent amount of metal:
Or a global resource of 511Mt @ 0.48% Cu and 0.13 g/t Au or 0.56% CuEq.
If we plot them on the USGS chart of doom, we can see if Beutong is good enough to tickle the hairy balls of a major mining company?
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| Note: the log scale to the axes |
Nope, at the moment it is nothing more than a friendly caress and a slight squeeze.
So what do Asiamet need to do to get it into the top right corner of the chart - the Acquisition Zone? To grab a major by the short and curlies, they'll need to:
- Double the resource but keep it at the same grade - 1Bt @ 0.56% CuEq
- Increase the grade, but keep the tonnage the same - ~500Mt @ 0.6% CuEq
To do this, they need to drill, but are there any obvious area where they can start?
I compiled the
summary drill-hole data for Beutong - leapfrog model is here -
link). Resources have been defined in 3 main areas.
East Porphyry
If we look at a plan map, we can see that the best intercepts all of the >0.5% Cu have come from the small (350m x 150m) quartz-stockwork. There is minor mineralization (<0.3% CuEq) in the host sedimentary units (grey). To the east sits an unmineralized (post-mineral) breccia. There is a small high-grade core, but this has been closed off (i.e. drilling has defined it limits with no obvious areas for expansion).
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| red line = surface outline of the stockwork zone |
Looking at a section through the East Porphyry, we can see the stockwork is narrow (200-300m wide) but a few drill-holes (e.g. hole BEU0800D01 - 293m @ 0.6% Cu and 0.11 g/t Au starting at ~450m depth) have intersected >0.5% Cu mineralization to ~700m depths.
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| The skarn zone sits to the north - left |
This deep continuation of mineralization hasn't been fully explored and with some targeted, long drill-holes will add some tonnage to the East Porphyry resources.
The question is, will anyone care that most of the potentially resources will be at >400m depth and probably beyond the limits for an open pit mine, and too small and low grade for a block cave?
West Porphyry
There has been much less drilling on the Western Porphyry zone, but the results are generally poorer than at the East Porphyry. Some 'round the world' drilling (holes going in every compass direction) have moderate intervals of generally low grade (>0.5% Cu and minor Au).
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| Green circles - areas where drilling has intersected >0.5% Cu |
However, there are a couple of areas where drilling hit some moderate zones of >0.5% Cu that need follow-up drilling to see if they are part of something more substantial or just some lucky hits.
Skarn
A small skarn zone is found just north of the East Porphyry. Its given some great hits - e.g. BC007-01 - 48m @ 1.63% Cu and 0.88\ g/t Au.
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| getting worse with depth |
However, it look like we have some supergene enrichment (
link - a very complicated presentation , but slide 20 is a good). With higher Cu grades close to surface and grades decreasing with depth.
Summary
Even tough there are some areas where the current resources can be added to, I don't think that there is enough in the current resource areas to make the project enticing enough for a major.
For me, I believe that Asiamet need to find something new. We know that porphyries tend to occur in clusters, and, if they have not already done so, a decent portion of the 2018 exploration budget should be used for regional exploration to find some new targets.
