Thursday, October 20, 2016

Bermingham - the skank of Keno Hill or the Milton Keynes of Canadian Silver Mines?

Note for Americans and other aliens: Milton Keynes is a new-ish city approximately halfway between London and Birmingham. It was built to be modern, efficient, healthy, and, all in all, a pleasant place to live. Many Britons find this amusing. (Neil Gaiman).

TL:DR version

  • Decent drill results, defined a small (6Moz) silver resource resource with a high grade core.
  • Good potential to expand known resources but upside is limited at ~15Moz silver.
  • good base metal credits, but minimal gold values.
I feel that the Bermingham vein has potential to contain up to 15 Moz of silver based on the current data, which is't huge, but I'm guessing this is the 'typical' size of the veins mined historically at Keno Hill. There will be 2-3 very large veins (>50Moz) and a multitude of smaller veins like Bermingham that were mined and processed through a central mill.

Putting it in perspective - most decent sizes mines producer 4-5Moz Ag a year, and so the current resources = 14 months production. Useful, but not something you'll take to the bank and build a mine on!

The geocrap bit.

Alexco have announced that they will be returning to drill more holes at Bermingham (link) where they intersected some spectacular silver grades in late 2015 (link).

In April 2015, an initial resource was calculated for the Bermingham vein (among other) that showed that they had defined a small, medium grade resource (link).

Not huge, but decent grades and a nice base metal kick
I took as much information that I could find from the technical reports and created a quick geology model to see what the potential was to expand these resources.

Here is the quick and dirty model of just the Bermingham vein, and it looks a big of a dogs dinner, with bulges and troughs, we know that the deposits is cut by several post-mineral (i.e. the faults moved after the veins were formed).

Just a case of joining the dots....
The Bermingham vein - the bulges and troughs are due to faults offsetting the vein.
So I built a new model and included the faults, which looks much nicer!

A couple of fault offsetting the 3-4 veins at Bermingham
One of the nice features of Leapfrog is that it can automatically calculate the true width of the vein from the various intercepts and we can apply a heat map to show where the vein is thick (red) or thin (blue).
That red blob forms a distinct trend (red >3m, green = 2m, blue <1m)
We can also model the metal distribution in the veins to see if there are any distinct trends or areas where the limits of mineralisation isn't well defined.

Silver - does it have a similar trend as the vein thickness figure above - thicker vein = more silver?
not much gold here....
Lead - similar to silver
Zinc - same as above
We can see this trend again (except for gold as there isn't much), there is a distinct trend in the grades, and we can use this to identify areas for follow-up exploration as we want to drill the good areas not the bad ones!

We can also see where there are areas that haven't been drilled.

Red polygons = undrilled targets
We can see that there is good potential to add to the current resources, but we can also quickly see that this won't grow into something huge, just a incremental increase in resources, and I feel that the upper limit for Bermingham is ~15Moz Ag at similar grades.

You can get the 3D model from here (link) have have a look for yourself.

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