Friday, October 25, 2019

Westhaven - Shovelnose

I've been wanting to compile the data for Westhaven's Shovelnose deposit for some time. They keep publishing decent grades and thicknesses (link, link and link), and I wanted to see how the data holds together.

Shovelnose is a good exploration story. Work commenced on the property in 2011. In 2016, drilling identified low-grade disseminated mineralization in silicified rhyolites in the Alpine and Tower zones. It was recognized that this could be the upper part of a high-grade epithermal system, which was discovered in 2018.

So, using the previous post on epithermal deposits as a guide, we'll look at the the data to see:
  1. Number of mineralized structures
  2. Size potential - vertical and horizontal extents of the mineralization

Mineralized structures

Westhaven tell us that they have 2 principal veins and maybe splay, but when you put the data in 3D, the picture becomes more complicated.

Red and orange = 2019 DH; green = 2018 DH

However, if you look at the silver, it appears to be restricted to the core of the mineralized structures.

Silver restricted to core of veins

From this I've created a series of veins. It is quite complicated, there are many ways that you can join the dots, but we can see 2 principal structures and several splays and parallel veins.

potentially multiple splay veins between principal structures

We can also see that the thickest and highest grades appear where one of the splays intersects the main vein.

Mineralization Extents


Note: My elevations are based on the Government of Canada 50K topomaps (link), and will vary by a few meters from Westhaven's surveyed drill-holes and collars

We know that in LS-Epithermal deposits, the good grade mineralization is restricted to a quite a tight vertical range. In earlier presentations (link), they used to include this slide:

just a 100m extent..

According to their geologists, the decent Au mineralization is found over a ~100m vertical range, from 1250 to 1150, which isn't very special, but with the power of excel, I disagree with them:


Please note - I've clipped the >50 g/t values to show a bit more detail for the <10 g/t Au area.

We can see that the majority of the >3 g/t Au samples fall between 950 and 1200m, and a higher grade (>5 g/t Au) core between 1000 and 1150m.

So we have a 250m apparent vertical extent to mineralization. Not bad


Please note - I've clipped the >300 g/t values to show a bit more detail for the <50 g/t Ag area.

We see a similar distribution for silver.


I've broken out the horizontal extents by the two principal veins. We want to the extent of the >3 g/t mineralization and if there are any high-grade (>5 g/t Au) zones that are can be extended or infilled (hot holes drive share-prices)

Main Vein

We can see that the majority of the >2.5 g/t samples fall within a specific area that appears to have a 500m horizontal extent and a 100-200m vertical extent.

We can see that the down-dip extension to mineralization appears to be open, but you can see how variable the grades are, we have several holes that hit minimal Au adjacent to hole SN18-25.

Secondary vein

On the second vein we see that the >2.5 g/t zone extends for at least 400m along strike and a 100-120m vertical extent. We can see that the zone appears to be open along strike, so there is good potential to extend this zone. We also see a consistent zone of >5 g/t Au mineralization (~150m x 120m) in the center of the vein.


So far Westhaven have discovered a decent epithernal system, with 2 principal veins with a couple of reasonable sized zones of mineralization. From the long sections we can see that the high-grade (>2.5 g/t Au) zones are well drilled (~50m drill-hole spacing), and the lateral extents appear to limited.

So, where do Westhaven go now? They could continue drilling the known areas and pumping out PRs with decent intercepts, but after a while they'll need to come up with a resource, and from my back of the envelope calculations the current drilling have defined around ~700Kt (assuming an average 2m vein width), which isn't enormous.

Therefore, it is nice to see that Westhaven are looking for new areas (link) to explore to build on their initial discoveries to see if they can find new veins and get the project big enough to attract interest from bigger companies.

You can get my 3D model from here (link)


  1. Thanks for your hard work. Would you be a buyer at this point?

    1. Not at the moment (as I'm a geologists I have no spare money to invest after buying the essentials - beer, wine and whisky).

      I would like to see them discover a second vein system as at the moment I feel that the initial discovery, albeit interesting, isn't sufficiently large to move up to the next level (i.e. bringing in a partner).

  2. How many ounces of gold would be there now approx.?

    1. I would guesstimate around 170,000 ounces of Au (ignoring Ag) using an eyeballing average grade of 7.5 g/t Au

  3. (700,000 (tonnes) X 2.7 (Specific Gravity) X 2.5 g/t Au)/ 31 (grams per oz Au = ~ 152,000 oz Au.

    This is of course capped at 2.5 g/t Au and doesn't take account of the silver so the true value is probably around ~ 170,000 oz Au (Eq)

    1. Why did you multiply by the SG? It seems to me that tonnes times grams per tonne divided by grams per ounce would give the correct result.

    2. Erg. I meant 700,000 cubic metres, X 2.7 SG I blame post rage as the blog ate my original post.

  4. Dan Oancea: 2.5 g/t is not economic in an u/g setting. Go over 5 g/t for economic mineralization. 100-150 m the height of the mineralized interval sounds typical/OK. 400m-500m the length of the mineralized block? Probably not. It will be made of several higher grade zones linked by lower grade zones. Stopes would/could be developed on the higher grade ore shoots only - unless they are such hi grade that you can afford mixing/blending them with the lower grade. 2.0m width? I don't know about that. At times drilling intercepted somewhat larger mineralized intervals (vein + small splays/veinlets) but I think that the width of the vein is less than 2.0 m. Maybe 0.65 m to 1.5 m which brings us to narrow vein mining with all its challenges. Lots of work to do ($ + luck) to achieve a 'critical mass' which will allow one to consider it economic to mine.

    1. I think the width is quite variable in the high grade portion, Vein #1 is right in the fault apparently. Look at the core, it is brecciated, has all sorts of "short and curlies" in addition to noted splays/stockworks, etc. Might be better to define a gpt-meter contour (at an u/g cutoff, 2.5gpt is probably fine) and see to what size panel it can be reasonably extended.

  5. I tend to agree with you on the need to find new veins. They do have a large property position with some interesting new targets. As for the current zones, the 50 m drill spacing will need to be tightened up to no more than 25 m to confirm continuity. There is a significant nugget effect here, which will need to be addressed. 2.5 g/t cutoff is probably too low unless there are are enough wide veins conducive to bulk mining. In any event, the current 76 M market cap is a bit high for this project - but is more reasonable than the >$100 m it was trading at in September. The sharp drop off in recent weeks is a realty check on how much work is left to be done. A nice discovery for sure. Needs more meat on the bones.

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