Tuesday, March 14, 2017

Tethyan Resources

Serbia hasn't been this popular since 1999. We've lusted over the intercepts that Reservoir had been reported prior to their takeover by Nevsun, and so many junior companies are heading there to hope that there are other world-class deposits to be found while enjoying a glass of Italian Riesling.

you want to be in the turquoise and moldy lemon colored areas.
We can see that there are a lot of deposits, and mineralization types, but only a few would you class as being any good.
  • Bor - 2.1Gt @ 0.64% Cu and 0.24 g/t Au
  • Majdanpek - 1Gt @ 0.6% Cu and 0.35 g/t Au
  • Chelopech - 60mt @ 1.2% Cu and 2.4 g/t Au
  • Timok - 1.7Mt @ 13.5 % Cu, 10.4 g/t Au and 35Mt @ 2.9% Cu, 1.7 g/t Au
The rest are decidedly average, but it is important to note that ALL the best deposits are found in the early morning-urine colored belt in the NE of the map (where the world Bulgaria is located)

This isn't where Tethyan have their projects. Gkcanica and Suva Ruda are found in the orange Vardar Zone that hosts some medium-sized low grade Cu-Au deposits, like:
  • Tulare - 523Mt @ 0.24% Cu and 0.23 g/t Au
  • Lece - 3.3Mt @ 3.7 g/t Au, 3.3% Zn, 1.5% Pb and 20 g/t Au.
This doesn't mean that there isn't a large deposit lurking somewhere in this belt, but does indicate that:

It ain't elephant country, mate


  • Small low grade porphyry Cu-Au deposit drilled at Rudnitza with 
  • Narrow zone of supergene enrichment
  • Mineral belt isn't well-endowed
Nothing here screams "major discovery", some average exploration holes, and it will be interesting to see what Tethyan do next. Will they stay-married to the project - keep spending more and more money on it as they have nowhere else to go, or start to do some regional exploration to see if they can find something better?


I am interested to see the relationship between the recent drilling and the drilling conducted by Phelps Dodge in 2004, especially holes PDRC-04-03 and 04. I'm going to guess that this drilling was designed to confirm the grades seen in those holes (does this old data exist?) and to see if mineralization continues to depth. Here are the new results:

Reasonable for initial drilling
A cursory glance at the data shows that for an early stage project, this is the first drilling, they hit some interesting grades, particularly gold (some consistent, sub-economic grades on its own) with a narrow zone of high-grade copper zone relatively close to surface.

However, if you take a bit of time and look at the maps and sections on the webpage (link), you can quickly see that 3 of the 4 holes have drilled the same rock from 3 different directions, and a single hole (002) has explored for the continuation of mineralization 100m along strike, where we can see the grades drop-off considerably (3D model here - link)

Left = gold, right = copper

Here is an annotated section, and you can see that all Tethyan have is a small, poorly mineralized porphyry deposit.The small high-grade supergene zone looks interesting, but is small and restricted to the porphyry. The main body is too low grade to really warrant further work, and the 'deeper' zone, is too deep and low grade to really be of interest.

I guess they were trying to 'better understand' the mineralization, but it is frustrating that a company that has spent all that time and money on permits, building  access roads and drill-pads that they didn't do something a bit more dynamic. Why drill the same rocks from three different directions?

Let's be reasonable, we are talking about a junior exploration company, funds are tight, they had a well mineralized hole (visually) in hole 001. They did a step out (hole 002) 100m away, and it didn;t get much. So, I assume they panicked, played it safe, and went back to poking around hole 001 to make that they hit something. It keeps the risk low, but also minimizes upside.

Without having some regional geophysics maps or regional geochem it is hard to gauge the potential outside the Rudnitza porphyry. Normally companies drill the best target first. so if that is the case, they may want to spread their wings and see if they can find something better elsewhere.

So, imagine that you have just finished hole 002, it was bad, and you are thinking "what the feck do I do now"? 

What would a weaselly geologist do?

Here is my alter-ego, FAG (the Fraudulent Angry Geologist), and ask him - what BS can be spun from this project?

We have to assume that the FAG has 1/4 a brain-cell and is evolved from stoats

Remember - if you are investing in Junior Mining stocks, you are the Rabbit!

You saw that there was some good stuff in hole 001, not much in 002, so let us re-imagine the drilling, taking the ~1200m that was drilled in holes 003 and 004 and see what we can do!

We know that the deeper mineralization is low grade, so why not focus on the near surface supergene zone, this can be drilled with a few 150-200m long drill-holes.
proposed holes in red - >0.5% grade shell in yellow
Plan view
That would have allowed you to release lots of press releases with 30-40m @ >1% Cu and >0.3 g/t Au. Imagine those CuEq and AuEq PR headlines, that would suck investors in.

Even better, if all 6 proposed holes hit the high-grade supergene zone you could do a nice BS resource report to define a small (200m x 200m x 30m) resource (3.25Mt @ 1% Cu or 70 million lbs of copper), and start promoting the heap leach potential. the opportunities are endless!

Tethyan, you missed a trick there!


  1. Disagree with your assessment on the regional geology. Skouries is a good deposit for one reason. High grade core of 60 Mt >1% Cu and >1 G/t Au. Bor. Your're looking at > 10 moz in Skouries and Olympiada. Tertiary also hosts Perama Hill and a bunch of epithermal deposits in Bulgaria and Turkey.

  2. Disagree with your assessment on the regional geology. Skouries is a good deposit for one reason. High grade core of 60 Mt >1% Cu and >1 G/t Au. Bor. Your're looking at > 10 moz in Skouries and Olympiada. Tertiary also hosts Perama Hill and a bunch of epithermal deposits in Bulgaria and Turkey.

    1. This I said you wanted to be in the turquoise (Skouries and Olympiada) and the dark yellow belts). they host the best deposits (I mistakenly included Skouries in the Vardar zone - which I've corrected).

      If you look at PCDs the deposits in the Vardar zone aren't very special (medium-sized and marginal grade)
      - Tulare = 523Mt @ 0.41 % CuEq or 0.56 g/t AuEq
      - Buchim (on the boundary) =150Mt @ 0.56% CuEq or 0.76 g/t AuEq

      What we want to see is the upside, which for porphyry deposits are decent holes that will interest a major to come in and JV the project. I don;t see that with Tethyan

  3. Hi AG,

    Fabian Baker here, Tethyan’s COO (offering a bit of proactive engagement..). Good to read your analysis, first up I’d be more than happy to chat and run through these results and plans for exploration in the year ahead, so feel free to get in touch (fabian@tethyan-resources.com).

    Clearly it is early days at Rudnitza, and similarly to your comments, we feel these first intersections are highly encouraging, but agree we’d like to see evidence of significant tonnes and/or higher grades. Still, it really is early days in the exploration of this system and our interpretation of the drill core is that these holes are hitting peripheral mineralisation (as the holes encountered phyllic and propylitic alteration, not potassic), and we have not yet found the core of the system where we’d hope to find higher grades.

    Just a note regarding the rush to drill, the terms on which the Serbian Ministry issued the Exploration Permit included the completion of minimum 2,250 m by the end of 2016, so with the need to satisfy this in mind, first step was to see the rocks (very little outcrop) and try to extend historic drilling. Which we did, extending known mineralisation from 244m to 567m depth (down hole) and laterally to some extent, plus mineralisation is still open particularly to the north and west.

    We also know we have drilled a small part of a much larger system based on surface mapping, soil sampling and recent ground magnetics, the rest of which now needs well thought-out exploration. We certainly don’t see it as time to move on yet, and hence we have a significant exploration programme planned for this year including IP geophysics and various spectral/mapping/petrographic methods to better understand the system in the hope of vectoring toward the source.

    Meanwhile, we also have a team busy on regional exploration throughout the broader region and building a pipeline of exploration projects remains an important part of Tethyan’s strategy.

    Exploration is the name of our game and as you’ll know countless discoveries over the last couple of decades were made on previously ‘explored’ ground and often outside of the most obvious anomalies. So for now we like what we’re seeing and are keen to push on, will make sure to get the facts out there and keep the ‘BS’ to the minimum.

    Thanks for following us, I look forward to talking and let’s hope we can generate some decent results in the coming months.

    1. Hello Fabian,
      Thank you for your reply. Ok, so there was a permitting pressure on you, I understand why you had to drill so much, but I'm not sure that I would drilled the way you did (I have to plead ignorance - i haven't seen the core) I would have drilled it a bit differently as I don't think holes 3 and 4 really add value to the project, and I would have maybe changed holes 4 and focused on the supergene to better understand it.

      It will be interesting to see how the drilling relates to the mag and particularly the IP data.

      Some cheap vectors that you can use are vein type (particularly B-vein density and location) and sulphide minerals - do you see any bornite in the core or just pyrite dominated with minor chalcopyrite?

      It would also be interesting to see what the distribution of other elements (e.g. Mo, Bi, Tl, Sb) are telling you, are you looking at a deeply eroded or shallowly eroded system. I've found that draping the geochem data on topography really help to see if you have erosion anomalies or where you are in the system.

      Regarding IP - this is something that irritates me endlessly, so many companies drill just the chargeability highs (that are associated with the pyrite halo), but many decent porphyries are found just in-board in a subtle low that corresponds to Cpy>Py.

      Working in other parts of the world, stream sed sampling works wonders, is there a publicly available stream sed database? If you cross those sample locations against drainage basins you'll find that even in the most prospective belts that large areas haven't been sampled and a cheap way to cover a lot of ground is to infill the gaps.

      If you can, try and invert you data, it will really help to pick out subsurface structures.

  4. Hey AG,
    Was wandering if you will be doing an update on Ana Paula. Also their presentation shows their big land package and also numerous targets. What are the chances, that timmins would be able to find new deposits.

    Thank you

    1. Yes! I need to rebuild the project, but I hope to have something done this week. A simple answer is that you want (rule of thumb) material grading >3 g/t Au for a decent sized underground operation. If they are getting that, all is good

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