As I'm still getting back into the swing of things, and I want to have a look at some of the recent discoveries being made in the Paterson Province in Western Australia.
If you want some background information on the geology and deposits of the area you can download an excellent summary on the geology and mineral deposits of that area (link) by the Geology Survey of Western Australia.
Compared to many areas of Australia, the Patterson Province is relatively unexplored. Its remoteness to the traditional gold belts and iron ore zones to the SW and W meant that semi-detailed exploration didn't really commenced in this area in the 1960s.
Early exploration in the 1970s and 1980s discovered 1 world-class deposit - Telfer Au-Cu mine (total production >10Moz Au) churning out >400Koz/year) and a couple of medium-sized copper deposits at Nifty (link) and Maroochydore (link).
So, it has been nice to read about a couple of the new, potentially large discoveries being made by Rio Tinto and Winu and Newcrest/Greatland Gold at Haverion.
We'll start with Winu, and I was surprised that Rio have been publishing a lot of exploration data from Winu (link and link), and so I've imported the data into Leapfrog to see what all the noise is about. You can get the Leapfrog model from here (link)
We have lots of impressive intercepts, including:
- 741m @ 0.45% Cu, 0.52 g/t Au
- 499m @ 0.4% Cu, 0.2 g/t Au
- 439m @ 0.42% Cu, 0.32 g/t Au
- 84m @ 0.62% Cu, 1.41 g/t Au
A nice high-grade core surrounded by lower grade mineralization. There appears to be some zonation, with an Au-rich core surrounded by more Cu dominant mineralization, with minor silver, but no-one cares about that.
We can also see that the mineralization is relatively shallow, ~100-150m depth, but with all deposits, it is important to get a sense of scale. We see so many projects that have great grades but all that quality is concentrated in a tiny package, here we don't have that problem!
Rio have drilled decent mineralization over a 2km strike length, that is impressive, we can even have stab and seeing how much Rio have found....
Pretty impressive, Rio appear to have found a large 500Mt, moderate grade ~0.5%CuEq Cu-Au deposit in the middle of nowhere. It is moderately deep (60-150m depth), there appears to be good potential to expand the mineralization to depth and along strike, so I will be see how this project evolves.
However, one big question to ask is - is this project big enough for Rio? I would expect that they would want something that is 2-3 times larger for development.
Next week - Havieron!
Some geology rubbish
In many other mineral districts companies have applied Zipf’s law to gauge their maturity - i.e. are there other deposits that have yet to be found.
A simple rule of thumb would be the 80:20 rule - 80% of the resources are found in just 20% of the deposits or 2-3 big deposits, a few medium-sized, and and loads of tiny ones.
Here are some examples from Davies el al (2018) - reference at bottom of post.
Yilgarn Au deposits
|Some massive deposits, quickly dropping down
Lets return to the Paterson Province
I've plotted on Telfer and Winu against a Zipf curve.
It is very interesting, if this area follows the Zipf curve, we can see that there could be a couple of 2-3Moz Au deposits and maybe 4-5 >1Moz Au deposits lurking around. Lets see how Haverion fits in.
It will also be interesting to see if someone will buy Telfer as Newcrest are open to offers (link)
Davies et al (2018) "Entering an immature exploration search space: Assessment of the potential
orogenic gold endowment of the Sandstone Greenstone Belt, Yilgarn Craton,
by application of Zipf’s law and comparison with the adjacent Agnew
Goldfield" in Ore Geology Reviews Volume 94, March 2018, Pages 326-350