I had a chat with Dr Hronsky at the 2017 AGM. He mentioned the...

I had a chat with Dr Hronsky at the 2017 AGM.

He mentioned the importance of major deep crustal features that sometimes have long life spans and their relation to ore deposits. These can provide conduits for mineralising events that become potential conceptual targets for exploration. The studies he and colleagues at WMC did in the 1990s led (directly and inidrectly) to the discovery of Nebo-Babel, Tropicana and Karlawinda (Francopan and subsequently others.). [Other approaches may also have had similar results - if budgets and confidence in geoscientists allowed the low? probability of success]

At that AGM I asked if he was surprised WMC came up with Au when they were targetting nickel at Karlawinda? No, because these deep structures are not selective in what they bring to surface was the gist of the response.

[The initial Francopan intersection was under some 200m of cover - what would be the probability of the first hole hitting something unexpected (good gold intersection) under so much cover? Pretty low I suspect UNLESS there was a big system around.]

As a vague rule of thumb the major faults do not have the deposits on them. It is the splays and lower order faults from mega faults that generally host orebodies. While the main faults may provide the deep plumbing systems the deposition sites tend to be elsewhere. There probably are exceptions.

The Boulder-Lefroy fault from +Kalgoorlie to Kambalda+ is an example which follows this rule of thumb, especially in the Kambalda area.



There are several variants of the WMC work done in the 1990s - This link is to the discovery concepts/history for the WMP [with lots of background info].