This is how Great Southern ‘cracked the nut’ on the enigmatic +21g/t Cox’s Find orebody
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Special Report: A late 2019, first pass drilling program at the historic Cox’s Find established that one – the gold is certainly there, and two – there’s still a lot more to find. Great Southern is now laying the groundwork for a phase 2 drilling program, designed to add ounces to this super high-grade deposit.
In late August, Great Southern (ASX:GSN) acquired the historic Cox’s Find project, about 70km from the gold mining hub of Laverton in WA.
Cox’s Find, which produced 77,000 ounces at more than 21 grams per tonne (g/t) between 1935 and 1942, was Western Mining Corporation’s (WMC) first foray into Australian gold production.
In today’s terms — when +5g/t is generally considered high grade — that would make it one of the highest-grade gold mines in Australia.
And yet, unlike many other revitalised gold mining projects, Great Southern didn’t have a lot of info to work with.
It’s certainly something the market has missed, says Dr Bryce Healy, Head of Exploration at Great Southern.
“It was quite incredible, the lack of exploration work that had been done given its history,” he told Stockhead.
“We literally didn’t have a historic drill hole through the main high-grade orebody, which is quite phenomenal.”
Instead of drilling, WMC would explore by sinking shafts and drives to test the gold content of the mineralised quartz veins by hand. That’s not a very efficient way to do things.
“Compare that with a project like Penny West, where [Spectrum Metals (ASX:SPX)] inherited tens of thousands of metres of exploration drilling,” Dr Healy says.
“We literally had to go in and look at this project with a fresh set of eyes, right from the word go.”
The maiden drilling program in December proved two things.
One, there was remnant gold in the currently defined high-grade orebody that could be extracted and stripped out in the near term.
The grade and width of the intersections – up to 143g/t — were consistent with what was mined by WMC between 1936 and 1942.
But more importantly, it gave Great Southern an idea of the ‘nature of the beast’ – and suggested there was a lot more gold to be found across the Cox’s Find project area.
Dr Healy says Great Southern was thrilled with the results of first program, and the way that the company’s exploration concepts and ideas around this deposit have developed.
“You always have that question in the back of your mind – ‘is this deposit finished? Why did WMC stop mining?’” he says.
“In the end, we said ‘well, there’s not enough exploration to say one way or another. It’s a question we have to answer by putting holes into the ground ourselves’.”
Great Southern are now in a position to take that next step and start drilling out into new areas and have a crack at adding ounces to this deposit — which is the exciting part.
Great Southern feel they are the first ones to have really cracked how this deposit holds together, Dr Healy says; pretty incredible, given that the deposit has been known since before the 1930s.
“Until we did the most recent work, we hadn’t appreciated the lack of extent or lack of understanding around the genesis and lithological hosts within the of the orebody ,” he says.
“We have a better understanding on the ‘conduits’ for the gold mineralisation.
“We could see evidence of this in the WMC workings and from our recent drilling.
“The biggest eye opener for us was that we now understand the ore genesis and what aspects were critical to the formation of these deposits.”
It like getting a set of keys to a pirate chest. We just have to find which key has the best fit.
Making that connection has now opened up a bunch of extensional drilling target areas, which literally do not have a hole in them, Dr Healy says.
“There’s a little bit of complexity to it, but it has given us really good guide to multiple near mine targets.
“Once we see the geological relationship with the ore zone characteristic, we should see the potential to host another Cox’s Find — another super high grade, 100,000oz deposit.”
Newly appointed COO Mr. Mark Major remarked that the geological efforts on reinterpretation of the orogenic gold genesis has taken this project to a new level. It’s now time to get the drill rigs turning, adding ounces and advancing our understanding even further.
This story was developed in collaboration with Great Southern Mining, a Stockhead advertiser at the time of publishing. This story does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.