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New age of discovery

14 Feb 2011

By Richard Roberts,  (Article from highgrade.net, 7 February 2011)

THE ‘discovery’, so far, of an extra 1.6 million ounces of gold at the Bullabulling project, west of Kalgoorlie in Western Australia, has focused attention on advances in computing power, smart software and the smarter people using data to cast old projects in a new light.

Juniors Auzex Resources and London-based GGG Resources, about to be dual listed after a successful capital raising in Australia, each own half of Bullabulling. They are winding up an 18,000m drilling program aimed at upgrading inferred resources to JORC measured and indicated status, and confirming continuity of mineralisation thought to extend over more than 6km of strike length.

Using old data, and new knowledge and technology, Auzex and GGG took a 400,000oz legacy resource at Bullabulling and turned it into a 2Moz inferred resource using the same cut-off grade (0.7gpt) as former owner Resolute. A lower cut-off employed on the back of the higher current gold price considerably expands the resource base.

Of course without much higher gold prices – $A1350/oz compared with $A350-400/oz when Resolute put about eight million tonnes of low-grade dirt through a plant that’s now in Tanzania, starting in the late 1980s – it’s arguable as to whether Bullabulling would have its new lease on life. But with that impetus, Auzex and GGG have pulled a rabbit out of the hat.

Or out of an old Resolute Access database, and a pile of excel spreadsheets that had been sitting gathering dust in a Melbourne apartment room.

“Nobody had bothered to sit down and put all the data together,” GGG chairman Dr Peter Ruxton said at a recent media briefing in Perth.

“You had 485km of drilling here – RAB, RC diamond – which is phenomenal for one deposit. None of that was put together in a single database [nor was any of the drill core kept!]. In those days back in the 1990s the computers weren’t big enough to run the lot. They ran it in different sections. And when you put the sections together in the modern computer you start to see things …

“We had it all put together over a three-month period – both ourselves and Auzex risked $350,000 to put the database together, and that’s why the resource jumped quite quickly from 430,000oz to what it is now.

“So we’ve been quite fortunate to get a tiger by the tail.”

Spatial data and predictive modelling specialist Kenex has been an integral part of the hunt. The New Zealand and Australian-based firm’s website spiel says its area of expertise is “positioned at the high end of the 'data knowledge transfer' value chain”. It put all the Bullabulling data together – a process that now includes the integration of new data.

“Previously the different pits and prospects were looked at independently and resource models were run on individual areas. With the current hardware and software levels, it is possible to combine the entire project and visualise and model the mineralisation through 10-20km of strike to get an overall view of the resource,” Kenex director and Australian operations manager Michelle Stokes told HighGrade Mining IT.

“This then allows optimisers to consider the entire project area as a single entity and evaluate costs accordingly.

“The database and other files and data files [for Bullabulling] were combined and verified through several iterations [work that is ongoing] to allow the entire project area to be covered at once.

“The new versions of Leapfrog and Micromine have been used for 3D visualisations and MapInfo was used to for larger-scale 2D exercises.”

Expert Leapfrog 3D geological modelling software user Toby Davis, who runs Impel Geoscience, has done all the new Bullabulling structural modelling for Auzex and GGG. He remembers – because he doesn’t have to cast his mind back too far – manually plotting drill sections on clear plastic film and inserting 20-30 of them into a wooden-frame box to create a 3D deposit view. The many forms of the box don’t seem to have a common name so Davis suggests the “Bucknell Frame” after former Plutonic Resources exploration manager Wally Bucknell, his boss at the time he worked on the Balcooma base metals deposit in Queensland.

What was important, though, was getting a 3D view of the geometry of the deposit.

“I think the increases in computing power have definitely changed the way geologists use data,” Davis told HighGrade Mining IT.

“I’m 38 so I started working as a geologist when everything was sections. Leapfrog does that sort of work in 20 minutes instead of … that work on the Balcooma deposit took two weeks to finish. So there has been a big change in the way geologists have been able to use their data with the aid of increased computing power.

“You can go in and look at a deposit where there is a lot of old data, and you can work out the first order geometry of it quickly – and that’s the nub of it as far as I’m concerned, to work out the geometry of the deposit – and Leapfrog is probably the best application for that at the moment.

“That gives you a context in which you can then do your geological investigation.

“The technology available now helps us look at a lot more data. It’s not just Leapfrog, it’s Mapinfo and a range of other packages. Michelle Stokes laughs and says the only reason we’re able to do all this stuff is because of pimply teenagers wanting to play 3D games.

“We can get the entire regional geophysical database on a laptop and you can sit in an airport lounge and do interpretations, and all that kind of stuff which we couldn’t do before, and it’s just having a lot of data available so that you can systematically work through the layers to really see what’s happening here and what’s happening there; to move between scales.

“What the last 10-15 years of developments in computing and software have done is made it possible to access and use larger volumes of data and to combine more disparate data types than was previously possible.

“We can now examine deposits at a larger range of scales easily and look at interrelationships between features more objectively. We are less constrained by type-models for mineral deposits than might have been the case in the past. So we can evolve our models and targets as the data dictates.”

Auzex Resources managing director John Lawton says new technologies are “increasing the probability of discovery in the most efficient and effective way … [shortening] the exploration cycle and reducing the cost of assessment and future discovery”.

“Tools such as digital field mapping systems through to sophisticated data management and modelling techniques are helping us reduce our costs and increasing our chances of success,” he says.

“The discovery of mineral resources is based on probability and for any company to be successful at the exploration end of the value chain it has to be able to efficiently integrate and assess large volumes of data including mineral occurrence data, geology and geochemistry to increase the probability of success. Effective targeting can only be done if all relevant data are compiled and integrated in a way that matches the ore deposit model being used and combined into a single mineral potential map.”

Davis takes a philosophical view.

“At its core, technology is the application of science to industry, which makes mineral exploration quintessentially technological,” he said.

“Software and computing is vital to the application of geology to exploration but there is a feedback loop because the new views of mineral systems that these programs give us are helping to develop the science which is the foundation of mineral exploration.”