New technologies are being developed to analyse chemical and mineralogical changes which might signify the presence of precious and critical minerals. These technologies include sophisticated sensors to sample rock properties (like those on the Mars rover) and innovative software to analyse the digital data from the sensors.
CSIRO's software packages Data Mosaic (DM) and The Spectral Geologist (TSG) are designed to interpret digital sensor data, turning numbers into geology. Geologists can then use this information to determine the likelihood that these rocks may contain valuable minerals.
Using advanced mathematics and machine learning, DM can process and reconfigure mineralogical data from TSG or chemical data from the samples to identify important changes in rock types.
Data Mosaic for interpretation of drill core data
Dr June Hill, principal research scientist at CSIRO Mineral Resources, says the old 'analogue' core analyses, using a naked eye and simple core logging tools, such as magnifying lens, acid test and tape measure, used to take days or weeks to get results.
DM can process the information from multiple drill cores in seconds and do it without human bias.
"Experienced specialists may be brilliant at analysing one type of rock and not so brilliant at others," says Dr Hill.
The more drill cores that are analysed and the more information that can be extracted from those cores, the more complete the picture of the subsurface becomes.
DM had two goals: to allow geologists to log drill cores objectively using numerical as well as visual information rapidly and produce graphical logs from the results that can be interactively interrogated.
As Australia and other nations transition to new energy forms, the need for critical minerals has become ever more urgent – and ever more pressing.
"The rocks that host these minerals are varied," says Dr Hill.
"There are so many of these critical minerals we need to find, and DM helps us to rapidly and accurately identify the rock types, which is vital for predicting the presence and type of mineralisation," she says.
Geoscience Australia currently lists about 26 critical minerals, including nickel, rare earths, lithium, silicon and cobalt - as well as industrial and precious metals such as copper and aluminium.
"Australia is well endowed with such minerals but we struggle to find them below the surface," Dr Hill says.
Geology will never be completely devoid of hypotheses or theories but the accuracy of software such as DM adds power to interpretations.
"The automation in DM allows you to test different ideas," Dr Hill says.
"It's interactive. You can ask it questions on the fly or interrogate the results in a number of different ways. If it doesn't accord with what you're looking for, you simply take another tack."
Many machine learning tools tend to demand a high degree of technical ability, but Data Mosaic has been designed with simplicity in mind, says CSIRO team leader and software developer, Sam Bradley.
Bradley says any geologist can log in, input data and “with a few button presses” be able to visualise the boundaries of their data.
As well as producing drill core plots it exports and arranges data in a spreadsheet form geologists are familiar with.
"The tech also has a very low barrier of entry," Bradley says.
"There's no need to set up complicated software. The user simply logs on to the website and starts playing around with it."
A suite of tools for mineral exploration
Data Mosaic is part of CSIRO’s Exploration Toolkit, an evolving incubator program which houses a suite of software tools.
CSIRO envisages geologists uploading data sets and running three or four programs from the kit to ascertain results.
"It's about delivering science much more quickly to the world," says Bradley.
"We don't want it to be something that sits only in the scientific realm. It has to be something that can be used by industry to give them meaningful results in the shortest possible time frame."
DM itself can be used by geology students or academics at university, by government geological surveys and by exploration companies mining a deposit or in the midst of tracking a resource.
The Spectral Geologist
Another vital piece of software that has been refined over time is The Spectral Geologist, which has undergone a several iterations since CSIRO first produced it in the 1990s.
It analyses reflectance spectra data – the light emitted from a mineral surface – and like Data Mosaic, seeks to discover what the eyes cannot physically see.
"We are restricted to our visible wavelength range, but reflectance spectra tools add more colours. They enable us to look at the infra red as well," says Dr Carsten Laukamp, CSIRO principal research scientist.
"The TSG software then comes in to help us to understand and translate it into something intelligible."
One of tools from which TSG derives data is the CSIRO-developed Hylogger, the hyper-spectral drill core scanner (commercialised with Australian METS Corescan Pty Ltd) but TSG also has its own in-built spectra reference library, which adds context to data uploaded from a core.
Data derived from the geo-chemistry of the core or petro-physical data related to physical properties can also be uploaded.
It's all part of adding power to the geologist’s convictions, says Laukamp.
"We can then say – yes – this really is a certain type of feldspar or this might be mica. It's a very fast way of processing it all and getting a quick answer," he says.
Part of the software's strength is its ability to recognise shifting geological trends which help direct the user to important changes in rock composition, which may help signify the nearness of a core to an ore deposit.
TSG has proven very successful in hunting down porphyry copper deposits. South American mining companies have used it to track copper deposits virtually.
"They know there is a certain type of mineral predominant and experience tells them that as they get closer to the ore, the minerals tend to change. They’re using TSG to track it down," Laukamp says.
Laukamp admits that the technology is still improving and that TSG does not yet have the capacity to include the largest hyper spectra data sets.
He cites the large collection of drill core data that is held in the AuScope National Virtual Core Library. It contains hyper-spectral information taken from six major geological surveys in Australia.
"We have 5000 drill cores from across the Australian continent, which amounts to about 1600 kilometres of drill cores," Laukamp says.
"This means we have millions of spectra data still out there, one of the largest databases for this kind of information available."
There may be data collections involved in the targeting of lithium, while others are related to seeking tungsten or copper.
"TSG can use the information of one or two drill cores – but we can’t yet look at the whole collection. We want to create a platform to carry the library and have that information made accessible to a software tool like TSG. We can’t do that just yet, but it’s the way forward."