Brisbane based company Gap Geophysics has developed new technologies to investigate greater depths during mineral exploration.
The company aims to provider deeper and faster techniques exploration techniques that go beyond traditional exploration methods.
GAP Geophysics CEO Dr Malcolm Cattach said there was a need to develop new technologies for deeper exploration as most of the relatively large deposits closer to the earth’s surface have already been found.
“Most prospective regions in Australia have already been surveyed using traditional electromagnetic (EM) technologies,” Cattach said.
“However, instrument limitations have meant that this surveying technique has only been effective in exploring the top 200-300 metres of the earth.”
EM surveys measure the response of the ground to an electromagnetic pulse produced by a geophysical transmitter, with an unusual response indicating mineralisation.
The achievable depth of the investigation depends on the sensitivity of the instruments of the measuring device and the power of the transmitter used to provide the EM pulse – provided by the company’s SAMSON Deep Penetration EM System.
SAMSON is based on the core sub-audio magnetics (SAM) receiver technology developed by Dr Cattach and his team over the past 25 years.
“SAM is a unique survey method which allows for the simultaneous, high definition mapping of both the magnetic and electrical properties of the ground using a fast sampling, caesium vapour magnetometer,” Cattach said.
“This sensor is very quick to deploy at ground level and is also amenable to continuous acquisition platforms such as a Helicopter and UAV.”
SAMSON has been used by BHP Billiton and Glencore’s Mt Isa Mines, and is currently being deployed at St George Mining’s Mt Alexander Project in Western Australia.
St George Mining executive chairman, John Prineas said the technology identified additional bodies in the Cathedrals Belt that had not been identified by previous EM surveys they used.
“These new targets provide an opportunity to make further discoveries of high‐grade mineralisation in the Cathedrals Belt with increasing potential for establishing continuity in some areas of mineralisation,” he said.
Gap Geophysics has also developed a range of high powered EM transmitters to support the SAMSON technology. These include the HPTX series transmitters, used with Gap’s Downhole EM surveys, that can achieve survey depths up to 2km.