Gap Geophysics CEO Dr Malcolm Cattach has been looking at a way to provide better, deeper, faster and cheaper exploration techniques so that ground beyond the limits of traditional exploration can be examined.
Cattach said because most sizable deposits close to the earth’s surface had probably already been discovered, there was a need to develop technologies capable of deeper exploration.
“Most prospective regions in Australia have already been surveyed using traditional electro-magnetic technologies,” he said.
“And this means that these areas are still unexplored at depth and are therefore still very prospective.”
Cattach said instrument limitations meant the EM technique had only been effective in exploring the top 200-300m of the earth, however, his company’s technology could reach up to 2km deep.
“Our SAMSON Deep Penetration EM System and other high power EM technologies have changed the face of exploration in Australia.”
An EM survey measures ground responses to an electromagnetic pulse emitted by a geophysical transmitter.
The depth able to be reached is then dependant on the sensitivity of the instrument and the power of the transmitter.
The SAMSON is based on the core Sub-Audio Magnetics receiver technology developed by Cattach and his team over the past 25 years.
Cattach said SAM was a unique survey method that allowed for the simultaneous, high definition mapping of both the magnetic and electrical properties of the ground using a fast sampling, caesium vapour magnetometer.
“This sensor is very quick to deploy at ground level and is also amenable to continuous acquisition platforms such as a helicopter and UAV,” he said.
“SAMSON has already been used by high profile mining companies in Australia such as BHP Billiton, Glencore and Sirius Resources and is being deployed by St George Mining at its Mt Alexander Project in WA with very promising results to date.”
St George Mining executive chairman John Prineas said the EM responses in the SAMSON survey were dazzling.
“SAMSON’s success in identifying additional conductive bodies in the Cathedrals Belt strongly suggest that the nickel- copper sulphide mineralisation in the Belt is even more extensive than previous EM surveys had indicated,” he said.
“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.”
Gap Geo is also working on a range of High Powered EM transmitters that enable ten times the effective power of conventional EM surveys.
Cattach said that for larger scale exploration they had developed a UAV with SAM technology, which will slash survey costs by half.
“The UAV can cover approximately 100km per day compared to standard ground EM surveys that can typically cover between 2-3km daily,” he said.
“The use of a UAV in exploration is an exciting development which should result in improved production and significant cost reductions for exploration companies.”
The UAV, kitted up with a SAM sensor, will now go through commissioning trials at a site near Hyden in WA in late February.
