A group of a dozen physicists and geologists from mining giant Rio Tinto and the University of Western Australia is two years away from commercial production of a tool that could dramatically expand the scope of mineral exploration in Australia.
VK1, a collaboration between the mining giant and the university, is an airborne gravity gradiometer that harnesses quantum physics, superconduction, liquid helium cryogenics and aerial survey data to solve the ultimate challenge facing iron ore miners: how can we see underground?
Australia has become a reasonably mature exploration environment, according to Stephen McIntosh, head of exploration at Rio Tinto.
“It is relatively well-explored in the exposed parts of the continent – areas that don’t have cover over the mineral deposit, or some form of material that is younger sitting on top of the mineral deposit.
“The dilemma for Australia is that somewhere between 70 and 80 percent of the continent is covered by something. You actually have to see through a veneer of something to explore underneath the surface – to a mineral deposit a few metres to hundreds of metres below your feet.”
Invariably the most accessible, high-grade deposits have been explored, but iron ore miners rarely know precisely what lies further beneath.
“For the majority of deposit types, there is nothing to say that a few hundred metres down from the earth’s surface that you wouldn’t find as many new deposits as we have found close to the surface,” McIntosh said.
“It’s a fertile playground down there but actually a very difficult one to play in.”
Oil and gas companies solve this problem using seismic surveys to discover gas deposits – because the telltale signs of a deposit tends to be a large basin tens of kilometres wide and several kilometres deep, with an anticline at the top where gas could potentially be trapped.
The signs of high grade iron ore deposits are tiny by contrast and surrounded by other geological noise. One of the key metrics used to consider a site for exploration is density – a measurement of the earth’s gravity field.
For the rest of this article, click here: http://www.itnews.com.au/News/388658,rio-tinto-digs-deeper-for-next-big-discovery.aspx