A story here, that I first picked up in the paper version of the Canberra Times, states that a number of farmers are outraged- OUTRAGED!- that their land has had an exploration license taken out on it. One might think that, perhaps, these people are environmentalists who oppose the extraction on non-renewable resources. Except that, just 6 years ago, they were fighting tooth-and-nail to stop wind turbines from being installed.
“Hall district beef producers Phil and Jan Peelgrane, who farm just over the northern border of the ACT, said they would ''lock the gate'' to keep out the mineral explorers, saying they didn't have the energy to mount another campaign against another company. The pair were among those who successfully fought against wind turbines proposed for the area by ActewAGL and later Japanese interests.”
I hope they do lock the gate. Science would provide their comeuppance.
When exploring for gold and copper in a new area, the first step is generally to look for electrically conductive minerals. Chalopyrite (CuFeS2, the main copper ore) and pyrite (FeS2, which is often associated with gold mineralization) are both electrical conductors (if you don’t believe this, take a multi-meter to your nearest museum gift shop or gem&mineral show and check for yourself on any ‘fool’s gold” on offer). While gold is, of course, an even better conductor, there is generally only a few parts-per-million of gold in gold ore, so the gold itself is hard to detect. But the sulfides can be quite abundant- several percent. And there are a variety of electromagnetic techniques that can be used to detect the presence of conductive minerals in the subsurface.
There are two main classes of electromagnetic surveys. Ground-based, and air-based. If these NIMBY farmers “lock the gates”, then instead of driving around in their paddocks and hammering electrodes into the ground, the exploration team will have to use an airborne survey instead.
And this is where karma comes into it. You can’t fly EM surveys through wind turbines (think gigantic propellers vs. helicopter-borne spiderweb-shaped antennae- not to mention the electromagnetic interference). So if the NIMBYs had embraced wind energy 6 years ago, then they would have been able to keep their skies free now. Instead, by locking the gates to this company, all they can guarantee themselves is having parallel 200 meter-spaced lines flown by really large, slow, low-flying helicopters. Not in their backyard, of course. Just a very small distance above it.