Gold isn’t just a pretty metal used in jewelry. It’s a vital component of plenty of electronic systems, and as such, we need to get our hands on as much of it as possible. It’s ludicrously rare though, with most of Earth’s having formed in the last moments of millions of dying, supermassive stars.
Most gold deposits get within mineable distances from the bowels of the planet via mineral veins, magmatic emplacement, and volcanic activity, and some of this filters out into large rivers or sedimentary basins. However, these sources of gold are initially quite hard to find.
A new study in the journal Geology reveals that there might be plenty right at the surface that we’ve overlooked for some time – and, curiously, termite nests and leaves might hold the key.
Researchers at the Australia-based Commonwealth Scientific and Industrial Research Organization (CSIRO) have spent some time gathering samples of surface sediment from a gold deposit named Moolart Well in Western Australia. Clusters of gold occurred the most wherever there was organic carbon, the type that is produced from biological processes.
Specifically, the most gold could be found in regions containing soil frequented by termites and acacia leaves. So what’s going on here? Are termites and these trees quite keen on a bit of bling, or is it all a bit of a weird coincidence?
Once upon a time, gold-rich deposits were emplaced deep below Australia. Slowly, during humid times within the last few million years, chemical and biological processes began causing the gold to dissolve away and leach into the overlying sediment.
Australia soon transitioned into a dry, arid environment for the most part, and the gold remained within this sediment. However, the burrowing nature of plenty of insects – including termites – appears to have accidentally forced a lot of this gold up towards the surface.
You might not find nuggets like this at the surface, but there's plenty to be taken out of the underlying mineral veins just below the surface. optimark/Shutterstock
In addition, acacia trees appear to have absorbed plenty of this gold (perhaps inadvertently), so much so that it’s detectable within their leaves. This means that termite mounds and acacias in Australia could be used to find gold lurking just beneath the surface within shallow mineral veins, accessible without needing extremely heavy-duty mining equipment. It almost goes without saying, however, that there will not always be gold in these locations, just that there is more likely to be gold nearer the surface there than elsewhere.
While most of the gold here is of course incredibly small – some of it is measurable on a nanoscale – it has been described in the study as often appearing as “clumps and larger clusters”, which should be music to the ears of anyone hoping to get into gold prospecting. Good hunting, everyone!