Saturday, March 08, 2008

TANAMI GOLD



I was all set to watch the ABC's Catalyst on Thursday when I was interrupted by a loony phone call involving a can opener, a neighbour and an Avon book. Don't ask, I couldn't do the saga justice by trying to blog it. Anyway I missed most of the segment on termites and how geologists are using them to look for minerals. I had read an article about this in New Scientist last year.
A geologist in the 1970s found a speck of ilmenite on the surface in the Kalahari desert. Ilmenite comes from kimberlite and kimberlite has diamonds and the geologist had just discovered the richest diamond deposit in the world, the Jwaneng diamond mine. That speck came from 40 metres down and was hauled to the surface by termites.

Australian researchers are developing techniques to sample termite mounds for traces of gold, diamonds and other minerals. The termites constantly have to repair the mounds to control the temperature and keep out predators so they tunnel down to the water table and bring back clay or wet rock and it's this deep soil that holds whatever traces of minerals. So instead of expensive drilling machines, geologists are using the services of termites for free.
The inside of the mounds is a type of regurgitated mud cement containing organic material, fine rock particles and geologists scan samples for elements such as chromium, titanium, arsenic, all of which can occur in rocks containing gold. The termite tunnels can go down 30 metres or more but researchers are also looking at Spinifex grass.
Chewed up spinifex has been found in the termite mounds and showed signs of mineralization. The spinifex put all their growing effort into sending down roots to groundwater, sometimes 50 metres or more. Sampling the grass shows the chemicals it has taken up with the water and accumulated in the leaves. Spinifex and termites concentrate different minerals but together this provides a geochemical picture of what could be underground. It sounds way out but in the Tanami desert less than 1 per cent of the landscape has rocks exposed above ground and these have revealed some of the largest gold deposits in Australia and since these rocks extend underneath it means that 99 per cent hasn't been sampled. Cue the termites.
The image above is north of the Granites gold mine in the Tanami Desert. It was taken during a combined dust storm and thunderstorm close to sunset. The Sun is wedged between dust and rain cloud.

13 comments:

Brian Hughes said...

Can't help thinking there's something ethically wrong about employing/enslaving termites in this manner. Wouldn't politicians do just as well?

River said...

Termites serving a useful purpose. Who knew?

River said...

Nix on the politicians. Termites are far far cheaper.......

Brian Hughes said...

River,

And more intelligent.

Bwca said...

when termites enter our houses we blast them with chemicals, when they mind their own business at their own mounds we turn it into a bloody mine.
make one want to resign
from Club Homo Sapien

Amy Clarke said...

Wow... makes you wonder if there are other instances of animal-related experiments like this going on. I know it's not in the same realm of corporate selfishness, but I do remember seeing a tea-leaf product the other day that boasted it had been picked by specially trained monkeys.

dysthymiac said...

oh Ms Amy Clarke I snchorkled reading your comment and now I think I need nose-repair.
Of course! Monkeys, even specially trained ones, won't be asking for holidays or sick pay. I'm guessing this would be INDJA, and can only hope those of us trying to get a phone call through to Telstra admin, are not answered, should we ever be answered, by a monkey, specially trained or not.

Davo said...

Wow... makes you wonder if there are other instances of animal-related experiments like this going on

Er, yes, actually. clever little ambulatory bipeds are analysing other little ambulatory bipeds. "Roo Poo". Apparently traces of "heavy metals" are brought up by Aussie flora, conveniently concentrated, chewed over, concentrated further,then re-deposited on the surface by kangaroos (who cover more territory than termites).

Reminds me of an old Brit adage .. "where there's mook (muck), there's money".

Helen said...

a loony phone call involving a can opener, a neighbour and an Avon book. Don't ask, I couldn't do the saga justice by trying to blog it.

I get the feeling that might be something to do with your mum, J.

River said...
Nix on the politicians. Termites are far far cheaper.......

Saturday, March 08, 2008 8:54:00 PM
Blogger Brian Hughes said...
River,
And more intelligent.


And do less damage.

JahTeh said...

Simon Bolster, a geochemist, once saw six snakes inside a termite mound so it looks like the politicians are already on the job.

Bwca, never mind the termites, have you found out about ducks tongues?

Oh Amy, have you heard about that very expensive coffee where the beans are ingested by some jungle animal and shot out the other end to be collected, ground up and drunk by idiot coffee freaks willing to pay.

Thank you Davo, I missed most of the bit on kangaroos but didn't miss the floating blue bottles and that frightening stinger.

Helen, how did you guess? I can name a few polies I'd like to shove down a termite mound at the moment.

Bwca said...

I have never eaten duck, I have never cooked a chicken.
Recently I babysat a pair of ducks and 8 ducklings.
When I turned the hose on them
(1. gentle spray,
2. tank water, no restrictions)

they all rushed it,
standing up on their tippy-toes, and held their wings and beaks open to fully enjoy the cool fun - it was divinely hysterically funny.
They were smacking their beaks open and shut and I must have been laughing too much to see tongues.

Middle Child said...

my goodness... you have to be an aquarian... so good to see someone with so much curiousity? WHY?WHY?WHY? a bit of a manta really

Anna Petts said...

Hihi! What a great blog, I actually came across this looking for a map of the surficial geology of the Tanami Region. This is actually my research you are discussing here, and its interesting to see your comments. In actual fact, sampling termite mounds is pretty non invasive, they will repair their mounds overnite. When you think about all the landclearing that goes on, to make roads for drill rigs and ponds to hold water for them, sampling a termite mound really prevents a lot of ecological disturbance, by proving the mineral prospectivity of the area. As long as the world needs metals, then mining will continue. I am really proud of my research I think 'greener' innovations like this will help prevent a lot of the environmental degradation intrinsic to mining operations.

River, you mentioned that 'termites serving a purpose'...Well, termites are a MASSIVELY important link in the ecological chain in northern Australia especially, as they are the main herbivores involved in harvesting grasses, as well as their nests and bioturbating activities integral to nutrient cycling.

Termites, and the mounds they create, have been a fascinating focus of my phd research! :D