KAT Exploration Inc (KATX)

[ShortonCash]

Am I correct in saying that the combination of magnetic and gravity anomalies would immediately suggest the possibility of basalts?

Absolutely

most astonishing rock full of iron oxide, hematitic, highly fractured – a breccia.

Absolutely

http://www.science.org.au/scientists/interviews/w/woodall.html

He conclusively proved that the copper had come out of the basalts that were on either side of the vein, in which there was the mineral magnetite. That magnetite can hold quite a lot of copper in its atomic structure. But, when magnetite is oxidised to hematite, the hematite can’t accommodate copper and so the copper is liberated and migrates. It had migrated into the cracks and formed the rich copper sulphide veins – a very simple concept, proved by good science right here in Canberra.

When Douglas had finished his PhD research, he came back to me in Kalgoorlie, where I lived for 25 years running these exploration projects, and we had a big strategy think-session, just the two of us, about what we should do. Douglas recommended that we go looking for oxidised basic lavas like those up in the Warburtons but on a much bigger scale. So now we were not thinking about looking for favourable host rocks, say for shales, which were known to be good hosts for copper; the strategy now was to look for where copper had been sourced in large enough quantities to form a major orebody. We based that strategy on Douglas’s PhD research at ANU. We had to go and find large volumes of mafic rock – iron­magnesium-rich rock – in which the magnetite had been oxidised to hematite, and the copper released to become an ore-forming solution which, if near the right plumbing system, might precipitate and form an orebody

.

(So if you have a barren hole...the copper could be elsewhere not that far away)

If here’s a small copper deposit, a gravity anomaly, and a magnetic anomaly and a structural intersection, let’s go and look where Hugh Rutter has all these other magnetic and gravity anomalies and see if there are strong structures there as well.’

Tim identified a small number of what he called ‘tectonic targets’: structural targets, coincident with the magnetic and gravity features, which could be and maybe were due to the sort of basic lava rocks or igneous rocks that Douglas thought would be the best source rocks. The first target we drilled was very close to a cattle watering hole dug out by a pastoralist to catch rainwater to water his cattle. He had excavated that dam at the same time as the world Olympic Games were being held in Melbourne, so he called it the ‘Olympic Dam’. And so this project, the testing of this structural feature coincident with magnetics and gravity anomalies, was called the Olympic Dam target. (The small dam was the only feature in the desert to identify it!)


The first drill hole: RDI in a remote desert,
38m at 1% copper.

As we drilled, beneath 300 metres of barren sediment the drill intersected a most astonishing rock full of iron oxide, hematitic, highly fractured – a breccia. Here was rock we’d never ever seen the likes of before.

We are in the first stages......