Thundelarra sets sights on Western Australia

Exploration in Australia is at its lowest level in two decades, but this belies the country’s geological potential, Robert Champion de Crespigny told delegates attending the annual convention of the Prospectors & Developers Association of Canada.

Phillip Crabb, president of Thundelarra Exploration (TLX-V), agrees with the former helmsman of Normandy Mining but says more entrepreneurs like him are what’s needed to increase the flow of investment dollars. “I think the fault does not lie with the Canadians,” he tells The Northern Miner. “We’ve got to get out and tell people exactly what is happening.”

Crabb has been coming to the convention for the past three years to promote his company’s efforts in Western Australia. Among the projects displayed in this year’s Investor’s Exchange was Phillips Range, which lies in the central Kimberly region and hosts Australia’s largest diamondiferous kimberlite body, Aires.

Past production from Aires amounted to 1,819 carats, and 95% of those stones were gem quality. In 1993, the best of the bunch were valued at US$150 per carat, for an overall average of US$100 per carat.

“We purchased the claims in 1996 on the understanding that kimberlites would occur in clusters,” says Crabb. “We conducted further exploration using various conventional techniques but not with a great deal of success.”

However, last year, the tides turned in Thundelarra’s favour when BHP Billiton (BHP-N) signed on as its partner. So far, the major has spent more than A$1.3 million to identify three diamondiferous kimberlite pipes: Persephone, Athena and Helena.

Recently, BHP Billiton recovered 173 microdiamonds from the Persephone pipe and 227 similar-sized stones from Athena body. The former parcel weighs 0.013 carat; the latter, 0.024 carat.

The stones are being studied further in South Africa.

Crabb notes that only 16 of the 56 anomalies detected by BHP Billiton’s proprietary airborne gravity technique have been drill-tested. Moreover, two-thirds of the 1,000-sq.-km land package remains to be surveyed, possibly by year-end.

BHP Billiton can earn a 60% interest in the property by funding exploration through the feasibility stage. The property lies 270 km northeast of the coastal town of Derby.

Thundelarra also showcased its East Kimberly polymetallic property, which covers 3,000 sq. km of the Halls Creek Mobile zone, north of the town of Halls Creek. Although more widely known for its role in the formation of the giant Argyle diamond deposit being mined by Rio Tinto (RTP-N), the structure is considered prospective for sulphide mineralization rich in platinum group metals (PGMs).

For instance, Platinum Australia and past operators have outlined 2.2 million tonnes in the Panton sill grading 6.04 grams combined PGMs, plus 0.41 gram gold, 0.27% nickel, 0.065% copper and 11.3% chromite. The estimate is based on a cutoff grade of 3 grams combined PGMs.

Mineralization is principally associated with five chromitite layers, each of which can be traced along strike for 4.5 km. Lower grades occur in the enclosing dunitic host, which represents the lower series of the intrusion that differentiates upwards into a gabrroic series of noritic gabbro, gabbro and anorthosite.

An ongoing feasibility study is being funded by London-listed Lonmin, which last year agreed to inject A$52 million into Platinum Australia in exchange for a 55% equity stake. Lonmin is the world’s third-largest miner of primary PGMs and is more widely known in North America for its recent foray in the Sudbury basin of northern Ontario.

Except for the McIntosh and Moola Bulla tenaments, Thundellara is exploring its ground alone. The exceptions are being managed by Falconbridge (FL-T), which, in partnership with Anglo American (AAUK-Q), can earn 70% interests by funding exploration over four years. Unfortunately, Falco refuses to divulge much in the way of details.

Nevertheless, Thundelarra is making waves Down Under with its progress at the Eileen Bore and Panton North licences. At the former, two of three sizable electromagnetic anomalies have been ruled out as being of metasedimentary origin; instead, each is thought to reflect copper and nickel mineralization similar to that found in 1978, about 200 metres to the south.

“Electromagnetic anomaly number eleven has never been sampled nor looked at, we believe, by any geologist,” said Crabb. “We do notice that a [nearby] creek contains anomalous nickel, copper, platinum, palladium and gold.”

The old BHP hole cut 54 metres (near-surface) averaging 0.83% copper and 0.31% nickel, plus 35 metres averaging 0.73 gram combined platinum, palladium and gold per tonne. This section, along with higher-grading gossanous outcrop and the geophysical results, is what is attracting interest from several majors, says Crabb.

Anomalies 10 and 11 are covered by a thin veneer of sandy soils, whereas anomaly 12 to the south is overlain by alluvial sediments. A suite of rock samples taken in the vicinity of each is being analyzed for metal content.

Drilling is set to begin shortly.

Thundelarra also plans to drill a large soil anomaly at the Panton North tenement, which lies immediately west of Eileen Bore. The anomaly overlies the same ultramafic-mafic sill hosting Platinum Australia’s deposit.

Holes will be sunk in the central portion of the anomaly, where up to 5.42 grams platinum-palladium-gold have been obtained from bedrock. About 1,000 metres are planned in all.

Thundelarra is also exploring the Yilgarn craton, which covers much of Western Australia’s southern region. Among its projects is Davyhurst, which straddles 14 km of the Zulieka shear, host to numerous gold mines that collectively form part of the so-called Eastern Goldfields district.

Australian-listed Perilya can earn a 65% interest in the project by spending $1.7 million on exploration over four years. Exploration is still at an early stage, but an explorer to the immediate north has intersected 5 metres of near-surface mineralization running 43.17 grams gold per tonne.

To the west, in the Southern Murchison area, Thundellara is exploring for gold and PGMs. Results for the latter bunch are as tantalizing as those found in the layered intrusions of the Nipissing-Huronian magmatic belt of northern Ontario.

Preliminary reverse-circulation drilling is testing the Dauphin showing, where more than half a gram of combined platinum and palladium was obtained from a 10-metre section of outcrop. A coincident soil anomaly stretches for 7 km along the contact of mafic and ultramafic rocks.

As for native claims, often a contentious issue the world over, Crabb considers Australia’s law difficult but not insurmountable: “We’ve learned in recent years that if we get out and sit down with the people, we’ve been able to achieve our own aims and those of the Aboriginals.

Thundelarra, which trades on both the Canadian Venture and Australian exchanges, has nearly 41 million shares outstanding, or roughly 47 million on a fully diluted basis. About 60% are divided between two companies, Ragged Range Mining and CDS & Co.