Having determined that the Jaguar high-grade base metal find in Western Australia is too small to develop as a stand-alone operation,
A joint venture between Inmet and Australian-listed
Inmet discovered the deposit a little more than a year ago during a first pass of drilling on the Teutonic Bore massive sulphide project, where exploration is ongoing.
Situated 260 km north of Kalgoorlie and 60 km north of Leonora, the Teutonic Bore project comprises a past-producing base metal mine and 500 sq. km of surrounding exploration tenements, which extend some 40 km north to south. Inmet is earning a 70% interest in the project from Pilbara by spending A$3.5 million on exploration before the end of 2004. Inmet is the operator and, to date, has spent A$2.7 million.
An open-pit and underground mine was in operation from 1980 to 1985 under a joint venture between Seltrust Mining and Mt. Isa Mines. A total of 1.5 million tonnes grading 11.4% zinc, 3.6% copper and 167 grams silver were treated during this period.
Inmet’s option agreement excludes all surface resources to a depth of 35 metres, and all mineral resources to a depth of 200 metres immediately below the old mine site, including tailings and stockpiles.
Inmet originally optioned the Teutonic Bore property package in October 2000. The company’s first task was to complete a ground electromagnetic (EM) survey using the Crone “deep EM” system over 21 km of favourable strike south of the mine. Inmet was targeting possible repetitions of the massive sulphide mineralization in the same stratigraphic package of mafic and hydrothermally altered felsic volcanics that hosted the former mine. The ground survey outlined conductors at depths not tested by previous geophysical surveys.
Drilling began in January 2002. The first two holes were drilled 600 metres apart on a 1,800-metre-long EM conductor, some 4 km south of the old mine site. The first hole intersected a 5.8-metre-thick sequence of interbedded mafic volcanic and graphitic shale containing anomalous copper and zinc values at a down-hole depth of 434 metres.
The second hole turned out to be the Jaguar discovery hole. Drilled at minus 70, hole 2 intersected 7.7 metres (5 metres estimated true width) of massive sulphides grading 16.1% zinc, 4.3% copper and 0.8% lead, plus 0.24 gram gold and 173 grams silver, starting at 485 metres down-hole, or 450 metres vertically.
Steeply dipping
Inmet drilled the deposit on roughly 50-to-100-metre centres and tested the northern and southern extensions of the EM anomaly. Thirty-one holes were completed during two rounds of drilling in 2002. The steeply dipping Jaguar massive sulphide zone is 400 metres long, extends for 350 metres vertically, and is 4 metres thick on average. It has not been fully closed off updip, where hole 23 intersected 1.9 metres of 9.5% zinc, 2.9% copper and 223 grams silver.
Stepping out from the zone, crews encountered mineralized stringer sulphides up to 500 metres south of Jaguar, whereas north of the zone, graphitic shales dominate.
A second EM target, 10 km south of the Jaguar discovery, was unsuccessfully tested with a single hole during the first pass of drilling. No mineralization was intersected, and the anomaly remains unexplained.
John Davis, managing director of Pilbara, says Inmet is preparing to drill-test two key regional targets: Snowy Wells and Snowys South. “The EM survey completed by Inmet in 2001-2002 at Teutonic Bore has been further refined by down-hole EM results at Jaguar to generate strong regional targets such as Snowy Wells,” he says.
An EM anomaly at Snowy Wells, 4 km south of Jaguar, is interpreted to contain two conductive zones.
The Snowys South target, 10 km south of the Jaguar deposit, is a strong, 3-km-long EM conductor that occurs close to ultramafic units containing anomalous nickel.
Inmet proposes extending its EM geophysical survey north of Jaguar, covering the old Teutonic Bore mine site and all other tenements to the north. This area has not been subjected to geophysical work since the early 1980s.
The Teutonic Bore concessions lie at the southern end of the Yandal greenstone belt, roughly halfway between LionOre Mining International’s newly commissioned Thunderbox gold mine and Sons of Gwalia’s Tarmoola open-pit gold mine.
Under the joint-venture agreement, Pilbara retains the right to explore for gold on the Teutonic Bore tenements. Should Pilbara outline a gold resource of more than 250,000 oz., Inmet has the right to earn a 70% interest by conducting further exploration to increase this to 1 million oz. within 12 months.
Air-core drilling
At year-end, Pilbara had completed a 17,000-metre air-core drilling program of 239 holes on 400-by-100-metre centres over a prospective 8-km-long structural corridor. Results are in hand for only a 3-km portion of the corridor, the best being a 13-metre intercept averaging 2.32 grams gold starting at 48 metres of depth on the Halloween prospect. Two adjacent holes contained peak anomalous values of 0.74 gram and 0.13 gram.
In ultramafic and mafic rocks, Pilbara did encounter anomalous nickel values of up to 0.44% in association with copper and zinc. These data have been forwarded on to Inmet for assessment.
Pilbara resumed its gold exploration drilling program at Teutonic Bore in mid-January.
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