Tiberon tables Nui Phao resource (December 03, 2001)

Vancouver — On the basis of 70 drill holes, Calgary-based junior Tiberon Minerals (TBR-V) has defined a near-surface tungsten deposit on its Nui Phao property in northern Vietnam.

Using a cutoff grade of 0.25% tungsten trioxide, the company estimates an indicated resource of 12.3 million tonnes grading 0.43% tungsten trioxide, 0.26% copper and 0.12% bismuth, plus 0.31 gram gold per tonne. In the inferred category are 10.2 million tonnes grading 0.47% tungsten trioxide, 0.27% copper, 0.13% bismuth and 0.26 gram gold.

The cutoff grade is based solely on tungsten trioxide recovery, with no value placed on gold, copper, bismuth or fluorite credits. The estimate was completed by Mineral Resource Development (MRDI), a division of AMECE&C Services.

“We are pleased with the results,” says Tiberon Vice-President Kevin Flaherty. “We only missed on three of the 103 holes drilled.”

Once the ongoing metallurgical study is complete, the addition of the credits could lower the cutoff grade and increase the overall tonnage. Metallurgical tests include processing options, recovery factors, product quality and grade, as well as process equipment sizing for tungsten and secondary products.

So far, 95 exploration and eight metallurgical drill holes have been completed on the promising project. The remaining 33 holes, not included in the resource estimate, will be used in a revised calculation, expected in February 2002.

With the drilling now complete, Tiberon feels that the size and grade of the deposit is sufficient to begin developmental planning. The company will now focus on the feasibility study, which includes metallurgical testing, environmental studies and securing permits for mining. Environmental work will begin in December, and the remainder of the prefeasibility work will be performed in the new year.

The tungsten skarn deposit defined in the indicated category covers a 250-by-150-metre tabular body down to a depth of 200 metres and remains open to the west and south. The resource is amenable to open-pit mining methods and has a low ratio of waste to potential ore. Mineralization occurs within, and is marginal to, a Cretaceous-aged granite that intrudes into carbonate and clastic sedimentary rocks. Much of the tungsten mineralization is characterized by coarse and medium grains of scheelite and is preferentially developed in magnetite-fluorite skarns, garnet skarns and amphibole skarns along the contacts. A subsequent greisenization episode overprinted all the lithologies. Coarse-grained tungsten mineralization, dominantly composed of the mineral scheelite, occurs with biotite, pyrrhotite and fluorite and overprints the granitic dykes, the pluton and the skarn units. Mineralization also consists of native gold, chalcopyrite, native bismuth and bismuthinite and beryllium.

“We have three rigs drilling the Nieu Chiem prospect,” said Flaherty, “and we plan initially to do four holes as a look-see. Then we’ll go back with a more defined plan.”

The company intends to spend about $100,000 on the Nieu Chiem drilling, break for Christmas, and then, once the assays are back, develop an exploration plan.

The Nui Chiem prospect, 1.5 km north of Nui Phao, hosts a strong geophysical anomaly with a 900-metre strike length that remains open to the north and west; it is associated with a coincident copper and gold-in-soil anomaly and with silicious pyritic rock float. Chip samples from the more gossanous specimens returned up to 1.8 parts per million gold, 5,100 ppm bismuth and 1,900 ppm copper.

Previously, two vertical holes were drilled into the prospect with a small portable scout drill. Hole 6 hit fresh rock at a depth of 53 metres but was unable to penetrate it to any significant extent. The other hole intersected only highly weathered material. Tiberon considers the target a possible copper-gold skarn.

Tiberon holds a 70% interest in the 47.9-sq.-km Nui Phao project, with the remainder held by Vietnamese parties. Tiberon is required to fund all of the exploration costs until the completion of the feasibility study, after which time all costs are to be shared equally. The property is in the northern province of Thai Nguyen, 90 km north of Hanoi.

Tiberon has 32.4 million shares fully diluted, no debt and $750,000 in the till.

Following Tiberon’s release of its resource estimate on Nov. 16, the Canadian Venture Exchange requested that the company clarify several of its prematurely exuberant comments about the project.

In a follow-up release on Nov. 21, the company retracted statements that characterized Nui Phao as being “world-class” and ranking among the top 10 tungsten-skarn deposits in the world.

If Nui Phao is ranked according to its tonnage against those deposits cited in the 1995 publication Geology of Canadian Mineral Deposit Types, Nui Phao would place among the top 10 deposits in terms of size. The Canadian Venture Exchange stated that comparing the resources of Nui Phao to the reserves and past production of the top 10 is inappropriate.

The company also put a new emphasis on the fact that the deposit essentially subcrops, as it lies beneath a weathered zone that is generally 20-40 metres thick.

Tiberon notes that a copy of MRDI’s final Nui Phao technical report will soon be available to the public through the CDNX’s public files and on SEDAR.