Pacifica sees mega-mine potential at Howard’s Pass

Whitehorse, Yukon — Improved prospects for zinc and new roads and rails in this northern territory have prompted Pacifica Resources (PAX-V) to revive a zinc-lead-silver project that has sat dormant for decades, despite ranking among the biggest worldwide.

“Howard’s Pass has been called the largest undeveloped zinc deposit in the world,” Pacifica President Harlan Meade told delegates at the Opportunities North 2005 conference, held in the Yukon’s capital city in September. “Skip the word, ‘undeveloped.’ It is the largest zinc deposit in the world.”

Howard’s Pass is a sedimentary exhalative (SEDEX) deposit within the Selwyn basin of eastern Yukon, straddling the border with the Northwest Territories. The project hosts vast resources within a 40-km-long belt of favourable geology, but a lack of infrastructure has stymied development since the first discoveries were made in the 1970s by predecessor companies Placer Dome (PDG-T, PDG-N) and U.S. Steel.

Pacifica acquired the deposit for $10 million to be paid over seven years, plus work commitments of $3.5 million in the first two years. The vendors retain a 1% net smelter royalty on production, and a 20% net profits royalty capped at $10 million on initial production.

Howard’s Pass was a bargain-basement acquisition, as previous operators had spent at least $20 million on exploration and underground bulk sampling through to 1982. While a global resource estimated at 1 billion tonnes was previously identified, the only estimate compliant with National Instrument 43-101 standards is for the XY and Anniv deposits, which together host an inferred resource of 115.4 million tonnes grading 5.41% zinc and 2.1% lead, with about 16 grams silver per tonne. The deposits also contain a further “potential resource” of about 367 million tonnes at 5.12% zinc and 1.9% lead.

Pacifica carried out a summer exploration program at Howard’s Pass this year, mostly focused on expanding resources in the XY and Anniv deposits amenable to open-pit mining methods, and identifying other potential open-pit deposits.

At the same time, the company launched a “first-pass” assessment of the project’s potential to become a world-class zinc mine, a process that is ongoing. But as Meade frankly admits, Howard’s Pass needs a number of things before mine planning can begin in earnest.

“It needs a railway,” says Meade. “It needs the governments of the Yukon and the Northwest Territories to work together. It needs the support of the First Nations, and it needs investors who believe in its potential.”

At the same conference, the Yukon government announced it was examining various proposals for new rail development in the territory, including one linking Alaska to rail lines at Fort Nelson, B.C. Such a route along the Robert Campbell Highway would benefit Howard’s Pass, along with other deposits in eastern Yukon, including Yukon Zinc’s (YZC-V) advanced Wolverine project southwest of Howard’s Pass.

Pacifica’s $3.5-million program at Howard’s Pass also included metallurgical test work to update and confirm test results from the 1970s and 1980s that included flotation, gravity and pressure-leach oxidation processes. A key element was testing to determine the effectiveness of using dense media separation (DMS) as a pre-concentration step prior to milling.

The company says initial test work was successful, with results suggesting potential to upgrade mineralization to 20% combined zinc and lead by separating heavier mineralization from the less-dense waste shale material.

“DMS turns Howard’s Pass into a potential high-grade operation,” Meade says, noting the “upgraded” grades obtained in test work are similar to those at Alaska’s producing Red Dog zinc-lead-silver mine, which is hosted in the same rocks as Howard’s Pass.

Another favourable aspect of the zinc-lead mineralization at Howard’s Pass is the lack of pyrite, which not only reduces potential for acid generation, but is beneficial to metallurgical separation of the fine-grained zinc and lead sulphide minerals. Previous metallurgical test work also showed that zinc and lead concentrates are low in arsenic, antimony and other deleterious elements.

Pacifica is also exploring its large land package in the Selwyn basin for cores of high-grade mineralization similar to those found within the core area of the XY deposit and within the same belt of rocks in Alaska. The company has discovered two new targets, the Brodel and Don Valley zones, which fill a 12-km gap between the Anniv and XY deposits.

Yukon Zinc owns about 10% of Pacifica, with the companies sharing some common management.