Western Copper expands Chile Colorado

Vancouver — The latest results from an 8,100 metre drill program targeting the Chile Colorado zone has expanded the area of base metal mineralization at the Penasquito property for owner Western Copper Holdings (WTC-T).

Lying in Mexico’s Concepcion del Oro district of Zacatecas state, Penasquito has been the subject of a resource definition drill program for the past six months. At the eastern extension of the Chile Colorado zone, hole 25 intersected a thick zone of oxide mineralization followed by 82 metres of primary mineralization grading 104 grams silver and 0.32 grams gold per tonne, plus 0.96% lead and 2.10% zinc starting at a depth of 356 metres.

Moving 50 metres to the south, hole35 cut 206 metres grading 105 grams silver from 240 metres downhole, while hole 39 was collared 50 metres to the east and cut several intervals of mineralization grading up to 102 grams silver and 0.5 gram gold over 40 metres from 332 metres downhole.

Hole 37 and 41 were collared 100 metres east of hole 35 and 75 metres north of hole 37, respectively with assay results pending.

Two holes tested the western extension of the zone. Hole 26 bottomed in mineralization after returning 188.7 metres grading 56 grams silver and 0.38 grams gold. Hole 28 cut 110.1 metres grading 33 grams silver, 0.26 gram gold, 0.12% lead and 0.7% zinc from 300 metres downhole.

At the Azul diatreme breccia, hole 27 was collared 150 metres north of hole 25 cut the mineralization at 410 metres downhole. Holes 30 and 34 tested the eastern contact of the diatreme breccia returning broad widths of low to moderate silver, low gold and elevated copper values. Hole 31 tested the northern contact of the breccia and hit 168 metres of 27 grams silver and 0.22 grams gold.

Moving to the eastern margin, hole 36 cut 128 metres averaging 27 grams silver, 0.1 gram gold, 0.13% lead and 0.2% zinc from 260 metres downhole.

Based on the results, the company believes that the Chile Colorado stockwork mineralization formed in the outer, lower temperature portion of a concentric alteration halo centered above and adjacent to a quartz-feldspar porphyry stock. After the formation of Chile Colorado, the quartz-feldspar porphyry stock erupted creating the Azul diatreme breccia. Disseminated and veinlet-controlled silver-gold-zinc-lead sulphides formed in open fractures and along the margins of the Azul diatreme breccia. So far about 20% of the prospective low temperature alteration halo outside the Chile Colorado area has been drill-tested.

The remaining assay results, along with metallurgical tests are expected within the next few weeks. Once all the results are in, engineering firm, SNC Lavalin with complete a resource calculation for the Chile Colorado zone.

Covering 32.5 sq. km of the historical Concepcion del Oro district, Penasquito hosts a 9-sq.-km mineralized system lying 30 metres below alluvial cover. Modern-day exploration over the prospective ground began in 1994 with Kennecott, a unit of Rio Tinto (RTP-N), completing several geochemical and geophysical surveys and drilling 71 holes. This work led to the discovery of polymetallic mineralization rich in silver, hosted in Cretaceous sandstones at the Chile Colorado zone, as well as two large breccia pipes and numerous, as-yet-untested anomalies.

Last year, Western Copper reacquired its 100% stake in the project after Hochschild dropped its option to earn a 68% interest. Hochschild spent more than US$1 million on exploration, mostly at the Chile Colorado prospect, where 11 core holes were drilled. As a result, silver-lead-zinc mineralization was delineated over an area of about 500 by 350 metres and to a depth of 300 metres. The weighted average of the mineralized intervals from 19 holes drilled at Chile Colorado by Kennecott, Western Copper and Hochschild is 0.54 gram gold and 100 grams silver, plus 0.8% lead and 1.8% zinc.