Augusta cuts wide copper at Rosemont (November 01, 2005)

Vancouver — Initial drilling by Augusta Resource (ARS-V, ARCFF-O) at its recently acquired Rosemont copper-molybdenum deposit in Pima Cty., Ariz., has intersected wide intervals of significant mineralization.

Since purchasing the project in June 2005, the company initiated a 10,000-metre drill campaign and prefeasibility study on the deposit. Drilling, looking to confirm downdip extension potential of the main Rosemont deposit, returned wide intervals of mineralization including 226 metres (from 244 metres downhole depth) grading 0.96% copper, 0.01% molybdenum and 12.8 grams silver per tonne in hole 2000. Within the interval, there were higher-grade sections including 22 metres averaging 1.97% copper and 23.5 grams silver, and 24 metres of 1.94% copper and 28.3 grams silver.

Holes 2001 and 2002 cut 216 metres of 0.77% copper and 260 metres of 0.57% copper, respectively, at similar down-hole depths to the initial hole.

In addition to confirming past results, the current drill program is expected to provide the necessary data to generate an updated resource calculation for the project. Expansion of the mineralized zone downdip, towards the east, would reduce the overall strip ratio within an ultimate pit limit by upgrading material that did not previously have sufficient drill density to be categorized as either measured or indicated in the resource model.

The Rosemont project consists of three main copper-molybdenum skarn deposits (the namesake Rosemont, Peach Elgin and Broadtop Butte), located southwest of Tucson and in proximity to a number of large producing copper mines operated by majors Phelps Dodge (PD-N) and Grupo Mexico subsidiary Asarco. Historical resources, calculated prior to implementation of National Instrument 43-101, are:

r Rosemont — 306 million tonnes grading 0.64% copper and 0.02% molybdenum in the sulphide portion, and 25 million tonnes averaging 0.46% copper in the oxide zone;

r Peach Elgin — 12 million tonnes grading 0.78% copper in the sulphide zone, and 9 million tonnes of 0.72% copper in the oxides; and

r Broadtop Butte — 8 million tonnes grading 0.77% copper and 0.04% molybdenum.

With its 34.9 million shares outstanding, Augusta posts a market capitalization of $71 million at its recent trading level of $2.04 per share.