0.82 g/t Au Over 197 Metres At Western Porphyry Zone

MONTREAL - Osisko Mining Corporation reported initial results from the 2009-2010 definition drill program on the Western Porphyry Zone, located on Osisko's 100%-owned Amphi property immediately adjacent to the Canadian Malartic property, and approximately 1.8 km northwest of the crusher and the 55,000-tpd mill currently being constructed for the Canadian Malartic project. The 82-hole, 21,000-metre definition drilling program, presently being executed on a 50 by 50-metre grid, was started at the end of 2009 following encouraging preliminary results obtained in 2008.
Sean Roosen, President and CEO, said, "The positive results from Western Porphyry, in addition to what Golden Valley Mines and Osisko have already reported from the Jeffrey Zone to the east, suggest there is excellent potential to add new ounces at Malartic. These deposits will most likely add future feed to the mill and thereby extend the life of the milling complex."
The drill data to date suggests the Western Porphyry Zone comprises a mineralized block 500 m long, 50 to 200 metres wide and 100 to 150 metres deep that is amenable to open-pit mining. The system is open at depth and further drill results of the 82-hole program will be issued as assays become available from the lab. Mineralization at Western Porphyry consists of fine disseminated/stockwork pyrite and gold in potassic and/or carbonate-altered porphyry and mafic/ultramafic volcanics. The porphyry-hosted mineralization is similar to that of the F Zone of the Canadian Malartic deposit. Occasional higher grade intersections (greater than 4 g/t Au) are related to classic Abitibi vein-type mineralization cutting the host lithologies.
All NQ core assays reported above were obtained by standard 50 g fire assaying-AA finish or gravimetric finish at ALS Chemex laboratories in Val d'Or, Quebec. Reported drill core weighted averages were calculated using a minimum of 0.40 g/t Au over successive maximum intervals of 20 metres with an upper cut-off of 30 g/t Au where indicated. Intersected drifts or lost core within mineralized intersections were incorporated as blank intervals.
Osisko follows strict QA-QC protocol measures in keeping with industry standards and regulatory reporting requirements. Mr. Robert Wares, P. Geo. and Executive Vice-President of Osisko, is the Qualified Person who has reviewed this news release and is responsible for the technical information reported herein, including verification of the data disclosed including the sampling, analytical and test data underlying the technical information.
The company's address is 1100 De La Gauchetire West, P.O. Box 211 Montreal, Quebec H3B 2S2, 514.735.7131, fax: 514.933.3290.