Osisko Mining Corporation
TSX : OSK
FRANKFURT : EWX

Osisko Mining Corporation

August 27, 2007 07:55 ET

Osisko Outlines New Mineralized System at Malartic

Mineralization in Western Porphyry Zone could extend over 1200 metres

MONTREAL, QUEBEC--(Marketwire - Aug. 27, 2007) - Osisko Exploration Ltd. (TSX VENTURE:OSK)( (FRANKFURT:EWX) is pleased to announce that results from a drill hole collared at the northwestern limit of the Canadian Malartic property, combined with preliminary compilation work on the recently acquired East Amphi property, indicates potential for a new, significant gold mineralized system in the Malartic camp, separate and distinct from the Canadian Malartic deposit.

Drilling in the 1980's on the Western Porphyry Zone, located approximately 1300 metres northwest of the western end of the Canadian Malartic deposit, outlined a mineralized system consisting of at least seven sets of mineralized auriferous quartz veins hosted by porphyry dyke swarms and volcanic rocks. The mineralized vein system is located within the Cadillac Break and was outlined over an area measuring 200 metres by 500 metres. The veins sets, however, were too narrow and intermittent to be of economic interest and little porphyry material was assayed outside of the vein sets.

Richmont Mines drilled a single inclined hole (FX06-01) at the southeastern limit of the system in 2006 and systematically assayed all drill core. This hole intersected 128.2 metres averaging 0.63 g/t Au (from 21.5 to 149.7 metres), all within porphyry. The porphyry dyke swarm continues beyond the Western Porphyry Zone in a southeastern direction for 700 metres, onto the Canadian Malartic property where it reaches the Malartic town limits. Osisko drilled a single inclined hole into porphyry (CM07-1011) at the town limits, i.e. 700 metres southeast of FX06-01, which returned 238.3 metres averaging 0.64 g/t Au (from 171.9 to 410.2 metres). In both holes, the porphyry contains few quartz veins and is relatively homogenously mineralized with 1 to 3 percent disseminated pyrite.

These results suggest potential for a large, low grade, porphyry-hosted gold system similar to that of the F Zone porphyry at Canadian Malartic. Geological compilation suggests that the entire porphyry swarm measures approximately 1200 meters in length, is 200 to 250 metres wide on surface, and that the swarm merges and expands into a single large intrusion that is 400 metres wide at a depth of 200 meters. It is worth noting that CM07-1011 stopped in mineralization, and that there has been no historical drilling in the Western Porphyry Zone designed or analyzed to test for a large tonnage, low grade gold deposit.

Osisko is now designing a reconnaissance drill program in order to test the bulk tonnage potential of the new mineralized zone. A series of holes collared along fences spaced two hundred metres apart will be drilled in the fall of 2007.

Commenting on the new discovery, Sean Roosen, President of Osisko stated: "We are very encouraged with ongoing exploration results on our property package in the Malartic camp and the potential it offers for low grade, bulk tonnage gold resources. The Western Porphyry Zone looks very promising and should it be mineralized throughout its 1200 metre length, we are obviously looking at potential for another significant gold resource, above and beyond what we are developing at the Canadian Malartic deposit. This zone offers a significant opportunity to outline new resources for Osisko and we are looking forward to continued exploration in this area".

In other developments, Osisko wishes to announce that The Board of Directors has approved an increase in the stock option program to a total of 13,400,000 from the previous maximum of 11,100,000 grantable options. The increase is to allow the Company to recruit and retain key individuals for the development of the Canadian Malartic Project.

The Canadian Malartic gold deposit and adjacent areas are being evaluated for a large-scale open pit, bulk-tonnage mining operation. An updated NI 43-101 compliant, inferred gold resource estimate on the main deposit was released on July 5, 2007 and the full report was filed on SEDAR on August 17, 2007. Mr. Robert Wares, P. Geo. and Executive Vice-President of Osisko, is the Qualified Person responsible for the technical information reported in this news release.

Contact Information

  • Osisko Exploration Ltd.
    John Burzynski
    Vice-President Corporate Development
    514-735-7131
    www.osisko.com
    or
    Osisko Exploration Ltd.
    Daniel Boase
    Investor Relations
    416-742-5600
    Toll Free: 1-866-580-8891