Osisko Mining Corporation
TSX : OSK
FRANKFURT : EWX

Osisko Mining Corporation

April 17, 2008 08:57 ET

Osisko Intersects Significant Gold Mineralization Over 800 Metres Strike Length at Jeffrey

Results include 54 metres averaging 1.25 g/t Au

MONTREAL, QUEBEC--(Marketwire - April 17, 2008) - Osisko Exploration Ltd. (TSX:OSK)(DEUTSCHE BOERSE:EWX) and Golden Valley Mines Ltd. (TSX VENTURE:GZZ) are pleased to announce results from a 2400 metre drill program on the Jeffrey Zone of the Malartic CHL property. The Jeffrey Zone is located at the southern extremity of the CHL porphyry intrusion, approximately 3.5 km east of the center of the Canadian Malartic deposit. This mineralized zone was tested with nine holes spaced 100 m apart along a total strike length of 800 metres. All holes in the Jeffrey Zone were oriented south, perpendicular to regional E-W fabric and were inclined 45 to 50 degrees. Significant near surface results include 53.9m averaging 1.25 g/t Au (hole CHL07-2022) and 40.5m averaging 1.39 g/t Au (hole CHL07-2021). Higher grade, deeper drilling results include 1.5m averaging 109.5 g/t Au (hole CHL07-2027) and 1.5m averaging 14.65 g/t Au (hole CHL07-2029). Results from the nine new holes are summarized in the table below:



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Hole No. Easting From (m) To (m) Length (m) Au g/t
CHL07-2021 7300E 24.5 65.0 40.5 1.39
CHL07-2022 7400E 12.1 66.0 53.9 1.25
And 126.0 148.0 22.0 1.12
CHL07-2023 7500E 62.8 85.3 22.5 0.99
CHL07-2024 7600E 45.8 62.7 16.9 1.08
CHL07-2025 7700E NIL
CHL07-2026 7800E 152.0 160.0 8.0 3.11
CHL07-2027 7900E 137.0 138.5 1.5 109.5
CHL07-2028 8000E 105.3 154.5 49.2 0.60
And 183.0 196.5 13.5 1.12
CHL07-2029 8100E 197.8 199.3 1.5 14.65
And 220.3 223.8 3.5 5.48
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Mineralization in the Jeffrey Zone consists of disseminated pyrite-gold in porphyry dykes and of narrower, higher grade mineralization in silicified porphyry or ultramafic schists. True widths are estimated at 70 to 80% of mineralized intersections. The zone remains open to the east and at depth.

Current structural interpretation indicates that the Jeffrey Zone and the Shaft Zone are located at the southern and northern extremities, respectively, of the CHL porphyry intrusion, which has been deformed into a Z-shaped body by sinistral strike-slip motion along the Cadillac Break. Initial drilling in the Shaft Zone by Osisko produced 8.4 metres averaging 8.82 g/t Au (see press release dated August 7, 2007). The geological model suggests potential for additional mineralization along dilation zones at the contact between the porphyry and the ultramafic schists, between the Jeffrey and Shaft Zones. Definition drilling on these zones will begin shortly, followed by reconnaissance drilling between the zones, aimed at testing the geological model.

Commenting on the new exploration results, Sean Roosen, President of Osisko stated: "We are very pleased with these latest drilling results on the Golden Valley joint-venture property. The Jeffrey and Shaft Zones demonstrate that the CHL property hosts significant potential to add to Osisko's resource balance sheet with both shallow, low-grade porphyry material as well as narrower, deeper, higher grade underground zones that could have a positive effect on the per-ounce mining and milling costs."

Osisko has the right to acquire a 70% interest in the Malartic CHL Property in consideration for $150,000 in cash payments over a four year period ($70,000 paid to date) and by completing a minimum $2,000,000 in exploration work over a four year period. Upon earning its 70% interest, Golden Valley will maintain a free-carried interest of 30% to production.

All NQ core assays reported above were obtained by standard 50 g fire assaying-AA finish at ALS Chemex laboratories in Val d'Or, Quebec. Reported weighted averages were calculated using a minimum of 0.4 g/t Au over successive maximum intervals of 20 metres with no upper cut-off of individual assays.

Osisko Exploration Ltd. is currently evaluating the Canadian Malartic gold deposit and adjacent areas for a large-scale open pit, bulk-tonnage mining operation. The Company is well-funded with approximately $160 million on hand and is carrying out an aggressive definition drilling and exploration campaign. An updated NI 43-101 compliant inferred gold resource estimate on the main Canadian Malartic deposit was released on July 5, 2007 and the full report is available on SEDAR.

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
    Toll Free: 1-800-735-7131
    www.osisko.com
    or
    Daniel Boase
    Investor Relations
    416-742-5600
    Toll Free: 1-866-580-8891