Osisko Mining Corporation
TSX : OSK
FRANKFURT : EWX

Osisko Mining Corporation

October 23, 2007 08:57 ET

Osisko Discovers Extension to Barnat Zone

MONTREAL, QUEBEC--(Marketwire - Oct. 23, 2007) - Osisko Exploration Ltd. (TSX VENTURE:OSK)(FRANKFURT:EWX) is pleased to announce that significant mineralization was intersected in DDH CM07-2008, collared 310 metres southeast of the South Barnat Zone. The overall intersection from 9.8 to 113.5 metres, including a barren zone from 49.9 to 71.7 metres, produced an average grade of 1.91 g/t Au over 103.7 metres. The new mineralized zone, hosted in a sequence of mineralized schistose carbonated ultramafic rocks and porphyry dykes, is open along strike to the east and contains intercepts of higher grade material, including 41.8 metres averaging 3.07 g/t Au:



--------------------------------------------------------------------
Hole No. From (m) To (m) Length (m) Au g/t
CM07-2008 9.8 49.9 40.1 1.73
And 71.7 113.5 41.8 3.07
including 71.7 77.4 5.7 12.37
--------------------------------------------------------------------


The South Barnat Zone is located within the Cadillac fault zone, 1200 metres northeast of the center of the Canadian Malartic deposit. The South Barnat Zone was investigated by Osisko with a series of holes drilled in 2006 (see Osisko press release of August 9, 2006) in which higher grade porphyry-hosted mineralization was intersected in five holes spanning a strike length of 230 metres. Results from those drill holes are again tabled below for reference purposes:



South Barnat 2006 drill results

--------------------------------------------------------------------
Hole No. From (m) To (m) Length (m) Au g/t
BA06-1004 24.2 71.3 47.1 2.23
including 54.0 58.5 4.5 7.89
BA06-1005 33.2 100.6 67.4 3.66
including 43.0 46.0 3.0 14.6
including 73.5 82.5 9.0 10.7
BA06-1006 106.2 117.7 11.5 3.56
BA06-1007 52.1 109.7 57.6 4.11
including 72.2 85.7 13.5 12.4
BA06-1008 14.5 128.0 113.5 1.01
And 150.5 152.0 1.50 9.63
--------------------------------------------------------------------


The mineralized intersection in DDH CM07-2008 is very significant as it occurs along the southeastern strike extension of the South Barnat Zone where it joins an area located immediately north of the old East Malartic mine workings. This suggests potential for near surface mineralization in the South Barnat Zone along a total strike length of 540 metres and potential for further mineralization to the east along the north wall of the past-producing East Malartic mine.

The South Barnat zone is one of several significant exploration targets currently being tested by Osisko in the Malartic camp. Drilling is ongoing in the Southeastern Extension of the Canadian Malartic deposit towards the Gouldie Zone, and the next priority target to be tested in November 2007 is the Western Porphyry Zone, located within the Cadillac fault zone approximately 1000 metres northwest of the Canadian Malartic deposit. The latter is a high priority target with a 1200 metre strike length (see August 27, 2008 press release) hosting potential for a large, low grade, porphyry-hosted gold system similar to that of the F Zone porphyry at Canadian Malartic. Other targets, such as further extensions to the South Barnat Zone, will be in drill tested in Q1 2008.

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 0.40 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 $80 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
    514-735-7131
    www.osisko.com
    or
    Daniel Boase
    Investor Relations
    416-742-5600
    Toll Free: 1-866-580-8891