Orex & Osisko: Reverse Circulation Drilling Results on Goldboro Gold Property

Montreal, 11/18/10 - Osisko Mining Corporation (TSX: OSK) (FRANKFURT: EWX) and Orex Exploration Inc. (TSX VENTURE: OX) (FRANKFURT: O5D) would like to provide shareholders with the results from the Reverse Circulation (RC) drilling program on the Goldboro Gold Property in Nova Scotia. RC drilling is a method for obtaining chip samples of mineral occurrences at or near surface, in both overburden and bedrock. A total of 64 RC holes (holes OSK10RC-130 to OSK10RC-194), representing 505 metres, were drilled on the Goldboro Gold Property. The highlights of the RC drilling campaign are presented below:

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HOLE #                LOCATION  FROM   TO  WIDTH        TYPE          ASSAY
                                 (m)  (m)    (m)                    (Au ppm)
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OSK10RC-135               East
                     Goldbrook     6    7      1  Overburden            0.82
OSK10RC-135               East
                     Goldbrook     7    8      1     Bedrock            1.38
OSK10RC-136               East
                     Goldbrook     4    5      1  Overburden            0.16
OSK10RC-137               East
                     Goldbrook     4    5      1     Bedrock           10.85
OSK10RC-141               East
                     Goldbrook     6    7      1  Overburden            0.31
OSK10RC-141               East
                     Goldbrook     7    8      1     Bedrock            0.20
OSK10RC-145               East
                     Goldbrook     5    6      1  Overburden            0.52
OSK10RC-145               East
                     Goldbrook     6    7      1     Bedrock            0.11
OSK10RC-145               East
                     Goldbrook     7    8      1     Bedrock            0.15
OSK10RC-147               East
                     Goldbrook     5    6      1     Bedrock           25.65
OSK10RC-148               East
                     Goldbrook     3    4      1  Overburden            0.12
OSK10RC-160          Ramp Area    10   11      1     Bedrock            0.73
OSK10RC-174          Ramp Area     6    7      1  Overburden            0.38
OSK10RC-174          Ramp Area     7    8      1     Bedrock            0.12
OSK10RC-178          Ramp Area    10   11      1  Overburden            0.74
OSK10RC-184          Ramp Area     4    5      1     Bedrock            0.15
OSK10RC-186          Ramp Area     3    4      1  Overburden            1.47
OSK10RC-186          Ramp Area     4    5      1  Overburden            0.58
OSK10RC-186          Ramp Area     5    6      1     Bedrock            0.56
OSK10RC-187          Ramp Area     8    9      1     Bedrock            0.17
OSK10RC-194               West
                     Goldbrook     3    4      1  Overburden            0.02
OSK10RC-194               West
                     Goldbrook     4    5      1  Overburden            1.17
OSK10RC-194               West
                     Goldbrook     5    6      1     Bedrock            0.04
OSK10RC-194               West
                     Goldbrook     6    7      1     Bedrock            4.23
OSK10RC-194               West
                     Goldbrook     7    8      1     Bedrock            0.60
OSK10RC-194               West
                     Goldbrook     8    9      1     Bedrock            2.80
OSK10RC-194               West
                     Goldbrook     9   10      1     Bedrock            0.66
OSK10RC-194               West
                     Goldbrook    10   11      1     Bedrock            0.63
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'The RC drilling results have successfully identified bedrock gold mineralization on the East Goldbrook portion of the Goldboro Gold Property, where there has not been a lot of historic drilling, as well as at West Goldbrook' said Mark Billings, President and CEO of Orex Exploration. 'We know that most of the gold-bearing structures at Goldboro come to surface. These RC drilling results particularly at East Goldbrook, which include 10.85 g/t Au and 25.65 g/t Au in two bedrock samples, provide us with some encouragement about the gold potential in these areas.'

Although some of the RC drilling results could be used in a future resource estimate, this program was not intended to expand the NI 43-101 resource estimate; rather it was designed to explore new areas on the Goldboro Gold Property. RC drilling is a cost effective way of testing potential near-surface gold mineralized structures identified by the ongoing exploration on the Property. The program has been successful in the identification of future diamond drilling target areas.

The Reverse Circulation drilling was conducted by Archibald Drilling and Blasting of Truro, Nova Scotia. Sampling was done along roadside at approximately 20-metre spacing (no grid pattern). Overburden samples were collected over a 1-metre downhole length above the bedrock overburden interface. Bedrock chip samples were collected at 1-metre downhole length from the top of bedrock, generally to depths of 1-3 metres, but up to 12 metres in selected holes. All samples collected during the program were delivered by Mercator Geological Services or Armour Transport to the Minerals Engineering Centre (MEC) at Dalhousie University in Halifax, Nova Scotia, where analysis was carried out.

Each sample submitted to MEC was subjected to multiple stages of jaw crushing until grains were less than 4.0 mm. Analytical splits of 200 grams were obtained by riffle splitting and then pulverized with a ring and puck pulverizer to a grain size of less than 0.15 mm. A 30-gram split of this fraction was collected and analyzed by Fire Assay, lead collection and Atomic Adsorption Spectrometry (AAS) finish.


Option on Goldboro Gold Property Granted to Osisko Mining Corporation

In order to acquire a 50% undivided interest in the Goldboro Gold Property on or before September 29, 2013 (the Initial Option), Osisko Mining Corporation shall incur exploration and development expenditures in the amount of at least $1,500,000 on or before September 29, 2010; in the aggregate amount of at least $3,500,000 on or before September 29, 2011; and in the aggregate amount of at least $8,000,000 over the following two years, that is, on or before September 29, 2013. Osisko Mining Corporation may, at its sole discretion, accelerate and apply exploration and development expenditures to future years' expenditures and, accordingly, the Initial Option may be exercised sooner. Osisko Mining Corporation shall solely fund a prefeasibility study to earn an aggregate 60% interest (that is, an additional 10% interest) in the Property on or before September 29, 2015 (the Additional Option).

Osisko Mining Corporation and Orex Exploration are pleased to report that Osisko Mining Corporation has spent more than the $1,500,000 required in exploration and development expenditures in the first year of the Initial Option.


About Osisko Mining Corporation

Osisko Mining Corporation is currently developing the Canadian Malartic gold deposit in Quebec and evaluating adjacent areas for a large-scale open pit, bulk tonnage mining operation. The Canadian Malartic deposit currently represents one of the biggest permitted gold reserves in Canada for a single deposit, and is still growing through ongoing drilling on new mineralized zones.


About Orex Exploration Inc.

Orex Exploration Inc. is a Canadian-based junior resource and exploration company trading under the symbol OX on the TSX Venture Exchange and O5D on the Frankfurt Stock Exchange. The Company holds a 100% interest in the Goldboro Gold Project in Nova Scotia.

The technical information contained in this news release has been prepared by Peter Webster, P.Geo., President of Mercator Geological Services, and Bruce Mitchell, P.Geo, Technical Advisors to Orex and Qualified Persons under National Instrument 43-101 regulations.


Neither the TSX Venture Exchange nor its regulation services provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release. The statements made in this news release that are not historical facts are 'forward-looking statements' and readers are cautioned that any such statements are not guarantees of future performance, and that actual developments or results, may vary materially from those in these 'forward-looking' statements.



Contacts:

For Osisko Mining Corporation (www.osisko.com)
John Burzynski, Vice-President, Corporate Development
514-735-7131

Sylvie Prud'homme, Manager, Investor Relations
514-735-7131
Toll-free : 1-888-674-7563

For Orex Exploration Inc. www.orexexploration.ca)
Mark Billings, President & CEO
514-296-1641
mark@atwaterfin.com

Leo Karabelas, Frontline Communications
905-553-7992
www.frontlineir.com