Osisko and Clifton Star Report 2009 Drill Results From the Duparquet Project

MONTREAL, QUEBEC, Feb 18, 2010 (MARKETWIRE via COMTEX) -- Osisko Mining Corporation ("Osisko") /quotes/comstock/11t!osk (CA:OSK 8.66, -0.24, -2.70%) (FRANKFURT: EWX) and Clifton Star Resources Inc ("Clifton") /quotes/comstock/11v!cfo (CA:CFO 6.42, -0.07, -1.08%) (FRANKFURT: C3T) are pleased to announce results from Clifton's 2009 drill program and extended core sampling program at the Duparquet Project located in the Abitibi region of Quebec. Drilling and extended sampling on selected holes were focused on three properties: Beattie, Donchester (eastern extension of Beattie) and Duquesne. Previous drilling and sampling by Clifton had focused on higher-grade veins or tabular breccias/shear zones located mostly within syenite porphyry intrusions. Current sampling and future drilling will focus on delineating broader zones of mineralization that may be amenable to large scale open-pit mining.

Highlights from 37 drill holes reported herein include 171.1 metres averaging 1.62 g/t Au (D09-01B), 99.5 metres averaging 1.29 g/t Au (B09-72) and 119.4 metres averaging 1.50 g/t Au (B09-92). Assay results are summarized in the table below:

Beattie-Donchester Properties
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Hole No.     Section    Zone   From (m)   To (m)  Length (m)   Au g/t
B09-69       630050E   North     106.5    178.5        72.0      1.85
B09-71       630775E      RW     153.5    174.0        20.5      1.74
B09-72       630800E      RW      10.0    109.5        99.5      1.95
B09-74       630800E      RW     156.0    183.0        27.0      1.40
B09-75       630800E      RW      36.0     63.0        27.0      3.60
Including                         36.0     45.0         9.0      6.22
And                              110.9    121.5        10.6      1.15
B09-79       630850E      RW      87.0    111.1        24.1      1.05
And                              169.2    191.5        22.3      1.72
B09-80       630125E   South       1.5     36.0        34.5      1.23
B09-81       629975E   North      84.0    108.0        24.0      2.11
B09-83       630000E   North      94.5    183.0        88.5      2.00
B09-84       630000E   North      12.0     43.5        31.5      1.26
including                         12.0     15.0         3.0      7.12
B09-85       630800E      RW       0.4     51.0        50.6      1.11
B09-86       630825E      RW       4.5     72.0        67.5      0.93
B09-87       630825E      RW       5.0     42.0        37.0      1.81
B09-88       630875E      RW      12.0     99.0        87.0      1.40
B09-89       630875E      RW      46.5     81.5        35.0      1.45
including                         65.0     69.0         4.0      3.93
B09-90       630875E      RW      18.0     52.5        34.5      0.67
And                              145.5    160.5        15.0      1.11
B09-91       630900E      RW      24.0     57.0        33.0      1.02
B09-92       630925E      RW      78.6    198.0       119.4      1.50
B09-93       630925E      RW      21.0     42.0        21.0      1.42
B09-94       630925E      RW      57.0    171.0       114.0      1.57
B09-95       630925E      RW      22.0     50.5        28.5      0.79
B09-100      630875E      RW      51.0    121.5        70.5      0.75
B09-106      630925E      RW     107.5    127.0        20.0      1.47
B09-107      630925E      RW      40.5     70.5        30.0      0.96
B09-109      631000E      RW      42.0     75.0        33.0      0.94
D99-02       631675E   North      92.7    133.2        40.5      2.74
D08-01       631825E   North     167.6    352.0       184.4      2.17
D08-02A      631900E   North     123.0    148.9        25.9      2.03
D08-07       631700E   North     650.4    712.6        62.2      2.01
D09-01B      631725E   North     156.0    327.1       171.1      1.62
D09-38       632175E   North     275.0    331.0        56.0      1.80
And                              436.7    468.7        32.0      1.58
And                              595.5    636.5        41.0      1.66
D09-40       632225E   North     298.6    329.9        31.3      1.71
D09-14       631875E   North      60.0     96.1        36.1      1.14
D09-38       632175E   North     436.7    468.7        32.0      1.58
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Duquesne Property
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Hole No.     Section      Zone From (m)   To (m)  Length (m)   Au g/t
DQ09-09      642100E Nipissing   304.0    321.0        17.0      5.31
including                        304.5    309.5         5.0     13.81
DQ09-10      642250E Nipissing    17.0     23.0         6.0      3.86
DQ09-13      632300E Nipissing    42.0     53.0        11.0      2.17
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Mineralization on the Beattie-Donchester properties consists mostly of tabular, subvertical zones of finely disseminated pyrite-gold and variable arsenopyrite in brecciated or sheared, potassic-altered syenite porphyry. The Beattie-Donchester syenite porphyry intrusion is the host to two past producing mines (Beattie and Donchester), and it has been the focus of the bulk of the previous drilling. It is an east-west striking, subvertical intrusive body, approximately 3300 metres long, 150 to 450 metres wide and at least 900 metres deep. The main mineralized zones, at least 2600 m long and up to 80 metres thick, occur at the north and south contacts of the intrusion. They are open to the east and west and at depth. Several anastomosing, subvertical mineralized zones also occur within the intrusion, such as RW and RS zones, and in the mafic volcanics north and south of the intrusion.

A second mineralized syenite porphyry intrusion occurs immediately southeast and parallel to the Beattie-Donchester intrusion. The Dumico porphyry is approximately 2200 metres long and 350 metres wide, and host to two known mineralized zones (Central Duparquet and Dumico) similar in nature to those of the Beattie-Donchester porphyry intrusion.

Total strike length of the mineralized porphyries is therefore about 5500 metres, and these will be the focus of the upcoming Osisko-Clifton exploration efforts. Since 1987 to the end of 2009, a total of 520 drill holes totaling 147,297 metres have been drilled on Clifton's Duparquet gold properties, and about 429 holes totaling 112,965 metres on the Beattie-Donchester properties alone. Assays from seven 2009 drill holes from the Beattie-Donchester program are pending and results are expected in the next two weeks.

For the 2010 season, Osisko has outlined a 120,000 metres drill program for the Duparquet project, which will consist of 100,000 metres definition program on Beattie-Donchester, as well as 20,000 definition program on Duquesne. The objective of the former program will be to define a bulk tonnage inferred resource by early 2011 on the mineralized Beattie-Donchester syenite porphyry complex. Four drills are presently mobilized and drilling commenced on both properties on February 15.