Osisko Updates Reserves at Canadian Malartic

Osisko Updates Reserves at Canadian Malartic 
MONTREAL, QUEBEC -- (Marketwire) -- 02/19/13 -- Osisko Mining
Corporation (TSX:OSK)(FRANKFURT:EWX) is pleased to provide an updated
reserve and resource estimate for its 100%-owned Canadian Malartic
project. This new estimate, calculated at US$1475 gold, combines the
reserves and resources of the main Canadian Malartic (CM) and South
Barnat deposits with those defined from satellite deposits. This
update reports reserves as well as global resources in all categories
as of January 1, 2013.  
The open pit Proven & Probable gold reserves (using US$1475 gold) now
stand at 10.1 million (M) ounces at a fully diluted average gold
grade of 1.01 g/t Au, following total production of 588,615 ounces of
gold since beginning of operations in 2011. Global Measured and
Indicated (M&I) resources above a cut-off grade of 0.31 (Barnat) to
0.34 g/t Au (Canadian Malartic and satellites) stand at 11.70 M
ounces gold, and global Inferred resources stand at 1.20 M ounces
gold. The global in situ resources include reserves but exclude
production. 
Reserve estimates using base case US$1475 engineered pit design with
0.31 g/t Au (Barnat) to 0.34 g/t Au (Canadian Malartic and
satellites) lower cut-off grade 


 
----------------------------------------------------------------------------
Canadian Malartic+Barnat          Tonnes (M)     Grade (g/t)       Au (M oz)
----------------------------------------------------------------------------
Proven Reserves                         41.8            0.94            1.26
----------------------------------------------------------------------------
Probable Reserves                      256.9            1.04            8.60
----------------------------------------------------------------------------
Proven & Probable Reserves             298.6            1.03            9.86
----------------------------------------------------------------------------
Gouldie+Jeffrey(i)                                                          
----------------------------------------------------------------------------
Proven Reserves                         3.66            0.78            0.09
----------------------------------------------------------------------------
Probable Reserves                       5.41           
 0.78            0.14
----------------------------------------------------------------------------
Proven & Probable Reserves              9.08            0.78            0.23
----------------------------------------------------------------------------
Stockpiles                                                                  
----------------------------------------------------------------------------
Proven Reserves                         3.47            0.51            0.06
----------------------------------------------------------------------------
Probable Reserves                       0.00            0.00            0.00
----------------------------------------------------------------------------
Proven & Probable Reserves              3.47            0.51            0.06
----------------------------------------------------------------------------
                                                                            
----------------------------------------------------------------------------
TOTAL                                                                       
----------------------------------------------------------------------------
Proven Reserves                         48.8            0.89            1.40
----------------------------------------------------------------------------
Probable Reserves                      261.8            1.04            8.72
----------------------------------------------------------------------------
Proven & Probable Reserves             310.6            1.01            10.1
----------------------------------------------------------------------------
(i) Jeffrey represents 70% portion owned by Osisko                          

 
For the purpose of the reserve estimate, the optimal Whittle pit
shell was used as a guideline for the manual design of the engineered
pit, and only the in-pit measured and indicated resources were
considered. Optimization parameters included: 


 
----------------------------------------------------------------------------
Parameter                                               Unit           Value
----------------------------------------------------------------------------
Gold price                                            US$/oz            1475
----------------------------------------------------------------------------
Royalties                                                  %      1.5 to 2.0
----------------------------------------------------------------------------
Refining cost                                         US$/oz            4.25
----------------------------------------------------------------------------
                                                                            
----------------------------------------------------------------------------
Processing cost                                 US$/t milled            8.50
----------------------------------------------------------------------------
Administration                                  US$/t milled            1.80
----------------------------------------------------------------------------
Rehabilitation                                  US$/t milled            0.25
----------------------------------------------------------------------------
Sustaining capital                              US$/t milled            0.52
----------------------------------------------------------------------------
Total ore cost                                  US$/t milled           11.07
----------------------------------------------------------------------------
                                                                            
----------------------------------------------------------------------------
Average Recovery CM                                        %           84.0%
----------------------------------------------------------------------------
Average Recovery Barnat                                    %           90.0%
----------------------------------------------------------------------------
Mining dilution                                            %              8%
----------------------------------------------------------------------------
Mining loss                                                %              0%
----------------------------------------------------------------------------
                                                                            
----------------------------------------------------------------------------
Cut-off grade Barnat                                  g/t Au            0.31
----------------------------------------------------------------------------
Cut-off grade CM+others                               g/t Au            0.33
----------------------------------------------------------------------------
                                                                            
----------------------------------------------------------------------------
Base mining cost rock                            US$/t mined    2.00 to 3.47
----------------------------------------------------------------------------
                                                 US$/bench/t                
Cost per bench below                                   mined           0.031
-----------
-----------------------------------------------------------------
Mining cost overburden                           US$/t mined            2.95
----------------------------------------------------------------------------
                                                                            
----------------------------------------------------------------------------
                                                                From 43.0 to
Max pit slope West Pit                              degrees           55.0
----------------------------------------------------------------------------
Density overburden                                      t/m3             2.0
----------------------------------------------------------------------------

 
The strip ratio in the main pit is estimated at 2.27 with average
diluted grade of 1.03 g/t Au based on a calculated dilution of 8%.
The quoted mineral reserve is exclusive of estimated historical stope
crown pillar losses, estimated at less than 150,000 ounces gold. The
Charlie zone has also been removed from the reserve statement as it
will not be mined due to environmental restrictions.  
Sensitivity of the Proven and Probable reserves to gold price has
been estimated using the same engineered pits and lower cut-off
grades (Jeffrey satellite pit excluded, 0.06% of total reserve): 


 
----------------------------------------------------------------------------
Gold Price (US$)                 Grade (g/t)      Tonnes (M)          Oz (M)
----------------------------------------------------------------------------
$1000                                   1.16           248.3            9.25
----------------------------------------------------------------------------
$1200                                   1.08           278.7            9.65
----------------------------------------------------------------------------
$1400                                   1.02           300.9            9.89
----------------------------------------------------------------------------
$1600                                   0.98           319.2            10.1
----------------------------------------------------------------------------
$1800                                   0.94           336.0            10.2
----------------------------------------------------------------------------
$2000                                   0.91           350.7            10.3
----------------------------------------------------------------------------

 
Updated Global Resource Estimates 
The global Measured and Indicated ("M&I") resource is 11.70 million
ounces of gold at an average undiluted grade of 1.05 g/t Au, with an
additional 1.20 million ounces gold at an average grade of 0.75 g/t
Au in the Inferred category, based on a lower cut-off grade of 0.31
to 0.34 g/t Au. The global resources include the above-stated
reserves but exclude past production. The tables below summarize the
estimates per deposit: 
Canadian Malartic Updated Global Resource Estimates 


 
----------------------------------------------------------------------------
                                                 Cut-off                    
Deposit              Measured          Indicated   (g/t)           Total M&I
          --------------------------------------        --------------------
           Grade Tonnes   Au  Grade Tonnes   Au          Grade  Tonnes   Au 
           (g/t)    (M)(M oz) (g/t)    (M)(M oz)         (g/t)     (M)(M oz)
----------------------------------------------------------------------------
CM +                                               0.31-                    
 Barnat     1.00   40.4  1.30  1.08  280.1  9.72    0.33  1.07   320.6  11.0
----------------------------------------------------------------------------
Gouldie     0.85   5.39  0.15  0.82   12.9  0.34    0.33  0.83    18.3  0.49
----------------------------------------------------------------------------
Jeffrey        -      -     -  0.70   8.43  0.19    0.34  0.70    8.43  0.19
----------------------------------------------------------------------------
Western                                                                     
 Porphyry      -      -     -     -      -     -       -     -       -     -
----------------------------------------------------------------------------
TOTAL       0.98   45.8  1.44  1.06  301.5 10.25    0.32  1.05   347.3 11.70
----------------------------------------------------------------------------
                                                                            
----------------------------------------------------------------------------
Deposit                                           Inferred     Cut-off (g/t)
                    --------------------------------------                  
                                                       Au                   
                       Grade (g/t)  Tonnes (M)      (M oz)                  
----------------------------------------------------------------------------
CM + Barnat                   0.81        30.5        0.79         0.31-0.33
----------------------------------------------------------------------------
Gouldie                       0.72        4.88        0.11              0.33
----------------------------------------------------------------------------
Jeffrey                       0.90        0.38        0.01              0.34
----------------------------------------------------------------------------
Western Porphyry              0.65        13.9        0.29              0.32
----------------------------------------------------------------------------
TOTAL                         0.75        49.6        1.20              0.33
----------------------------------------------------------------------------

 
Details on the parameters of the resource estimates are as follows: 


 
--  The database comprised a total of 800,252 metres of drilling completed
    and assayed by Osisko as of the end of November 2012 (core and in-pit RC
    drilling) on a maximum 25 m x 25 metre grid, as well as 347,352 metres
    of historical drilling validated and retained from a larger database of
    historical drilling (Canadian Malartic Mines and Lac Minerals). All NQ
    or HQ core assays reported by Osisko were obtained by standard 50 g fire
    assaying-AA finish or gravimetric finish at ALS Chemex laboratories in
    Val d'Or, Quebec. 
--  The database also comprised a total of 696,220 assays with an average of
    1.38 metre per sample for a total of 961,755 assayed metres. 
--  The estimates were done using Ordinary Kriging (OK) as the
    geostatistical interpolation method based on 5.0 metre analytical
    composites. Resources were also estimated using Inverse Distance Squared
    (ID2) interpolation for testing and comparative purposes, which produced
    similar results, i.e. less than 2 percent difference in total ounces at
    all cut-offs. 
--  Calculations were based on original samples cut to a maximum of 10 g/t
    to 70 g/t Au depending on the domain. The apparent reduction in the gold
    content varies from 0 to 14.5% depending of the domains. All five metre
    composites were calculated based on cut original data. 
--  All estimates were based on a Parent Cell dimension of 20 metres E, 10
    metres N and 10 metres height with estimation parameters determine
d by
    variography. 
--  Geological interpretation identified thirty-seven different domains
    (sixteen in Canadian Malartic, thirteen in South-Barnat and eight in
    Gouldie). 
--  Underground voids were modeled from historical mine plans and adjusted
    according to positions of drill intersections in stopes and drifts. Void
    volumes of stopes were increased by one metre along all edges to
    compensate for uncertainties. The void models were then used to deplete
    the resource estimate. All samples located within the voids were also
    removed from the estimate. 
--  Tonnage estimates were based on rock densities of 2.69 tonnes/cubic
    metre for the porphyry, 2.75 for altered sediments and 2.83 for altered
    ultramafic rocks. 
--  The US$1475 engineered pit has approximate maximum dimensions of 3,560
    metres in length, 1,265 metres in width and a vertical depth of 410
    metres. 

 
Mr. Donald Gervais, P. Geo, Technical Services Director at Canadian
Malartic, and Mr. Robert Wares, Hon. D.Sc., P. Geo. and Chief
Geologist of Osisko, are the Qualified Persons who have reviewed this
news release and are responsible for the technical information
reported herein, including verification of the data disclosed. 
Cautionary Notes Concerning Estimates of Mineral Resources  
This news release uses the terms measured, indicated and inferred
resources as a relative measure of the level of confidence in the
resource estimate. Readers are cautioned that mineral resources are
not economic mineral reserves and that the economic viability of
resources that are not mineral reserves has not been demonstrated. In
addition, inferred resources are considered too geologically
speculative to have any economic considerations applied to them. It
cannot be assumed that all or any part of an inferred mineral
resource will ever be upgraded to a higher category. Under Canadian
rules, estimates of inferred mineral resources may not form the basis
of feasibility or pre-feasibility studies or economic studies except
for Preliminary Assessment as defined under NI 43-101. Readers are
cautioned not to assume that further work on the stated resources
will lead to mineral reserves that can be mined economically. 
Forward-Looking Statements  
Certain statements contained in this press release may be deemed
"forward-looking statements". All statements in this release, other
than statements of historical fact, that address events or
developments that Osisko expects to occur, are forward looking
statements. Forward looking statements are statements that are not
historical facts and are generally, but not always, identified by the
words "expects", "plans", "anticipates", "believes", "intends",
"estimates", "projects", "potential", "scheduled" and similar
expressions, or that events or conditions "will", "would", "may",
"could" or "should" occur including, without limitation, that mining
of the deposits identified in this press release will be executed
fully and will return values identified in the foregoing estimate.
Although Osisko believes the expectations expressed in such
forward-looking statements are based on reasonable assumptions,
including, without limitation, that all technical, political and
financial conditions will be met in order to continue mining
operations at Canadian Malartic to allow for the full extraction of
the mining reserves, such statements are not guarantees of future
performance and actual results may differ materially from those in
forward looking statements. Factors that could cause the actual
results to differ materially from those in forward-looking statements
include gold prices, access to skilled consultants, mining
development and construction personnel, results of exploration and
development activities, Osisko's limited experience with production
and mining operations, uninsured risks, regulatory framework and
changes, defects in title, availability of personnel, materials and
equipment, timeliness of government approvals, actual performance of
facilities, equipment and processes relative to specifications and
expectations, unanticipated environmental impacts on operations
market prices, continued availability of capital and financing and
general economic, market or business conditions. These factors are
discussed in greater detail in Osisko's most recent Annual
Information Form and in the most recent Management Discussion and
Analysis filed on SEDAR, which also provide additional general
assumptions in connection with these statements. Osisko cautions that
the foregoing list of important factors is not exhaustive. Investors
and others who base themselves on forward-looking statements should
carefully consider the above factors as well as the uncertainties
they represent and the risk they entail. Osisko believes that the
expectations reflected in those forward-looking statements are
reasonable, but no assurance can be given that these expectations
will prove to be correct and such forward-looking statements included
in this press release should not be unduly relied upon. These
statements speak only as of the date of this press release.
Contacts:
John Burzynski
Vice-President Corporate Development
(416) 363-8653
www.osisko.com 
Sylvie Prud'homme
Director of Investor Relations
(514) 735-7131
Toll Free: 1-888-674-7563
 
 
Press spacebar to pause and continue. Press esc to stop.