Advertisement
Details on the parameters of the resource estimates are as follows:
-- The database comprised a total of 2,144 holes for 629,367 metres of drilling completed and assayed by Brett Resources and Osisko as of the end of April 2012 on a minimum 25 m x 25 m grid. (All NQ core assays reported by Osisko were obtained by standard 50 g fire assaying-AA finish or gravimetric finish at ALS Chemex laboratories.)-- The database also comprised a total of 413,412 assays with an average of 1.5 metre per sample for a total of 618,596 assayed metres.-- The estimates were done using Ordinary Kriging (OK) interpolation as the geostatistical method based on 5.0 metres analytical composites.-- All estimates are based on a block dimension of 10 metres E, 10 metres N and 12 metres height with estimation parameters determined by variography.-- Geological interpretation identified a Main domain and several smaller domains (that surround the Main domain. The Main domain is a tabular zone that dips to the southeast and includes the A, Mitta and 41 zones on surface. The RAB was recognized as a separate southern domain that was ignored for the purposes of the global and in-pit resource estimate.-- Calculations are based on original samples capped to a maximum of 15 g/t Au for the Main domain, resulting in 99 capped intervals with an overall gold loss of 2.0%. Capping for the smaller domains was at 10 g/t for variable gold losses between 0.8% and 2.2%. All 5-metres composites are calculated based on cut original data.-- Tonnage estimates are based on an average rock density of 2.74 tonnes/cubic metre for the altered tonalite host rock.-- The global resource estimates using the lower cut-off of 0.50 g/t Au is emphasized for reporting purposes, which is higher than the in-pit cut- off of 0.31-0.33 g/t Au estimated for the US$1,400 Whittle shell.-- With respect to the previously published in-pit inferred resource (see November 7, 2011 press release), although base-case gold price was increased from US$1,200/oz to US$1,400/oz, the increased unit processing cost (from US$6.66/t to US$8.75/t) and mining costs (from US$1.61/t to US$1.98/t) and decreased recovery (from 91% to 87-88%) have made the new pit shells slightly smaller than before.
The two US$1,400 Whittle shells have approximate maximum dimensions of 2,500 metres in total length, 1,050 metres in width and a vertical depth to 380 metres. Pit optimization parameters are summarized in the table below:
----------------------------------------------------------------------------Parameter Unit Value----------------------------------------------------------------------------Gold price US$/oz 1400----------------------------------------------------------------------------Royalties % 2.0%----------------------------------------------------------------------------Refining cost US$/oz 5.0--------------------------------------------------------------------------------------------------------------------------------------------------------Processing cost US$/t milled 8.75----------------------------------------------------------------------------Administration US$/t milled 1.75----------------------------------------------------------------------------Rehabilitation US$/t milled 0.25----------------------------------------------------------------------------Sustaining capital US$/t milled 0.52----------------------------------------------------------------------------Total ore cost US$/t milled 11.27--------------------------------------------------------------------------------------------------------------------------------------------------------Recovery West Pit % 88.0%----------------------------------------------------------------------------Recovery East Pit % 87.0%----------------------------------------------------------------------------Mining dilution % 0%----------------------------------------------------------------------------Mining loss % 0%--------------------------------------------------------------------------------------------------------------------------------------------------------Cut-off grade West Pit g/tAu 0.31----------------------------------------------------------------------------Cut-off grade East Pit g/tAu 0.33--------------------------------------------------------------------------------------------------------------------------------------------------------Base mining cost rock US$/t mined 1.98----------------------------------------------------------------------------Reference elevation m 430----------------------------------------------------------------------------Cost per bench below US$/bench/t mined 0.046----------------------------------------------------------------------------Mining cost overburden US$/t mined 3.50--------------------------------------------------------------------------------------------------------------------------------------------------------Max pit slope West Pit degrees From 41.3 to 50.3----------------------------------------------------------------------------Max pit slope East Pit degrees From 45.4 to 48.6----------------------------------------------------------------------------Density overburden t/m3 2.0----------------------------------------------------------------------------
