KSM (Kerr-Sulphurets-Mitchell): RESOURCES
All disclosure of a scientific or technical nature was prepared by, or under the supervision of, William E. Threlkeld (Licensed Registered Geologist #790 in the State of Washington), a Vice President of Seabridge. Mr. Threlkeld is a "Qualified Person" under National Instrument 43-101.
A breakdown of resources by project and resource category is available at Reserves/Resources.
A significant amount of work has been performed on the Kerr-Sulphurets project by previous owners including Placer Dome. Reputable drilling contractors and laboratories were used for sampling and assaying. Mr. Threlkeld has concluded the work performed by previous owners is reliable and adequate for establishing the degree of confidence necessary for estimating and classifying a mineral resource according to NI 43-101.
Separate resource models were developed by Placer Dome in 1993 for the Kerr and Sulphurets Gold Zone. Both studies were based on geological cross-sections and incorporating lithologic, structural, alteration and mineralogical controls to manually develop detailed polygonal bands and blocks at selected cut-off grades. Geostatistical estimates of grade were not utilized.
At Sulphurets, Placer Dome estimated an indicated gold resource of 1.3 million ounces of gold and 277 million pounds of copper contained in 39.3 million tonnes grading 1.05 grams of gold per tonne and 0.32% copper at a 0.50 gram per tonne cut-off. In the inferred category, Placer Dome estimated an additional 458,000 ounces of gold and 113 million pounds of copper contained in 15.5 million tonnes grading 0.92 grams of gold per tonne and 0.33% copper.
The Kerr deposit was modelled by Placer Dome as a copper-gold porphyry system containing an indicated resource of 809,000 ounces of gold and 1,208 million pounds of copper contained in 74.0 million tonnes grading 0.74% copper and 0.34 grams of gold at a 0.40% copper grade cut-off. In the inferred category, Placer Dome estimated an additional 794,000 ounces of gold and 1,119 million pounds of copper contained in 66.8 million tonnes grading 0.37 grams of gold per tonne and 0.76% copper.
Mineral resources which are not mineral reserves do not have demonstrated economic viability.
Following a detailed review of the supporting data and the independent historical mineral resource estimates by Placer Dome, Mr. Threlkeld confirmed that the historical resource estimates of Placer Dome disclosed above are relevant and reliable. Mr. Threlkeld has also confirmed that the definitions of "measured resource", "indicated resource" and "inferred resource" used by Placer Dome when calculating resources do not differ from the definitions of those terms in NI 43-101.
2010 Resource Estimate
Based upon the results from four major drill programs at KSM conducted by Seabridge in 2006, 2007, 2008 and 2009, Resource Modeling Inc. ("RMI"), an independent, expert consultancy has prepared a series of updated NI 43-101 compliant resource estimates, for the Mitchell, Kerr and Sulphurets zones. The results of the study dated January 2010 were as follows:
RMI estimated gold and copper grades using inverse distance weighting methods within gold and copper grade envelopes that were constructed for the Mitchell, Sulphurets and Kerr zones. The grade models were validated visually and by comparisons with nearest neighbor models. The estimated block grades were classified into measured, indicated and inferred mineral resource categories based on mineralized continuity that was determined both visually and statistically (i.e. variogram ranges) together with the proximity to drill hole data. Recoverable gold equivalent grades were calculated using a $650 gold price with a 70% recovery rate and a $2.00 copper price with an 85% recovery rate.
The drill hole database for the KSM project incorporated 355 core holes totaling approximately 94,500 meters. Over 95% of the holes at Mitchell were drilled by Seabridge during 2006-2009. The majority of the Sulphurets assay data were collected by Seabridge, Placer Dome and Esso Minerals Ltd. The majority of the drilling data for the Kerr zone were collected by Placer Dome during the early 1990s. RMI has reviewed the quality assurance/quality control ("QA/QC") protocols and results from Seabridge's 2006-2009 drilling programs and has deemed that the number and type of gold and copper standard reference materials (standards, blanks, and duplicates) were reasonable. Based on the performance of those standard reference materials, RMI believed that the Seabridge drill samples were reproducible and suitable for estimating mineral resources. RMI has been able to review the Placer Dome QA/QC data for the Sulphurets and Kerr zones and found the data to be reliable. No Esso QA/QC data were available for review. Based on these results, RMI deemed the assay data for the Kerr and Sulphurets zones to be reliable for estimating resources.
RMI is an independent consulting firm under the direction of Michael J. Lechner, Licensed Registered Geologist (Arizona) #37753, P.Geo. (British Columbia) #155344, AIPG CPG #10690 and a Qualified Person under NI 43-101.
Third-party, Independent Review
A third-party, independent review of Seabridge Gold's resource estimates for the KSM project was completed in mid March, 2010 by Behre Dolbear & Company, a leading international mining consulting firm. Based on their analysis, Behre Dolbear confirms that the KSM resource model is reasonable and appropriate. Furthermore, Behre Dolbear confirms that the resource estimates prepared by RMI and dated January 2010 are accurate, conform to industry practices and comply with the standards set out in NI 43-101. In their review, Behre Dolbear considered alternate resource estimation procedures and parameters and concluded that any resulting differences in resource estimates and classifications are not significant, and that RMI's project-wide estimation of measured and indicated resources is conservative.
The scope of work for Behre Dolbear's review included visual inspection of drill core and a thorough examination of drilling, sampling, assaying and chain of custody procedures. Their review concluded that all Seabridge's work met or exceeded industry standards. In addition, Behre Dolbear states that quality assurance and quality control procedures employed by Seabridge were excellent and that the gold and copper standard assay comparisons and blank sample analysis were outstanding. The Behre Dolbear review was commissioned as part of the process of preparing a Preliminary Feasibility Study.
Behre Dolbear is one of the oldest, continually operating, minerals industry advisory firms in the world. Since 1911, they have specialized in studies for financial institutions, mining companies, governments and governmental agencies, legal firms, and other parties with interests in the minerals industry. Behre Dolbear's global experience covers the full spectrum of technical, operational and financial issues in a broad range of commodities including base and precious metals. The Behre Dolbear review was undertaken by Joseph A. Kantor, Michael Fitzsimonds and Dr. Stanley K. Hamilton, all of whom are Qualified Persons under NI 43-101. Behre Dolbear has reviewed and consented to this disclosure.
2011 Resource Estimate
In February, 2011, Seabridge announced a new resource estimate following its successful 2010 drilling campaign. The updated resource estimate was prepared by Resource Modeling Inc. ("RMI") of Stites, Idaho and incorporates the new Iron Cap zone (see news release dated February 8, 2011) as well as increases at KSM's three other deposits.
The following table summarizes the global resource estimate for KSM:
The new KSM resource model will be incorporated into an updated Preliminary Feasibility Study (PFS) scheduled for completion in April 2011. Proven and probable reserves are expected to climb in the new PFS.
RMI estimated gold and copper grades using inverse distance weighting methods within geologically constrained gold and copper grade domains that were constructed for the Mitchell, Sulphurets, Kerr and Iron Cap zones. The grade models were validated visually and by comparisons with nearest neighbor models. The estimated block grades were classified into indicated and inferred mineral resource categories based on mineralized continuity that was determined both visually and statistically (i.e. variogram ranges and gold equivalent indicator probability models) together with proximity to drilling data. To facilitate comparisons with previous resource estimates, recoverable gold equivalent grades were calculated using the same $650 gold price with a 70% gold recovery rate and a $2.00 copper price with an 85% copper recovery rate. The cutoff grade for resource tabulation was set at 0.50 grams per tonne (g/t) gold equivalent, also consistent with the cutoff grade used for previous KSM resource estimates.
The drill hole database for the KSM project now incorporates 440 diamond core holes totaling approximately 123,625 meters. Over 96% of the holes at Mitchell were drilled by Seabridge from 2006 through 2010. Approximately 87% of the total Iron Cap meterage was drilled by Seabridge in 2010. The majority of the Sulphurets assay data were collected by Seabridge (53%), Placer Dome (23%) and Esso Minerals Ltd (9%). The remaining 15% of the Sulphurets drilling data were collected by Falconbridge and two other operators. The majority of the drilling data for the Kerr zone were collected by Placer Dome during the early 1990s. RMI has reviewed the quality assurance/quality control ("QA/QC") protocols and results from Seabridge's 2006-2010 drilling programs and has deemed that the number and type of gold and copper standard reference materials (standards, blanks, and duplicates) were reasonable. Based on the performance of those standard reference materials, RMI believes that the Seabridge drill samples are reproducible and suitable for estimating mineral resources. RMI reviewed the Placer Dome QA/QC data for the Sulphurets and Kerr zones and found the data to be reliable. No Esso QA/QC data were available for review but RMI notes that the assay results from those holes compare favoarably with nearby Seabridge drill holes. Based on QA/QC results and drill campaign comparisons, it is RMI':s opinion that the assay data for the Kerr and Sulphurets zones are reliable for estimating resources.
Gold resource estimates included herein were prepared by RMI under the direction of Michael Lechner, who is independent of Seabridge and a Qualified Person as defined by National Instrument 43-101. Mr. Lechner is a highly regarded expert in his field and frequently undertakes independent resource estimates for major mining companies. Mr. Lechner has reviewed and approved this disclosure.
Exploration activities by Seabridge Gold at the KSM project have been conducted under the supervision of William E. Threlkeld, Registered Professional Geologist, Senior Vice President of the Company and a Qualified Person as defined by National Instrument 43-101. Rigorous quality control/quality assurance protocols were employed during the drill programs including the submission of blanks and standard reference materials along with duplicate samples in every batch of assays. Cross-check analyses were conducted at a second external laboratory on 10% of the samples. The core samples were assayed at Eco Tech Laboratory Ltd., Kamloops, B.C., using fire assay atomic adsorption methods for gold and total digestion ICP methods for other elements.
