Aurizon Reports Mineral Reserve Replenishment and Mineral Resource Update for Casa Berardi Mine
VANCOUVER, BRITISH COLUMBIA -- (Marketwire) -- 02/27/12 -- Aurizon Mines Ltd. (TSX: ARZ)(NYSE Amex: AZK) is pleased to report the replenishment of mineral reserves and an 81% increase in measured and indicated mineral resources at its Casa Berardi mine, located in north western Quebec, Canada.
Highlights include the following:
-- An increase of 12% in mineral reserves, before mining depletion. Net of
mining depletion, mineral reserves at December 31, 2011 totalled
1,459,000 ounces of gold.
-- An increase of 81% in measured and indicated mineral resources to
1,495,000 ounces of gold and a decrease of 18% in inferred mineral
resources to 616,000 ounces of gold.
-- A significant increase in probable mineral reserves in Zones 118 and
123; Zone 118 with an increase of 44% to 301,000 ounces of gold; and
Zone 123 with an increase of 92% to 226,000 ounces of gold. Zones 118
and 123 remain open down dip.
-- A significant increase and conversion from inferred to indicated mineral
resources in Zone 160: indicated mineral resources of 366,000 ounces for
the open pit; and indicated mineral resources of 75,000 ounces for
underground.
-- An increase of 159,000 ounces of gold in the measured mineral resources
of the South West Zone due to a re-interpretation of the data and
updated resource calculation.
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CASA BERARDI MINE
MINERAL RESERVES AND RESOURCES SUMMARY(1)
as at December 31,
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2011 2010 2011
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Gain
(loss)
Ounces
Net of
Grade Grade 2011
Grams/ Gold Grams/ Gold Produc-
Tonnes tonne Ounces Tonnes tonne Ounces tion
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Mineral
Reserves
Proven and
Probable
Under-
ground 4,685,000 6.7 1,007,000 4,057,000 7.7 1,005,000 2,000
Open pit 3,796,000 3.7 452,000 3,796,000 3.7 452,000 0
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Total
Mineral
Reserves 8,481,000 5.3 1,459,000 7,854,000 5.8 1,457,000 2,000
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Mineral
Resources
Measured and
Indicated
Under-
ground 5,115,000 6.5 1,063,000 3,766,000 6.3 759,000 304,000
Open pit 5,752,000 2.3 432,000 715,000 2.9 66,000 366,000
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Total
Measured &
Indicated
Resources 10,867,000 4.3 1,495,000 4,481,000 5.7 825,000 670,000
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Inferred
Mineral
Resources 4,947,000 3.9 616,000 3,981,000 5.8 748,000 (132,000)
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(1) See accompanying notes below detailed mineral reserve and mineral
resource tables for definitions, parameters, and assumptions.
'This is the fifth consecutive year that Casa Berardi has renewed or increased mineral reserves,' said George Paspalas, President and CEO, adding 'We are confident that our 2012 $9.4 million exploration program will continue to expand and upgrade existing mineral resources. Casa Berardi continues to confirm that it delivers reliable, sustainable and profitable production that will continue well into the future.'
Casa Berardi Mine
The Casa Berardi gold deposits are located along a five kilometre east-west mineralized corridor. They include the East and West mines, and the Principal Zones. The Casa Berardi gold deposits can be classified as an Archean sedimentary-hosted lode gold deposit. The gold mineralization is superimposed on a continuous graphitic mudrock unit corresponding to the Casa Berardi Fault plane. Gold occurs mainly south of the Casa Berardi Fault, and occasionally on both sides of the fault.
The mine has produced approximately 1.5 million recovered gold ounces since commencing production in 1986, including 800,300 recovered ounces since Aurizon recommenced production in November 2006.
The mine produced a record of 163,845 ounces of gold in 2011.
Proven and Probable Mineral Reserves have been renewed as a result of the following:
-- At the West Mine, the 2011 mine production in Zones 113, Lower Inter,
North West and 115 have been replaced by gains in mineral reserves
primarily from Zone 118 and Zone 123S.
-- Mineral reserves were estimated using an average long-term gold price of
US$1,250 per ounce, compared to US$950 per ounce in 2010 both using a
Canadian dollar at parity against the US dollar. A minimum cut off grade
of 3.6 grams of gold per tonne was used for the underground zones, based
on long term operating costs and gold prices. A minimum cut off grade of
1.2 grams and 0.5 grams of gold per tonne was used, respectively, for
the East Mine and Principal Zone open pits. In 2010, the minimum cut off
grade was 4.1 grams of gold per tonne for the underground zones.
-- As a result of the new economic parameters used on mineral reserves
(long term operating costs and gold prices), low grade mineral reserves
in the South West Zone have increased by 331% of ounces in probable
mineral reserves to 46,100 ounces of gold.
-- As the mining industry is currently experiencing gold prices that are
higher than US$1,250 per ounce, the operations periodically mine ore
that is not included in mineral reserves as the grades are lower than
the long term minimum cut-off grades.
Changes in Casa Berardi Mineral Reserves
The following table shows the main components of the change in mineral reserves during 2011:
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Tonnes Gold Ounces
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Mineral Reserves - December 31, 2010 7,854,000 1,457,000
Resources conversion(1) 1,289,000 177,000
Mining depletion(2) (661,000) (175,000)
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Mineral Reserves - December 31, 2011 8,481,000 1,459,000
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(1) Resource conversion resulted in the addition of 177,000 ounces to
mineral reserves, representing a 12% increase.
(2) Mining depletion represents mineral reserves mined and processed in
2011 before milling recoveries and exclude 5,000 ounces mined outside
of the reserves established at the beginning of the year and,
therefore, does not correspond to the actual 2011 gold production of
163,845 ounces.
Mine Plan for Mineral Reserves
-- The mine plan for the current mineral reserves totals 8.5 million tonnes
of ore, grading 5.3 grams of gold per tonne to be mined over 9 years
(2012 to 2020). Underground production will come from Zones 113, Lower
Inter, 118, 123S, six smaller West Mine zones and the East Mine at an
average production rate of 160,000 ounces per year. Open pit production
will originate from the Principal Zone and the East Mine by 2014, at an
average rate of 1,000 tonnes per day, and will progressively replace
underground production.
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CASA BERARDI MINE
MINERAL RESERVE ESTIMATE
As at December 31,
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2011 2010
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Grade Grade
Grams/ Gold Grams/ Gold
Tonnes tonne Ounces Tonnes tonne Ounces
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Lower Inter (LI) 323,000 6.9 72,000 910,000 8.0 233,200
North West (NW) 42,000 5.5 7,400 42,000 5.8 7,900
113 261,000 8.1 68,300 587,000 8.8 167,000
115 46,000 9.0 13,300 147,000 11.4 54,100
Principal -
Open Pit 89,000 6.3 18,000 89,000 6.3 18,000
East mine -
Open Pit 407,000 4.2 54,400 407,000 4.2 54,400
East mine -
Underground 88,000 6.3 17,800 88,000 6.3 17,800
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Total Proven
Reserves 1,257,000 6.2 251,100 2,271,000 7.6 552,400
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Lower Inter (LI) 69,000 7.4 16,600 30,000 8.2 7,900
South West (SW) 350,000 4.1 46,100 72,000 4.6 10,700
109 121,000 5.6 21,500 114,000 5.7 21,000
111 54,000 4.7 8,200 37,000 5.4 6,400
113 601,000 8.4 162,700 402,000 9.9 127,800
115 56,000 11.9 21,400 0 0.0 0
117S 19,000 7.0 4,300 19,000 7.0 4,300
118 1,473,000 6.4 301,200 1,021,000 6.4 208,600
123S 1,088,000 6.5 225,700 493,000 7.4 117,700
Principal -
Open Pit 3,072,000 3.6 352,400 3,072,000 3.6 352,400
East Mine -
Open Pit 228,000 3.7 26,800 228,000 3.7 26,800
East Mine -
Underground 63,000 8.2 16,500 63,000 8.2 16,500
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Low-Grade
Development 31,000 3.9 3,900 31,000 3.9 3,900
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Total Probable
Reserves 7,225,000 5.2 1,207,500 5,583,000 5.0 904,100
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Total Proven and
Probable Reserves 8,481,000 5.3 1,459,000 7,854,000 5.8 1,457,000
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Notes:
(1) Open pit mineral reserves were estimated by BBA and underground mineral
reserves were estimated by Aurizon personnel.
(2) Mineral reserves and resources estimates have been completed in
accordance with the CIM Standards with regards to mineral reserves and
mineral resources estimates. Mineral resources are exclusive of mineral
reserves. Mining depletion for 2011 is included in 2011 Mineral
reserves.
(3) Mineral Reserves are estimated at a cut-off grade of 3.64 g/t Au for
underground, and 1.2 g/t Au for East Mine open pit and 0.5g/t Au for
Principal open pit.
(4) Mineral Reserves are estimated using an average long-term gold price of
US$1,250 per ounce and a US$/C$exchange rate of 1:1.
(5) A minimum mining width of three metres was used.
(6) Totals may not represent the sum of the parts due to rounding.
(7) See Appendix A for additional technical parameters.
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CASA BERARDI MINE
MEASURED AND INDICATED MINERAL RESOURCE ESTIMATES
As at December 31,
----------------------------------------------------------------------------
2011 2010
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Grade Grade
Grams/ Gold Grams/ Gold
Tonnes tonne Ounces Tonnes tonne Ounces
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Measured Mineral
Resources
Lower Inter 208,000 6.4 43,000 122,000 5.1 19,800
113 161,000 6.7 35,000 290,000 6.6 61,300
113-5 0 0.0 0 10,000 5.7 1,900
115 300 4.3 50 9,000 4.9 1,500
115-2 0 0.0 0 34,000 12.2 13,200
South West 795,000 6.2 159,300 0 0.0 0
North West 200 4.5 30 9,000 5.0 1,400
Principal -
Underground 153,000 7.3 36,000 153,000 7.3 36,000
East Mine -
Open Pit 311,000 3.1 31,300 311,000 3.1 31,300
East Mine
Underground 216,000 6.5 45,500 216,000 6.5 45,500
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Total Measured
Resources 1,845,000 5.9 350,300 1,155,000 5.7 211,900
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Indicated Mineral
Resources
South West 146,000 8.9 41,600 300,000 4.7 45,000
Lower Inter 60,000 7.5 14,400 3,000 8.8 900
Inter 0 0.0 0 124,000 4.4 17,700
109 17,000 4.2 2,300 21,000 4.3 2,900
111 38,000 5.7 6,900 52,000 5.2 8,800
113 339,000 5.7 62,400 46,000 5.1 7,600
113-5 0 0.0 0 2,000 6.0 400
113(S4) 0 0.0 0 245,000 5.5 43,000
115 8,000 4.2 1,100 0 0.0 0
115-2 0 0.0 0 4,000 10.3 1,300
118 802,000 5.5 143,000 518,000 5.2 86,900
123S 279,000 6.3 56,900 136,000 5.4 23,700
Principal
Underground 1,257,000 7.4 298,500 1,257,000 7.4 298,500
East Mine -
Open Pit 404,000 2.7 34,500 404,000 2.7 34,500
East Mine
Underground 90,000 6.3 18,100 90,000 6.3 18,100
160 - Open Pit 5,037,000 2.3 366,000 0 0.0 0
160 Underground 420,000 5.6 75,400 0 0.0 0
152 125,000 5.8 23,200 125,000 5.8 23,200
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Total Indicated
Resources 9,021,000 3.9 1,144,200 3,327,000 5.7 612,400
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Total Measured &
Indicated
Resources 10,867,000 4.3 1,495,000 4,481,000 5.7 825,000
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CASA BERARDI MINE
INFERRED MINERAL RESOURCE ESTIMATES
As at December 31,
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2011 2010
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Grade Grade
Grams/ Gold Grams/ Gold
Tonnes tonne Ounces Tonnes tonne Ounces
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Inferred Mineral
Resources
South West 8,000 10.6 2,700 0 0.0 0
104 115,000 6.6 24,500 115,000 6.6 24,500
113(S4) 0 0.0 0 15,000 5.8 2,700
118 716,000 7.0 161,300 369,000 7.9 94,200
123S 477,000 6.8 104,100 909,000 8.0 234,100
Principal -
Open Pit 655,000 2.5 53,200 655,000 2.5 53,200
Principal
underground 628,000 6.6 132,700 628,000 6.6 132,700
East Mine -
Open Pit 310,000 3.0 30,200 310,000 3.0 30,200
East Mine
Underground 156,000 9.1 45,600 156,000 9.1 45,600
152 13,000 8.2 3,500 13,000 8.2 3,500
East Mine Cherty 0 0.0 0 225,000 6.8 49,300
160 In Pit
Resources 1,704,000 0.6 30,100 131,000 1.7 7,100
160 Underground 165,000 5.3 27,800 455,000 4.8 70,800
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Total Inferred
Resources 4,947,000 3.9 616,000 3,981,000 5.8 748,000
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Notes:
(1) Open pit mineral resources of Principal and East Mine were estimated by
BBA. Open pit mineral resources of 160 zone and underground mineral
resources of 160 and South West zones were reported in an internal
report by InnovExplo-Consulting Firm to Aurizon Mines. The remaining
underground mineral resources were estimated by Aurizon personnel.
(2) CIM definitions were followed for Mineral Resources estimates.
(3) Mineral Resources are estimated at cut-off grades of:
- 4 g/t Au for West Mine, Principal Mine and East Mine underground.
- 3 g/t Au for 104 zone in the West Mine. This zone was estimated by
Aurizon in 2000 using 2D polygons on longitudinal sections and
reviewed by RPA in 2005.
- 1.30 g/t Au for the East Mine - Open Pit
- 0.5g/t Au for the Principal - Open Pit Mineral Resources are estimated
using an average long-term gold price of US$950 per ounce, and a
US$/C$exchange rate of 1:1
- 0.3 g/t Au for the 160 zone - Open Pit Mineral Resources are estimated
using an average long-term gold price of US$1,250 per ounce, and a
US$/C$exchange rate of 1 :1.
(4) Mineral resources of 113-5 and 113(S4) zones were merged into 113 Zone;
115-2 zone was merged into 115 Zone; Inter zone was merged into South
West Zone; East Mine Cherty was merged into 160 Zone.
(5) Minimum mining widths of two to three metres were used.
(6) Mineral Resources are exclusive of Mineral Reserves.
(7) Totals may not represent the sum of the parts due to rounding.
(8) Mineral resources which are not mineral reserves do not have
demonstrated economic viability.
(9) See Appendix B for additional technical parameters.
Comparison with 2010 Mineral Resources
The main variance in the mineral resource estimates between 2011 and 2010
are as follows:
-- Geological re-interpretation of mineralized zones after drilling
programs (Zone 113, Lower Inter and mainly 118, 123S, 160 open pit and
underground) and new resource calculations.
-- Geological re-interpretation and a new 3D block model of mineralized
Zone South West.
-- Conversion of inferred mineral resources (-132,000 oz) into indicated
and measured (+670,000 oz); or of indicated into measured mineral
resources.
-- Conversion of mineral resources (-212,000 oz) into mineral reserves
(+200,500 oz) after completion of economic mining plan for Zones 118 and
123S.
-- Mining depletion of mineral resources (-4,900 oz from Zone 113).
Outlook
Aurizon intends to utilize its strong cash flow to upgrade mineral resources to mineral reserves in order to extend and optimize the current mine plan.
In addition to the Principal Zone's open pit reserves, there are measured and indicated mineral resources that are located beneath the pit shell totalling 1,411,000 tonnes at an average grade of 7.4 grams per tonne, for 334,500 ounces of gold, and inferred mineral resources totalling 628,000 tonnes at an average grade of 6.6 grams per tonne, for 132,700 ounces of gold. The Company plans to drill these zones in 2012 from the 280 metre track drift to assess the potential of establishing a mineral reserve that can be mined from underground.
Aurizon has also increased and converted inferred mineral resources into indicated mineral resources in Zone 160. Aurizon intends to complete a scoping study to assess the relative risks and opportunities of mining Zone 160 by open pit.
The 550 level exploration track drift will be utilized as a drilling platform to extend the continuity between the Principal Zone and Zones 118 and 123S.
In 2012, $16.7 million is budgeted for the deepening of the West Mine production shaft a further 285 metres to provide access to the lower portion of the 113, 118 and 123 Zones. The shaft, currently at a depth of 795 metres, will be extended to approximately 1,080 metres below surface, which will provide access at the 1,010 metre level to develop a drift from the shaft to Zones 118 and 123. The shaft deepening is expected to be completed near the end of 2012 and commissioned by the first quarter of 2013.
Quality control
Underground mineral reserve and resource estimates, implementation and the quality control program were prepared and supervised by Sylvain Picard P. Eng., Principal Mine Geologist for Casa Berardi, and a 'qualified person' as defined by the National Instrument 43-101.
Mineral reserve and resource estimates for the Principal Mine and East Mine open pits were prepared by BBA Inc. The 'qualified person' for BBA Inc., as defined by National Instrument 43-101, is Patrice Live, Eng.
Information of a technical and scientific nature in the press release has been prepared under the supervision of Christian Bourcier, P. Eng., General Manager for Casa Berardi, and a 'qualified person' as defined by the National Instrument 43-101.
Additional Information
One sketch is attached showing the updated mineral reserve and resource outlines at the Casa Berardi Gold Mine. Two appendices attached to this release detail the technical parameters used for the mineral reserve estimates (Appendix A) and the mineral resource estimates (Appendix B). All other information previously released on Casa Berardi is also available on the Aurizon website at www.aurizon.com.
To view accompanying map, visit the following link: http://media3.marketwire.com/docs/Sketch_0227.pdf
About Aurizon
Aurizon is a gold producer with a growth strategy focused on developing its existing projects in the Abitibi region of north-western Quebec, one of the world's most favourable mining jurisdictions and prolific gold and base metal regions, and by increasing its asset base through accretive transactions. Aurizon shares trade on the Toronto Stock Exchange under the symbol 'ARZ' and on the NYSE Amex under the symbol 'AZK'. Additional information on Aurizon and its properties is available on Aurizon's website at http://www.aurizon.com.
FORWARD-LOOKING STATEMENTS AND INFORMATION
This news release contains 'forward-looking statements' and 'forward-looking information' within the meaning of applicable securities regulations in Canada and the United States (collectively, 'forward-looking information'). The forward-looking information contained in this news release is made as of the date of this news release. Except as required under applicable securities legislation, the Company does not intend, and does not assume any obligation, to update this forward-looking information. Forward-looking information includes, but is not limited to, statements with respect to mineral reserve and mineral resource estimates, the 2012 Casa Berardi mine plan and estimates of gold production, grade and long-term average gold prices, anticipated effect of completed drill results on the Casa Berardi project, planned work programs, completion of a scoping study, strategic plans, profitability, future upgrading of mineral resources, completion of deepening of the West Mine production shaft and expected outcomes. Often, but not always, forward-looking information can be identified by the use of words such as 'plans', 'expects, 'is expected', 'budget', 'scheduled', 'estimates', forecasts', 'intends', 'anticipates', or 'believes', or the negatives thereof or variations of such words and phrases or statements that certain actions, events or results 'may', 'could', 'would', 'might', or 'will' be taken, occur or be achieved.
The forward-looking information contained in this news release is based on certain assumptions that the Company believes are reasonable, including, with respect to mineral reserve and resource estimates, the key assumptions and parameters on which such estimates are based, as set out in the Appendices attached to this news release and the technical report for the property that the current price of and demand for gold will be sustained or will improve, the supply of gold will remain stable, that the general business and economic conditions will not change in a material adverse manner, that financing will be available if and when needed on reasonable terms and that the Company will not experience any material accident, labour dispute, or failure of plant or equipment.
However, forward-looking information involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any future results, performance or achievements expressed or implied by the forward-looking information. Such factors include, among others, conclusions of economic evaluations, the risk that actual results of exploration activities will be different than anticipated, that cost of labour, equipment or materials will increase more than expected, that the future price of gold will decline, that the Canadian dollar will strengthen against the U.S. dollar, that mineral resources and reserves are not as estimated, that actual costs or actual results of reclamation activities are greater than expected; that changes in project parameters as plans continue to be refined may result in increased costs, of unexpected variations in mineral resources and reserves, grade or recovery rates, of failure of plant, equipment or processes to operate as anticipated, of accidents, labour disputes and other risks generally associated with mining, unanticipated delays in obtaining governmental approvals or financing or in the completion of development or construction activities, as well as those factors and other risks more fully described in Aurizon's Annual Information Form filed with the securities commission of all of the provinces and territories of Canada and in Aurizon's Annual Report on Form 40-F filed with the United States Securities and Exchange Commission, which are available on Sedar at www.sedar.com and on Edgar at www.sec.gov/. Although the Company has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward-looking information, there may be other factors that cause actions, events or results to not be as anticipated, estimated or intended. There can be no assurance that forward-looking information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Readers are cautioned not to place undue reliance on forward-looking information due to the inherent uncertainty thereof.
CAUTIONARY NOTE TO US READERS
As a Canadian reporting issuer, the Company is subject to rules, policies and regulations issued by Canadian regulatory authorities and is required to provide detailed information regarding its properties including mineralization, drilling, sampling and analysis, security of samples and mineral resource and mineral reserve estimates. The Company is required to describe mineral reserves associated with its properties utilizing Canadian Institute of Mining, Metallurgy and Petroleum ('CIM') definitions of 'proven' or 'probable', which categories of reserves are recognized by Canadian regulations but differ from those definitions recognized by the United States Securities and Exchange Commission ('SEC'). Further, the Company is required to describe mineral resources associated with its properties utilizing CIM definitions of 'measured', 'indicated' or 'inferred', which categories of resources are recognized by Canadian regulations but are not recognized by the SEC.
The SEC allows mining companies, in their filings with the SEC to disclose only those mineral deposits they can economically and legally extract or produce. Accordingly, information contained in this News Release regarding our mineral deposits may not be comparable to similar information made public by U.S. companies subject to the reporting and disclosure requirements under the United States federal securities laws and the rules and regulations of the Commission thereunder.
In particular, this News Release uses the term 'measured' and 'indicated' resources. U.S. readers are cautioned that while that term is recognized and required by Canadian regulations, the SEC does not recognize it. U.S. investors are cautioned not to assume that any part or all of mineral deposits in this category will ever be converted into mineral reserves.
This News Release also uses the term 'inferred' resources. U.S. readers are cautioned that while this term is recognized and required by Canadian regulations, the SEC does not recognize it. 'Inferred resources' have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. 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, except in rare cases. U.S. investors are cautioned not to assume that part or all of an inferred resource exists, or is economically or legally mineable.
APPENDIX A
Technical Parameters - Mineral Reserve Estimate
The technical parameters for the mineral reserve estimate are as follows:
-- Mineral reserve estimations were based on 3D block models for all zones
except the South West Zone; the few remaining zones that were estimated
using 2D polygonal methods are not included in mineral reserves.
-- For the underground operation, the selected mining method is usually
Sequential Transversal and Longitudinal Long Hole when the vein is
larger than 10 metres and Longitudinal Long Hole Retreat when the vein
is less than 10 metres. The stoping sequence includes cemented rockfill
of the primary stoping sequence, cemented and unconsolidated rockfill
for the longitudinal retreat and unconsolidated rockfill for secondary
stoping sequence.
-- Stope dilution has been calculated from numerical modeling on the basis
of the stability of the stope openings, ore deposit geometry and mining
method. The amount of dilution was reduced for stopes of smaller
dimensions on the fringes of the zone, and increased for stopes with
unfavourable geometry. In addition, each stope was assigned a backfill
dilution percentage based on number of walls of fill and type of mucking
floor. Dilution quantities were estimated for each stope, including
hanging wall/footwall sloughage, and backfill dilution, where
applicable. As a result, the dilution averages 20.5%.
-- Extraction was estimated at 90% for primary stopes, and 95% for
secondary stopes.
-- A minimum cut off grade of 3.6 grams of gold per tonne was used based on
long term operating costs and gold prices for most of the underground
zones in the West Mine; except for zones 118 and 123S, where cut off
grades of 4.5 and 4.7 grams of gold per tonne, respectively, were
applied based on long term operating costs. For the East Mine crown
pillar and for Principal open pit, a minimum cut off grade of 1.2 and
0.5 grams of gold per tonne was respectively used based on long term
operating costs and gold prices.
-- Bulk density is different for each zone and is based on density
determinations. Bulk density varies from 2.70 tonnes per cubic metre
(e.g. Zone 113) to 2.90 tonnes per cubic metre (e.g. Principal Zones). A
bulk density of 2.77 tonnes per cubic metre was used for zones that have
no density determinations (e.g. East Mine) and is based on historical
data.
-- Mineral reserves are estimated using an average long-term gold price of
US$1250 per ounce and a US$/C$ exchange rate of 1:1.
-- Minimum underground mining widths of three metres were used.
-- West Mine mineral reserves are based on new information acquired from
the definition drilling completed in 2011. Information from the
definition drilling is being used to outline the precise ore stope
dimensions. Footwall drifts, which are set 20 metres apart vertically,
are being used as the collar locations of the current drill program.
-- East Mine open pit reserves are contained in the crown pillar left
behind by previous mining. Open pit optimization and detailed design
were updated in 2008. A dilution factor of 20% was applied to open pit
mineralization within the pit design, and above the 1.2 grams of gold
per tonne cut-off grade. It is anticipated that the East mine crown
pillar open pit will have a depth of 80 metres. The zone is covered by
18 metres of silt and clay overburden. Stripping ratio is estimated at
17:1.
-- The East Mine underground reserves are based on a plan to re-establish
access to old workings, and mine pillars and levels left behind during
previous operations. Stope sizes are not standardized. Mining methods
include longhole stoping where access can be attained for both top and
bottom cuts and cut and fill methods where only undercuts are
accessible.
-- Principal open pit reserves are contained in a 150 metre crown pillar.
Open pit optimization and detailed design were generated in 2010. A
dilution factor of 10% was applied to open pit mineralization within the
pit design, and above the 0.5 gram of gold per tonne cut-off grade. The
zone is covered by an average of 45 metres of silt and clay overburden.
Stripping ratio is estimated at 14.6:1.
Appendix B
Technical Parameters - Mineral Resource Estimate
The technical parameters for the mineral resource estimate are as follows:
-- Open pit mineral resources of Principal and East Mine were estimated by
BBA. Open pit mineral resources of 160 zone and underground mineral
resources of 160 and South West zones were reported in an internal
report by InnovExplo-Consulting Firm to Aurizon Mines. The remaining
underground mineral resources were estimated by Aurizon personnel.
-- Mineral resources are estimated using an average long-term gold price of
US$1,250 per ounce, and a US$/C$ exchange of 1:1.
-- Grade estimation was usually carried out from 3D block solids. Drill
holes as well as development samples were used for grade interpolation.
The small zone 104 was estimated previously by Aurizon, using 2D
polygonal on longitudinal sections and has been reviewed by Scott Wilson
RPA in 2010.
-- Different minimum cut off grades were used as follows:
-- 4.0 grams of gold per tonne was used based on long term operating
costs and gold prices for most of the underground zones in the West
Mine, for the underground Principal Zone and the underground East
Mine.
-- 3.0 grams of gold per tonne was used for small zone 104 previously
estimated by 2D polygons on longitudinal sections.
-- 1.3 grams of gold per tonne was used based on long term operating
costs and gold prices for most of the open pit crown pillar at the
East Mine.
-- 0.5 grams of gold per tonne was used based on long term operating
costs and gold prices for the crown pillar at the Principal Mine.
-- 0.3 grams of gold per tonne was used based on long term operating
costs and gold prices for the crown pillar at the 160 Zone.
-- A total of 38 mineralized zones have been modeled at the Principal Zone.
As the mineralized system extends close to surface bedrock and the
mineralized zones are close enough to each other to envisage open pit
mining, the zones were modeled by using 0.5 gram of gold per tonne
threshold. The current block size is 1.25 metres north-south by 2.5
metres east-west by 5.0 metres vertical. The host rock is of volcanic
and sedimentary origin.
-- Bulk density is different for each zone and is based on density
determinations. Bulk density varies from 2.70 tonne per cubic metre
(e.g. Zone 113) to 2.90 tonne per cubic metre (e.g. Principal Zones). A
bulk density of 2.77 tonne per cubic metre was used for zones that have
no density determinations (e.g. East Mine) and is based on historical
data.
-- Minimum underground mining widths of two to three metres.
U.S. Registration (File 001-31893)
News Release Issue No. 2 - 2012
Contacts:
Aurizon Mines Ltd.
George Paspalas
President & CEO
604-687-6600
Aurizon Mines Ltd.
Martin Bergeron
Vice President Operations
819-874-4511
Aurizon Mines Ltd.
Investor Relations
604-687-6600 or Toll Free: 1-800-411-GOLD (4653)
604-687-3932 (FAX)
jennifer.north@aurizon.com / info@aurizon.com
www.aurizon.com