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Press release from CNW Group

Alacer Gold announces 23% increase of Higginsville Mineral Reserve estimate to 875,000 ounces

Sunday, February 05, 2012

Alacer Gold announces 23% increase of Higginsville Mineral Reserve estimate to 875,000 ounces20:49 EST Sunday, February 05, 2012ENGLEWOOD, CO, Feb. 6, 2012 /CNW/ - Alacer Gold Corp. ("Alacer" or the "Company") [TSX:ASR, ASX:AQG] announces updated Mineral Resource and Reserve estimates for its Higginsville Gold Operations in Australia. The Mineral Reserve estimate has increased by 164,000 ounces (net of mining depletion over 18 months) to 7.9 million tonnes at 3.5g/t gold, containing 875,000 ounces, as detailed in the table below.Mineral Reserve for Higginsville Operations as at December 31, 2011 ProvenProbableTotal Reserves Tonnes(kt)Grade (g/t)Ounces (koz)Tonnes(kt)Grade (g/t)Ounces (koz)Tonnes (kt)Grade (g/t)Ounces (koz)Trident Underground5955.096       3,1084.5447       3,703 4.6543 Chalice Underground---       1,0494.3144        1,049 4.3144 Fairplay Underground---1396.429139 6.429 Open Pits---        2,7041.7151        2,704 1.7151 Stockpiles*2820.87- --            282 0.87 Total8773.7104       7,000 3.4771        7,877 3.5875 Note:  Rounding differences will occur. The Mineral Reserve methodology and cut-off grades are summarised in the Technical Procedural Section below.The above estimate is based on a gold price of US$1,350 per ounce (*Includes satellite and Trident low-grade stockpiles).Edward Dowling, President and CEO of Alacer, stated "This updated Higginsville Reserve is the culmination of extensive drilling and other work since July 2010. The net increase of 164,000 ounces is quite significant considering that the Higginsville Gold Operations produced more than 230,000 ounces of gold during the 18 months to December 2011.The increased reserves are largely due to down-plunge extensions of the Trident orebody. The Trident Reserve was about 500,000 ounces when mining started four years ago, more than 500,000 ounces have now been produced from Trident, and the Trident reserve remains more than 500,000 ounces.It is important to note that the Measured and Indicated Resources for Trident and Chalice total a combined 5.7Mt at 4.9g/t gold, containing 895,000 ounces.  Further drilling should progressively convert more resources to reserves as well as continuing to extend both resources.  These efforts take time, but we are excited about the likelihood of additional high-margin ores as demonstrated by the recent high-grade discovery at Corona within the Higginsville Line of Lode.An increasing proportion of Higginsville feed should be high-grade ore from underground mines following the ramp-up of Chalice ore production later this year. This will take Higginsville a long way towards the target of processing 1.5Mtpa at a head grade of 4.5g/t gold, thus producing approximately 200,000 ounces per annum."The primary components of the net Reserve increase of 164,000 ounces since the previous (July 2010) estimate are:Despite Trident being the predominant ore source for Higginsville, the Trident Underground Mineral Reserve increased by 47,000 ounces largely as a result of additional ounces in the Artemis and Helios Lodes, partially offset by mining depleting the Western Zone, Apollo and Athena Lodes.The Chalice Mineral Reserve increased by 26,000 ounces and reflects the identification of the new lodes in the footwall to the main Olympus Lode. The grade has decreased slightly due to additional drilling and conversion to reserves of resources up-dip of the Olympus Lode.The updated estimate includes a maiden Fairplay Underground Mineral Reserve of 29,000 ounces. This relatively high-grade reserve would potentially be accessed from the floor of the planned Fairplay Pit.Systematic evaluation of existing Mineral Resources has increased open-pit Mineral Reserves by a total of 79,000 ounces, predominantly from the Pluto, Musket, Mitchell and Vine deposits.The updated Mineral Reserve was estimated at a gold price of US$1,350 per ounce, compared with $1,200 per ounce for the July 2010 Mineral Reserve.The Higginsville Mineral Resource was previously stated at July 1, 2011. This previous estimate has been adjusted to reflect mining depletion totaling 61,302 ounces over the six months to December 31, 2011. The updated estimate is tabulated below.Mineral Resource for Higginsville Operations as at December 31, 2011 MeasuredIndicatedMeasured & IndicatedInferredAsset / ProjectTonnes(kt)Au Grade(g/t)Au Ozs(koz)Tonnes(kt)Au Grade(g/t)Au Ozs(koz)Tonnes(kt)Au Grade(g/t)Au Ozs(koz)Tonnes(kt)Au Grade(g/t)Au Ozs(koz)Trident1,2524.61873,1595.25254,4115.07116253.979Chalice---1,2504.61841,2504.61843364.448Fairplay Area---2,6691.91652,6691.91651452.110Palaeochannels---1,2032.1811,2032.1811211.87Lake Cowan---1,7731.6921,7731.692561.12Other1940.744342.6366282.0409231.750Total1,4454.119110,4893.21,08311,9343.31,2742,2052.8196Note:  Rounding differences will occur. Resource methodology and cut-off grades are summarised in the Technical Procedural Section below.Mineral Resources are quoted inclusive of Mineral Reserves.Further Mineral Resource and Reserve UpdatesAlacer intends to provide an updated Çöpler Mineral Resource estimate during Q1 2012.An updated Mineral Reserve estimate for the South Kalgoorlie Operations is expected to be announced following completion of underground mining feasibility studies for the Mt Marion West and HBJ deposits, and review by the Alacer Board of the South Kalgoorlie Expansion Project.Technical Procedural InformationThe information in this report which relates to Exploration Results and the Mineral Resources is based on information prepared by Chris Newman, a full-time employee of Alacer, who is a Member of the Australasian Institute of Mining and Metallurgy and a Member of the Australian Institute of Geoscientists. Mr Newman has sufficient experience which is relevant to the style of mineralization and type of deposit under consideration and to the activity which is being undertaking to qualify as a Competent Person as defined in the 2004 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves" and a qualified person pursuant to National Instrument 43-101 of the Canadian Securities Administrators. Mr Newman consents to the inclusion in the report of the matters based on this information in the form and context in which it appears.The information in this report which relates to Mineral Reserves is based on information prepared by Paul Thompson, a full-time employee of Alacer, who is a Fellow of the Australasian Institute of Mining and Metallurgy. Mr Thompson has sufficient experience which is relevant to the style of mineralization and type of deposit under consideration and to the activity which is being undertaking to qualify as a Competent Person as defined in the 2004 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves" and a qualified person pursuant to National Instrument 43-101 of the Canadian Securities Administrators. Mr Thompson consents to the inclusion in the report of the matters based on this information in the form and context in which it appears.Trident Resource Estimation MethodologyDrillhole data used in the Trident Resource comprised predominantly underground and surface diamond holes, with some RC and underground sludge holes used. All diamond drillhole collar locations were surveyed by contract mine surveyors. Drillholes were routinely surveyed downhole using techniques ranging from Eastman single shot and Reflex single shot cameras to gyroscopic downhole surveying equipment. Drillhole spacing for the majority of the Resource ranged from 10m x 15m to 60m x 60m.Drill core was logged (lithology, alteration, structure, mineralization, veining) in detail then stored and validated in electronic databases. Following logging, the drill core was sawn half core and submitted for assaying. Dependant on the orebody geometry and size, sample lengths were constrained by geology, alteration or structural boundaries with lengths varying between 0.5m to 1.1m.Gold analysis of the samples was undertaken using a combination of 1kg LeachWell, 500g Pulverise and Leach (PAL) and 50g Fire Assay. Industry standard reference material and blanks were utilised to check on laboratory assay quality control.Assays were composited to 1 metre lengths and assessed for appropriate top-cuts. The Athena domains were assigned various top-cuts (Athena 10 & 40 - 250g/t gold; Athena 30 - 350g/t gold and Athena 50 - 90g/t gold); the Artemis domains were assigned a top-cut of 100g/t gold; Apollo, Western Zone, Eos, E-Veins, Poseidon and Eastern Zone domains were assigned a top-cut of 50g/t gold; and Helios domains were assigned a top-cut of 25g/t gold.  All top-cuts were based on composited drillhole data.A bulk density of 2.89g/cm3 was applied to all domains hosted within gabbro and mafic assemblages and the waste rock, based on a total of 453 samples taken throughout the deposit.  The laminated quartz lodes (Athena 10, 30 and 50) had a 2.7g/cm3 bulk density applied to these domains.The grade estimation methods included ID2 (Western Zone, Eastern Zone, Eos, E-Veins, Poseidon and Athena 40), ID0 (Athena 10, 30 and 50), assigned grades based on development mapping and sampling (Athena 10, 30 and 50) and Ordinary Kriging (Apollo). Parent block sizes were set at 10m *, 10m (y) and 10m (z), with the minimum sub-cell size dependant on the lode thickness.A lower cut-off grade of 1.0g/t gold was applied to the thicker orebodies (Western Zone, Apollo, Athena 40, Helios) whereas a 2.0g/t gold lower cut-off grade was applied to the thinner Athena, Eos and E Veins, Eastern Zone, Poseidon and Artemis orebodies to reflect historical stope-mining methodologies.The Resource estimate has been classified based on data density, data quality, confidence in the geological interpretation and confidence in the estimation.Chalice Resource Estimation MethodologyDrillhole data used in the Chalice Resource comprised predominantly surface and minor underground diamond holes.  All of Alacer's diamond drillhole collar locations were surveyed by contract mine surveyors using a RTK GPS.  Where identified, historical drillhole collar locations were surveyed using a RTK GPS, with no reliable records available for the collar survey methods for the historical holes.  Alacer drillholes were routinely surveyed downhole using gyroscopic surveying equipment.  No reliable data exist for the downhole surveying technique utilised for the historic drillholes.  Drillhole spacing for the majority of the Resource ranges from 20m x 20m to 40m x 40m.Drill core was logged (lithology, alteration, structure, mineralization, veining) in detail then stored and validated in electronic databases. Following logging, the drill core was sawn to half core and submitted for assaying.  The sample lengths were constrained by geology, alteration or structural boundaries with lengths varying from 0.4m to 1.0m.Gold analysis of the samples was undertaken using a combination of predominantly Fire Assay (20 - 50g charges), Aqua Regia and 1kg LeachWell. Industry standard reference material and blanks were utilised to check on laboratory assay quality control, although no reliable QA/QC data was located for the sampling completed prior to Alacer.Assays were composited to 1 metre lengths and assessed for appropriate top-cuts. The Atlas domain was assigned a top-cut of 25g/t gold; the Olympus domains were assigned a top-cut of 60g/t Gold; with the Olympus Hangingwall and Footwall domains assigned various top-cuts if there were extreme values present in the dataset.  All top-cuts were based on composited drill-hole data.A bulk density of 3.03g/cm3 was applied to the Olympus domains; 3.03g/cm3 to the Atlas domain; 3.02g/cm3 to the un-mineralized amphibolites; and 2.61g/cm3 to the felsic units, based on 69 samples through the various domains/lithologies at Chalice. The grade estimation method used was ID2 for all the mineralized domains. Parent block sizes were set at 10m *, 10m (y) and 10m (z), with the minimum sub-cell size set at 1.5m *, 2.5m (y) and 2.5m (z).A lower cut-off grade of 2.0g/t gold was applied to the main domains (Atlas and Olympus) whereas a 3.0 g/t gold lower cut-off grade was applied to the thinner hangingwall and footwall domains to reflect likely mining and haulage scenarios.The Resource estimate has been classified based on data density, data quality, confidence in the geological interpretation and confidence in the estimation.Other Higginsville Resources Estimation MethodologyDrillhole data used in the Vine, Fairplay and Lake Cowan Resources comprised predominantly surface RC and minor surface diamond holes.  All of Alacer's drillhole collar locations were surveyed by contract mine surveyors using either a differential or RTK GPS.  There are no reliable records available for the collar survey methods for the historical holes.  Alacer drillholes were routinely surveyed downhole via an Eastman Single Shot survey camera at 30m intervals.  No reliable data exist for the down-hole surveying technique utilised for the historic drillholes.  Drillhole spacing for the majority of these Resources vary between 10m x 10m and 40m x 40m.For the RC holes, logging of lithology, alteration, mineralization and veining was undertaken on 1 metre composited RC samples.  The diamond drill core was logged in detail for lithology, structure, alteration, mineralization and veining.  All logs have been stored and validated in electronic databases.RC samples were collected as 1 metre composites via an on-rig cyclone and splitter assembly and then submitted for assaying.  After logging, the drill core was sawn half core and submitted for assaying, with the sample lengths constrained by geology, alteration or structural boundaries with lengths varying from 0.4m to 1.0m.Gold analysis of the samples was undertaken using a combination of 500g Pulverise and Leach (PAL), Fire Assay (20 - 50g charges), Aqua Regia and 1kg LeachWell. Industry standard reference material and blanks were utilised to check on laboratory assay quality control, although no reliable QA/QC data was located for the sampling completed prior to Alacer.Assays were composited to 1 metre lengths and assessed for appropriate top-cuts.  For Vine, the 550 domain was assigned a top-cut of 250g/t gold with a top-cut of 20g/t gold assigned to the samples in the 650 domain.  For the Fairplay region, a top-cut of 40g/t gold was assigned to the main Fairplay domains, 25g/t gold for the Fairplay East domains and 60g/t gold for the Fairplay North domains.  For the three deposits at Lake Cowan (Josephine, Napolean and Louis) a top-cut of 15g/t gold was applied.  All top-cuts were based on composited drillhole data.As a significant proportion of these deposits are situated near the surface, various bulk densities were applied based on the degree of weathering and the host rock type.  For the lodes contained within completely weathered material, a bulk density of 1.6g/cm3 was applied, for the transitional saprock zone a bulk density of 2.2g/cm3 was applied and for fresh rock a bulk density of 2.85g/cm3 was applied.  A bulk density of 2.7g/cm3 was applied to the quartz-rich domains at Vine.  Bulk density testwork at Vine and Fairplay confirmed the validity of these bulk densities for the various zones in the weathering profile as well as the fresh rock.The grade estimation method varied between the three deposits depending on the drill density and style of mineralization.  At Vine, a rolling average (ID) method was adopted for the nuggetty gold distribution of the 550 lode, with an ID2 method utilised for the remaining Vine mineralized domains.  At Fairplay an ID2 interpolation method was used for all the domains.  The Lake Cowan resource estimate utilised a mixture of ID2 and Ordinary Kriging for the various lodes.  Parent block sizes were set at 10m *, 10m (y) and 10m (z) for all the resources at Fairplay and Lake Cowan, with the minimum sub-cell size set at 1.0m *, 1.0m (y) and 0.5m (z).  For Vine the parent block sizes were set at 5m *, 5m (y) and 5m (z), with the minimum sub-cell size set at 1.0m *, 1.0m (y) and 1.0m (z).A lower cut-off grade of 0.8g/t gold was applied to the domains at Lake Cowan whereas a 0.5g/t gold lower cut-off grade was applied to the Vine and Fairplay resources to reflect likely mining, haulage and processing scenarios.The Resource estimate has been classified based on data density, data quality, confidence in the geological interpretation and confidence in the estimation.Underground and Open Pit Reserve EstimationMining parameters - All underground reserve physicals were compiled from first principle applications - with stope shapes constructed from manually digitised 2.5m vertical increments. All stope shapes represent "Drill and Blast ready" profiles and have been depleted of development physicals. Generic hangingwall and footwall offsets have been used for each mining area in addition to dilution parameters associated with nearby fault domains, development intersections and adjacent ground conditions. Open pits have been initially frame-worked from Whittle shells, with subsequent refinement to produce open pit designs. All open pits have specific design parameters to account for localised conditions as well as oxide / fresh rock material.Geotechnical parameters - Geotechnical analysis and review has been completed for each mining area to determine the appropriate stable underground mining spans and pit wall angles based on rock type, rock mass conditions and mining sequence / methodology.  Experience from mining the Trident orebody and from several existing open pits was used to validate design parameters, whereby appropriate geotechnical data comprised of back analysis of existing underground and open pits, geotechnical mapping and geotechnical drilling.  Additionally, new Reserve mining areas are geotechnically assessed based upon available diamond core and insitu stress measurements enabling the calculation of theoretical stable spans. This work is undertaken with the guidance of Higginsville's external consultant with key findings and recommendations documented.Metallurgical parameters - Trident and several open pits in the current reserve have been mined and processed in recent history.  Assumed processing recoveries were 97% for Trident, 94% for Chalice and an average of 89% for other open pit and underground reserves.  Metallurgical testwork was completed where no existing plant performance information was available.Economic Parameters - In order to define the profitability of the assets appropriate commodity parameters were applied.  In the case of underground parameters separate cut-off grades were calculated for each mining method per orebody type in order for the analysis to account for variations in costings. Where appropriate historical costs were applied. A single cut-off was used for pit optimisation. Additional private royalties where applied where appropriate. A gold price of $1,350/oz was used to optimize these projects. Due to the short-term schedule of the Vine Open Pit, a spot price of $1,700/oz was utilised.Mining Costs - The mining costs were derived from either current mining operations or, where contracts were not existing, from current industry standards / quotes gathered from a number of external sources. For the underground reserves, a majority of the costings were determined from the existing mining contractor's schedule of rates (Australian Contract Mining - ACM). Open pit costs were gathered from current operations as well as indicative benchmark rates from Alacer's South Kalgoorlie Operation.Processing Costs - Processing costs for reserves were based on processing costs from the existing Higginsville gold plant at a processing rate of 1.35 Mtpa.Capital Costs - Capital costs are largely associated with pre-stripping for open pits and for development and infrastructure for the underground mines. All capital costs were accounted for in the mine specific NPV calculations as well as the macro Higginsville calculations. Capital costings were derived from either existing Higginsville contracts and / or external quotes.Current Mineral Reserve figures are stated as at December 31, 2011 with depletion by production where relevant. A comparison with the previous reserve is tabulated below.Table 2: Higginsville - Mineral Reserves Comparison Previous*As at December 31, 2011ChangeAsset / ProjectTonnes(kt)Au Grade(g/t)Contained AuOunces(koz)Tonnes(kt)Au Grade(g/t)Contained Au Ounces(koz)Tonnes(kt)Au Grade(g/t)Contained Au Ounces(koz)Trident Underground3,2194.84963,7034.6543484(0.2)47Chalice Underground7275.11181,0494.3144322(0.8)26Fairplay Underground---1396.4291396.429Open Pits1,2262.0782,7041.71511,478(0.3)73Stockpiles5051.2192820.87(223)(0.4)(12)Total5,6773.97117,8773.58752,200(0.4)164* The previous Mineral Reserve is at 1 July 2010 and is detailed in NI 43-101 Technical Report of the Mining Operations and Exploration Tenements of Avoca Resources Limited, Western Australia completed by SRK Consulting and dated 15 December 2010.There are no known environmental, permitting, legal, taxation, political or other relevant issues that would materially affect the estimates of the Mineral Reserves.Due to rounding of figures small discrepancies may exist.All resource numbers quoted in this release are reported inclusive of reserves. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.Cautionary StatementsCertain statements contained in this report constitute forward-looking information, future oriented financial information, or financial outlooks (collectively "forward-looking information") within the meaning of Canadian securities laws. Forward-looking information may relate to this report and other matters identified in Alacer's public filings, Alacer's future outlook and anticipated events or results and, in some cases, can be identified by terminology such as "may", "will", "could", "should", "expect", "plan", "anticipate", "believe", "intend", "estimate", "projects", "predict", "potential", "continue" or other similar expressions concerning matters that are not historical facts and include, but are not limited in any manner to, those with respect to proposed exploration, communications with local stakeholders and community relations, status of negotiations of joint ventures, commodity prices, mineral resources, mineral reserves, realization of mineral reserves, existence or realization of mineral resource estimates, the timing and amount of future production, timing of studies and analysis, the timing of construction of the proposed mines and process facilities, capital and operating expenditures, economic conditions, availability of sufficient financing, exploration plans and any and all other timing, exploration, development, operational, financial, economic, legal, social, regulatory and political factors that may influence future events or conditions. Such forward-looking statements are based on a number of material factors and assumptions, including, but not limited in any manner, those disclosed in any other Alacer filings, and include exploration results and the ability to explore, the ultimate determination of mineral reserves, availability and final receipt of required approvals, titles, licenses and permits, sufficient working capital to develop and operate the mines, access to adequate services and supplies, commodity prices, ability to meet production targets, foreign currency exchange rates, interest rates, access to capital markets and associated cost of funds, availability of a qualified work force, ability to negotiate, finalize and execute relevant agreements, lack of social opposition to the mines, lack of legal challenges with respect to the property or the Company and the ultimate ability to mine, process and sell mineral products on economically favorable terms. While we consider these assumptions to be reasonable based on information currently available to us, they may prove to be incorrect. Actual results may vary from such forward-looking information for a variety of reasons, including but not limited to risks and uncertainties disclosed in other Alacer filings at www.sedar.com and other unforeseen events or circumstances. Other than as required by law, Alacer does not intend, and undertakes no obligation to update any forward-looking information to reflect, among other things, new information or future events.For further information: Edward Dowling or Lisa Maestas - North America at +1-303-292-1299 Roger Howe - Australia at +61-405-419-139