Let's keep this front and centre today - Shaft Creek Resource Estimate Update
posted on
May 31, 2012 12:20PM
CUU own 25% Schaft Creek: proven/probable min. reserves/940.8m tonnes = 0.27% copper, 0.19 g/t gold, 0.018% moly and 1.72 g/t silver containing: 5.6b lbs copper, 5.8m ounces gold, 363.5m lbs moly and 51.7m ounces silver; (Recoverable CuEq 0.46%)
CONTAINING A MEASURED AND INDICATED RESOURCE OF 7.1 BILLION POUNDS COPPER, 455.3 MILLION POUNDS MOLYBDENUM, 7.3 MILLION OUNCES GOLD AND 66.7 MILLION OUNCES OF SILVER
AND
AN INFERRED RESOURCE OF 2.9 BILLION POUNDS OF COPPER, 206.2 MILLION POUNDS OF MOLYBDENUM, 3.3 MILLION OUNCES OF GOLD AND 31.6 MILLION OUNCES OF SILVER
VANCOUVER, May 31, 2012 /CNW/ - ("Copper Fox" or the "Company") (TSX-V: CUU) is pleased to provide its shareholders with the results of the recently completed National Instrument 43-101 ("NI 43-101") resource estimate for the Schaft Creek copper-gold-molybdenum-silver deposit located in northwest British Columbia, Canada. The resource estimate was prepared by Tetra Tech Wardrop ("Tetra Tech") and the NI 43-101 report disclosing the resource will be filed on SEDAR within 45 days. Highlights of the resource estimate for the Schaft Creek deposit using a 0.15% copper equivalent cut-off (Base Case) are as follows:
Highlights:
a) | The Measured Resource is comprised of 146.6 million tonnes grading 0.31% copper, 0.017% molybdenum, 0.24g/t gold and 1.78g/t silver (containing 1.0 billion pounds copper, 55.6 million pounds molybdenum, 1.15 million ounces gold and 8.40 million ounces silver; | |||
b) | The Indicated Resource is comprised of 1.08 billion tonnes grading 0.26% copper, 0.017% molybdenum, 0.18g/t gold and 1.68g/t silver containing 6.1 billion pounds copper, 399.7 million pounds molybdenum, 6.22 million ounces gold and 58.34 million ounces silver; | |||
c) | The combined Measured and Indicated Resource is comprised of 1.23 billion tonnes grading 0.26% copper, 0.017% molybdenum, 0.19g/t gold and 1.69g/t silver containing 7.11 billion pounds copper, 455.3 million pounds molybdenum, 7.37 million ounces gold and 66.74 million ounces silver; | |||
d) | The Inferred Resource is comprised of 597.2 million tonnes grading 0.22% copper, 0.016% molybdenum, 0.17g/t gold and 1.65g/t silver containing 2.87 billion pounds copper, 206.3 million pounds molybdenum, 3.36 million ounces gold and 31.60 million ounces silver, and; | |||
e) | The resource estimate includes the silver content of the mineralization in both the Paramount and Liard zones. |
Elmer B. Stewart, President and CEO of Copper Fox stated, "The Measured and Inferred Resource categories, the total copper-molybdenum-gold-silver content and the fact that the deposit is still open in several directions (along strike) indicates a new dimension to the potential size of the Schaft Creek deposit. Additional drilling will have to be completed to realize this potential and define the un-explored portions of the Schaft Creek deposit. It is noteworthy that the current Measured and Indicated Resource exceeds 1.2 billion tonnes and incorporates the silver content which is expected to have a positive impact on the economics of the Schaft Creek deposit. The important criteria in selecting a cut-off grade in a resource estimate is the average grade of the metals, tonnes and contained metal content. The resource estimate shows substantial increases in both tonnes and copper-molybdenum-gold-silver content at both the 0.15% and 0.20% CuEq levels of cut-off. Given the very minimal decrease in average grade for each metal, we have been able to select a 0.15% CuEq cut-off. The Base Case results will be used to complete the Feasibility Study for the Schaft Creek project which is expected to be completed by mid to late summer 2012."
The significant increase in resources being reported is due in part to exploration results achieved in 2011 along with the variation in methodology used between the 2011 and 2012 resource estimates. The updated resource estimate prepared by Tetra Tech reports an insitu estimate of the mineral resource categories for the Schaft Creek deposit. The resource estimate prepared in 2011 was completed using an optimized pit shell using various economic parameters (see News Release dated July 11, 2011). As part of its work in completing the 2012 Feasibility Study, Tetra Tech is preparing a new optimized pit shell design based on current economic parameters that it will specify.
Base Case
Copper Fox has selected the 0.15% copper equivalent ("Cu Eq.") cut-off for its base case resource estimate (see Table-1). A 0.15% Cu Eq. cut-off was the minimum grade of copper equivalent estimated by Tetra Tech required (using the estimated copper recovery rate, the milling and sales cost) to break-even on an operating cost per tonne basis.
Resource Estimate
The effective date of the mineral resource estimate is May 23rd, 2012. Mineral resources were estimated for the Liard (also referred to as the Main) zone and the Paramount (previously referred to as the Paramount-Breccia) zone separately. The mineral resources were estimated using criteria consistent with the CIM Definition Standards (2010) and in conformity with CIM "Estimation of Mineral Resources and Mineral Reserves Best Practice" (2003) guidelines. The estimated mineral resources using a 0.15% Cu Eq. cut-off grade are categorized and tabulated in Table-1. The Base Case numbers presented in the following tables have been rounded to reflect "Best Practice Principals" as established by the CIM.
Table-1: Mineral Resource Estimate - Schaft Creek Deposit
Robert Morrison - Ph.D., MAusIMM (CP), P.Geo., Effective Date: May 23rd, 2012
Resource | Cut-off | Copper | Molybdenum | Gold | Silver | Contained Metal | ||||
Category | CuEq (%) | Tonnes | (%) | (%) | (g/t) | (g/t) | Cu (Lbs) | Mo (Lbs) | Au (ozs) | Ag ( ozs) |
Measured | 0.15 | 146,615,300 | 0.31 | 0.017 | 0.24 | 1.78 | 1,001,824,600 | 55,624,000 | 1,149,100 | 8,402,700 |
Indicated | 0.15 | 1,081,939,500 | 0.26 | 0.017 | 0.18 | 1.68 | 6,104,400,000 | 399,718,500 | 6,218,000 | 58,335,500 |
Measured & Indicated | 0.15 | 1,228,554,800 | 0.26 | 0.017 | 0.19 | 1.69 | 7,106,224,600 | 455,342,500 | 7,368,000 | 66,738,200 |
Inferred | 0.15 | 597,191,300 | 0.22 | 0.016 | 0.17 | 1.65 | 2,872,034,300 | 206,252,100 | 3,359,600 | 31,601,400 |
Cautionary Note to Investors:
While the terms "measured (mineral) resource", "indicated (mineral) resource" and "inferred (mineral) resource" are recognized and required by National Instrument 43-101 - Standards of Disclosure for Mineral Projects, investors are cautioned that except for that portion of mineral resources classified as mineral reserves, mineral resources do not have demonstrated economic viability. Investors are cautioned not to assume that all or any part of measured or indicated mineral resources will ever be upgraded into mineral reserves. Additionally, investors are cautioned that inferred mineral resources have a high degree of uncertainty as to their existence, as to whether they can be economically or legally mined, or will ever be upgraded to a higher category.
Resource Estimation Methodology
The Schaft Creek model used for this resource estimate was constructed using DatamineTM software (Version 3.20.6420.0). Blocks (parent cells) measuring 15 m by 15 m by 15 m were used in completing the resource estimation. All easting, northing and elevation are based on UTM coordinate system (Zone 9).
X Origin | Y Origin | Z Origin | XINC | YINC | ZINC | Number X |
Number Y |
Number Z |
378400 mE | 6357700 mN | 0.00 mRL | 15m | 15m | 15m | 200 | 267 | 120 |
The total block model encompassed a volume of 3,000 m (east-west) by 4,005 m (north - south) by 1,800 m (elevation). A series of closed wireframes and wireframe surfaces (DTM's) were used to define the Schaft Creek resource.
Drill holes
A total of 286 drill holes with 16,501 composited (4 m) drill hole intervals (approximately 65,843 metres) were used by Tetra Tech in estimating the mineral resources for the Schaft Creek deposit.
Grade Capping and Compositing
Statistical analyses of the drill hole assay data indicated that capping was required to manage the outliers in the sample population. Silver was capped at 18 g/t, gold was capped at 2 g/t, copper was capped at 1.8% and molybdenum was capped at 0.25%. Density measurements recorded spurious SG results above 3.8 and below 1.5. These outlier density values were assigned an absent value prior to estimation, while metal values that exceeded the cap were re-assigned the cap value. The drill holes were subsequently composited to 4 m lengths. This length was chosen as it slightly exceeded all the major individual sample lengths.
Estimation Domains
Two broad estimation domains, the Liard zone and the Paramount zone, were modeled and estimated independently of each other. To complete Ordinary Kriging (OK), variography was completed for all estimated metals in the Liard zone and Paramount zone separately. Variogram orientations were used as the sample search orientation. Sample search ranges coincided with maximum variogram ranges such that pass 1 used the radii of the maximum variogram ranges, pass 2 used twice the radii and pass 3 uses three times the radii.
To estimate the metal content, the maximum number of samples allowed was 24. Only 3 samples were allowed from the same drill hole. The minimum number of samples used was 20 for the first pass, 16 for the second pass and 12 for the third pass. For estimating density, the minimum number of samples used was 12 for the first pass, 9 for the second pass and 6 for the third pass. Density estimation for the blocks was completed using Inverse Distance Squared (ID2) and thus variography was not required. Where density could not be estimated successfully, it was assigned the average value of 2.69 for fresh rock. The density of the waste rock was not estimated and was assigned a value of 2.69. The density of the overburden was not estimated and assigned a value of 2.
A separate model was completed for comparative purposes using Inverse Distance Squared (ID2) and Nearest Neighbor (NN) estimates. The Nearest Neighbour method was used for density, while both ID2 and NN were used to compare the reported OK results. Theses parallel estimates confirmed and supported the original resource estimates.
The procedures used for the purposes of the resource estimate (at a 0.15% Cu Eq. cut-off) are:
a) | Sample assays were composited to 4 m metre intervals for grade interpolation. | |||
b) | Copper equivalent grade shell wireframes, using a 0.25% cut-off, were generated to confine the extrapolation of grade in the Tetra Tech model. The Liard zone wireframe measures approximately 1.0 km (east-west) by 1.5 km (north-south) by 0.6 km (elevation) for a total contained volume of approximately 430,984,600 cubic metres. The Paramount zone wireframe measures approximately 0.4 km (east-west) by 1.3 km (north-south) by 0.6 km (elevation) for a total contained volume of approximately 276,177,700 cubic metres. No metal grade values were assigned (e.g. average grade, correlation coefficient, etc.) if any assays were missing. |
Resource Statement
The sensitivity of the mineral resource in the Schaft Creek deposit (includes the Liard and Paramount zones) to either a reduction or increase in copper equivalent cut-off is shown in Table-2. The base case mineral resource above a 0.20% Cu Eq. cut-off is reported separately within the Paramount zone (in Table-3) and within the Liard zone (in Table-4).
Block Model Validation
Comparisons of different estimation techniques (Ordinary Kriging, Inverse Distance Squared, and Nearest Neighbor) show similar statistics and thus help validate the resource model. In comparison with drill holes, block model mean grades are slightly less, reflecting positive skewness of the estimation dataset, whereas the negative skewness in the density data corresponds to slightly higher mean densities for the block model.
Copper Equivalent
Copper grade as a combined function of copper, molybdenum, gold, and silver was calculated within each of the estimated blocks. The calculation of the copper equivalent is based on Tetra Tech long-range metal prices.
Cu1 = (cu_ok*2.97*22.0462) where Cu metal = $US 2.97 per pound | |||||
Cu2 = (mo_ok*0.609*16.80*22.0462) where Mo metal = $US 16.80 per pound | |||||
Cu3 = (au_ok*0.706/31.1035*1256.00) where Au metal = $US 1,256.00 per ounce | |||||
Cu4 = (ag_ok*0.434/31.1035*20.38) where Ag metal = $US 20.38 per ounce | |||||
Cu5 = Cu1 + Cu2 + Cu3 + Cu4 | |||||
cu_eq = (Cu5/2.97/22.0462) |
Resource Classification
As part of the resource estimate, the LaGrange Multiplier (LG) and the F-Function (F) were estimated into each block (cell) using the same estimation parameters as copper. These two functions were used to calculate out Kriging Efficiency (KE - up to 100%) and the Theoretical Slope of Regression (ZZ - 0 to 1). Both KE and ZZ are used to evaluate the quality or confidence of the Ordinary Kriged estimation where:
BV = 1-F [where BV = block variance] | |||||
KE = (BV-KV)/BV*100 [where KV = kriging variance] | |||||
ZZ = (BV-KV+abs(LG))/(BV-KV+2*abs(LG)) |
The resource classification was assigned to each cell as a function of the cell's ZZ. If the ZZ was greater than 0.95, the cell was classified as Measured. If the ZZ was between 0.25 and 0.95, the cell was classified as Indicated. If the ZZ was below 0.25, the cell was classified as Inferred.
This method takes into consideration sample support, drill density and variography in assigning resource classification. This method is applied to each block (cell). The method may fail to provide a single contiguous volume of Measured, Indicated and Inferred resources as would be expected using a solid wireframe. However, the 0.95 cut-off reflects a reasonably continuous Measured resource, and the 0.25 cut-off agrees with the volume of Indicated resource.
Table-2: Sensitivity of Mineral Resource to Cut-Off Grade
Robert Morrison - Ph.D., MAusIMM (CP), P.Geo. Effective Date May 23rd, 2012:
Resource | Cut-off | Copper | Molybdenum | Gold | Silver | Cu Eq | ||
Category | CuEq (%) | Tonnes | (%) | (%) | (g/t) | (g/t) | (%) | |
Measured | 0.10 | 147,635,596 | 0.308 | 0.017 | 0.243 | 1.779 | 0.481 | |
Base Case | 0.15 | 146,615,287 | 0.310 | 0.017 | 0.244 | 1.783 | 0.483 | |
0.20 | 143,941,114 | 0.314 | 0.017 | 0.246 | 1.793 | 0.489 | ||
0.25 | 137,927,871 | 0.321 | 0.018 | 0.252 | 1.813 | 0.500 | ||
0.30 | 126,829,423 | 0.334 | 0.019 | 0.260 | 1.852 | 0.520 | ||
0.35 | 110,534,082 | 0.353 | 0.020 | 0.272 | 1.906 | 0.548 | ||
Indicated | 0.10 | 1,102,969,036 | 0.252 | 0.017 | 0.177 | 1.669 | 0.394 | |
Base Case | 0.15 | 1,081,939,528 | 0.256 | 0.017 | 0.179 | 1.677 | 0.399 | |
0.20 | 1,021,909,252 | 0.265 | 0.017 | 0.182 | 1.694 | 0.412 | ||
0.25 | 915,477,325 | 0.279 | 0.019 | 0.190 | 1.730 | 0.433 | ||
0.30 | 770,430,025 | 0.298 | 0.020 | 0.203 | 1.794 | 0.463 | ||
0.35 | 612,662,375 | 0.320 | 0.022 | 0.219 | 1.880 | 0.498 | ||
Inferred | 0.10 | 616,607,156 | 0.213 | 0.015 | 0.174 | 1.634 | 0.349 | |
Base Case | 0.15 | 597,191,283 | 0.218 | 0.016 | 0.175 | 1.646 | 0.356 | |
0.20 | 538,065,824 | 0.232 | 0.017 | 0.179 | 1.665 | 0.375 | ||
0.25 | 450,670,341 | 0.251 | 0.019 | 0.188 | 1.713 | 0.404 | ||
0.30 | 355,826,449 | 0.272 | 0.021 | 0.203 | 1.795 | 0.439 | ||
0.35 | 264,462,368 | 0.295 | 0.023 | 0.223 | 1.899 | 0.478 |
Table-3: Mineral Resource Reported within the Paramount zone (at 0.15% Cu Eq. cut-off)
Resource | Cut-off | Copper | Molybdenum | Gold | Silver | Cu Eq | Contained Metal | ||||
Category | CuEq (%) | Tonnes | (%) | (%) | (g/t) | (g/t) | (%) | Cu (Lbs) | Mo (Lbs) | Au (ozs) | Ag (ozs) |
Measured | 0.20 | 20,594,900 | 0.31 | 0.022 | 0.20 | 1.92 | 0.49 | 142,180,100 | 10,088,200 | 130,400 | 1,274,000 |
Indicated | 0.20 | 467,372,400 | 0.28 | 0.021 | 0.18 | 1.80 | 0.39 | 2,851,836,100 | 217,815,100 | 2,585,600 | 27,080,800 |
Measured & Indicated | 0.20 | 487,967,300 | 0.28 | 0.022 | 0.17 | 1.81 | 0.41 | 2,994,016,200 | 227,903,300 | 2,716,000 | 28,354,800 |
Inferred | 0.20 | 237,715,000 | 0.28 | 0.022 | 0.21 | 1.88 | 0.31 | 1,489,381,100 | 118,552,000 | 1,576,300 | 14,452,300 |
Table-4: Mineral Resource Reported within the Liard zone (Main) at 0.15% Cu Eq. cut-off
Resource | Cut-off | Copper | Molybdenum | Gold | Silver | Cu Eq | Contained Metal | ||||
Category | CuEq (%) | Tonnes | (%) | (%) | (g/t) | (g/t) | (%) | Cu (Lbs) | Mo (Lbs) | Au (ozs) | Ag ( ozs) |
Measured | 0.15 | 126,020,300 | 0.31 | 0.016 | 0.25 | 1.77 | 0.48 | 859,644,500 | 45,535,800 | 1,019,600 | 7,128,700 |
Indicated | 0.15 | 614,567,200 | 0.24 | 0.013 | 0.19 | 1.59 | 0.37 | 3,252,563,900 | 181,903,400 | 3,632,400 | 31,254,700 |
Measured & Indicated | 0.15 | 740,587,500 | 0.25 | 0.014 | 0.20 | 1.61 | 0.41 | 4,112,208,400 | 227,439,200 | 4,652,000 | 38,383,400 |
Inferred | 0.15 | 357,461,100 | 0.18 | 0.011 | 0.16 | 1.49 | 0.31 | 1,382,653,200 | 87,700,100 | 1,783,300 | 17,149,100 |
About Copper Fox
Copper Fox is a Canadian-based resource development company listed on the TSX Venture Exchange (TSX-V:CUU) with a corporate office in Calgary and an operations office in Vancouver and is involved in the exploration and development of the Schaft Creek copper-gold-molybdenum-silver deposit located in northwest British Columbia, Canada.
The Company is working on completing a feasibility study on the Schaft Creek mineral deposit, one of the largest undeveloped copper, gold, molybdenum and silver deposits in North America. The feasibility study is being led by Tetra Tech Wardrop on a minimum 120,000 tpd open pit mine and is expected to be completed mid-late summer, 2012.
Copper Fox holds title and a 100% working interest in the Schaft Creek project consisting of 44,265.52 hectares (109,382 acres). Included in this total are the "Schedule A" mineral tenures originally conveyed to Copper Fox pursuant to the option agreement dated January 1, 2002 between Teck Resources Limited ("Teck") and Copper Fox (the "Teck Option Agreement"), which consist of 8,334.34 hectares (20,594 acres). The "Schedule A" mineral tenures are subject to a 3.5% Net Profits Interest held by Royal Gold, Inc., a 30% carried Net Proceeds Interest held by Liard Copper Mines Limited ("Liard") and, together with the additional mineral tenures obtained by Copper Fox within the "Area of Interest" provided for in the Teck Option Agreement, an earn back option held by Teck. On completion of the feasibility study, Copper Fox will earn Teck's 78% interest in Liard. Teck's earn back option to acquire either, 20%, 40% or 75%, of Copper Fox's interest in the Schaft Creek property is triggered upon delivery of a positive feasibility study to Teck. Should Teck elect to exercise its option for 75%, Teck is required to fund subsequent property expenditures up to a total of 400% of those incurred by Copper Fox ($75.9 million to January 31, 2012) and arrange for project financing, including the Copper Fox portion. For full details of the Teck earn back option please refer to the Company's website www.copperfoxmetals.com.
The remainder of Copper Fox's registered interests in mineral tenures in British Columbia total 35,931.18 hectares (88,788 acres). These interests have been acquired by Copper Fox through mineral tenure acquisitions and mineral tenure purchase agreements subsequent to Copper Fox entering into the Teck Option Agreement. Certain portions of these registered mineral tenures are subject to inclusion within the Schaft Creek project pursuant to the terms of the "Area of Interest" provisions of the Teck Option Agreement.
Robert Morrison - Ph.D., MAusIMM (CP),P. Geo., of TETRA TECH is the Qualified Person who prepared the mineral resource estimate disclosed in this news release. Elmer B. Stewart, MSc. P. Geol., President of Copper Fox, is the Company's nominated Qualified Person pursuant to National Instrument 43-101, Standards for Disclosure for Mineral Projects, has reviewed the technical information disclosed in this news release.
*United States investors are advised that current Mineral Resources are not current Mineral Reserves and do not have demonstrated economic viability. All figures are rounded to reflect the relative accuracy of the estimate and in keeping with "best practice principles".
On behalf of the Board of Directors
Elmer B. Stewart
President and Chief Executive Officer
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
Cautionary Note Regarding Forward-Looking Information
This news release contains "forward-looking information" within the meaning of the Canadian securities laws. Forward-looking information is generally identifiable by use of the words "believes," "may," "plans," "will," "anticipates," "intends," "budgets", "could", "estimates", "expects", "forecasts", "projects" and similar expressions, and the negative of such expressions. Forward-looking information in this news release include statements about the recently completed resource estimate for the Schaft Creek deposit; the receipt and filing of a National Instrument 43-101 compliant report related to the updated resource estimate; the completion of the feasibility study for the Schaft Creek project; potential existence and size of mineralization within the Schaft Creek project; estimated timing and amounts of future expenditures and "earn-back" options; geological interpretations and potential mineral recovery processes. Information concerning mineral reserve and resource estimates also may be deemed to be forward-looking information in that it reflects a prediction of the mineralization that would be encountered if a mineral deposit were developed and mined.
In connection with the forward-looking information contained in this news release, Copper Fox has made numerous assumptions, regarding, among other things: the geological, metallurgical, engineering, financial and economic advice that Copper Fox has received is reliable, and is based upon practices and methodologies which are consistent with industry standards; and the continued financing of the Feasibility Study; and the anticipated analytical results of the current drilling program. While Copper Fox considers these assumptions to be reasonable, these assumptions are inherently subject to significant uncertainties and contingencies. Additionally, there are known and unknown risk factors which could cause Copper Fox's actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking information contained herein. Known risk factors include, among others: the actual mineralization in the Schaft Creek deposit may not be as favorable as suggested by the updated resource estimate; the NI 43-101 report related to the updated resource estimate may not be filed within the anticipated timeframe, or at all; the updated resource estimates may not be included in the feasibility study; the feasibility study may not be completed within the contemplated time frame, or at all; the possibility that future drilling on the Schaft Creek project may not occur on a timely basis, or at all; fluctuations in copper and other commodity prices and currency exchange rates; uncertainties relating to interpretation of drill results and the geology, continuity and grade of mineral deposits; uncertainty of estimates of capital and operating costs, recovery rates, and estimated economic return; the need to obtain additional financing to develop properties and uncertainty as to the availability and terms of future financing; the possibility of delay in exploration or development programs or in construction projects and uncertainty of meeting anticipated program milestones; uncertainty as to timely availability of permits and other governmental approvals
A more complete discussion of the risks and uncertainties facing Copper Fox is disclosed in Copper Fox's continuous disclosure filings with Canadian securities regulatory authorities at www.sedar.com. All forward-looking information herein is qualified in its entirety by this cautionary statement, and Copper Fox disclaims any obligation to revise or update any such forward-looking information or to publicly announce the result of any revisions to any of the forward-looking information contained herein to reflect future results, events or developments, except as required by law.
Investor line 1-866-913-1910 or J. Michael Smith, EVP, at 1-604-689-5080