Highland Copper Reports Resource Estimate for the Copperwood Project, Michigan
LONGUEUIL, QUEBEC--(Marketwired - May 11, 2015) - Highland Copper Company Inc. (TSX VENTURE:HI) ("Highland" or the "Company") is pleased to announce a mineral resource estimate for its 100%-owned Copperwood Project located in Gogebic County, in the western Upper Peninsula of Michigan, U.S.A. (see Figure 1).
The mineral resource estimate prepared by G Mining Services Inc. ("G Mining"), an independent Canadian mining consulting firm, has been estimated at 29.1 million tonnes grading an average of 1.65% copper and 4.51g/t silver containing 1.06 billion pounds of copper and 4.2 million ounces of silver in the measured and indicated resource category, using a cut-off grade of 1.0%.
Highland acquired the Copperwood Project from Orvana Minerals Corp. ("Orvana") in 2014. The resource estimate reported by Orvana was reported by Highland as an historical estimate. Highland retained the services of G Mining who have completed the necessary work to verify the historical estimate. The current mineral resource estimate is based on 1,726 assay results from 324 324 diamond drill holes totaling 59,230 meters, drilled by three companies between 1956 and 2013.
Copperwood Project |
Mineral Resource Estimate - April 15, 2015 |
Deposits | Resource Category | Tonnage (Mt) | Copper Grade (%) | Silver Grade (g/t) | Copper Contained (M lbs) | Silver Contained (M oz) |
Copperwood | Measured | 22.5 | 1.73 | 5.08 | 861 | 3.7 |
Indicated | 6.6 | 1.37 | 2.56 | 200 | 0.5 | |
M + I | 29.1 | 1.65 | 4.51 | 1061 | 4.2 | |
Inferred | 1.9 | 1.24 | 2.36 | 52 | 0.1 | |
Satellites | Inferred | 38.6 | 1.23 | 2.09 | 1050 | 2.6 |
Notes on Mineral Resource Estimate
- Mineral Resources are reported using a copper price of 3.00$/lb and a silver price of 20$/oz
- A payable rate of 96.5% for copper and 90% for silver was assumed
- The Copperwood feasibility study reported metallurgical testing with recovery of 86% for copper and 50% for silver
- Cut-off grade of 1.0% copper was used
- Operating costs are estimated at 49$/t of ore including ore transportation to a plant at the White Pine site
- An NSR sliding scale royalty is applicable and equivalent to 3.0% at $3.00/lb
- Measured, Indicated and Inferred Mineral Resources have a drill hole spacing of 175 m, 250 m, and 350 m, respectively
- No mining dilution and mining loss were considered for the Mineral Resources
- Rock bulk densities are based on rock types, % copper and proximity to specific gravity measurements
- Classification of Mineral Resources conforms to CIM definitions
- The qualified person for the estimate is Mr. Réjean Sirois, P. Eng, Vice President Geology and Resources for G Mining Services Inc. The estimate has an effective date of April 15, 2015
- Mineral resources that are not mineral reserves do not have demonstrated economic viability. The estimate of mineral resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.
- The quantity and grade of reported inferred resources in this estimation are uncertain in nature and there has been insufficient exploration to define these inferred resources as indicated or measured mineral resources.
Selection of cut-off grades and resource estimate
The table below shows the sensitivity of constrained resource estimates to the cut-off grade for the Copperwood Project:
Sensitivity of the Copperwood Project |
Constrained Mineral Resource Estimate by Cut-Off Grades |
Measured & Indicated | |||||
Cut-off Grade (% Cu) | Tonnage (Mt) | Grade Cu (%) | Copper Contained (Mlbs) | Grade Ag (g/t) | Silver Contained (Moz) |
2.0% | 7.6 | 2.15 | 360 | 7.09 | 1.7 |
1.5% | 16.9 | 1.93 | 721 | 5.98 | 3.3 |
1.0% | 29.1 | 1.65 | 1,061 | 4.51 | 4.2 |
0.8% | 33.3 | 1.56 | 1,144 | 4.12 | 4.4 |
Figure 2 shows the distribution of the copper mineralization around the Copperwood Project.
Mineral Resource Estimate Methodology
The estimate was conducted in a block model limited by a single mineralized domain, interpreted as the Copper Bearing Sequence ("CBS": Gray Laminated, Red Massive, and Domino beds). Hanging wall and footwall surfaces of the CBS were modelled and merged to create the mineralization solid. The footwall surface was adjusted beforehand to keep a minimum thickness of 2.2 m throughout the deposit, acting as the minimum mining height. Uncapped raw assays were composited into zone composites (one composite per drill hole) with a minimum thickness of 2.2 m. Variography studies highlighted a near horizontally isotropic distribution of copper and a low nugget effect on copper and silver grades. Block sizes of 10 m by 10 m horizontally, with a 2.5 m height were used in the block model. A uniform bulk density of 2.7 g/cm3 was used for all rock sequences in the model. Copper and silver grades were estimated using the Ordinary Kriging (OK) interpolation method in three successive passes, using ellipse ranges of 175 m, 250 m, and 350 m.
To define resource categories, G Mining outlined groups of globally similar interpolation passes. Measured Mineral Resources thus constitute the bulk of the mineral resources in the Copperwood Deposit (as defined below) area and include blocks interpolated generally in the first pass. Indicated Mineral Resources are located at the periphery of the measured category where blocks are generally interpolated in the second pass and are limited to the Copperwood Deposit. All other interpolated blocks are categorized in the Inferred Mineral Resource category, including all blocks in the Satellite Deposits (as defined below).
Resources are reported using a cut-off grade of 1.0% Cu, based on an underground "Room and Pillar" mining scenario. Mineral Resources were classified according to the CIM Definition Standards on Mineral Resources and Mineral Reserves.
Data Verification
The QP responsible for the mineral resource estimates has supervised and reviewed the available data used in the Mineral Resource estimate, including drill logs, assay certificates, down-hole surveys, and additional supporting information sources. Very few mistakes were found in the course of the database validation and were promptly corrected by Highland. The QP is of the opinion that the drill hole database is in good condition and could be used with confidence in the Mineral Resource estimate.
The Copperwood Project
The Company indirectly owns the Copperwood Project, which is comprised of long-term mineral leases totaling 941 contiguous hectares (the "Copperwood Deposit") and options to convert into mineral leases an additional 1,559 ha of mineral rights on three mineralized zones adjacent to the Copperwood Deposit (the "Satellite Deposits"). The Company also owns approximately 700 hectares of surface rights that secure access and provide space for infrastructure related to the potential development of a mine.
The Copperwood Deposit was the subject of a feasibility study completed by the former owner in 2012 and all major permits were obtained, including the State of Michigan Part 632 Mining Permit.
Geology of the Copperwood Project
The Copperwood copper-silver deposits are hosted by the Mesoproterozoic Nonesuch Formation, an assemblage of lacustrine and fluvial sediments deposited into an intracratonic rift. Mineralization is found within three conformable units collectively forming the Parting Shale at the base of the Nonesuch Formation. The Domino unit is the principal copper host and is characterized by black shale with a mean thickness of 1.6 m. The Red Massive unit is made by siltstone and sandstone and has a mean thickness of 0.3 m. The Grey Laminated unit is a grey siltstone with a mean thickness of 1.0 m. Chalcocite is the only copper-bearing sulphide. The Nonesuch Formation is contained by the broad and northwest-plunging Presqu'isle Syncline structure. The Copperwood Deposit is found on the south limb of the syncline, while the Satellite Deposits are found elsewhere on the syncline (see Figure 3).
The Copperwood copper-silver mineralization is interpreted to be a sediment-hosted deposit of the reduced facies class, also referred as of Kupferschiefer-type.
Plans for 2015
Highland is currently conducting pre-feasibility level studies on the integration of the Copperwood, White Pine North, and Keweenaw Projects, with the aim of maximizing synergies, minimizing development costs and reducing overall environmental impact. This study includes trade-off analysis on infrastructures, mining methods and metallurgical alternatives, and is planned to be completed by year-end, subject to the availability of necessary financing.
Qualified Persons
Réjean Sirois, P. Eng, Vice President of Geology and Resources for G Mining is the qualified person, as defined in National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101"), responsible for the mineral resource estimates for the Copperwood Project as reported herein. He has read and approved the relevant technical portions of this news release related to the mineral resource estimates for which he is responsible.
The balance of the technical information contained in this news release has been reviewed and approved by Carlos H. Bertoni, P. Geo., Vice President, Project Development for the Company. Mr. Bertoni is a qualified person as defined in NI 43-101.
G Mining is completing an NI 43-101 technical report for the mineral resource estimate, to be filed on SEDAR within 45 days of this press release.
About Highland
Highland Copper Company Inc. is a Canadian exploration company focused on exploring and developing copper projects in the Upper Peninsula of Michigan, U.S.A. Highland has approximately $3.3 million in cash at March 31, 2015 and has 129,542,192 common shares issued and outstanding listed on the TSXV under the symbol 'HI'. Additional information about Highland is available on the Company's website at www.highlandcopper.com and on SEDAR at www.sedar.com.
CAUTIONARY STATEMENT
Certain statements contained in this press release constitute forward looking information under the provisions of Canadian securities laws. Such statements include without limitation the Company's objectives to integrate the Copperwood, White Pine North, and Keweenaw Projects so that the Copperwood deposits can be mined at lower cost and with reduced environmental impact, as well as statements about the completion and timing of pre-feasibility studies. Forward-looking information is based on what management believes to be reasonable assumptions and estimates at the date the statements are made, and is subject to a variety of risks and uncertainties and other factors that could cause actual events or results to differ materially from those projected in the forward-looking information. These factors include the inherent risks involved in the exploration and development of mineral properties, the availability of financing for the development of the Company's mineral projects on reasonable terms, the uncertainties involved in interpreting drilling results and other geological data, the accuracy of the estimates for metal prices, metal recoveries, mining costs, and other key parameters for the Copperwood Project resources, uncertainty relating to the receipt of regulatory and governmental approvals for the Company's mineral projects and other operations, and risks related to the Company's ability to execute its corporate strategies. The Company does not intend to update these forward-looking statements and information, except as required by law. Accordingly, readers are advised not to place undue reliance on forward-looking statements.
Neither the 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.
To view Figure 1, please visit the following link: http://media3.marketwire.com/docs/hi0511fig1.pdf.
To view Figure 2, please visit the following link: http://media3.marketwire.com/docs/hi0511fig2.pdf.
To view Figure 3, please visit the following link: http://media3.marketwire.com/docs/hi0511fig3.pdf.
Contact
Highland Copper Company Inc.
David Fennell
Executive Chairman
1 450 677 2455
Highland Copper Company Inc.
James Crombie
Interim President and CEO
1.450.677.2455
info@highlandcopper.com
www.highlandcopper.com