Jan 10 2013
Highland Copper Company Inc. ("Highland" or the "Company") is pleased to announce results for 52 additional diamond drill holes from the 543S chalcocite deposit at the Keweenaw copper project in the Upper Peninsula of Michigan, U.S.A.
Some of the higher-grade intersections in holes for which all assays have been received and checked include the following:
- CEN397: 14.4 meters of 4.78% Cu and 1.3 g/t Ag including
- 7.6 meters of 8.15% Cu and 0.8 g/t Ag including
- 4.1 meters of 11.50% Cu and 0.9 g/t Ag
- CEN452: 22.7 meters of 3.80% Cu and 11.8 g/t Ag including
- 9.2 meters of 5.64% Cu and 25.7 g/t Ag, and
- 1.8 meters of 8.41% Cu and 2.7 g/t Ag
- CEN340: 18.0 meters of 3.20% Cu and 15.3 g/t Ag including
- 2.5 meters of 11.15% Cu and 50.8 g/t Ag
- CEN410: 8.2 meters of 3.32% Cu and 2.1 g/t Ag
- CEN376: 5.6 meters of 8.36% Cu and 20.7 g/t Ag
Sampling of visually-identified high grade copper intersections is on approximate 0.5 meter intervals adjusted for the geology. Individual high grade samples tend to cluster in continuous zones within broader envelopes of lower grade material. Contacts with adjacent unmineralized wall rocks may be sharp or gradational.
Considerable lengths of lower grade mineralization continue to be intersected, with several examples below:
- CEN377: 49.5 meters of 1.14% Cu and 2.6 g/t Ag
- CEN368: 45.4 meters of 0.93% Cu and 2.3 g/t Ag including
- 2.3 meters of 4.95% Cu and 8.6 g/t Ag and
- 1.5 meters of 2.81% Cu and 1.4 g/t Ag
- CEN323: 44.0 meters of 0.75% Cu and 1.5 g/t Ag including
- 5.0 meters of 3.57% Cu and 4.0 g/t Ag
- CEN418: 36.7 meters of 1.32% Cu and 5.4 g/t Ag including
- 6.2 meters of 5.89% Cu and 4.8 g/t Ag
Lower grade copper intersections are hosted in basalt lava flow top breccias, but also occur along the contacts of or within dacite sills that occasionally cut across the lavas at low angles. Mineralization containing less than 0.75% Cu was not included in the historic resource estimate of the 543S deposit, although these lower grade intersections could provide additional upside for the deposit at current copper prices. Increased silver grades often accompany increased copper grades, but this relationship is not consistent. Assay composites results for the 52 holes reported here are summarized in Table 1 (click here for a link to Table 1: http://media3.marketwire.com/docs/AssayTable.pdf).
"The internal continuity of high grade copper intersections in individual drill holes and the unusual length of the lower grade intersections continue to be impressive," said Dr. Ross R. Grunwald, PhD, Vice president - Exploration for Highland. "With the drilling by Highland and previous exploration groups, the drill hole spacing on the 543S deposit is now 30 meters or less, thought sufficient to initiate a database audit leading to a resource estimate. Eight holes remain to be completed in the eastern portion of 543S and drills will then be moved to the G-2 prospect, 11 miles east. Work will continue through the winter with two machines."
Geology
Lens-like zones of mineralization, largely in brecciated tops of amygdaloidal Precambrian basalt lava flows, consist mostly of primary chalcocite accompanied by small amounts of native copper and native silver. Silver in the copper-bearing zones varies mostly from 1-15 g/tonne Ag. Traces of other sulfide minerals are also present. Mineralization comes to the bedrock surface and is covered by 3 to 30 meters of glacial deposits. The 543S deposit is in the western portion of a 20-mile long belt of chalcocite prospects that extends east from a belt of large native copper mines, centered near the town of Calumet, Michigan, that were mined for about 130 years before closing in 1968 due to low copper prices.
The 2012 drill holes are within an area of 101 historic diamond drill holes called the 543S sulphide deposit, a zone of chalcocite mineralization that was explored from 1973-1977 and briefly in the mid-nineties. The 543S deposit contains a historic resource estimate of 4.5 million short tons averaging 2.27% Cu at a 0.75% Cu cut-off grade as described in a Technical Report by Behre Dolbear & Company, Ltd. titled "Centennial and Kingston Native Copper, 543S, and Other Copper Sulfide Properties, Houghton and Keweenaw Counties, Michigan, USA'' dated September 29, 2011. The historical resource estimate is contained in six separate lenses averaging 5.0 meters (16.5 ft.) true thickness that dip about 40° to the north. The Company has not completed the work necessary to classify the historical estimate mentioned above as current mineral resources under Canadian National Instrument 43-101 ("NI 43-101"). The Company is not treating the historical estimate as current mineral resources as defined in NI 43-101 and the historical estimate should not be relied upon.
Highland's objective is to verify the non-compliant historic drill results with compliant assay data by reducing the historic drill hole spacing and twinning selected historic holes to establish a resource estimate compliant with NI 43-101. Resource modeling is expected to begin in early 2013.
Highland Exploration Program to Date
Current composite assay results from drilling are summarized in Table 1 (click here for link to Table 1). Drill hole locations are on Figure 1 at the end of this news release. Figure 2 is a cross section on line 500E that illustrates the continuity of mineralization at a 0.20% Cu cut-off (excluding silver). Additional sections were reported in earlier news releases. Summarizing progress to date at the 543S deposit:
Drilling start date - July 17, 2012
Holes drilled - 164
Meters drilled - 24,686
Assays complete and released for - 98 holes
Mineralized intersections - 82 holes
No significant mineralization - 16 holes
Average thickness of all reported +0.20% Cu intersections per hole - 18.9 meters
Approximate lateral dimensions - 260 meters NW-SE by 600 meters NE-SW
Average grade of all reported +0.20% Cu composite intersections drilled by Highland:
- Numerical average for all drill holes - 1.77% Cu
- Weighted by cumulative length of composites in each hole - 1.57% Cu
The average thickness normally includes several separate mineralized lenses in each hole. The lateral dimensions indicated by Highland's drilling to date are similar to those reported in the Technical Report by Behre Dolbear & Company, Ltd., referenced above. The lower average grade of the composite intersections compared to the grade reported in the Technical Report is due to a lower cut-off grade (0.20% Cu) used by Highland compared to that used for the historic resource estimate (0.75% Cu) and to the unexpectedly long intersections in the interval 0.20-0.75% Cu that envelope the higher grade mineralization. Unmineralized holes are generally on the edge of the 543S deposit and are not included in the averages.
Drilling, Sampling, Assaying and QAQC
The 2012 drill holes are mostly on cross sections spaced at 30 meter intervals between the historic 60 meter grid lines at the 543S deposit. All holes reported on Table 1 are inclined to the south along section lines shown on Figure 1. Drill hole inclinations are selected to approximate a true width intersection of the mineralized lenses based on regional information on the dips of the lava flows. Holes reported as unmineralized contain less than 3 continuous meters averaging at least 0.20% Cu and are mostly confined to edges of the 543S deposit. Down-hole surveys are made for all holes.
All technical information for the 543S exploration program is collected under a formal quality assurance and quality control (QAQC) program that has been reviewed by two independent qualified persons as defined in NI 43-101. Samples are taken under the direction of qualified geologists and stored in sealed bags. Samples are then placed in sealed containers and delivered via courier or common carrier to Accurassay Labs and ActLabs, both certified analytical facilities in Thunder Bay, Ontario, Canada for analysis. Copper and silver contents are determined at both labs using a four acid digestion procedure.
The technical information contained in this news release has been reviewed and approved by Ross R. Grunwald, PhD., Vice president - Exploration for the Company. Dr. Grunwald is a qualified person as defined in NI 43-101.
Keweenaw Copper Project
The Keweenaw Copper Project covers about 13,000 acres of mineral rights and is being explored under a Mining Venture Agreement between Highland and BRP LLC. The agreement allows Highland to earn a 65 percent interest by spending US$11.5 million in expenditures on the project and providing a feasibility study by October 26, 2015. More information about the Keweenaw Copper Project is available in Behre Dolbear's NI 43-101 Technical Report, 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 statements about: the Company's exploration plans and objectives to complete a mineral resource estimate and resource modeling; and other statements and information expressing anticipated results of the Company's operations and exploration. Such statements reflect the Company's views as at the date of this press release and are subject to certain risks, uncertainties and assumptions. Many factors, known and unknown, could cause the actual results to be materially different from those expressed or implied by such forward looking statements. Such risks include, but are not limited to: the volatility of copper price; the uncertainty of exploration results, capital expenditure requirements and other costs; the uncertainties related to the Company's ability to acquire a 65% interest in the Keweenaw project; currency fluctuations; the availability of financing for additional capital requirements, cost of exploration and development programs; mining risks; risks associated with governmental and environmental regulation and obtaining all the necessary permits for the development of the project; and risks associated with global economic growth. The Company does not intend, and does not assume any obligation, 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.
United States investors are cautioned not to assume that all or any part of a mineral resource, if confirmed, will ever be converted into mineral reserves. Mineral resources have a great amount of uncertainty as to their existence, and as to their economic and legal feasibility.
Source: http://www.highlandcopper.com/