This is the third, and final, set of drilling results, comprising three holes out of the 15 new exploration holes drilled during the 2013 field season at Bornite. Two additional metallurgical holes have also been completed and will eventually be incorporated into the model once metallurgical testing has been completed. In total, 17 holes totaling approximately 8,140 meters were drilled during the 2013 drilling campaign at Bornite.
The 2013 drilling campaign was designed to expand mineralization in two discrete settings: 1) near-surface, moderate-grade (~1% copper) and potentially open-pit amenable mineralization at the Ruby Creek zone; and 2) deeper, higher-grade and potentially underground exploitable mineralization of both the South Reef and Ruby Creek zones.
This press release reports on the last three deep offset holes to the north on both the South Reef and Ruby Creek zones. Most significantly, all three drill holes appear to strengthen the likelihood that these two significant zones are linked, which could potentially increase the scale and the economics of future operations.
Highlights
All three holes intersected significant intervals of high-grade copper mineralization:
At a cutoff grade of 0.5% copper the results are as follows:
RC13-227 intersected one mineralized interval, starting at 321.0 meters and ending at 382.4 meters, for a 61.3 meter composite interval with a weighted average grade of 1.54% copper.
RC13-231 intersected one mineralized interval, starting at 727.7 meters and ending at 802.5 meters, for a 74.8 meter composite interval with a weighted average grade of 1.81% copper.
RC13-233 intersected one mineralized interval, starting at 716.3 meters and ending at 760.2 meters, for a 43.9 meter composite interval with a weighted average grade of 1.64% copper.
At a cutoff grade of 2.0% copper the results are as follows:
RC13-227 intersected one mineralized interval, starting at 360.5 meters and ending at 370.5 meters, for a 10.0 meter composite interval with a weighted average grade of 2.28% copper.
RC13-231 intersected two mineralized intervals, starting at 767.4 meters and ending at 792.5 meters (25.1 meter interval), for a combined 19.1 meter composite interval with a weighted average grade of 3.18% copper and comprised of:
6.6 meters at a grade of 3.91% copper; and
12.5 meters at a grade of 2.78% copper.
RC13-233 intersected one mineralized interval, starting at 728.9 meters and ending at 736.1 meters, for a 7.2 meter composite interval with a weighted average grade of 2.73% copper.
"The latest drilling results from Bornite strengthen our belief that the South Reef and Ruby Creek zones coalesce into a wide, continuous, and thick zone of high-quality copper mineralization extending approximately one kilometer down dip and over one kilometer along strike," said Rick Van Nieuwenhuyse , NovaCopper’s President and Chief Executive Officer. "It should also be noted that last summer’s core re-logging and re-assaying program is expected to provide a sufficient basis for an expansion of the near-surface, potentially open-pittable mineralization at Bornite. All of the 2013 drilling will be incorporated into a resource update for Bornite, which is expected to be completed in 2014."
In addition, results at a more selective higher-grade cutoff of 2.0% copper are presented in Table 2. At a 2.0% copper cutoff grade drill hole RC13-227 intersected one mineralized interval totaling 10.0 meters averaging 2.28% copper, RC13-231 intersected two mineralized intervals totaling 19.1 meters averaging 3.18% copper, and RC13-233 intersected one mineralized interval totaling 7.2 meters averaging 2.73% copper.
Footnotes to Drill Interval Tables:
1) Significant interval defined as a minimum 20% x meter Cu interval
2) Cutoff grade of 0.5% Cu and 2.0% Cu respectively
3) Internal dilution up to 5 continuous meters of 0.5% Cu
4) Some rounding errors may occur
5) Individual composite intervals of >2.0% Cu are highlighted
6) Though mineralization is tabular and shallowly dipping – no true thicknesses are implied in the results
Exploration in 2013 at Bornite was designed to further define and advance both the shallow moderate-grade open-pit potential and the high-grade underground resources. The open-pit target covers the shallow surface projection of the historically drilled Lower Reef and the smaller but higher grade mineralized area, the Upper Reef, which is located stratigraphically higher in the carbonate stratigraphy. These two areas of mineralization define a NNE-trending zone called the Ruby Creek zone which management believes may have the potential to be an open-pit mining operation. Grades in this zone grade from 0.84% to 1.19% copper (Indicated resources of 6.8 million tonnes at 1.19% copper and Inferred resources of 0.84% copper) as reported in the NI 43-101 technical report titled "Technical Report for the Bornite Deposit," dated January 31, 2013 and filed on SEDAR and EDGAR on February 8, 2013 (the "Bornite Technical Report").
Down-dip and lateral exploration on the Lower Reef in 2011 and 2012 led to the discovery of the South Reef zone, a parallel NNE-trending zone of high-grade mineralization as reported in the Bornite Technical Report. This year’s drilling has now linked the two NNE-tending mineralized zones in the Lower Reef at depth into one continuous mineralized zone. The four most northerly holes exploring the Lower Reef (the last three of which are reported herein) suggest a high-grade continuous zone of stratiform copper mineralization over a kilometer in width with thicknesses exceeding 100 meters.
Results of the pre-2013 drilling at Bornite, which are disclosed in the Bornite Technical Report, yielded a potentially open-pittable Indicated Resource of 6.8 million tonnes at 1.19% Cu for 178.7 million pounds of contained copper and Inferred Resource of 47.7 million tonnes of 0.84% Cu for 883.2 million pounds of contained copper at a 0.5% copper cutoff grade. Resources for the potentially underground exploitable resources at the South Reef zone are reported as containing Inferred Resources of 43.1 million tonnes at 2.54% Cu for 2,409 million pounds of contained copper at a 1.0% copper cutoff grade. An updated resource estimate for the Bornite Project and NI 43-101 compliant technical report are anticipated to be completed in 2014.
Copper mineralization at the Ruby Creek and South Reef zones are hosted within broad dolomitized limestones within the Devonian-age Bornite Carbonate Sequence. Mineralization is selectively developed in massive dolostones and both sedimentary and hydrothermal breccias. The mineralized system is strongly zoned with a distal zinc-rich pyrite halo surrounding progressively more proximal chalcopyrite stockworks and disseminations, bornite stockworks and disseminations, and finally, local semi-massive sulphide zones of chalcocite, bornite, and chalcopyrite.
Quality Control
The drill program and sampling protocol were managed by qualified persons employed by NovaCopper. The diamond drill holes were typically collared at HQ diameter drill core and reduced to NQ diameter during the drilling process. Samples were collected using a 0.5-meter minimum length, three-meter maximum length and 1.5-meter average sample length. Drill core recovery averaged 90%. Three quality control samples (one blank, one standard and one duplicate) were inserted into each batch of 20 samples. The drill core was sawn, with half sent to ALS Chemex in Fairbanks for sample preparation and the sample pulps forwarded to ALS’s North Vancouver facility for analysis. ALS Minerals in North Vancouver, B.C. , Canada , is a facility certified as ISO 9001:2008 and accredited to ISO / IEC 17025:2005 from the Standards Council of Canada . NovaCopper will also be submitting 5% of the assay intervals from prospective lithologies to an independent check assay lab.
