Trilogy Metals Reports Final Drill Results At Alaska Project
VANCOUVER - Trilogy Metals Inc. reported the third, and final, set of copper and cobalt assay results for five holes from the 2018 summer exploration diamond drilling program at the Bornite Project, a part of the Company's Upper Kobuk Mineral Projects (UKMP) located in the Ambler Mining District of Northwest Alaska. Assay results from these five holes comprise approximately 3,024 meters from the 10,123-meter drill campaign. All five of the drill holes contain significant copper mineralization and were designed as infill and extension holes to the 300 to 400 meter step-out holes drilled by the Company's previous round of drilling completed in 2017.
Rick Van Nieuwenhuyse, President and CEO of Trilogy Metals said, "The latest drilling results confirm the extent and continuity of the copper and cobalt mineralized system at the Bornite Project, and continue to demonstrate that the system is open. The results from drill hole RC18-0254 show additional thick zones of continuous copper-cobalt mineralization which is what was seen in RC13-0224, which contains 236.0 meters of 1.90% copper, including 6.6 meters of 7.70% copper. Hole RC18-0254 is approximately 150 meters to the southwest of RC13-0224. Within the central part of the Bornite deposit, drill holes RC18-0252, RC18-0255 and RC18-0256 partially in-fill the doughnut hole – an area previously undrilled.. These three drill holes extend the mineralized envelope towards the surface - potentially expanding the open pit resource. The results from RC18-0251 extend the South Reef Zone up-dip to the south – albeit at lower grades but the mineralized system remains open up-dip towards the surface. Overall, all four of these holes (RC18-0251, RC18-0252, RC18-0255 and RC18-0256) show that the South Reef mineralization is open up dip and joins with the Main Lower Reef mineralization that makes up the open pit resource."
This year's program was comprised of 12 drill holes totaling approximately 10,123 meters through a combination of infill and expansion drill holes in and around the known deposit. The original drilling campaign was budgeted to be 8,000 meters but was subsequently expanded to 10,000 meters with the addition of two more drill rigs. The 2018 program followed up on drilling completed during the 2017 exploration program, which was one of the larger programs in the history of drilling at the Bornite Project. During 2017, the Company drilled nine diamond drill holes comprising 8,437 meters to test the extension of the currently defined resource.
The objective of the 2018 drill campaign is to infill and expand the currently defined open pit and underground mineral resources. Mineralization within the Bornite deposit occurs as a series of "Reefs" hosted by both the Upper and Lower Bornite Carbonate sequences separated by generally unmineralized phyllite units. The Cu-Co mineralization at Bornite occurs in three distinct carbonate zones, the Upper Reef, the Lower Reef, and the South Reef. All three zones were drill tested this year.
Mineralization is typically observed as breccia matrix replacement and is generally dominated by chalcopyrite and sometimes by bornite with chalcocite – particularly in the higher-grade zones. Mineralization can also be observed as vein and replacement zones containing chalcopyrite and calcite/dolomite gangue.
The resource estimate utilized assay data from drill holes completed by the Company between 2011 and 2013 and re-sampled historic holes Kennecott drilled in the 1960s and 1970s. Assays from historic Kennecott holes that were not re-sampled were also used in the resource estimation. On June 5th, 2018 the Company announced an updated resource estimate for the Bornite project of 5.5 billion pounds of copper inferred resource at a grade of 1.74% Cu and 913 million pounds of copper indicated resource at a grade of 1.02% Cu and total inferred cobalt resources (in-pit and below-pit) of 182.4 million tonnes grading 0.019% Co for 77 million pounds of contained cobalt. Trilogy Metals filed a National Instrument 43-101 technical report in July 2018.
The drill program, sampling protocol and data verification were managed by qualified persons employed by the Company. Diamond drill holes were typically collared at PQ or HQ diameter drill core and reduced to HQ and NQ diameter during the drilling process. Samples were collected using a 0.2-meter minimum length, 2.5-meter maximum length and 1.9-meter average sample length. Drill core recovery averaged 93% overall and 95% within the prospective lithologies. Three quality control samples (one blank, one standard and one duplicate) were inserted into each batch of 20 samples.