- Multiple intercepts in Northwest Expo Zone 1 encounter gold-enriched copper porphyry mineralization
- NW23-09 intercepted 36.0m grading 1.64g/t Au Eq. and 29.7m grading 1.05 g/t Au Eq.
- NW23-11 intercepted 64.5m grading 1.21g/t Au Eq.
- NW23-12 intercepted 112.7m grading 0.94g/t Au Eq. including extensive higher-grade intervals
- Additional assays anticipated to be received by October
- Second phase drill program at Northwest Expo commenced on September 8, 2023
- The Company continues to target an initial inferred resource by the end of 2023
Vancouver, B.C. – Northisle Copper and Gold Inc. (TSX-V: NCX) (“Northisle” or the “Company”) is pleased to announce that it has received the first assay results from its 2023 drill program at Northwest Expo which confirm that the gold-enriched copper porphyry mineralization in Zone 1 at Northwest Expo, is consistent with the company’s objective of defining an initial resource in this area by the end of 2023.
Sam Lee, President & CEO of Northisle stated “These results are some of the best ever at the North Island Project. The drill holes demonstrate continuity from previous drilling in the gold-enriched zone at Northwest Expo and support the potential of the project, and this area in particular, to show significantly higher grades. We are awaiting final Phase 1 drill results from Northwest Expo and Goodspeed and have initiated our fully-funded Phase 2 drill program. Our goal continues to be an initial resource at Northwest Expo in 2023.”
Summary of 2023 Drill Results to Date
Northisle’s 2023 intercepts in the gold-enriched copper porphyry in Zone 1 are summarized in Table 1. With four of eight holes now received at Northwest Expo, three holes intersected significant mineralization consistent with the hypothesized mineralized envelope in Zone 1.
Table 1: Zone 1 Significant 2023 Intercepts
|Hole ID||From (m)||To (m)||Interval (m)||True Width (m)||Au Grade (g/t)||Cu Grade (%)||Mo Grade (%)||Re Grade (g/t)||Au Eq. Grade (g/t)||Cu Eq.
Copper and gold equivalent calculations based on the following metal prices which were used in the Company’s 2021 PEA on the North Island Project: Cu = US$3.25/lb, Au = US$1,650/oz, Mo = US$10/lb, Re = $1,256/kg. Calculations assume 100% recovery; totals may not add due to rounding Note on equivalent calculation: Copper equivalent is determined by calculating total contained metal value/ tonne, dividing by the copper price, and then dividing the resultant number of pounds of copper by 2204.6. Gold equivalent is determined by calculating total contained metal value/tonne, dividing by the gold price, and then multiplying the resultant number of troy ounces of gold by 31.103. Analyzed metal equivalent calculations are reported for illustrative purposes only. The metal chosen for reporting on an equivalent basis is the one that contributes the most dollar value after accounting for assumed recoveries, which is expected to be gold for Northwest Expo and copper for the overall North Island project.
NW23-10 was targeted down-dip on the northern limit of the target area and intersected an interpreted fault. Figure 1 shows the location and collar data for the completed drill holes at Northwest Expo. Assays from four additional holes at Northwest Expo are pending.
Details of Northwest Expo Zone 1 Drilling Results
2023 drilling has been focused on better defining the mineralized area within Zone 1 with the goal of completing a resource estimate, following relogging of historical drilling in the context of several drill holes completed by Northisle in 2021 showing important geological features not recognized in the historical drill holes, as well as an extensive surface geophysics program completed on the property during 2022. Details of the 2021 drilling at Northwest Expo can be found in Northisle’s press release dated January 25, 2022 (https://www.northisle.ca/news/northisle-intersects-84-8m-grading-1-20g-t-au-eq-including-25m-grading-1-46g-t-au-eq-in-high-grade-gold-rich-porphyry-zone-at-northwest-expo/), while the results of the surface geophysics program can be found in our press release dated January 23, 2023 (https://www.northisle.ca/news/northisle-announces-positive-results-of-surface-exploration-program/).
Figure 2 below shows known drilling at Northwest Expo by Northisle and previous operators from an aerial view.
- Note: Yellow highlighted/red text are Northisle’s drill holes.
- Yellow highlighted/black text are Northisle’s drill holes awaiting assays
- Green highlighted/yellow text are historic drill holes
Zone 1 at Northwest Expo is underlain by Jurassic Bonanza Formation andesitic volcaniclastics, flows and feldspar porphyry dykes and minor diorite with intense silica-clay-pyrite (SCP) alteration imposed upon them, as well as hydrothermal breccias and silica-brine immiscibility (gusano) textured rocks (SIM) emanating from an aerially extensive hydrothermal system. Mineralization occurs predominantly in characteristic chlorite-magnetite altered rocks (CMG) with varying amounts in SCP altered rocks.
Figure 3 shows the location of all known drill holes in Zone 1, including significant intercepts of mineralization to date (red lines adjacent to drill holes). Also shown in black vertical lines are the locations of the north-south sections shown in Figure 4 and Figure 5. Figure 6 shows a common legend for Figures 3, 4 and 5.
Figure 4 shows Section 569200E which includes two 2023 drill holes (NW23-09 and NW23-10) as well as drill holes by previous operators. Mineralization extends into the SCP altered rocks in EC08-254. A narrow dyke cuts through the middle of the mineralized zone in this section.
Figure 5 shows Section 569300E and is of particular note as there is an increased presence of SIM (gusano) textured rock which is the host of mineralization in this area. There is also an increase in the length of the mineralized intercept which amounts to 162.4m interpreted true width. The SIM (gusano) alteration feature increases in abundance to the southeast. Field mapping of alteration and clay mineral analyses suggests that a porphyry centre may be located further south east of Zone 1. This area will be prioritized for future exploration.
Northisle has re-logged the core from the previous programs at Northwest Expo. Check assays have not been carried out on this core, however the mineralized lithologies observed and relogged, as well as related assays results, are consistent with adjacent holes drilled, logged and assayed by Northisle. Results of the previous programs at Northwest Expo were first disclosed in the following reports:
- Baker, D. (2005). Geological, Geochemical, Geophysical and Diamond Drilling Report on the Hushamu Property, Volumes A, B, C
- Lehtinen, J., and Awmack, H. (2007). Diamond Drilling Report on the Hushamu Property
- Baldys, C., Burgert, A. and Houle, J. (2008). Technical Report on the Island Copper Property
Logging, Sampling and Assaying Procedures
The diamond drill core logging and sampling program was carried out under a rigorous quality assurance / quality control program using industry best practices. Drill intersections in this release are typically HQ to 100 m and NQ thereafter to the end of holes. After drilling, core was logged for geology, structure, and geotechnical characteristics utilizing Geospark© core logging software, then marked for sampling and photographed on site. The cores for analyses were marked for sampling based on geological intervals with individual samples 3 m or less in length. Drill core was cut lengthwise in half with a core saw. Half-core was sent for assays reported in this news release. Prior to cutting core for assay bulk density was also determined on site by taking 15 to 20 cm lengths of whole core of each lithology at 10 m intervals. The ends of these were then cut at right angle to the core axis, retaining all pieces to be returned to the core box for later sample cutting and analysis. The diameter of each core sampled for bulk density was measured at each end with digital calipers to 3 decimal places and recorded. The length of the core was measured on four sides at 90 degrees to each other, to 2 decimal places and recorded. The software averaged the lengths and diameters. The mass of the dry core was measured twice on an Ohaus© balance to 2 decimal places. If no discrepancy occurred the measurement was recorded. If there was a discrepancy the measuring was repeated until no discrepancy between 2 measurements occurred. The density was calculated using the formula Bulk Density = π times r² times h (where r is radius of core and h is length of core). Certified standard masses are used to calibrate the scale balance used for bulk density determinations. The balance in the core logging area was levelled on a large concrete block to avoid vibration, was leveled, and surrounded by a wooden partition to avoid wind affecting the balance. The measurements were recorded in Geospark© logging software and Bulk Density calculated to 2 decimal places.
A total of 5% assay standards or blanks and 5% core duplicates are included in the sample stream as a quality control measure and are reviewed after analyses are received. Standards were obtained from WCM Minerals, Vancouver, CDN Minerals, Langley and OREAS, Canada. Blanks were obtained from unmineralized course bagged limestone landscaping rock. Standards and blanks in 2023 drill results to date have been approved as acceptable. Duplicate data add to the long-term estimates of precision for assay data on the project and precision for drill results reported is deemed to be within acceptable levels. Samples were sent to the MSALABS in Langley, BC where the samples were dried, then crushed, split and a 250 g split was pulverized to 85% passing -200 mesh (-75µm) size pulps. Clean crush material was passed through the crusher and clean silica was pulverized between each sample. The pulps were analyzed for gold by fire assay fusion of 50 g of the 250 g split. Total gold content was determined by digesting the silver doré bead from the fusion and then analysing by AA (MSA Code FAS-121). All samples were also analyzed for multiple elements by taking a 0.25 g of the 250g split which was heated in HNO3, HClO4 and HF to fuming and taken to dryness. The residue was dissolved in HCl and then analyzed utilizing ICP-MS (MSA Code IMS-230). Any sulphur analysis from this latter analysis with a value greater than 10% was reanalyzed utilizing a Leco sulfur analyzer. Iron and Tungsten accelerators are added to the sample and a stream of oxygen is passed over the sample in the induction furnace. As the sample is heated, sulfur dioxide released from the sample is measured by an IR detection system and the Total Sulphur content is determined. (MSA Code SPM-210). MSALABS (Langley) is an independent, international ISO/IEC 17025:2005 accredited laboratory.
Pulps and rejects of holes with significant assay intervals are stored at Western Mineral Storage. The remaining split core is indexed and stored at Northisle logging and office facility in Port Hardy, BC.
Results in this news release are length weighted averages.
Robin Tolbert, P.Geo., Vice President Exploration of Northisle and a Qualified Person as defined by National Instrument 43-101, has reviewed and approved the scientific and technical disclosure contained in this news release, including the sampling, analytical and test data.
Northisle Copper and Gold Inc. is a Vancouver-based company whose mission is to become a leading and sustainable mineral resource company for the future. Northisle owns the North Island Project, which is one of the most promising copper and gold porphyry deposits in Canada. The North Island Project is located near Port Hardy, British Columbia on a 33,149-hectare block of mineral titles 100% owned by Northisle stretching 50 kilometres northwest from the now closed Island Copper Mine operated by BHP Billiton. Northisle recently completed an updated preliminary economic assessment for the North Island Project and is now focused on advancement of the project through a prefeasibility study while continuing exploration within this highly prospective land package.
For more information on Northisle please visit the Company’s website at www.northisle.ca.
On behalf of Northisle Copper and Gold Inc.
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 news release.
This news release contains forward-looking statements. These forward-looking statements are based upon the reasonable beliefs of Northisle and its management as of the date of this news release; however, forward-looking statements involve risks and uncertainties and are based upon factors that may change and assumptions that may prove, with the passage of time, to be incorrect as a result of exploration and other risk factors associated with mineral exploration and development that are beyond the control of Northisle. Accordingly, undue reliance should not be placed upon such statements. If factors materially change or assumptions are materially incorrect, the actual results, performance or achievements of Northisle may be materially different from any future results, performances or achievements expressed or implied by such forward-looking statements. Northisle does not undertake any obligation to update or revise any forward-looking statements to reflect new information, future events or otherwise, except as required by applicable law.