RE:New Copper-Gold Saúva Discovery at Chapada 2022-02-10 17:10 ET - News Release
Mr. Peter Rockandel reports
LUNDIN MINING ANNOUNCES NEW COPPER-GOLD SAUVA DISCOVERY AT CHAPADA
Lundin Mining Corp. has discovered a new copper-gold mineralized system called Sauva, located approximately 15 kilomeres north of the Chapada mine, in the state of Goias, Brazil.
As part of Lundin Mining's ongoing exploration program aimed at increasing the Mineral Resource estimation at Chapada, diamond drilling was initiated at Sauva in the third quarter of 2021 within a recently acquired exploration concession (Figure 1). Initial drilling was designed to test for the source of a strong soil copper anomaly (>1,000 ppm Cu) that was located along strike from the previously identified Formiga prospect. The first two drill holes at Sauva confirmed the presence of shallow high-grade copper-gold mineralization. Further drilling was undertaken to evaluate the potential and to date a total of forty-seven (47) holes have been completed defining a mineralized area measuring approximately 750 meters by 650 meters, with assay results available for 29 holes (Table 1). The mineralization currently remains open in all directions.
Highlights from initial drilling include:
Hole FOR-113: 55.48 m at 0.88 per cent Cu and 1.15 g/t Au or 1.72 per cent CuEq1, from 6.52 m
Including: 27.26 m at 1.30 per cent Cu and 1.89 g/t Au or 2.68 per cent CuEq, from 33.74 m
Hole FOR-115: 65.45 m at 0.61 per cent Cu and 0.70 g/t Au or 1.12 per cent CuEq, from 23.55 m
Including: 18.41 m at 1.26 per cent Cu and 1.92 g/t Au or 2.66 per cent CuEq, from 50.43 m
Hole FOR-123: 64.25 m at 0.72 per cent Cu and 1.10 g/t Au or 1.51 per cent CuEq, from 158.45 m
Including: 43.25 m at 0.90 per cent Cu and 1.52 g/t Au or 2.01 per cent CuEq, from 158.45 m
And: 70.40 m at 0.42 per cent Cu and 0.11 g/t Au or 0.50 per cent CuEq, from 248.70 m
Including: 8.56 m at 1.04 per cent Cu and 0.16 g/t Au or 1.16 per cent CuEq, from 248.70 m
Hole FOR-135: 57.31 m at 0.79 per cent Cu and 1.06 g/t Au or 1.56 per cent CuEq, from 8.29 m
Including: 17.95 m at 1.27 per cent Cu and 1.98 g/t Au or 2.71 per cent CuEq, from 32.05 m
And: 12.80 m at 0.44 per cent Cu and 0.11 g/t Au or 0.52 per cent CuEq, from 189.20 m
Hole FOR-148: 74.06 m at 0.81 per cent Cu and 1.27 g/t Au or 1.74 per cent CuEq, from 116.00 m
Including: 19.39 m at 1.80 per cent Cu and 3.61 g/t Au or 4.43 per cent CuEq, from 149.61 m
Lundin Mining President and CEO, Peter Rockandel, commented "The shallow and high-grade copper-gold mineralization discovered at Sauva is a clear example of the growth optionality that stems from Lundin Mining's successful track record of aggressive near-mine and brownfields exploration at all of our operations. Implications that this new high-grade mineralized system may have for our on-going expansion studies of Chapada will be evaluated as this discovery evolves during the year."
Ciara Talbot, Vice President, Exploration, added "We are very pleased with this early-stage discovery within the exploration concessions identified and acquired as part of last year's federal auction process. This discovery supports our view that numerous opportunities exist to increase the size and quality of our Mineral Resource base at Chapada."
1 Copper equivalent grades (CuEq) are for comparative purposes only. Calculations are uncut and recovery is assumed to be 100 per cent as metallurgical data is insufficient to allow for estimation of metal recoveries. Copper equivalence (CuEq per cent) is calculated as: CuEq per cent = Cu per cent + (Au g/t x 0.7292), employing metal prices of Cu - US$3.00/lb, Au - US$1,500/oz.
Sauva Discovery
In 2015, the Chapada exploration team identified the Formiga exploration target, approximately 15 km north of the mine, based on positive chip sampling and regional mapping. The first drill holes at Formiga intercepted skarn style alteration comprising hydrothermal assemblage of garnet-epidote-amphibole-diopside in metasedimentary rocks. Then, during soil sampling in the region in 2016, additional disseminated copper-gold targets in the Formiga sector were identified along strike in metadiorite with hydrothermal alteration similar to what is being mined at Chapada. This trend of mineralized occurrences appeared to extend off the exploration concession to the west.
Following the acquisition of Chapada by Lundin Mining in 2019, a Mineral Inventory Range Analysis study was undertaken to refine the exploration strategy, including the prioritization of potential mineral concession acquisitions ahead of the anticipated federal auction. In the first half of 2021, Lundin Mining acquired 37 new exploration concessions through the auction process, covering 58,048 hectares and increasing the total land position around the Chapada mine by over 120 per cent. This included the concession immediately west of Formiga. Two initial drill holes, FOR-112 and FOR-113, were designed to test for the source of a strong soil copper anomaly (>1,000 ppm Cu) on this newly acquired concession along strike from Formiga. Both drill holes confirmed the presence of shallow high-grade copper-gold mineralization, which has become the Sauva prospect discovery.
Sauva Exploration Results
Following the initial discovery of the Sauva in September 2021, an aggressive exploration drilling campaign was commenced with five drill rigs to better define the potential size of the discovery. Forty-three (43) drill holes, totaling 12,850 meters, had been completed at Sauva as of December 2021. Almost all drill holes intercepted the mineralized layer containing high chalcopyrite with (plus or minus) bornite content and with the majority returning intersections with grades above 1.0 per cent CuEq, confirming the potential for significant, shallow and high-grade copper-gold mineralization. The location of the drill hole collars are shown in Figures 2 and 3, along with an approximate outline of where mineralized horizons have been intersected. The mineralization continues to remain open in all directions.
Mineralization at Sauva is comprised of disseminated and vein-hosted bornite and chalcopyrite hosted by biotitic and quartz-feldspar altered rocks. The high-grade mineralization (>1.0 per cent CuEq) is associated with bornite greater than chalcopyrite, or chalcopyrite greater than bornite sulfide zones. Lower grade mineralization (>0.3 per cent CuEq) is associated with chalcopyrite and pyrite + chalcopyrite sulfide zones. A representative cross section of the mineralized horizons is presented in Figure 4. The hydrothermal alteration zone is currently interpreted to generally follow a northeast trend, but individual high-grade orientations vary and detailed modeling remains in progress.
2022 Exploration Program
Lundin Mining is evaluating and interpreting the results reported in Table 1 and continues to explore for extensions to the mineralization. There are presently three rigs drilling in the Sauva sector testing areas to the northeast and west of the discovery area. Aggressive and methodical exploration of the sector is planned for 2022 as part of the $10 million exploration program at Chapada. Additional drill rigs and approximately fifty (50) holes are planned to test northeast along strike to towards the Formiga sector, as well as step out in other directions, as seen in Figure 2.
Technical Information and Quality Assurance
The drill holes were collared at HQ diameter from soil to altered rock and changed to NQ when fresh rock was encountered. The drill rods were three meters long and the wireline core drilling method was employed. The majority of holes were drilled at an azimuth of 120degree and a 70degree dip, perpendicular to interpreted strike and the mineralized horizon. However, some holes were drilled at other orientations where ideal surface access was not possible at the time. Downhole surveys were taken by the drilling contractor upon completion of the drill hole. All drill holes were surveyed every three (3) meters downhole using a Reflex GYRO SPRINT-IQ(TM) electronic surveying instrument. Generally, the deviation was below 5 per cent, and no significant deviation issues were found to date. Collar surveys were taken by GPS with CenterPoint RTX in UTM coordinates, SAD 69 Brazil datum, 22 South Zone. Drill hole collars were cased and protected at the surface with a cement block affixed with a metal tag stamped with the drill hole number, final depth, inclination, azimuth, and start and finish dates.