Project of the Week: Enduro Metals

25th October 2021

 

 

This week, Enduro Metals (TSXV: ENDR; OTC: ENDMF; FSE: SOG) made it clear why Newmont Lake is their flagship property. Hosted in the so-called Golden Triangle of British Columbia, the claim is home to 4 mineralized systems associated with porphyry copper (Cu) - gold (Au) mineralization (Fig. 1). With new data from Burgundy Ridge, the exploration team has announced the confirmation of the existence an alkalic porphyry system from a deep core containing an interval of more than 300 m of ore (0.7% copper equivalent, CuEq). This week, we’re digging deeper on the Burgundy Ridge project - the newest porphyry discovery in the Golden Triangle.

Fig. 1. A. Map of the Golden Triangle indicating major discoveries and amount of drilling exploration in each area. B. Claim location of the Newmont Lake project and the four projects hosted within: Burgundy Ridge, McLymont, Cuba, and Chachi.
Fig. 1. A. Map of the Golden Triangle indicating major discoveries and amount of drilling exploration in each area. B. Claim location of the Newmont Lake project and the four projects hosted within: Burgundy Ridge, McLymont, Cuba, and Chachi.

The Golden Triangle hosts a wealth of newly discovered deposits and reserves, such as the next-door Galore Creek porphyry, owned by TECK Resources. The Newmont Lake deposit lies along a NW lineation along the US-Canada border between these other known mineral systems (Fig. 1). Despite this, the Newmont Lake area has received relatively little attention compared to other productive areas in the Golden Triangle. In 2018, Enduro Metals (formerly Crystal Lake Mining) took charge of the mining prospect and put in a few new exploratory holes and geophysical surveys. Initial results were promising, and existing infrastructure of the Golden Triangle caused a positive spike in investment with eyes towards the future. Now, as of their news release on Monday, October 18th - the future is here!

Burgundy Ridge Porphyry System

Discovered in the 2019 drilling season, the Burgundy Ridge deposit is an alkalic porphyry system with zones of high-grade hydrothermal breccia and mineralized potassic alteration zones. The geology and hydrothermal mineralization at Burgundy Ridge exhibits many similarities to its neighbor, the Galore Creek Porphyry, including extremely alkalic magmatism, oxidizing fluids, and Cu-Au-Ag mineralization (Micko et al., 2014). The breccia zones at Burgundy Ridge, mineralized with up to 0.76 g/t Au, 0.82% Cu, 13.2 g/t Ag, and 0.3% Zn, hint at extensive hydrothermal fluid flux through the system - exactly what is needed to generate a giant porphyry deposit(Fig. 2). Nearby trench exploration and drilling in the 2019 season uncovered potassic alteration associated with disseminated chalcopyrite, the dominant ore mineral in copper porphyry systems. If the 2019 exploration season found the smoke, the hunt was on for the fire.

Figure 2. Drill Hole BR21-001 with downhole copper equivalent (CuEq) and interpreted anomaly. Note those high-grade intervals well over 1 wt% CuEq!
Figure 2. Drill Hole BR21-001 with downhole copper equivalent (CuEq) and interpreted anomaly. Note those high-grade intervals well over 1 wt% CuEq!

Monday, Enduro Metals released their latest update on the Burgundy Ridge project - with data from their first deep drill hole, BR21-001, intersecting 331m of 0.71% CuEq starting at surface, including 146m of 1.00% CuEq from 139m (Fig. 3). The highest grade intercept from this core is just at the surface with 18.27m of 3.00% CuEq, though similar intervals exist at lower depths. Coupled with the 2019 drill holes, BR21-001 confirms the existence of massive porphyry-style mineralization at Burgundy Ridge. In general, cores with ore intervals of this size reflect large alteration and mineralization haloes — a tantalizing discovery for any exploration company.

Figure 3. A. Hydrothermal breccia infilled by chalcopyrite, sphalerite, and pyrite representing late mineralization. Red clasts of host rock overprinted with potassic alteration host low-grade chalcopyrite mineralization. B. Potassic alteration in a breccia composted of syenite clasts, infilled with hydrothermal biotite and other gangue minerals. Mineralization is chalcopyrite and pyrite and contains > 1% Cu, > 1 g/t Au, and > 2 g/t Ag.
Figure 3. A. Hydrothermal breccia infilled by chalcopyrite, sphalerite, and pyrite representing late mineralization. Red clasts of host rock overprinted with potassic alteration host low-grade chalcopyrite mineralization. B. Potassic alteration in a breccia composted of syenite clasts, infilled with hydrothermal biotite and other gangue minerals. Mineralization is chalcopyrite and pyrite and contains > 1% Cu, > 1 g/t Au, and > 2 g/t Ag.

Alkalic porphyries like Burgundy Ridge are often associated with Au mineralization (Sillitoe, 2003; Chiaradia, 2020), and the evidence of both copper and gold makes for an exciting prospect. Gangue mineral geochemistry in stockwork and propylitic alteration zones and aeromagnetic data supports the idea of a northeast batholith feeding the alkalic porphyry style mineralization. Multiple styles of distal mineralization lie along this trajectory, such as epithermal, skarn, and carbonate replacement style deposits at other Enduro-owned locations (e.g., Cuba and Chachi projects). It seems like Enduro Metals may have a claim with an entire suite of porphyry and associated ore bodies.

Overprinting mineralization styles intercepted by the ore indicate a late Cu-Zn-Ag mineralizing event, associated with chalcopyrite, sphalerite, and pyrite as infill in hydrothermal breccias. The clasts in these breccias host potassic alteration (K-feldspar + hematite) in addition to disseminated chalcopyrite, representing the earlier stages of porphyry mineralization. Overlapping hydrothermal features like this occur through a process called telescoping, in which low temperature mineralization overprints higher temperature mineralization during cooling of the porphyry system. This can indicate higher temperature mineralization at depth, which can increase life of mine and the total endowment of a porphyry system. On the other hand, lower temperature mineralization which comes late (e.g., Pb, Zn, Ag) are mostly present in lower-temperature mineralization events. The exciting part about Burgundy Ridge? The high Zn content of the rocks at the Burgundy Ridge deposit indicates that Enduro has only tapped the fringes of a larger system.

Figure 4. Enduro Metals CEO, Cole Evans, getting his face on the outcrop the proper way during a field visit in 2019.
Figure 4. Enduro Metals CEO, Cole Evans, getting his face on the outcrop the proper way during a field visit in 2019.

CEO Cole Evans is rightfully optimistic. “The combination of grade, size, and accessible location of the discovery makes Burgundy a top-tier copper-gold exploration target, sandwiched between two world-class porphyry camps at Galore Creek and KSM”, he said in a recent news release (Fig. 3). Next on the docket? Enduro hopes to release new results from the 2021 campaign quickly- with additional core logs from the Burgundy Ridge porphyry as well as the associated deposits at Chachi and Cuba projects.

Figure 5. Delivery! Future supplies will be delivered via the new winter road which is currently being developed. New infrastructure means faster, more cost efficient exploration programs moving forward.
Figure 5. Delivery! Future supplies will be delivered via the new winter road which is currently being developed. New infrastructure means faster, more cost efficient exploration programs moving forward.

In terms of continuing exploration, the infrastructure around the Burgundy Ridge project is well established and expanding. Two nearby airfields, as well as previously established mining operations in the district, make this an ideal exploration project for the Enduro Metals team. The development of a winter road is underway, connecting the claim area to the provincial highway. This will allow Enduro to conduct future exploration earlier and at much lower costs than previous campaigns (helicopters are expensive, trucks are cheaper!). In addition to the new road, Enduro is designing and building a new water supply system to feed diamond drill rigs up to 3km away in all conditions. The continued expansion of the infrastructure will facilitate the growth of this project as activity ramps up.

The Burgundy Ridge project, and the associated mineralization at the McLymont, Chachi, and Cuba projects on the same property offer an incredibly exciting opportunity for Cu-Au exploration and investment opportunities. It’s not every day a team has such good news from their drill cores - and it’s hard to undervalue such long intervals of ore. Is it the next Galore Creek? Let’s not jump the smoking gun just yet, but stay tuned as we get more news from Enduro Metals!

References

Enduro Metals News Release: https://endurometals.com/enduro-discovers-new-copper-gold-porphyry-at-newmont-lake-drill-intersects-331m-of-0-71-cueq-starting-at-surface-including-146m-of-1-00-cueq/

Enduro Metals Project Page: https://endurometals.com/newmont/

Chiaradia, M., 2020. Gold endowments of porphyry deposits controlled by precipitation efficiency. Nature communications11(1), pp.1-10.

Micko, J., Tosdal, R.M., Bissig, T., Chamberlain, C.M. and Simpson, K.A., 2014. Hydrothermal alteration and mineralization of the Galore Creek alkalic Cu-Au porphyry deposit, northwestern British Columbia, Canada. Economic Geology109(4), pp.891-914.

Sillitoe, R.H., 2002. Some metallogenic features of gold and copper deposits related to alkaline rocks and consequences for exploration. Mineralium Deposita37(1), pp.4-13.

Aaron Hantsche

View posts by Aaron Hantsche
Aaron Hantsche recently obtained his PhD in Geology from the University of Geneva in Switzerland, where he studied distal Pb-Zn skarn deposits in southern Bulgaria. Magmatic-hydrothermal deposits are his primary focus, with a bent towards geochemical vectoring tools and field geology. In addition to his work as a geologist, Aaron is a director for the science communication platform, Ore Deposits Hub. His passion for mineral deposits and geo-communication led him to join the Spotlight Mining writing team in October 2021.