A porphyry discovery beneath the Lunahuasi copper-gold project in Argentina increases the long-term value of the project. Credit: NGEx Minerals
NGEx Minerals’ (TSXV: NGEX) shares jumped nearly 20% on Wednesday after drill results in Argentina revealed the presence of a bigger underlying porphyry system than previously thought.
Drillhole DPDH027 at the Lunahuasi project returned 0.52% copper and 0.32 grams gold per tonne over 1,619.4 metres from 385.6 to 2,005 metres depth, ending in open potassic-altered diorite porphyry, NGEx said Wednesday. The discovery opens up a new district-scale porphyry target west of the known high-sulphidation veins.
With NGEx having finished 25,003 meters of Phase 3 drilling on May 8, assays for the remaining 10,369 meters across 12 holes should come in by mid-2025. The company is refining its targets and looking for partners for prefeasibility studies.
“Drillhole DPDH027 opens up an entirely new dimension of the Lunahuasi project, adding to the potential of what this giant mineral system will ultimately become,” president and CEO Wojtek Wodzicki said in a press release. “While our near-term efforts will target the high-grade vein system, the porphyry discovery significantly increases the long-term value of the project.”
Canaccord Genuity mining analyst Peter Bell agreed with Wodzicki’s assessment, saying in a note Wednesday that while confirmation of the porphyry was expected, the new discovery provides long-term value and highlights the exceptional strength of the mineralizing system.
“We are focused on the high-grade, high-sulphidation mineralization but believe the discovery of a new porphyry system provides long-term value,” Bell said. “NGEx’s concessions are in a very prospective part of the world, and we believe this early success at Lunahuasi sets the stage for an exciting exploration story that is heightened when compared to nearby projects such as Filo del Sol.”
BMO Capital Markets Research mining analyst Rene Cartier said in a note te drilling confirmed NGEx’s interpretation of the geological setting. “The discovery opens up a large exploration target at the project with long-term value, though it is deeper, and gives NGEx optionality as it plans for future exploration campaigns,” Cartier said.
Global copper inventories sit near decade lows as demand from electrification and renewable energy grows. Investors are eyeing projects that offer both high-grade veins for early cash flow and bulk-tonnage porphyries for scale.
Lunahuasi’s dual-style mineralization fits that model and underpinned NGEx’s intra-day rally. The stock rose 17% to C$14.28 in late afternoon trading, giving NGEx a market capitalization of roughly C$3 billion.
District scale
Lunahuasi sits in the fast-growing Vicuña district. It’s 6 km north of Lundin Mining (TSX: LUN) and BHP’s (ASX: BHP) joint Filo del Sol deposit and 8 km west of Lundin’s Josemaría. Both are major copper-gold projects nearing prefeasibility or construction. Nearby, McEwen Mining’s (NYSE, TSX: MUX) Los Azules and Lundin’s Fruta del Norte over the border in Ecuador illustrate the international rush for tier-one porphyries.
Argentina’s San Juan province has cut mining royalties and improved foreign-exchange repatriation, drawing major explorers. NGEx’s path parallels that of peers. Filo del Sol’s discovery hole on May 13, 2021 reported 858 metres at 1.8% copper-equivalent comprising 0.86% copper and 0.7 grams gold per tonne (plus 48.1 grams silver) from 188 metres downhole, ending in mineralization.
When compared to the firm’s internal mineral inventory for Lunahuasi of 33.3 million tonnes at 2.12% copper, 1.09 grams gold per tonne and 41.02 grams silver for 706,700 tonnes of copper, “these results are strong,” Bell said.
High-grade cuts
Hole DPDH027 revealed a notable high-grade section. It measured 876.4 metres, averaging 0.59% copper and 0.48 grams gold in high-sulphidation mineralization. This section spanned from 385.6 to 1,262 metres. The company also reported a deeper interval of 743 metres grading 0.44% copper and 0.13 grams gold in porphyry-style mineralization.
The change from high-sulphidation to porphyry mineralization shows a shift in copper minerals. Enargite and chalcocite switch to chalcopyrite and bornite, cyanide-soluble copper goes down and residual copper increases, the company said.
Step-out hole DPDH028 hit 53.5 metres at 7.79% copper-equivalent, comprising 3.89% copper and 2.96 grams gold per tonne. Hole DPDH029 hit 157 metres at 2.16% copper-equivalent or 1.67% copper and 0.49 grams gold per tonne. The deposit remains open in all directions and every hole has returned many mineralized intervals, the company said.