Ivanhoe Electric updates Santa Cruz project, Arizona
Ivanhoe Electric Inc. [NYSE-IE; TSX-IE] Executive Chairman Robert Friedland and President and CEO Taylor Melvin provided an update on ongoing infill and exploration drilling and technical work at the Santa Cruz Copper Project, located west of Casa Grande, Arizona.
Friedland commented: “Our extensive exploration and development drilling programs at the Santa Cruz Copper Project have yielded very strong results and continue to uncover the full potential of the project. By incorporating sustainable technologies and renewable energy into the upcoming Prefeasibility Study and leveraging cutting-edge underground material handling methods, we are advancing studies at Santa Cruz for a modern, high-grade, underground copper mine with very low projected carbon dioxide-equivalent emissions.”
Melvin commented: “The fourth quarter of 2023 was an important time for the advancement of our Santa Cruz Copper Project in Arizona. We significantly increased our development drilling activity and received substantial assays from recent exploration drilling. In addition to raising our level of confidence in the Santa Cruz and East Ridge mineral resource estimates, recent infill drilling identified a large, high-grade oxide domain in the Santa Cruz deposit. This domain contains higher copper grades and is located in better quality ground conditions than previously modeled in our 2023 Initial Assessment. Our ongoing development drilling and test work will support the studies required for our Santa Cruz Prefeasibility Study, which we expect to complete before the end of Q2 2025. Beyond our development drilling at Santa Cruz and East Ridge, assays from recent step-out exploration at Texaco Ridge identified wide zones of primary sulfide mineralization that could provide future growth for our Santa Cruz Project.”
The December 2022 Mineral Resource Estimate that formed the basis for the September 2023 Initial Assessment was modeled from 153,000 metres of drilling in 170 diamond drill holes. Since the effective date of the 2022 Mineral Resource Estimate, Ivanhoe Electric has completed an additional 76 drill holes, totaling 55,964 metres, with 25,176 metres drilled since the September 2023 Initial Assessment.
Drilling activity at Santa Cruz ramped up in Q4 2023, with eight rigs drilling nearly 10,000 metres in November alone.
Recent drilling at Santa Cruz has confirmed the presence of high-grade soluble copper within mineralized oracle granite in an area that was previously classified as an exotic domain within the 2022 Mineral Resource estimate. We are referring to this domain as the Verde Domain.
The Verde Domain has higher grades, better rock mass conditions and lower water flow rates compared to previous modeling. The improved ground characteristics combined with higher copper grades provide upside potential in terms of possible mining method, mining rate, and metallurgical recovery compared to what was modeled for this area in the Initial Assessment. The opportunity to mine the Verde Domain in he relatively early years is being studied; this has the potential to accelerate capital payback and boost project economics. The mineralization intersected within the Verde Domain in drill hole SCC-125 includes 66 metres of 2.85% total copper from 595 metres, including 56.75 metres at 3.22% total copper from 598 metres.
High-grade intersections within SCC-125 include 17.05 metres of 4.69% total copper from 602 metres and 11 metres of 4.87% total copper from 626 metres.
The Initial Assessment is based on 105.2 million tonnes of modeled mill feed from the current indicated and inferred mineral resource with an average grade 1.58% total copper. The goal of the current development drilling program is to increase the quality and confidence of the indicated mineral resource in order to convert a greater portion of resources to probable mineral reserves as part of the Prefeasibility Study. In 2023, we completed 76 drill holes in support of this conversion effort.
The Texaco Ridge Exploration Area was identified by Ivanhoe Electric’s proprietary Typhoon™ 3D Induced Polarization Survey in September 2022. Ivanhoe Electric drilled 10 holes totaling 8,606 metres with a single rig at Texaco Ridge during the first half of 2023. The intention of this drilling was to step out into areas beyond the drilled Texaco Deposit that showed high mineralization potential based on Typhoon™ survey results.
Hole SCC-122 at Texaco Ridge intersected broad primary sulfides with an intercept of 327 metres of 0.81% total copper (from 564 metres), using a 0.39% total copper cut-off. This intercept includes several zones at the same 0.8% total copper cut-off grade as the nearby Texaco mineral resource: a chalcocite-enriched zone of 18 metres of 1.65% total copper (from 564 metres); a primary sulfide zone of 28 metres of 0.91% total copper (from 604 metres depth); a primary sulfide zone of 49 metres of 0.86% total copper (from 682 metres depth) and a primary sulfide zone of 63 metres of 0.89% total copper (from 797 metres depth)
Step-out drilling to the southwest has intersected high-grade soluble copper that remains open. Drill hole SCC-135 includes several zones of soluble copper mineralization at the same 0.8% total copper cut-off grade as the nearby Texaco Mineral Resource: 12.75 metres of 2.02% total copper (1.97% total soluble copper) from 649 metres depth as well as 6.37 metres of 2.50% total copper (2.48% total soluble copper) from 667 metres depth.
Step-out drilling to the northeast, highlighted by drill hole SCC-133, has intersected a broad intercept of enriched sulfide material containing 67 metres of 0.90% total copper (0.57% total soluble copper) from 615 metres.
SCC-122 and its step-out drill holes have demonstrated that the primary sulfide system remains open in several directions, while drill holes SCC-133 and SCC-135 show the potential for additional soluble copper mineralization.
All Texaco Ridge drill holes lie entirely outside the December 2022 Texaco Resource boundary.
Exploratory drilling at the Texaco Deposit area has also demonstrated the potential expansion of the primary sulfide area. Drill hole SCC-144, drilled just outside the edge of the December 2022 Texaco mineral resource, intersected a thick intercept dominated by primary sulfides including 191.75 metres of 0.73% total copper (from 619 metres depth) using a 0.39% total copper cut-off. This includes several intercepts at the same 0.8% cut-off grade of the nearby Texaco Resource: a soluble zone of 22.36 metres of 0.92% total copper (0.88% soluble copper) from 625 metres depth; a primary sulfide zone of 40 metres of 1.09% total copper from 712 meters depth and a primary sulfide zone of 13.64 metres of 0.99% total copper from 768.80 metres depth.
SCC-144’s position over 300 meters southwest from SCC-019, and outside the Texaco Indicated and Inferred Resources, demonstrates the potential for new zones of high-grade primary sulfide in the Texaco Deposit area.
Since completing the Initial Assessment in September 2023, work on the Santa Cruz Prefeasibility Study has commenced and is ongoing.
The renewable mineral exploration permits are managed by the Arizona State Land Department. Ivanhoe Electric has had prepared an independent technical report summary for the Santa Cruz Project prepared under SEC Regulation S-K, Subpart 1300 and an independent technical report prepared under Canadian NI 43-101.