Arizona Sonoran Reports 11 Billion Pounds of Contained Copper in updated Cactus Mineral Resource Estimate in the Measured and Indicated Category, 75% of which is Leachable Material
Highlights:
-
Infill drilling converted
51% of the Inferred material to Measured & Indicated (“M&I”), while dropping the overall M&I grade by15% due to the inclusion of lower grade near surface material fromParks /Salyer South (formerly MainSpring) -
Updated total Cactus Project MRE including Primary Sulphide material:
-
Measured and Indicated: 1,143 million short tons @
0.48% Total Copper (“CuT”) for 11.0 billion pounds or 5.5 million short tons of contained copper -
Inferred: 233 million short tons @
0.37% CuT for 1.7 billion pounds of copper or 0.85 million short tons of contained copper, representing a decrease of56% due to conversion to M&I -
75% of the Cactus Project M&I copper pounds are leachable
-
Measured and Indicated: 1,143 million short tons @
-
Parks /Salyer Deposit:-
100% of the near surface, low grade copper mineralization atParks /Salyer South converted to the Indicated category -
Changes to the M&I classification from the 2024 Parks/Salyer MRE include:
-
52% increase to 514.1 million short tons above cut‑off -
31% increase of total copper pounds to 6.3 billion -
14% grade reduction to0.61% CuT and0.49% Total soluble copper (“Cu TSol”) - due to incorporating near surface and lower gradeParks /Salyer South material into the Indicated classification
-
-
90% of theParks /Salyer copper pounds in the M&I classification are leachable
-
-
Cactus West and Cactus East Deposits:
- Mineral Resources expanded to the north, southwest, and at depth to the basement through expansion and infill drilling programs
- Reporting of first Measured mineral resources within the Cactus East deposit from finalization of infill drilling program
-
Changes to the M&I classification from 2024 Cactus West and Cactus East MRE include:
-
151% increase to 557.6 million short tons above cut‑off -
184% increase of total copper pounds to 4.43 billion pounds -
19% grade reduction to0.40% CuT and0.20% Cu TSol - due to incorporating lower grade Primary Sulphide mineralization surrounding and below the existing Cactus West pit.
-
- |
Comparisons of MRE in this press release represent comparisons between the reported MREs from September 2025 and July 2024. The September 2025 MRE is based on a |
George Ogilvie, Arizona Sonoran Copper Company President and CEO commented, “Through a series of land acquisitions from 2020-2024, a series of scope changes took place as the Project continuously and materially increased the access to mineral resources, resulting in the evolution of the Project’s strong economics, as most recently outlined in the 2024 PEA.
“Drilling successfully incorporated
“The path forward now is to reflect these updated mineral resource estimates into the pending 2025 PFS, anticipated in the fourth quarter of 2025, and effectively advance three key workstreams – a Definitive Feasibility Study, permit amendments and project financing. We believe this work will support a final investment decision as early as Q4 2026.”
Table 1 below reports the September 16, 2025, Cactus Project MRE, comprised of the
Table 1: The Cactus Project MRE (September 16, 2025)
Material
|
Tons
|
Grade
|
Grade
|
Contained
|
Contained
|
Contained Total Cu Short Tons |
Contained Total Cu Tonnes |
Total Leachable |
101,500 |
0.91 |
0.79 |
1,853,400 |
1,605,800 |
926,700 |
840,700 |
Total Primary |
29,900 |
0.42 |
0.05 |
251,000 |
30,200 |
125,500 |
113,800 |
Total Measured |
131,400 |
0.80 |
0.62 |
2,104,400 |
1,636,000 |
1,052,200 |
954,500 |
Total Leachable |
658,000 |
0.48 |
0.42 |
6,354,900 |
5,580,200 |
3,177,400 |
2,882,500 |
Total Primary |
353,400 |
0.36 |
0.04 |
2,535,900 |
270,900 |
1,268,000 |
1,150,300 |
Total Indicated |
1,011,400 |
0.44 |
0.29 |
8,890,800 |
5,851,100 |
4,445,400 |
4,032,800 |
Total Leachable |
759,500 |
0.54 |
0.47 |
8,208,300 |
7,186,000 |
4,104,200 |
3,723,200 |
Total Primary |
383,200 |
0.36 |
0.04 |
2,786,900 |
301,100 |
1,393,400 |
1,264,100 |
Total M&I |
1,142,800 |
0.48 |
0.33 |
10,995,200 |
7,487,100 |
5,497,600 |
4,987,300 |
Total Leachable |
95,100 |
0.40 |
0.34 |
760,900 |
653,400 |
380,500 |
345,200 |
Total Primary |
138,400 |
0.34 |
0.04 |
947,100 |
121,500 |
473,600 |
429,600 |
Total Inferred |
233,400 |
0.37 |
0.17 |
1,708,100 |
774,900 |
854,100 |
774,800 |
NOTES:
- Total soluble copper grades (Cu TSol) are reported using sequential assaying to calculate the soluble copper grade. Leachable material includes oxide and secondary enriched material types. Primary includes Primary Sulfide material. Tons are reported as short tons.
-
Stockpile mineral resource estimates have an effective date of March 1, 2022, Cactus and
Parks /Salyer mineral resource estimates have an effective date of September 16, 2025. All mineral resource estimates use a copper price ofUS /lb.$4.20 -
Technical and economic parameters defining mineral resource conceptual pit shells: mining cost
US /t; G&A$2.43 US /t,$0.55 10% dilution, and 44°-46° pit slope angle. -
Technical and economic parameters defining underground mineral resource estimates: mining cost
US /t, G&A$27.62 US /t, and$0.55 5% dilution. Underground mineral resource estimates are only reported for material located outside of the conceptual open pit mineral resource estimate shells. Designation as open pit or underground mineral resources are conceptual and not indicative of the mining method that may be employed at the mine design stage. -
Technical and economic parameters defining processing: Oxide heap leach (HL) processing cost of
US /t assuming$2.24 86.3% recoveries, enriched HL processing cost ofUS /t assuming$2.13 90.5% recoveries, sulphide mill processing cost ofUS /t assuming$8.50 92% recoveries. HL selling cost ofUS /lb; Mill selling cost of$0.27 US /lb.$0.62 -
Royalties of
2.54% applies to the Cactus private lands and an assumed2.50% applies to state lands. No royalties apply to theParks /Salyer South (formerly, the MainSpring property). -
Variable cut-off grades were reported depending on material type, conceptual mining method, potential processing method, and applicable royalties. For Cactus private lands and state lands - Oxide conceptual open pit or underground material =
0.087% or0.483% TSol respectively; conceptual enriched open pit or underground material =0.081% or0.459% TSol respectively; conceptual Primary Sulphide open pit or underground material =0.197% or0.600% CuT respectively. ForParks /Salyer South – conceptual Oxide open pit or underground material =0.085% or0.471% TSol respectively; enriched open pit or underground material =0.079% or0.447% TSol respectively; conceptual Primary Sulphide open pit or underground material =0.192% or0.585% CuT respectively. Stockpile cutoff =0.095% TSol. - Mineral resources, which are not mineral reserves, do not have demonstrated economic viability. The estimate of mineral resources may be materially affected by environmental, permitting, legal, title, sociopolitical, marketing, or other relevant factors. See also more detailed cautionary statements at the end of this press release.
- The quantity and grade of reported Inferred mineral resources in this estimation are uncertain in nature and there is insufficient exploration to define these Inferred mineral resources as an Indicated or Measured mineral resource estimate; it is uncertain if further exploration will result in upgrading Inferred mineral resources to an Indicated or Measured classification. See also more detailed cautionary statements at the end of this press release.
- Totals may not add up due to rounding.
Cactus Project Mineral Resources Estimate
Following a successful infill to Indicated conversion drilling program at the
The
The Cactus West mineral resource estimate largely reflects a drilling program focused on the high-grade mineralization in the north, expansion drilling in the south and southwest, and an enlarged Primary Sulphide zone extending to the basement fault. The Cactus West drilling program focused both on infilling known mineralization around the periphery and beneath the Cactus West pit and stepping out around the pit on 1,000 ft (304 m) drill centers from the known extents of mineralization. These efforts expanded the high-grade oxide and enriched mineralization north of the Cactus West pit, and robustly in-filled to the south, southwest and beneath the Cactus West pit. Oxide and enriched mineralization extend at least 1,000 ft (304 m) north, south, and southwest of the pit, and Primary Sulphide mineralization extends at least 1,500 ft (457 m) under the Cactus West pit. The drilling indicates there is expansion potential around the Cactus West mineral resources, to the north of the pit and between Cactus West and Cactus East.
For the purposes of the 2025 MRE update, the Cactus Project deposits, including Cactus East, reports as open pit mineral resources in compliance with Reasonable Prospects for Eventual Economic Extraction (“RPEEE”).
Drilling programs
A substantial amount of data was added to the geological and mineral resource models through the latest drill program, including copper assay analyses of drill core and through detailed, visual logging of drill core. The additional data helped to refine the spatial understanding of both the geology and metal content of the Cactus deposits. While some spatial changes were made, overall metal content was consistent with previous modeling efforts.
The updated Cactus Project MRE is supported by an additional 235,000 ft (70,715 m) of drilling that targeted infill drilling at the near surface southern extension of the
TABLE 2:
Material
|
Tons
|
Grade
|
Grade
|
Contained
(k lbs) |
Contained
(k lbs) |
Contained Total Cu Short Tons |
Contained Total Cu Tonnes |
Total Leachable |
46,400 |
1.07 |
0.91 |
996,500.0 |
842,900 |
498,300 |
452,000 |
Total Primary |
11,200 |
0.53 |
0.06 |
119,000.0 |
13,000 |
59,500 |
54,000 |
Total Measured |
57,600 |
0.97 |
0.74 |
1,115,500.0 |
855,900 |
557,800 |
506,000 |
Total Leachable |
406,600 |
0.58 |
0.51 |
4,682,500 |
4,160,500 |
2,341,300 |
2,124,000 |
Total Primary |
49,800 |
0.51 |
0.07 |
506,900 |
69,000 |
253,500 |
229,900 |
Total Indicated |
456,400 |
0.57 |
0.46 |
5,189,400 |
4,229,500 |
2,594,700 |
2,353,900 |
Total Leachable |
453,000 |
0.63 |
0.55 |
5,679,000 |
5,003,300 |
2,839,500 |
2,576,000 |
Total Primary |
61,000 |
0.51 |
0.07 |
626,000 |
82,000 |
313,000 |
284,000 |
Total M&I |
514,100 |
0.61 |
0.49 |
6,304,900 |
5,085,300 |
3,152,500 |
2,859,900 |
Total Leachable |
22,100 |
0.60 |
0.54 |
265,600 |
239,900 |
132,800 |
120,500 |
Total Primary |
1,700 |
0.84 |
0.35 |
28,100 |
11,800 |
14,100 |
12,700 |
Total Inferred |
23,800 |
0.62 |
0.53 |
293,700 |
251,700 |
146,900 |
133,200 |
NOTES: refer to TABLE 1
TABLE 3: Cactus West and East MRE September 16, 2025.
Material
|
Tons
|
Grade
|
Grade
|
Contained
(k lbs) |
Contained
(k lbs) |
Contained Total Cu Short Tons |
Contained Total Cu Tonnes |
Total Leachable |
55,100 |
0.78 |
0.69 |
857,000 |
762,900 |
428,500 |
388,700 |
Total Primary |
18,700 |
0.35 |
0.05 |
131,900 |
17,200 |
66,000 |
59,800 |
Total Measured |
73,700 |
0.67 |
0.53 |
988,900 |
780,100 |
494,500 |
448,600 |
Total Leachable |
180,300 |
0.39 |
0.33 |
1,414,900 |
1,202,200 |
707,500 |
641,800 |
Total Primary |
303,600 |
0.33 |
0.03 |
2,029,000 |
201,900 |
1,014,500 |
920,300 |
Total Indicated |
483,900 |
0.36 |
0.15 |
3,443,900 |
1,404,000 |
1,722,000 |
1,562,100 |
Total Leachable |
235,400 |
0.48 |
0.42 |
2,271,900 |
1,965,000 |
1,136,000 |
1,030,500 |
Total Primary |
322,200 |
0.34 |
0.03 |
2,160,900 |
219,100 |
1,080,500 |
980,200 |
Total M&I |
557,600 |
0.40 |
0.20 |
4,432,800 |
2,184,200 |
2,216,400 |
2,010,700 |
Total Leachable |
71,700 |
0.34 |
0.29 |
491,800 |
410,500 |
245,900 |
223,100 |
Total Primary |
136,700 |
0.34 |
0.04 |
919,000 |
109,700 |
459,500 |
416,900 |
Total Inferred |
208,400 |
0.34 |
0.12 |
1,410,800 |
520,200 |
705,400 |
639,900 |
NOTES: refer to TABLE 1
TABLE 4: Stockpile MRE September 16, 2025.
Material
|
Tons
|
Grade
|
Grade
|
Contained
(k lbs) |
Contained
(k lbs) |
Contained Total Cu Short Tons |
Contained Total Cu Tonnes |
Total Leachable |
71,100 |
0.18 |
0.15 |
257,400 |
217,600 |
128,700 |
116,800 |
Total Indicated |
71,100 |
0.18 |
0.15 |
257,400 |
217,600 |
128,700 |
116,800 |
Total Leachable |
71,100 |
0.18 |
0.15 |
257,400 |
217,600 |
128,700 |
116,800 |
Total M&I |
71,100 |
0.18 |
0.15 |
257,400 |
217,600 |
128,700 |
116,800 |
Total Leachable |
1,200 |
0.15 |
0.13 |
3,600 |
3,000 |
1,800 |
1,600 |
Total Inferred |
1,200 |
0.15 |
0.13 |
3,600 |
3,000 |
1,800 |
1,600 |
NOTES: refer to TABLE 1
Table 5: The Cactus Project MRE, as of September 16, 2025 and as Compared to July 11, 2024 using like-for-like
Material Type |
PREVIOUS Mineral Resource Estimate |
UPDATED Mineral Resource Estimate at |
VARIANCE |
||||
(As of July 11, 2024) |
(As of September 16, 2025) |
||||||
|
Tons |
Grade |
Contained |
Tons |
Grade |
Contained |
Cu lbs
|
Kt |
CuT % |
Cu k lbs |
Kt |
CuT % |
Cu k lbs |
||
Leachable |
55,200 |
0.94 |
1,032,200 |
99,500 |
0.93 |
1,846,500 |
|
Primary |
12,300 |
0.51 |
124,400 |
26,400 |
0.44 |
231,400 |
|
Total Measured |
67,500 |
0.86 |
1,156,500 |
125,900 |
0.83 |
2,077,900 |
|
Leachable |
414,800 |
0.60 |
4,965,000 |
616,100 |
0.50 |
6,163,600 |
|
Primary |
150,400 |
0.39 |
1,173,300 |
301,500 |
0.37 |
2,243,900 |
|
Total Indicated |
565,200 |
0.54 |
6,138,200 |
917,600 |
0.46 |
8,407,600 |
|
Leachable |
470,000 |
0.64 |
5,997,200 |
715,600 |
0.56 |
8,010,100 |
|
Primary |
162,700 |
0.40 |
1,297,600 |
327,900 |
0.38 |
2,475,300 |
|
Total M&I |
632,600 |
0.58 |
7,294,800 |
1,043,500 |
0.50 |
10,485,500 |
|
Leachable |
299,600 |
0.43 |
2,572,400 |
70,000 |
0.44 |
623,100 |
- |
Primary |
174,500 |
0.36 |
1,267,500 |
101,200 |
0.36 |
726,400 |
- |
Total Inferred |
474,000 |
0.41 |
3,839,900 |
171,200 |
0.39 |
1,349,500 |
- |
NOTES:
- For full details on the 2024 MRE, see the Company’s most recent Annual Information Form dated March 27, 2025 (the “AIF”) filed under the Company’s issuer profile on SEDAR+ (www.sedarplus.ca) and available on its website (www.arizonasonoran.com).
- For applicable Notes to this Table 5, see the notes to the table entitled “Cactus Project – Total Measured, Indicated, and Inferred Mineral Resource” on page 33 of the AIF.
Cactus Project Mineral Resource Modelling
The geological modelling, statistical analysis, and mineral resource estimation in respect of the updated Cactus Project MRE were prepared by the ASCU resource team and by Allan Schappert – CPG #11758, who is an independent qualified person as defined by National Instrument 43-101– Standards of Disclosure for Mineral Projects (“NI 43-101”).
The updated Cactus Project MRE updates are based upon updated drilling data and interpretations. The Cactus Mineral Resource model was developed in
The mineralized domains are consistent with domaining for porphyry copper systems. Mineralized domains represent combinations of rock type and copper mineral zonation associated with secondary copper enrichment weathering processes. The main mineral zones are leached, oxide, enriched, and primary sulphide. Mineral zones are determined by logging and the assay attributes of sequential copper analyses.
Physical density measurements have been undertaken across the deposits, both historically by ASARCO, and more recently by ASCU. Density measurements on inground deposits use the wet / dry weight method and comprise 3,372 samples for Cactus and 722 samples for
Copper resource grades were estimated using Ordinary Kriging, using 20 ft (6.1 m) composites and top cutting determined by log normal probability plots on a per domain basis. Grade estimates were validated using visual and statistical methods including statistical distribution comparisons, visual comparison against the drilling data on sections, swath plots comparing block grades trends against de-clustered composites, and by smoothing checks using change of support. The effective date of the Cactus Project MRE is September 16, 2025. The 2025 Cactus Project MRE will form the basis of a PFS technical report prepared in accordance with NI 43-101, and prepared by M3 Engineering, which will be filed on SEDAR+ under the Company’s issuer profile within 45 days of the disclosure of the PFS results later this year and will also be available at such time on the Company’s website.
Quality Assurance / Quality Control
Drilling completed on the project between 2020 and 2024 was supervised by on-site ASCU personnel who prepared core samples for assay and implemented a full QA/QC program using blanks, standards, and duplicates to monitor analytical accuracy and precision. The samples were sealed on site and shipped to Skyline Laboratories in
Scientific and technical information contained in this news release has been reviewed and verified by Allan Schappert – CPG #11758, who is an independent qualified person as defined by NI 43-101.
Links from the Press Release
Figures 1-4: https://arizonasonoran.com/projects/cactus-mine-project/press-release-images/
2024 Annual Information Form: https://arizonasonoran.com/investors/corporate-filings/
Neither the TSX nor the regulating authority has approved or disproved the information contained in this news release.
About Arizona Sonoran Copper Company (www.arizonasonoran.com | www.cactusmine.com)
ASCU’s objective is to become a mid-tier copper producer with low operating costs and to develop the Cactus Project that could generate robust returns for investors and provide a long term sustainable and responsible operation for the community and all stakeholders. The Company’s principal asset is a
Cautionary Statements regarding Forward-Looking Statements and Other Matters
Forward-Looking Statements
All statements, other than statements of historical fact, contained or incorporated by reference in this press release constitute “forward-looking statements” and “forward-looking information” (collectively, “forward-looking statements”) within the meaning of applicable Canadian and
Mineral Resource Estimates
Until mineral deposits are actually mined and processed, copper and other mineral resources must be considered as estimates only. Mineral resource estimates that are not classified as mineral reserves do not have demonstrated economic viability. The estimation of mineral resources is inherently uncertain, involves subjective judgement about many relevant factors and may be materially affected by, among other things, environmental, permitting, legal, title, taxation, socio-political, marketing, or other known and unknown risks, uncertainties, contingencies and other factors described in the foregoing Cautionary Statements on Forward-Looking Statements. The quantity and grade of reported “inferred” mineral resource estimates are uncertain in nature and there has been insufficient exploration to define “inferred” mineral resource estimates as an “indicated” or “measured” mineral resource and it is uncertain if further exploration will result in upgrading “inferred” mineral resource estimates to an “indicated” or “measured” mineral resource category. Inferred mineral resource estimates may not form the basis of feasibility or pre-feasibility studies or economic studies except for preliminary economic assessments. The accuracy of any mineral resource estimate is a function of the quantity and quality of available data, and of the assumptions made and judgments used in engineering and geological interpretation, which may prove to be unreliable and depend, to a certain extent, upon the analysis of drilling results and statistical inferences that may ultimately prove to be inaccurate. It cannot be assumed that all or any part of a “inferred”, “indicated” or “measured” mineral resource estimate will ever be upgraded to a higher category including a mineral reserve. The mineral resource estimates declared by the Company were estimated, categorized and reported using standards and definitions in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves (the “CIM Standards”) in accordance with National Instrument 43-101 of the Canadian Securities Administrators (“NI 43-101”), which governs the public disclosure of scientific and technical information concerning mineral projects.
The terms “mineral resource”, “measured mineral resource”, “indicated mineral resource” and “inferred mineral resource” as disclosed by the Company are Canadian mining terms defined in the CIM Standards (collectively, the “CIM Definitions”) in accordance with NI 43-101. NI 43-101 establishes standards for all public disclosure that a Canadian issuer makes of scientific and technical information concerning mineral projects. These Canadian standards differ from the requirements of the United States Securities and Exchange Commission (the “SEC”) applicable to
Preliminary Economic Assessments
The 2024 Preliminary Economic Assessment (or 2024 PEA) referenced in this press release and summarized in the 2024 PEA Technical Report is only a conceptual study of the potential viability of the Cactus Project and the economic and technical viability of the Cactus Project has not been demonstrated. The 2024 PEA is preliminary in nature and provides only an initial, high-level review of the Cactus Project’s potential and design options; there is no certainty that the 2024 PEA will be realized. For further detail on the Cactus Project and the 2024 PEA, including applicable technical notes and cautionary statements, please refer to the Company’s press release dated August 7, 2024 and the 2024 PEA Technical Report, both available on the Company’s website at www.arizonasonoran.com and under its issuer profile at www.sedarplus.ca.
View source version on businesswire.com: https://www.businesswire.com/news/home/20250916903203/en/
Alison Dwoskin, Director, Investor Relations
647-233-4348
adwoskin@arizonasonoran.com
George Ogilvie, President, CEO and Director
416-723-0458
gogilvie@arizonasonoran.com
Source: Arizona Sonoran Copper Company Inc.