History

Phase I Drill Campaign

In early 2021, ATEX completed a 1,708 metre Reverse Circulation “RC” program (Phase I) with the goal of exploring the potential of the epithermal gold oxide deposit.

Phase II Drill Campaign

In 2022, ATEX completed its initial drill program designed to follow up on and expand the copper-gold porphyry-style mineralization at depth at Valeriano. This mineralization was initially encountered by the previous operator in 2013. The Phase II program was designed to further define and extend high-grade copper-gold mineralization intersected in hole VALDD13-014¹, which returned 1,194 metres of 0.73% CuEq (0.52% Cu, 0.24 g/t Au and 36ppm Mo), including 1.00% CuEq (0.72% Cu, 0.28 g/t Au and 21 ppm Mo) over 272 metres. ATEX drill holes following up on this hole, ATXD17² and ATXD19², were drilled as 200 metre step outs to the southwest and northeast, respectively to test the high-grade extension.

ATXD17, the most impressive from the Phase II program at Valeriano, was reported on June 13, 2022. This hole was drilled 200 metres southwest of VALDD13-014 and demonstrated the continuity of the high-grade target zone, intersecting 1,160 metres of 0.78% CuEq (0.53% Cu, 0.28 g/t Au, 70ppm Mo), including 1.03% CuEq (0.69% Cu, 0.39g/t Au, 70ppm Mo) over 550 metres. Hole ATXD19, collared 200 metres northeast of VALDD13-014 and lost at a depth of 1,309 metres due to operational issues, did not reach the high-grade target zone. Despite not reaching its target depth, ATXD19 intersected 647 metres of 0.65% CuEq (0.5% Cu, 0.15 g/t Au, 60ppm Mo), establishing continuity of copper gold mineralization a further 200 metres to the northeast.

Phase III Drill Campaign

The Phase III, 2022-2023 exploration program commenced in October 2022 with the goal of extending the high-grade trend intersected in holes ATXD17 and VALDD13-014. The program successfully concluded in late May 2023. The realized objectives of the program were:

• expanding the mineralized footprint,
• the discovery of an additional trend (Western Trend)

This program was ATEX’s first drill campaign at Valeriano utilizing directional drilling, which allowed for the testing of multiple targets off a single hole. Using this approach maximized the efficiency of the programme and will continue to be utilized in future phases of exploration to reduce costs and deliver results to market more quickly.

Phase III drilling commenced in October 2022 and included eight diamond drill holes (four from surface and four daughter holes) totaling 12,512.9 metres. The Phase III campaign was developed with the intention of expanding the mineralized corridor through step out drilling along strike, primarily to the northeast as well as testing new targets along this corridor and seeking to define the continuity and geometry of the high-grade trend intersected in Phase II.

As part of this program, historical drill hole VALDD12-011 was re-entered from surface and two directional daughter holes, ATXD11A³ and ATXD11B⁵, were drilled from starting depths of 855.0 metres and 697.0 metres respectively. Additional directional daughter holes were completed from ATXD22⁶, with ATXD22A⁶ starting at 921.35 metres and ATXD22B⁷ starting at 444.3 metres.

Holes from drilled from surface in Phase III included, ATXD21⁴, ATXD22 (mother), ATXD23⁶ and ATXD24⁷. 

Phase IV Drill Campaign

Approximately 12,000m of diamond drilling was completed in the Phase IV drill program, started in October 2023, and concluded in May 2024. The goals of the Phase IV program were to to further define and extend the high-grade porphyry trends intersected in Phase II and III and explore beyond the defined dimensions of the mineralized corridor.

ATEX continued to use directional diamond drilling in the Phase IV program, which allowed the company to realize an effective total of 20,100m drilled in the event all holes had been drilled from surface.

Four daughter holes - ATXD12A, ATXD16A, ATXD17A, ATXD17B - and two mother holes - ATXD25 and ATXD26 - were completed in the Phase IV program, with an additional two daughter holes and one mother hole partially completed - ATXD25A, ATXD26A and ATXD27 - were paused at the end of Phase IV⁸.

Summaries of highlighted results for Phases I-IV are presented on the map in Figure 1 with ATEX results in Tables 1, 2 and 4.

Figure 1. ATEX and Historical Drilling at Valeriano

Table 1. Summary of Significant Copper-Gold Porphyry Assay Results

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(1) CuEq values reflect those used in original press release results
*Holes ATXD25A, ATXD26A and ATXD27 were paused at end of Phase IV and will be re-entered during the Phase V program

Table 2. Summary Results for ATEX Phase I Near Surface Oxide Gold Drilling

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Exploration pre-ATEX

Exploration at Valeriano commenced in the 1980’s. Initial regional exploration, consisting of outcrop and float sampling, returned anomalous results followed by the acquisition of the concessions by the vendor. Further sampling and trenching was carried out through the 1980’s and into the 1990’s, targeting the near surface alteration features. Through the 1990’s, various drill campaigns were completed by three operators, Phelps Dodge (1989-1991), Barrick (1995-1997) and Hochschild (2011-2013). The initial focus of exploration was on the near-surface oxide gold potential, transitioning to a focus on the porphyry potential by 2013. To date, 32,365 metres in in 78 holes (20,982 metres of diamond drill core and 11,383 metres of RC drilling) have been completed on the property. Work by historical operators is summarized below in Table 3.

Table 3. Historical Exploration Activities

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*Special studies include Petrography, Fluid inclusions, SWIR and age-dating

During the 1990’s, Phelps Dodge and later Barrick explored the Valeriano property for near-surface gold mineralization, drilling 47 holes to an average and maximum depth of 267 metres and 550 metres, respectively. The drill programs outlined a zone of near-surface, high sulphidation, epithermal gold mineralization over an area of approximately 400 metres by 400 metres to depths of approximately 100 metres below surface⁵. Drill intercepts included 89 metres of 1.50 g/t Au (drill hole RDH-V27¹) and 0.62 g/t Au over 170 metres (RDH-V31¹). 

In 2010, Hochschild optioned the Valeriano property and completed 16 diamond drill holes in three campaigns for a total of 14,270 metres. During the second drill campaign, Hochschild recognized porphyry-style alteration at depth and in the third season they drilled three holes, collared approximately 225 metres to 375 metres apart, to depths of up to 1,878 metres, intersecting well-defined mineralized advanced argillic and phyllic alteration zones before entering a chalcopyrite and bornite-bearing, potassic-altered granodioritic porphyry system.  

A summary of drilling completed till the end of the Phase IV program (concluded in May 2024) are shown below in Table 4.

Table 4. Summary of Drilling at Valeriano 1989-2024

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*Does not include mother portion of re-entered drill holes
**Includes abandoned/re-drilled holes

¹ For further information, please see ATEX’s NI 43-101 compliant technical report titled “Independent Technical Report for the Valeriano Copper-Gold Project, Atacama Region, Chile” with an effective date of September 1, 2023, prepared for ATEX by SRK Consulting (Chile) SpA. A copy of the foregoing technical report is available on ATEX’s website and also under ATEX’s SEDAR+ profile at www.sedarplus.com. As set out in the foregoing technical report, Copper Equivalent (CuEq) is calculated assuming US$ 3.15/lb copper (Cu), US$ 1,800/oz gold (Au), US$ 23/oz Silver (Ag), and US$ 20/lb Molybdenum (Mo) and metallurgical recoveries of 90% for Cu, 70% for Au, 80% for Ag, and 60% for Mo using the formula CuEq % = Cu % + (6481.488523 * Au g/t) + (94.6503085864 * Ag g/t) + (4.2328042328 * Mo g/t). 

² For ATXD17 and ATXD19 results, procedures and QA/QC information, see press release from June 13, 2022.

³ For ATXD11A results, procedures and QA/QC information, see press release from February 7, 2023

⁴  For ATXD21, results, procedures and QA/QC information, see press release from February 27, 2023

⁵  For ATXD11B, results, procedures and QA/QC information, see press release from March 30, 2023

⁶ For ATXD22, ATXD22A and ATXD23 results, procedures and QA/QC information, see press release from June 5, 2023.

⁷  For ATXD22B and ATXD24 results, procedures and QA/QC information, see press release from July 13, 2023.

⁸ For ATXD16A, ATXD17A, ATXD12A, ATXD25, AXTD17B, ATXD26, ATXD25A, ATXD26A and ATXD27 results, procedures and QA/QC information, see press release from June 25, 2024.