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 VALDD-141, 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, ATXD-172 and ATXD-192, were drilled as 200 metre step outs to the southwest and northeast, respectively to test the high-grade extension.
ATXD-17, the most impressive from the Phase II program at Valeriano, was reported on June 13, 2022. This hole was drilled 200 metres southwest of VAL-DD14 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 ATXD-19, collared 200 metres northeast of VALDD-14 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, ATXD-19 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 ATXD-17 and VALDD-14. In addition, the objectives of the program were:
- expanding the mineralized footprint and
- testing for parallel porphyry trends to the east and west.
This program is ATEX’s first drill campaign at Valeriano utilizing directional drilling, which allows for the testing of multiple targets off a single hole. Using this approach maximizes the efficiency of current and future drilling.
Phase III results include the first daughter-hole drilled from historical hole VALDD-111, ATXD-11A3, which returned 1,270 metres of 0.63% CuEq (0.43% Cu, 0.2g/t Au and 52ppm Mo), extending the Central high-grade porphyry trend over 200 metres northeast from VALDD-14. Drillhole ATXD-214, drilled to test the southwest extension of central porphyry trend, intercepted multiple intervals of mineralization, including 428 metres of 0.48% CuEq (0.31% Cu, 0.2 g/t Au and 56ppm Mo) and 168 metres of 0.59% CuEq (0.41% Cu, 0.2g/t Au and 60ppm Mo).
Significant Porphyry intersections are summarized below in Table 1.
Table 1. Summary of Significant Copper-Gold Porphyry Assay Results
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 2.
|Company||Period||Surface samples||Trenching (m)||Geophysics IP (Km)||Geophysics Mag (Km)||Mapping||Special Studies*|
Table 2. Historical exploration activities
*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 for drilling completed till the end of the H1 2022 field season is shown below in Table 3.
Table 3. Summary of drilling at Valeriano 1989-2022
For ATXD-11A, the copper equivalent “CuEq” grade was calculated using a copper price of $3.50/lbs, gold price of $1,950/oz and molybdenum price of $18.00/lbs (all prices in US$).
For other released holes from 2021 though to current releases, the CuEq grade was calculated using a copper price of $2.60/lbs, gold price of $1,450/oz and molybdenum price of $11.00/lbs (all prices in US$). The formula for calculating the copper-equivalent is: CuEq% = ((Cu%/100 * Cu $/tonne) + (Au g/t * Au $/gr.) + (Mo%/100 * Mo $/tonne)) / Cu $/tonne.
1 For further information on historical drillholes and exploration, please see NI 43-101 technical report titled: “NI 43-101 Technical Report, Valeriano Project Inferred Resource Estimates, Atacama Region, Chile”, with an effective date of November 13, 2020, and available under the ATEX Resources SEDAR profile.
2 For ATXD-17 and ATXD-19 results, procedures and QA/QC information, see press release from June 13, 2022.
3 For ATXD-11A, results, procedures and QA/QC information, see press release from February 7, 2023.
4 For ATXD-21 results, procedures and QA/QC information, see press release from February 27, 2023.
5 For further information, please see NI 43-101 technical report titled: “NI 43-101 Technical Report, Valeriano Project Inferred Resource Estimates, Atacama Region, Chile”, with an effective date of November 13, 2020, and available under the ATEX Resources SEDAR profile.