ATEX optioned the Valeriano property in 2019 and completed initial resource estimates for the copper-gold porphyry and epithermal gold oxide deposits in late 2020.
In early 2021, ATEX completed a 1,708 metre Reverse Circulation “RC” program with the goal of exploring the growth potential of the epithermal gold oxide deposit.
The 2022 exploration program was designed to follow up on and expand the copper-gold porphyry-style mineralization initially encountered by the previous operator in 2013. This program was designed to further define and extend high-grade copper-gold mineralization intersected in hole VALDD-14, which returned 1,194 metres of 0.73% CuEq, including 1.00% CuEq over 272 metres. ATEX drill holes following up on this hole were drilled as 200 metre step outs to the northeast and southwest to test the high-grade extension.
Hole ATXD-17, the most impressive hole drilled to date at Valeriano, with results reported on June 13, 2022, was drilled 200 metres southwest of VALDD14 and demonstrated the continuity of the high-grade target zone, intersecting 1,160 metres of 0.78% CuEq, including 1.03% CuEq over 550 metres. Hole ATXD-19, collared 200 metres northeast of VALDD-14, was lost at a depth of 1,309 metres due to operational issues and did not reach the high-grade target zone. Despite not reaching its target depth, ATXD-19 intersected 647 metres of 0.65% CuEq, establishing continuity of copper gold mineralization a further 200 metres to the northeast. Of note, the top 650-metre intervals with +0.4% CuEq reported in VALDD-14 (0.63% CuEq) and, in ATXD-17 (0.64% CuEq) are comparable to the grades in ATXD-19 and prove the consistency of the porphyry mineralization.
Significant Porphyry intersections are summarized below in Table 1.
| HoleID | From (metres) |
To (metres) |
Interval1 (metres) |
Cu (%) |
Au (g/t) |
Mo (ppm) |
CuEq2 (%) |
Hole Length (metres) |
|---|---|---|---|---|---|---|---|---|
| ATXD-17 | 802 | 1,962 | 1,160 | 0.53 | 0.28 | 70 | 0.78 | 2,057 |
| including | 1,280 | 1,830 | 550 | 0.69 | 0.39 | 70 | 1.03 | |
| ATXD-193 | 662 | 1,309 | 647 | 0.50 | 0.15 | 60 | 0.65 | 1,309 |
| VALDD-09 | 898 | 1,750 | 852 | 0.47 | 0.16 | 89 | 0.64 | 1,878 |
| VALDD-14 | 614 | 1,808 | 1,194 | 0.52 | 0.24 | 36 | 0.73 | 1,845 |
| including | 1,420 | 1,692 | 272 | 0.72 | 0.28 | 21 | 1.00 | |
| VALDD-16 | 576 | 1,621 | 1,045 | 0.39 | 0.17 | 54 | 0.54 | 1,621 |
Table 1. Summary of Significant Copper-Gold Porphyry Assay Results1
- The copper-equivalent grade was calculated using a copper price of $2.60/lb, gold price of $1,450/oz and molybdenum price of $11.00/lb (all prices in US$). Metal recoveries were not considered. The formula for calculating the copper-equivalent is: CuEq% = ((Cu%/100 * Cu $/tonne) + (Au g/t * Au $/gr.) + (Mo%/100 * Mo $/tonne)) / Cu $/tonne.
- Unless otherwise indicated, intervals are composited at a 0.40% CuEq cut-off and a 10 m width internal dilution. All intervals are reported as core lengths as the true lengths of the intervals are unknown at this time.
- ATXD-19 includes a 24 m interval grading 0.35% CuEq from 762 to 786 m.
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 2.
| Company | Period | Surface samples | Trenching (m) | Geophysics IP (Km) | Geophysics Mag (Km) | Mapping | Special Studies* |
|---|---|---|---|---|---|---|---|
| J. Ambrus | 1986 | 107 | ✓ | ||||
| Rayrock | 1988 | 403 | 720.0 | ✓ | ✓ | ||
| Phelps Dodge | 1989-1991 | 27 | 961.0 | ✓ | |||
| Newmont | 1993-1994 | 450.0 | 32.0 | ✓ | ✓ | ||
| Barrick | 1995-1997 | 693 | 664.0 | 15.3 | 51.7 | ✓ | ✓ |
| Hochschild | 2010-2014 | 36.0 | ✓ | ✓ | |||
| Totals | 1,230 | 2,795.0 | 51.3 | 83.7 |
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 surface. Drill intercepts included 89 metres of 1.50 g/t Au (drill hole RDH-V27) and 0.62 g/t Au over 170 metres (RDH-V31).
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.
| Company | Target | Period | RC | DDH | Holes | Total | ||
|---|---|---|---|---|---|---|---|---|
| # | metres | # | metres | # | meters | |||
| Phelps Dodge | Au-Ox/Cu | 1989-1991 | 18 | 3,500.0 | 9 | 2,902.7 | 27 | 6,402.7 |
| Barrick | Au-Ox | 1995-1997 | 20 | 6,175.0 | 20 | 6,175.0 | ||
| Hochschild | Cu-Au Porphyry | 2011-2013 | 16 | 14,269.7 | 16 | 14,269.7 | ||
| ATEX | Au-Ox | 2021-2022 | 12 | 1,708.0 | ||||
| Cu-Au Porphyry | 3 | 3,809.7 | 15 | 5,517.7 | ||||
| Totals | 1989-2021 | 50 | 11,383.0 | 28 | 20,982.1 | 78 | 32,365.1 | |
Table 3. Summary of drilling at Valeriano 1989-2022