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SUNSTONE METALS LTD Capital/Financing Update 2023
65870_rns_2023-11-08_427b312b-6361-4c7b-ae9d-77b09ee9847e.pdf
Capital/Financing Update
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9 NOVEMBER 2023
Bramaderos Project, Southern Ecuador
Large Exploration Target shows Limon on track to be a substantial gold-silver deposit
Mineralisation modelled from surface to 400m deep; Drilling will now target growth and Resource conversion
- Significant Exploration Target outlined at the Limon epithermal gold-silver discovery within the Bramaderos project
- Initial Exploration Target comprises the Limon 'Central Shoot', the surrounding mineralised area measuring 800m x 300m, and 3 of the additional 6 satellite targets outlined to date
- The Exploration Target extends from surface to depths of up to 400m below surface
- The Exploration Target is in addition to the December 2022 Resource of 2.7Moz AuEq1 for Brama-Alba gold-copper-silver porphyry mineralisation
- It is also in addition to the December 2022 porphyry gold-copper-silver Exploration Target of 3.3 to 8.6Moz AuEq1 from Brama-Alba, Melonal, and a small porphyry at Limon
- Excellent metallurgy from Limon has been confirmed with recoveries of over 90% for both gold and silver
- Next steps include surface exploration at all targets to expand the gold-silver system and to define the next phase of drilling to enable a Mineral Resource estimate
Sunstone Metals Ltd (ASX: STM) is pleased to announce the initial Exploration Target for the Limon goldsilver discovery, that is within the Bramaderos Project.
The Limon Exploration Target has been prepared and reported in accordance with the JORC Code (2012) and consists of between approximately 30 and 44 million tonnes at a grade of between 0.9 and 1.2g/t AuEq*, for between 0.9 and 1.7mill oz AuEq (see Table 1). The AuEq calculation for Limon is provided below and comprises contribution from gold and silver only.
The potential tonnage, grade and quantity of the Exploration Target is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource for the target area reported. It is uncertain if further exploration will result in the estimation of a Mineral Resource.
*The gold equivalent calculation formula is AuEq(g/t) = Au(ppm) + (Ag (ppm)/82). The prices used were US$1,800/oz gold and US$22/oz silver. Recoveries are estimated at over 90% for gold and 90% for silver from metallurgical studies. In Sunstone's opinion all the elements included in the metal equivalents calculation have reasonable potential to be recovered and sold.
1 See qualifying statements in the About Sunstone Metals section on page 12.
Sunstone Managing Director Malcolm Norris said the Exploration Target showed Limon was a large discovery with significant development potential.
"This initial Exploration Target highlights the scope for a substantial resource and a significant development at Limon," Mr Norris said.
"We believe there is every potential for a staged development at Bramaderos with Limon being the higher grade, lower cost, first off development that paves the way for a larger development across multiple porphyry deposits of gold, copper and silver. These options will be further assessed as we complete more drilling and infrastructure studies.
"The total inventory is growing at Bramaderos, and we are moving towards our stated goal of a 10Moz gold district.
"And it must be emphasized that Limon, and other areas of mineralisation at Bramaderos, are ideally located for a mining development. There is existing grid power (93% renewable), the Pan American Highway is within 3 km of the gold-silver-copper deposits, the area is between 900 – 1,100m above sea level, and Ecuador has a clearly defined process for moving from exploration to development".
Zone Min Tonnage (mill) Max Tonnage (mill) Min Grade g/t AuEq Max Grade g/t AuEq Min. kAuEq Ounces Max. kAuEq Ounces Notes (Tonnage estimates use a Specific Gravity of 2.7g/cc) Central Shoot 20 31 0.9 1.2 580 1,200 ~170 x ~170 x 250m and x 400m for tonnage range; assumes 2 higher grade sub-shoots within Central Shoot area Domain surrounding Central Shoot 5 7 0.9 1.2 145 270 including holes 33, 39, 41; plus 2 areas of mineralisation ~60m x 60m x 250-350m Anomaly A 1.7 2 0.9 1.2 50 75 each area min 50m x 50m x 250m-300m vert Anomaly B 1.7 2 0.9 1.2 50 75 each area min 50m x 50m x 250m-300m vert Anomaly C 1.7 2 0.9 1.2 50 75 each area min 50m x 50m x 250m-300m vert 30.1 44 0.9 1.2 875 1,700 0.9 1.7 million ounces AuEq
Table 1: Limon Epithermal Exploration Target components showing approximate grade and tonnage ranges.
Figure 1: Limon gold in soils map showing extensive anomalous gold over an area of 1.7km x 700m. The black outlined areas are those referred to in Table 1 and form the basis of the Exploration Target. Red circled areas are key sub-targets. The red dashed line shows the deeper Limon porphyry target outline with fingers that extend to surface to the NW and the East. Follow-up exploration activities are discussed in the text.
The Limon gold-silver discovery
The Limon gold-silver epithermal discovery has moved from discovery to Exploration Target in less than 10 months. The epithermal system was first identified in hole LMDD012 drilled in January 2023. The discovery hole for the Limon gold-silver epithermal system was hole LMDD017 which intersected 176.7m at 1.1g/t AuEq* (0.97g/t gold and 10.1g/t silver), from 6.8m, and was drilled in February 2023.
The Limon gold-silver discovery is classified as an Intermediate Sulphidation epithermal deposit (ISE). It is expected that multiple shoots will be discovered within the broad 1.7km x 700m Limon alteration system.
The Limon deposit also sits adjacent to and above the Limon porphyry target. Drill hole LMDD010 drilled what is interpreted to be a shallow finger of a much larger porphyry system intersecting 79m at 0.52g/t gold, 0.195 copper and 9.4g/t silver, below a trench that returned 98m at 0.71g/t gold and 0.23% copper. The very large compelling porphyry target (Figure 1), interpreted to sit below these shallow ISE intersections, will be drilled in 2024.
Data used for the Exploration Target
The Exploration Target was estimated on Target Prospects where there was a combination of diamond drilling (by Sunstone), geological mapping, trenching, geochemistry (soils) and to a lesser extent geophysical data (magnetics) that support the geological and mineralisation concept model.
Approximately 9,530m of diamond drilling in 31 holes (LMDD012 – 015, and LMDD017 – 043) has been completed during 2023 focussed on the Limon gold-silver epithermal system. Of these 31 holes, 27 have been drilled into the central shoot area. Two have been drilled to the SE of the central shoot (LMDD039 and 041), one to the NW (LMDD033), and one well to the NW (LMDD042). Two holes drilled by Sunstone in late 2022, LMDD008 and 009, also intersected epithermal-related gold and silver mineralisation.
The Limon alteration area has been covered with soil sampling on a 50m x 50m grid. This survey is an important exploration method which identified several gold-in soil anomalies that are primary targets for drilling. The soil geochemical data is further interpreted using related element associations typical of epithermal systems, such as areas of coincident or overlapping gold, silver, zinc, lead, copper, tellurium, and arsenic anomalies.
Target areas have also been strengthened using alteration mineralogy from a hand-held Terraspec instrument. These data assist in mapping the alteration zones most likely to be associated with epithermal mineralisation.
Standard geological mapping and rock chip sampling has also been undertaken across the Limon target area.
Some trenching has been completed, and more trenching is currently in progress (Figure 1).
Exploration Target estimation methodology
The volume ranges for the initial Exploration Target in the Central Shoot were estimated using cross sections and 3-D modelling in Leapfrog software, based upon an analysis of drilling, mineralised rock types, grade distribution, potential for extrapolation of mineralisation continuity and interpreted geological risk.
The volume ranges for the other components were estimated from geological interpretation and guided by extent of surface geochemical anomalism, supplemented by preliminary drilling. A conservative approach was taken to the potential distribution of gold and silver bearing veins.
The Central Shoot has been outlined based on the geological interpretation of the gold- and silver- bearing mineralised fault and vein networks with both NE and NW trending trends, and dissemination of gold and silver into various host rocks. Within the Central Zone there are sub-domains of very high grade – as seen in holes LMDD017, 026, 038, and 040 (Table 3). These very high grades are interpreted to be associated with hydrothermal breccias at fault intersections. The Exploration Target assumes that at least one other subdomain of high grade will be drilled during subsequent drill programs. This will likely increase the overall grade and increase contained ounces.
Grade ranges in Table 1 have been selected based on average intervals from existing drilling over broad intersections (see Table 3 and Figure 2 to support these selections).
Table 2: Summary of Exploration Targets at the Bramaderos Project - in addition to the published Brama-Alba MRE (see ASX announcement dated 13 December 2022)
| Zone | MinTonnage(mill) | MaxTonnage(mill) | MinGrade g/tAuEq | MaxGrade g/tAuEq | Min. AuEqOunces | Max. AuEqOunces |
|---|---|---|---|---|---|---|
| Brama-Alba-Melonal-LimonPorphyry Exploration Target | 255 | 360 | 0.4 | 0.74 | 3,300,000 | 8,600,000 |
| gold-copper-silver porphyrystyle; geological definitionLimon Epithermal Exploration | ||||||
| Targetgold-silver epithermal style;geological definition | 30 | 44 | 0.9 | 1.2 | 900,000 | 1,700,000 |
4,200,000 10,300,000
Figure 2: Limon epithermal gold-silver system in plan view, showing multiple mineralised structures in green. Highgrade domains are at intersections of NE and WNW trending structures. Several additional targets have been defined based on gold-in soil and zinc-in-soil anomalies, and structural interpretation and follow-up drilling will be undertaken on these targets in 2024. See Figure 1 for a broader context within the very large Limon target area.
About Bramaderos
The Limon target area is located 2.7km north-east of the Brama-Alba-Melonal gold-copper deposits. The Bramaderos Project currently hosts a porphyry gold-copper-silver Mineral Resource estimate of 2.7Moz AuEq at Brama-Alba, and a porphyry Exploration Target of between 3.3Moz and 8.6Moz AuEq within 255 to 360Mt at a grade between 0.40 and 0.74g/t AuEq (Figure 3; see ASX announcement dated 13 December 2022, and qualifying statements in the 'About Sunstone Metals' section on page 12 of this announcement).
The Bramaderos project straddles the Pan American highway (Figure 3), and is close to available hydroelectric power, supporting the economics of potential development opportunities. Ecuador sources 93% of its power from renewables and is ideally placed to participate in the global demand for clean energy sourced metals. The project is also supported by nearby commercial airports and significant cities (Loja, population 200,000) and has strong community support. The project area is covered by 3 valid concessions and exploration plans are in place to continue to explore multiple gold-silver epithermal and gold-coppersilver porphyry opportunities.
| From | To (m) | Interval | AuEq | Au | Ag | Zn | Cu (%) | ||
|---|---|---|---|---|---|---|---|---|---|
| Drill Hole | EOH (m) | (m) | (m) | (g/t) | (g/t) | (g/t) | (%) | ||
| LMDD043 | 370.03 | 0.0 | 35.0 | 35.0 | 0.20 | 0.14 | 4.9 | 0.20 | 0.01 |
| 74.0 | 81.0 | 7.0 | 0.23 | 0.12 | 8.3 | 0.25 | 0.01 | ||
| 94.0 | 109.0 | 15.0 | 0.29 | 0.09 | 16.1 | 0.16 | 0.00 | ||
| 169.0 | 173.0 | 4.0 | 0.77 | 0.44 | 27.4 | 0.25 | 0.01 | ||
| 182.5 | 183.5 | 1.0 | 0.68 | 0.60 | 6.8 | 0.14 | 0.00 | ||
| 189.5 | 190.5 | 1.0 | 0.56 | 0.48 | 6.7 | 0.08 | 0.00 | ||
| 201.5 | 225.0 | 23.5 | 0.37 | 0.32 | 4.0 | 0.19 | 0.03 | ||
| incl. | 215.5 | 225.0 | 9.5 | 0.39 | 0.37 | 1.8 | 0.03 | 0.04 | |
| 280.0 | 281.0 | 1.0 | 0.56 | 0.55 | 0.9 | 0.01 | 0.00 | ||
| 304.0 | 315.0 | 11.0 | 0.40 | 0.35 | 4.2 | 0.18 | 0.00 | ||
| 333.0 | 339.0 | 6.0 | 0.15 | 0.15 | 0.4 | 0.05 | 0.01 | ||
| LMDD042 | 359.26 | 241.8 | 259.0 | 17.2 | 0.17 | 0.16 | 0.4 | 0.01 | 0.00 |
| LMDD041 | 398.43 | 0.0 | 88.0 | 88.0 | 0.20 | 0.19 | 0.8 | 0.06 | 0.01 |
| incl. | 18.0 | 20.0 | 2.0 | 1.61 | 1.60 | 0.8 | 0.01 | 0.00 | |
| and | 63.0 | 67.0 | 4.0 | 1.37 | 1.37 | 0.3 | 0.01 | 0.00 | |
| LMDD040 | 407.50 | 15.0 | 17.0 | 2.0 | 1.05 | 1.01 | 2.9 | 0.03 | 0.02 |
| 74.0 | 343.0 | 269.0 | 1.05 | 0.82 | 18.5 | 0.29 | 0.02 | ||
| incl. | 78.0 | 80.0 | 2.0 | 1.80 | 0.92 | 72.2 | 0.89 | 0.15 | |
| and | 190.0 | 314.0 | 124.0 | 1.93 | 1.54 | 31.8 | 0.15 | 0.01 | |
| incl. | 191.0 | 217.0 | 26.0 | 1.53 | 1.21 | 26.1 | 0.27 | 0.01 | |
| incl. | 212.3 | 213.0 | 0.7 | 9.73 | 8.53 | 98.2 | 0.08 | 0.01 | |
| and | 256.0 | 265.5 | 9.5 | 1.07 | 0.69 | 30.9 | 0.06 | 0.01 | |
| and | 280.0 | 291.0 | 11.0 | 14.15 | 12.33 | 149.3 | 0.02 | 0.00 | |
| incl. | 283.0 | 285.0 | 2.0 | 72.04 | 62.95 | 745.5 | 0.01 | 0.00 | |
| and | 304.0 | 314.0 | 10.0 | 1.37 | 0.66 | 58.0 | 0.09 | 0.01 | |
| and | 328.0 | 332.5 | 4.5 | 0.64 | 0.52 | 9.8 | 0.29 | 0.10 | |
| 364.8 | 365.8 | 1.0 | 0.26 | 0.14 | 10.1 | 0.03 | 0.54 | ||
| LMDD039 | 340.84 | 72.0 | 75.0 | 3.0 | 0.21 | 0.17 | 3.4 | 0.002 | 0.00 |
Table 3: Summary of mineralised epithermal intersections in selected Limon drill holes. AuEq is calculated using gold and silver only, there is no contribution from base metals.
| 88.0 | 90.0 | 2.0 | 0.35 | 0.27 | 6.9 | 0.03 | 0.00 | ||
|---|---|---|---|---|---|---|---|---|---|
| 94.5 | 99.0 | 4.5 | 1.20 | 0.94 | 21.3 | 2.57 | 0.27 | ||
| 177.0 | 179.0 | 2.0 | 0.59 | 0.47 | 9.7 | 1.11 | 0.02 | ||
| 183.0 | 188.0 | 5.0 | 0.35 | 0.31 | 3.1 | 0.07 | 0.00 | ||
| 207.0 | 209.0 | 2.0 | 0.60 | 0.51 | 7.5 | 0.59 | 0.01 | ||
| 211.0 | 212.0 | 1.0 | 1.11 | 1.05 | 4.9 | 0.53 | 0.00 | ||
| 279.0 | 280.0 | $1.0,$ | 0.59 | 0.56 | 2.7 | 0.37 | 0.01 | ||
| 282.0 | 284.0 | 2.0 | 0.42 | 0.22 | 16.3 | 1.59 | 0.02 | ||
| LMDD038 | 312.58 | 6.0 | 186.1 | 180.1 | 0.96 | 0.87 | 7.7 | 0.22 | 0.01 |
| incl. | 6.0 | 74.0 | 68.0 | 0.57 | 0.51 | 4.8 | 0.29 | 0.03 | |
| incl. | 29.0 | 34.0 | 5.0 | 1.07 | 1.04 | 2.4 | 0.41 | 0.07 | |
| incl. | 51.6 | 59.6 | 8.0 | 1.13 | 1.06 | 5.5 | 0.05 | 0.00 | |
| incl. | 61.6 | 64.0 | 2.5 | 1.14 | 1.05 | 7.4 | 0.44 | 0.01 | |
| incl. | 69.0 | 71.0 | 2.0 | 1.09 | 0.81 | 23.2 | 1.13 | 0.07 | |
| 82.0 | 86.0 | 4.0 | 0.26 | 0.22 | 3.1 | 0.86 | 0.01 | ||
| 98.0 | 186.1 | 88.1 | 1.50 | 1.36 | 11.6 | 0.17 | 0.00 | ||
| incl. | 99.0 | 107.0 | 8.0 | 4.43 | 3.72 | 58.5 | 0.79 | 0.01 | |
| incl. | 102.0 | 107.0 | 5.0 | 6.27 | 5.29 | 80.6 | 1.07 | 0.01 | |
| and | 112.0 | 122.6 | 10.6 | 1.78 | 1.59 | 15.4 | 0.05 | 0.00 | |
| and | 136.0 | 144.0 | 8.0 | 2.10 | 2.07 | 2.1 | 0.01 | 0.00 | |
| incl. | 138.0 | 140.0 | 2.0 | 6.53 | 6.48 | 4.3 | 0.03 | 0.00 | |
| and | 150.0 | 166.0 | 16.0 | 2.83 | 2.66 | 14.3 | 0.14 | 0.00 | |
| incl. | 158.0 | 163.4 | 5.3 | 5.74 | 5.41 | 27.4 | 0.16 | 0.00 | |
| incl. | 158.0 | 159.0 | 1.0 | 16.51 | 15.30 | 98.8 | 0.24 | 0.00 | |
| LMDD037 | 303.17 | 33.0 | 40.0 | 7.0 | 0.20 | 0.19 | 0.6 | 0.00 | 0.01 |
| 220.0 | 221.0 | 1.0 | 0.26 | 0.26 | 0.1 | 0.00 | 0.01 | ||
| LMDD036 | 235.70 | 7.0 | 8.0 | $1.0,$ | 0.54 | 0.52 | 1.8 | 0.12 | 0.02 |
| 18.0 | 22.0 | 4.0 | 0.17 | 0.15 | 1.5 | 0.49 | 0.05 | ||
| 40.0 | 44.0 | 4.0 | 0.19 | 0.18 | 0.7 | 0.08 | 0.02 | ||
| 180.3 | 186.3 | 6.0 | 0.20 | 0.19 | 0.8 | 0.01 | 0.11 | ||
| LMDD035 | 237.48 | 51.0 | 146.0 | 95.0 | 0.58 | 0.52 | 4.5 | 0.04 | 0.02 |
| 71.8 | 77.8 | 6.0 | 3.30 | 2.70 | 48.9 | 0.10 | 0.03 | ||
| 98.0 | 101.1 | 3.1 | 0.99 | 0.98 | 1.1 | 0.03 | 0.01 | ||
| 120.0 | 128.0 | 8.0 | 1.02 | 1.01 | $1.2$ | 0.01 | 0.00 | ||
| 183.0 | 204.1 | 21.1 | 0.54 | 0.52 | 1.3 | 0.12 | 0.00 | ||
| LMDD033 | 277.86 | 0.0 | 10.0 | 10.0 | 0.21 | 0.17 | 3.2 | 0.01 | 0.01 |
| 16.0 | 20.0 | 4.0 | 0.29 | 0.28 | 1.1 | 0.06 | 0.01 | ||
| 261.4 | 272.0 | 10.6 | 2.34 | 2.33 | 0.6 | 0.01 | 0.02 | ||
| 261.4 | 262.5 | 1.1 | 2.48 | 2.47 | 0.9 | 0.01 | 0.09 | ||
| 270.0 | 272.0 | 2.0 | 9.35 | 9.35 | 0.1 | 0.01 | 0.00 | ||
| LMDD032 | 343.26 | 6.0 | 215.0 | 209.0 | 0.58 | 0.51 | 5.7 | 0.23 | 0.02 |
| 26.0 | 41.0 | 15.0 | 0.77 | 0.65 | 9.8 | 0.35 | 0.08 | ||
| 76.0 | 84.0 | 8.0 | 1.50 | 1.40 | 8.5 | 0.30 | 0.03 | ||
| 106.0 | 115.0 | 9.0 | 1.05 | 0.94 | 8.6 | 0.15 | 0.00 | ||
| 141.0 | 145.0 | 4.0 | 1.10 | 1.03 | 5.4 | 0.07 | 0.00 | ||
| 155.0 | 167.2 | 12.2 | 1.76 | 1.59 | 13.8 | 0.23 | 0.01 | ||
| 159.9 | 165.8 | 5.8 | 2.66 | 2.50 | 13.0 | 0.31 | 0.00 |
| 176.4 | 188.5 | 12.2 | 1.38 | 1.23 | 12.1 | 0.07 | 0.00 | ||
|---|---|---|---|---|---|---|---|---|---|
| 184.5 | 188.5 | 4.0 | 2.98 | 2.68 | 24.6 | 0.10 | 0.00 | ||
| LMDD031 | 397.13 | 6.0 | 161.0 | 155.0 | 0.47 | 0.37 | 7.9 | 0.59 | 0.03 |
| incl. | 17.4 | 20.3 | 2.9 | 1.61 | 1.32 | 24.0 | 2.13 | 0.09 | |
| and | 41.0 | 49.0 | 8.0 | 1.99 | 1.69 | 24.3 | 0.61 | 0.03 | |
| and | 106.5 | 125.0 | 18.5 | 1.17 | 0.89 | 22.9 | 0.26 | 0.04 | |
| 175.0 | 181.0 | 6.0 | 0.22 | 0.17 | 4.0 | 0.89 | 0.05 | ||
| 195.0 | 200.2 | 5.2 | 0.12 | 0.05 | 5.7 | 0.94 | 0.04 | ||
| 295.2 | 328.7 | 33.5 | 0.15 | 0.11 | 3.4 | 1.83 | 0.05 | ||
| LMDD030 | 406.25 | 46.0 | 289.0 | 243.0 | 1.32 | 1.11 | 16.9 | 0.36 | 0.02 |
| 48.0 | 224.0 | 176.0 | 1.49 | 1.27 | 18.0 | 0.22 | 0.01 | ||
| 152.0 | 194.0 | 42.0 | 3.90 | 3.37 | 43.3 | 0.29 | 0.01 | ||
| LMDD026 | 334.30 | 90.0 | 275.0 | 185.0 | 2.85 | 2.67 | 15.0 | 0.50 | 0.02 |
| 106.0 | 207.0 | 101.0 | 4.88 | 4.65 | 18.9 | 0.14 | 0.00 | ||
| 146.0 | 177.0 | 31.0 | 12.93 | 12.53 | 32.7 | 0.16 | 0.00 | ||
| 171.4 | 179.0 | 7.6 | 42.69 | 42.15 | 43.9 | 0.26 | 0.01 | ||
| 201.0 | 207.0 | 6.0 | 2.60 | 2.38 | 18.2 | 0.19 | 0.00 | ||
| 235.0 | 252.0 | 17.0 | 1.01 | 0.59 | 34.3 | 1.81 | 0.10 | ||
| 268.0 | 275.0 | 7.0 | 1.11 | 0.92 | 15.6 | 2.78 | 0.20 | ||
| LMDD017 | 214.92 | 6.8 | 183.5 | 176.7 | 1.09 | 0.97 | 10.1 | 0.20 | 0.11 |
| incl. | 81.2 | 96.2 | 15.0 | 4.00 | 3.91 | 7.69 | 0.34 | 0.01 | |
| incl. | 81.2 | 82.9 | 1.7 | 22.28 | 22.20 | 6.8 | 0.09 | 0.00 | |
| and | 157.5 | 183.5 | 26.0 | 2.46 | 2.02 | 36.2 | 0.14 | 0.00 | |
| LMDD009 | 414.89 | 138.0 | 171.7 | 33.7 | 0.28 | 0.27 | 1.0 | 0.13 | 0.01 |
| incl. | 140.0 | 159.7 | 19.7 | 0.36 | 0.34 | 1.3 | 0.06 | 0.01 |
Figure 3: Bramaderos concession showing the location of Limon and other gold-copper porphyry (yellow) and goldsilver epithermal targets (orange). The background image is gold-in-soil highlighting the potential scale increase to be delivered with more drilling at Bramaderos across multiple targets. Drilling activity during 2023 has been focussed on the Limon gold-silver epithermal opportunity.
Figure 4: Location of Sunstone's Bramaderos and El Palmar projects, Ecuador.
Table 4: Limon drill hole location details for LMDD030 – 043. Collars for all holes have been surveyed with differential GPS.
| Drill HoleNumber | Easting(PSAD56) | Northing(PSAD56) | RL (m) | Dip(degrees) | Azimuth (PSAD56Grid) (degrees) | EOH (m) |
|---|---|---|---|---|---|---|
| LMDD030 | 635020.368 | 9551070.371 | 919.359 | -70 | 303 | 406.25 |
| LMDD031 | 635021.456 | 9551070.536 | 919.286 | -80 | 330 | 397.13 |
| LMDD032 | 634842.587 | 9551146.089 | 863.942 | -55 | 105 | 343.26 |
| LMDD033 | 634717.431 | 9551358.275 | 902.284 | -45 | 199 | 277.86 |
| LMDD034 | 634842.333 | 9551145.384 | 863.91 | -55 | 120 | 346.10 |
| LMDD035 | 634889.235 | 9550978.497 | 887.91 | -50 | 330 | 237.48 |
| LMDD036 | 634848.567 | 9551146.506 | 863.756 | -45 | 263 | 235.70 |
| LMDD037 | 634889.702 | 9550976.625 | 887.794 | -65 | 286 | 303.17 |
| LMDD038 | 634842.58 | 9551146.291 | 863.798 | -55 | 95 | 312.58 |
| LMDD039 | 635139.27 | 9550960.247 | 899.685 | -45 | 142 | 340.84 |
| LMDD040 | 635004.168 | 9551183.445 | 945.382 | -63 | 202 | 407.5 |
| LMDD041 | 635086.932 | 9550853.415 | 901.045 | -45 | 152 | 398.43 |
| LMDD042 | 634572.279 | 9551430.164 | 858.952 | -35 | 264 | 359.26 |
| LMDD043 | 635068.241 | 9551002.011 | 898.341 | -35 | 290 | 370.03 |
For further information, please visit www.sunstonemetals.com.au
Mr Malcolm Norris Managing Director Sunstone Metals Ltd Tel: 07 3368 9888 Email: [email protected]
Media: Paul Armstrong Read Corporate +61 8 9388 1474
About Sunstone Metals
Sunstone has an advanced portfolio of exploration projects in Ecuador. The portfolio comprises:
The Bramaderos Gold-Copper Project where Sunstone owns an 87.5% interest, and SolGold Canada, Inc. (formerly Cornerstone Capital Resources) a subsidiary of SolGold, holding 12.5% (loan carried through to start of commercial production) (see ASX announcement dated 10th April 2017, 28th August 2019, and 7 January 2020). The Bramaderos gold-copper project is located in Loja province, southern Ecuador, and is highly prospective for the discovery of large porphyry gold-copper systems, and high-grade epithermal gold systems. The Bramaderos concession is host to multiple fertile mineralised systems with significant discovery potential.
The Brama-Alba deposit, within the Bramaderos concession contains an initial Mineral Resource estimate of 156Mt at 0.53g/t AuEq for 2.7Moz gold-equivalent*. In addition to this is the Bramaderos project Exploration Target of between 3.3Moz and 8.6Moz AuEq within 255 to 360Mt at a grade between 0.40 and 0.74g/t AuEq (see ASX release dated December 13, 2022).
| JORCClassification | Tonnage(Mt) | Au(g/t) | Cu(%) | Ag(g/t) | AuEq(g/t) | AuEq(Mozs) |
|---|---|---|---|---|---|---|
| Indicated | 9 | 0.38 | 0.09 | 1.1 | 0.53 | 0.2 |
| Inferred | 147 | 0.35 | 0.11 | 1.3 | 0.53 | 2.5 |
| Total | 156 | 0.35 | 0.11 | 1.3 | 0.53 | 2.7 |
The company confirms that it is not aware of any new information or data that materially affects the information included in the original market announcement for the Mineral Resource estimate and Exploration Target referred to above and, that all material assumptions and technical parameters underpinning the estimates continue to apply and have not materially changed. The company confirms that the form and context in which the Competent Person's findings are presented have not been materially modified from the original market announcement.
The potential quantity and grade of the Exploration Target is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource for the target area reported. It is uncertain if further exploration will result in the estimation of a Mineral Resource.
*The gold equivalent calculation formula is AuEq(g/t) = (Au grade x Au price x Au recov / 31.1035) + (Ag grade x Ag price x Ag recov / 31.1035) + (Cu grade x Cu price x Cu recov / 100)) / (Au price x Au recov / 31.1035). The prices used were US$1,800/oz gold and US$9,500/t copper and US$22/oz silver. Recoveries are estimated at 89% for gold, 85% for copper, and 60% for silver based on metallurgical studies. In Sunstone's opinion all the elements included in the metal equivalents calculation have reasonable potential to be recovered and sold.
The El Palmar Copper-Gold Project where Sunstone holds 70% of the highly prospective 800ha El Palmar gold-copper porphyry project in Ecuador. Sunstone can acquire 100% through a Staged Acquisition Agreement. A Staged Acquisition Agreement to acquire the nearby Verde Chico Project has also been signed. The El Palmar and Verde Chico gold-copper projects are located in Imbabura province, northern Ecuador, within the same geological belt that includes the giant Alpala, Tandayama-America and Llurimagua porphyry copper-gold and copper-molybdenum deposits.
Competent Persons Statement
The information in this report that relates to exploration results is based upon information reviewed by Dr Bruce Rohrlach who is a Member of the Australasian Institute of Mining and Metallurgy. Dr Rohrlach is a full-time employee of Sunstone Metals Ltd and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves". Dr Rohrlach consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.
Mr Malcolm Norris, Managing Director of Sunstone Metals Ltd., has authorised this announcement to be lodged with the ASX.
| ORC Code explanation | Commentary | |
|---|---|---|
| Samplingtechniques | • Nature and quality of sampling (e.g. cut channels,random chips, or specific specialised industry standardmeasurement tools appropriate to the minerals underinvestigation, such as downhole gamma sondes, orhandheld XRF instruments, etc.). These examples shouldnot be taken as limiting the broad meaning of sampling. | • The results announced here are from diamond drillingsamples. The drill core sampling was carried out usinghalf core, generally at 1-2m intervals. |
| Include reference to measures taken to ensure sample$\bullet$representivity and the appropriate calibration of anymeasurement tools or systems used. | · Core recovery was good, and core aligned prior tosplitting. | |
| Aspects of the determination of mineralisation that areMaterial to the Public Report. In cases where 'industrystandard' work has been done this would be relativelysimple (e.g. 'reverse circulation drilling was used toobtain 1 m samples from which 3 kg was pulverised toproduce a 30 g charge for fire assay'). In other cases,more explanation may be required, such as where thereis coarse gold that has inherent sampling problems.Unusual commodities or mineralisation types (e.g.submarine nodules) may warrant disclosure of detailedinformation. | · Diamond drilling, rock chip and channel samplingpoints have been guided by geological mapping. Thedrill samples from Limon were dried, crushed to 70%passing 2mm, Split 1000g and pulverised to 85%passing 75microns. A 20g portion of this sample wasused for multi-element analysis (IMS-230) and a 30gsample for Fire Assay Au (FAS-111). | |
| Drillingtechniques | · Drill type (eg core, reverse circulation, open-holehammer, rotary air blast, auger, Bangka, sonic, etc) anddetails (e.g. core diameter, triple or standard tube, depthof diamond tails, face-sampling bit or other type,whether core is oriented and if so, by what method, etc). | • Current drilling by Sunstone is diamond core drillingand has drilled to various depths up to 720m. Thediamond core was drilled delivering either HTW(70.9mm) or NTW (56mm) core. Drill core is orientedusing a Reflex ACT II tool for bottom of hole. |
| Drill samplerecovery | Method of recording and assessing core and chip samplerecoveries and results assessed. | · Diamond core recovery data for the Limon drillingwas measured for each drill run and captured in adigital logging software package. The data has beenreviewed and core recovery was approximately 100%throughout. |
| Measures taken to maximise sample recovery and ensurerepresentative nature of the samples. | • Core recovery at Limon was good, no extra measureswere taken to maximise sample recovery. | |
| Whether a relationship exists between sample recovery$\bullet$and grade and whether sample bias may have occurreddue to preferential loss/gain of fine/coarse material. | · No relationship between sample recovery and gradehas been established. | |
| Logging | Whether core and chip samples have been geologically$\bullet$and geotechnically logged to a level of detail to supportappropriate Mineral Resource estimation, miningstudies and metallurgical studies. | • Drill samples, trench samples and rock chips werelogged for lithology, weathering,structure,mineralogy, mineralisation, colour, and other features.Logging and sampling were carried out according toSunstone's internal protocols and QAQC procedureswhich comply with industry standards. |
| Whether logging is qualitative or quantitative in nature.Core (or costean, channel, etc.) photography. | • Drill samples, and trench and rock chip samples arefor lithology,weathering,structure,loggedmineralogy, mineralisation, colour, and other features. | |
| The total length and percentage of the relevant$\bullet$intersections logged. | • The drill holes and trenches are logged in full, fromstart to finish of the excavation. | |
| Sub-samplingtechniquesand sample | • If core, whether cut or sawn and whether quarter, half orall core taken. | • Half core was used to provide the samples that weresubmitted for assay. Quarter core samples were taken$\sim$ 1 in every 28 samples for duplicate sampling. Theremaining core is left in the core trays. |
| preparation | • If non-core, whether riffled, tube sampled, rotary split,etc. and whether sampled wet or dry. | $\bullet$ N/A. |
| • For all sample types, the nature, quality andappropriateness of the sample preparation technique. | • Surface and drill core samples from Limon were sent tothe LAC y Asociados Cia. Ltda. Sample PreparationFacility in Cuenca, Ecuador for sample preparation.The standard sample preparation for drill core samples(Code PRP-910) is: Drying the sample, crushing to sizefraction $70%$ <2mm and splitting the sample to a 250gportion by riffle or Boyd rotary splitter. The 250g |
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Quality control procedures adopted for all sub-sampling$\bullet$stages to maximise representivity of samples. | sample is then pulverised to $>85%$ passing 75 micronsand then split into two 50g pulp samples. Then one ofthe pulp samples was sent to the MS AnalyticalLaboratory in Vancouver (Unit 1, 20120 102ndAvenue, Langley, BC V1M 4B4, Canada) for gold andbase metal analysis.• The sample preparation is carried out according toindustry standard practices using highly appropriatesample preparation techniques.· Sunstone used an industry standard QAQCprogramme involving Certified Reference Materials"standards" and blank samples, which were introducedin the assay batches.• Standards (Certified Reference Materials) or analyticalblanks were submitted at a rate of 1 in 28 samples.Field duplicates were also taken at a rate ofapproximately 1 in 28 samples.• The check or duplicate assay results are reported alongwith the sample assay values in the final analysisreport. | |
| • Measures taken to ensure that the sampling isrepresentative of the in-situ material collected, includingfor instance results for field duplicate/second-halfsampling. | • For diamond core, the routine sample procedure is toalways take the half/quarter core to the right of theorientation line (looking down hole) or the cut line (incases where the orientation line was not reliable).• Once assay results are received the results fromsamplesare comparedduplicatewiththecorresponding routine sample to ascertain whether thesampling is representative. | |
| Whether sample sizes are appropriate to the grain size of$\bullet$the material being sampled. | Sample sizes are considered to be appropriate for thestyle of sampling undertaken and the grainsize of thematerial, and correctly represent the style and type ofmineralisation at the exploration stage. | |
| Quality ofassay data andlaboratorytests | • The nature, quality and appropriateness of the assayingand laboratory procedures used and whether thetechnique is considered partial or total. | Sunstone uses a fire assay gold technique for Auassays (FAS-111) and a four acid multi elementtechnique (IMS-230) for a suite of 48 elements. FAS-111 involves Au by Fire Assay on a 30-gram aliquot,fusion and atomic absorption spectroscopy (AAS) attrace levels. IMS-20 is considered a near total 4 acidtechnique using a 20g aliquot followed by multi-element analysis by ICP-AES/MS at ultra-trace levels.This analysis technique is considered suitable for thisstyle of mineralisation. |
| • For geophysical tools, spectrometers, handheld XRFinstruments, etc., the parameters used in determining theanalysis including instrument make and model, readingtimes, calibrations factors applied and their derivation,etc. | Handheld XRF data, together with detailed geologicallogging, are used as a guide to areas of potentialmineralisation and samples from these areas are sentfor laboratory analysis as described above. | |
| • Nature of quality control procedures adopted (e.g.standards, blanks, duplicates, external laboratorychecks) and whether acceptable levels of accuracy (i.e.lack of bias) and precision have been established. | Standards, blanks and duplicates are inserted $\sim$ 1/28samples. The values of the standards range from lowto high grade and are considered appropriate tomonitor performance of values near cut-off and nearthe mean grade of the deposit.• The check sampling results are monitored, andperformance issues are communicated tothelaboratory if necessary. | |
| Verification ofsampling and | The verification of significant intersections by either$\bullet$independent or alternative company personnel. | • Procedure checks have been completed by theCompetent Person for exploration results for thisannouncement. |
| assaying | The use of twinned holes. | Twin holes have not been drilled in these areas.$\bullet$ |
| Documentation of primary data, data entry procedures,data verification, data storage (physical and electronic)protocols. | Sunstone sampling data were imported and validatedusing Excel. |
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| • Discuss any adjustment to assay data. | • Assay data were not adjusted. Core loss intervals areassigned assay values of zero where present. | |
| Location ofdata points | • Accuracy and quality of surveys used to locate drill holes(collar and down-hole surveys), trenches, mine workingsand other locations used in Mineral Resource estimation. | Sample co-ordinates are located by GPS and for trenchsamples measured along the length of the trench. |
| Specification of the grid system used.٠ | Ecuador projection parameters:٠ | |
| ParameterValue | ||
| International 1924Reference Ellipsoid | ||
| Semi Major Axis | ||
| Inverse Flattening $(1/f)$ | ||
| UTM Zone -17S (DatumType of ProjectionPSAD 56 ) | ||
| Central Meridian:$-81.0000$ | ||
| 0.0000Latitude of Origin | ||
| Scale on Central Meridian0.9996 | ||
| False Northing10000000 | ||
| False Easting500000 | ||
| Quality and adequacy of topographic control. | • The topographic control was compared againstpublished maps and satellite imagery and found to begood quality. | |
| Data spacingand | • Data spacing for reporting of Exploration Results. | • The drill core samples were collected from diamonddrill holes from the Limon target, and with samplelength generally ranging between $1.0 - 2.0$ m. |
| distribution | Whether the data spacing, and distribution is sufficientto establish the degree of geological and gradecontinuity appropriate for the Mineral Resource and OreReserve estimation procedure(s) and classificationsapplied. | • The data from these samples does not contribute to anyresource estimate nor implies any grade continuity. |
| • Whether sample compositing has been applied. | • No sample compositing was done. | |
| Orientation ofdata inrelation togeological | Whether the orientation of sampling achieves unbiasedsampling of possible structures and the extent to whichthis is known, considering the deposit type. | Drilling orientations were appropriate for theinterpreted geology providing representative samples.Trench orientations and rock chip locations were$\bullet$appropriate for the interpreted geology providingrepresentative samples. |
| structure | • If the relationship between the drilling orientation andthe orientation of key mineralised structures isconsidered to have introduced a sampling bias, thisshould be assessed and reported if material. | • No sampling bias is expected at this stage. |
| Samplesecurity | The measures taken to ensure sample security.$\bullet$ | · Sunstone sampling procedures indicate individualsamples were given due attention.• Sample security was managed through sealedindividual samples and sealed bags of multiplesamples for secure delivery to the laboratory bypermanent staff of the joint venture.• MS Analytical is an internationally accreditedlaboratory that has all its internal procedures heavilyscrutinised in order to maintain their accreditation. MSAnalytical is accredited to ISO/IEC 17025 2005Accredited Methods. |
| Audits orreviews | The results of any audits or reviews of sampling$\bullet$techniques and data. | • Sunstone's sampling techniques and data have beenaudited multiple times by independent miningconsultants during various project assessments. Theseaudits have concluded that the sampling techniques |
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| and data management are to industry standards.• All historical data has been validated to the bestdegree possible and migrated into a database. |
TABLE 1 – Section 2: Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineraltenement andland tenurestatus | •Type, reference name/number, location and ownershipincluding agreements or material issues with thirdparties such as joint ventures, partnerships, overridingroyalties, nativetitle interests,historicalsites,wilderness or national park and environmentalsettings. | •The Bramaderos Exploration Concession is located inthe Loja Province of southern Ecuador. The concessionwas granted to La Plata Minerales S.A. ("PLAMIN") inJanuary 2017. PLAMIN is a subsidiary of SunstoneMetals Ltd. The concession is subject to a Joint Venturebetween SolGold Canada Inc. (12.5%) and SunstoneMetals Ltd. (87.5%). There are no declared wildernessareas or national parks within or adjoining the concessionarea. There are no established native title interests. |
| •The security of the tenure held at the time of reportingalong with any known impediments to obtaining alicence to operate in the area. | •The Bramaderos Exploration Concession was granted toLa Plata Minerales S.A. ("PLAMIN") in January 2017.PLAMIN is now a subsidiary of Sunstone Metals Ltd.The Bramaderos Concession is subject to a Joint Venturebetween Sunstone Metals and SolGold. Sunstone has an87.5% interest in the JV. SolGold's 12.5% interest is loancarried. | |
| Explorationdone by otherparties | •Acknowledgment and appraisal of exploration by otherparties. | •The historic exploration at Bramaderos was completedby various groups over the period 1970-1984, 2001-2002and 2004-2007. Most of the readily available historicdata has been acquired and compiled into databases anda GIS project. Exploration by other parties has includedstream sediment surveys, geological mapping, rock chipsampling (888 samples) and grid-based soil sampling(1324 samples), trenching and channel sampling (17trenches), ground magnetic surveys (31 line kilometres),electrical IP surveys and diamond drilling (10426m). |
| Geology | •Deposittype,geologicalsettingandstyleofmineralisation. | •The deposit style being explored for includes intrusionrelated and stockwork hosted porphyry Au-Cu systemsplus epithermal gold-silver-polymetallic veins. Thesetting at Limon is a volcanic arc setting of Cretaceousage intrusions. |
| Drill holeInformation | •A summary of all information material to theunderstanding of the exploration results including atabulation of the following information for all Materialdrill holes:a. easting and northing of the drill hole collarb. elevation or RL (Reduced Level – elevation abovesea level in metres) of the drill hole collarc.dip and azimuth of the holed. down hole length and interception depthe.hole length. | •Details of the samples discussed in this announcementare in the body of the text.•See Figures 1-3 for the location of soil sampling anddrilling activities at Limon, and nearby areas. |
| •If the exclusion of this information is justified on thebasis that the information is not Material and thisexclusion does not detract from the understanding ofthe report, the Competent Person should clearlyexplain why this is the case. | •Information included in announcement. | |
| Dataaggregationmethods | •In reporting Exploration Results, weighting averagingtechniques,maximumand/orminimumgradetruncations (e.g. cutting of high grades) and cut-offgrades are usually Material and should be stated. | •Weighted averages were calculated over reportedintervals according to sample length.•No grade cut-offs were applied. |
| Criteria | JORC Code explanation | C ommentary |
|---|---|---|
| • Where aggregate intercepts incorporate short lengthsof high-grade results and longer lengths of low-graderesults, the procedure used for such aggregationshould be stated and some typical examples of suchaggregations should be shown in detail. | No aggregating of intervals undertaken at this stage.$\bullet$ | |
| The assumptions used for any reporting of metal$\bullet$equivalent values should be clearly stated. | During 2023, preliminary metallurgical studies wereperformed at Base Metal Laboratories in Kamloops,Canada, and are indicating a standard grind withflotation circuit followed by cyanide leaching.Depending on grind size, this initial testwork hasdemonstrated that overall estimated recoveries for thecombined process are in excess of 90% for both goldand silver.Preliminary metallurgical studies for the gold-copper-silver porphyry mineralisation are indicating a standardgrind with a flotation circuit. Stage one will recovercopper and the majority of gold as a saleableconcentrate. Stage two is a finer grind with a cyanideleach for gold on site. Current, overall estimatedrecoveries for the combined process are 86% for copperand 89% for gold. | |
| Relationshipbetweenmineralisation | If the geometry of the mineralisation with respect to thedrill-hole angle is known, its nature should bereported. | Figures 1-3 show the interpreted strike orientation of themineralised lodes based on mapping and interpretationof detailed magnetic data. |
| widths andinterceptlengths | • If it is not known and only the down hole lengths arereported, there should be a clear statement to thiseffect (e.g. 'down hole length, true width not known'). | True widths of mineralised lodes are not well defined atthis stage. |
| Diagrams | Appropriate maps and sections (with scales) and$\bullet$tabulations of intercepts should be included for anysignificant discovery being reported. These shouldinclude, but not be limited to a plan view of drill holecollar locations and appropriate sectional views. | See Figures 1-2 for maps showing distribution ofsamples. |
| Balancedreporting | Where comprehensive reporting of all Exploration$\bullet$Results is not practicable, representative reporting ofboth low and high grades and/or widths should bepracticed to avoid misleading reporting of ExplorationResults. | • Figures 1-2 show the current interpretations of geology. |
| Othersubstantiveexplorationdata | Other exploration data, if meaningful and material,should be reported) including (but not limited to):geological observations; geophysical survey results;geochemical survey results; bulk samples - size andmethod of treatment; metallurgical test results; bulkdensity, groundwater, geotechnical and rockcharacteristics; potential deleterious or contaminatingsubstances. | Figures 1-2 above show various datasets that are beingused to identify target areas and to guide current andfuture drilling. |
| Further work | • The nature and scale of planned further work (e.g. testsfor lateral extensions or depth extensions or large- | The planned exploration program is outlined in theannouncement. |
| scale step-out drilling).• Diagrams clearly highlighting the areas of possibleincludingthemaingeologicalextensions.interpretations and future drilling areas, provided thisinformation is not commercially sensitive. | See Figures 1-3 which show areas for furtherexploration. |