Cornerstone Capital Resources Inc. provide an independently verified update regarding the Mineral Resource Estimate for the Tandayama-Ameríca porphyry copper-gold satellite deposit located 3km north of the Alpala Deposit at its Cascabel copper-gold porphyry joint venture project in northern Ecuador in which Cornerstone has a 15% interest2 financed through to completion of a feasibility study and repayable out of Cornerstone's share of project earnings, plus 6.85% of the shares of joint venture partner and Project operator SolGold Plc, for a total direct and indirect interest in Cascabel of 20.8%. On 30 March 2022, a data cut-off was applied to the TAM dataset for the purposes of an updated Mineral Resource Estimation. The TAM MRE#2 dataset comprised 30,892m of diamond drilling from holes 1-41, 458m of surface rock-saw channel sampling from 72 outcrops, and 29,631.6m of final assay results from holes 1-40.

This equates to an additional 15,065.6m of final assays results received since the recent release of TAM maiden MRE. The estimation process followed the Canadian Institute of Mining, Metallurgy and Petroleum “Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines”. The Mineral Resource Estimate is stated in accordance with CIM Definition Standards and Canadian National Instrument 43-101.

Ordinary Kriging (“OK”) was run in three search passes and with soft boundaries using Leapfrog Edge software. The estimation of Cu and Au was confined within 3D estimation domains, which were based on the combination of two 3D wireframe interpretations: Grade Shell Interpretation: Low-, Medium- and High-Grade shells equating to CuEq cut-off grades of 0.15%, 0.30% and 0.45% respectively. Lithological Interpretation: Modelling of seven rock groups, comprising “D10” (Pre-Mineral Diorite Host Rock), “EM” (Early-Mineral Quartz Diorite and Diorite), “IBX” (Pre-Mineral Intrusive Breccia), “IM” (Intra-mineral Quartz Diorite and Diorite), “LM” (Late-mineral Diorite), “PM” (Post-mineral Quartz Diorite and Diorite), “V” (Pre-Mineral Volcanic Host Rocks), and “SOI” (soil and oxidised rock).

Model validation tests have not exhibited any material bias between the input composite grades and the block model estimates. The TAM MRE is constrained within a 3D Open Pit Optimised Shape (“OP”) and an Underground Optimised Shape (“UG”), whereby the UG “daylights” into the floor of the OP. The TAM deposit shares the same geological and structural setting as the Alpala deposit.

Mineralization is hosted within a complex of middle to late-Eocene (Bartonian) hornblende-bearing diorites, quartz diorites and intrusive breccias that intrude volcanic host rocks to form a complex of stocks, dykes, and breccia pipes. The trend of mineralization throughout the TAM deposit is defined by a northwest (315?) trending intrusive complex inclined steeply (78?) towards the northeast. Surface mapping data was supported by structural measurements taken from orientated drill core provided data from 127 intrusive contacts and 3062 B-type quartz veins.

Copper and gold mineralization is intimately associated with porphyry style B-type quartz-chalcopyrite veins and stockworks, centred upon an early-mineral causal quartz-diorite intrusion (QD10), and cut by a series of intra-mineral, late-mineral and post-mineral stocks dykes and breccias of diorite, hornblende diorite, and quartz diorite. Intrusions have emplaced episodically such that each subsequent intrusion has introduced mineralizing fluids (and subsequent arrays of mineralized veins) into the TAM system, and/or remobilizing and enriching existing mineralization or contributed to localized overprinting of pre-existing mineralization. The geological character of the porphyry stocks /dykes encountered through drilling to date indicate a well-preserved porphyry system with significant potential for greater depth extent.

Individual mineralized porphyry dykes are observed to have emplaced within a vertical column of over 1,000m. The full size and tenor of the TAM system has not yet been tested. Mineralization remains open to the south and east and at depth.

Further surface geochemical anomalies to the east of the current drilling area require drill testing. The cut-off grades used for reporting have been based on up to date third party metal price research, forecasting of Cu and Au prices, and a cost structure from mining studies currently being reviewed. Costs include mining, processing and general and administration (“G&A”).

Net Smelter Return (“NSR”) includes metallurgical recoveries and off-site realisation (“TC/RC”) including royalties and utilising metal prices of Cu at US$3.30/lb and Au at US$1,700/oz. Cut-off grades have been developed independently for open pit mining methods and underground bulk mining methods. The cut-off grade for potentially open pittable material has been calculated at 0.16% CuEq using a copper equivalency factor of 0.632, while the cut-off grade for material potentially mineable by a bulk underground mining method such as block caving has been calculated at 0.28% CuEq using a copper equivalency factor of 0.654.

Optimization was completed in two stages, with the open pit optimization initially applied to the block model, and the remaining material was then considered for underground optimization. The open pit optimization was completed using the conventional Lerchs-Grossman optimization routine implemented in Whittle software, and the revenue factor one pit was selected for reporting the Mineral Resource. The QP considers that the open pit portion of the reported Mineral Resource, has reasonable prospects for eventual economic extraction at the specified cut-off grade.

Subsequently, a three-dimensional Underground Optimized Shape (“UOS”) was generated using Datamine software at a cut-off grade of 0.28% CuEq. This cut-off grade was based on costs associated with the block cave mining method. The UOS maximizes the tonnes above the cut-off while ensuring that all material was part of a minimum mining unit with geometry appropriate for a block cave of 120 m length by 120 m width by 200 m height.

These minimum mining dimensions for a block cave are consistent with Mining Plus's experience and the resulting shape contains planned internal and edge dilution that the QP considers appropriate. It is noteworthy that the OP and UG optimized shapes are not described as “mineable shapes”. Mining factors excluded from this analysis include, but are not limited to, capital costs (non-mining, access and footprint establishment), regional pillars, footprint geometries, unplanned dilution and the time value of money.

However, the shape does enclose a contiguous and appropriately diluted Mineral Resource that, by virtue of its grade and geometry, should be considered for inclusion within a mineable shape.