The Don Mario property is underlain by Lower to Middle Proterozoic metamorphic rocks of the Cristal Sequence that comprise a portion of the Bolivian Shield’s Adventura Complex. The Cristal Sequence is composed of medium to high grade metasedimentary units such as biotite schist, mica schist, quartzite, biotite–plagioclase gneiss and calcsilicates gneiss, as well as lesser amounts of pegmatite and amphibolite dikes. The Cristal Schist belt subunit hosts the Don Mario mine’s Upper and Lower Mineralized Zones as well as the nearby CF, Don Mario North, and Don Mario South gold prospects (Wright et al., 2009).

Mining and exploration programs to date on the property have shown the Don Mario deposit to consist of the gold-enriched LMZ and the copper-enriched UMZ. The LMZ is characterized by a well-developed northwest striking and steeply northeast dipping structural/lithologic corridor that constrains gold-coppersilver mineralization as well as distinctive alteration assemblages. Alteration associated with gold-coppersilver mineralization commonly takes the form of iron carbonate, white mica, biotite, quartz, albite, andalusite, staurolite, garnet, cordierite, gedrite and anthophylllite-cummingtonite. Spatial disposition of the LMZ and UMZ deposits may be of structural derivation, with the calc- silicate dominated and synclinally folded UMZ host sequence representing a shearing- associated “flower structure” above the sheared LMZ.

Past workers have characterized mineralization at the Don Mario deposit as being structurally focused or shear zone related. However, as outlined by Wright et al. (2009), alternative views on deposit genesis include skarn association, banded iron formation-hosted structural association, and deformed, syngenetic massive sulphide association,. In contrast to these, the deposit was more recently classified by Arce Burgoa (2009) as being a deformed example of the Iron Ore copper Gold (IOCG) association.

Four principal mineral deposits on the Don Mario property have contributed to commercial mining operations to date. The most significant of these are the UMZ and LMZ. The CF deposit is located 500 meters northwest along strike from the LMZ and UMZ and supported a limited amount of open pit mining from 2009 to 2011. All occur within the Cristal Schist Belt and the Don Mario Shear Zone. Orvana also mined LMZ style mineralization from the Las Tojas (LT) deposit during the 2009 to 2011 period. This deposit i located about 12 km northwest of Don Mario mine and is associated with an un-named shear zone within the Eastern Schist Belt that is separate from, but parallels, the Cristal Schist Belt. Summary points relating to the main gold-copper-silver deposits of the Don Mario property are highlighted below:

Don Mario Shear Zone (Cristal Schist Belt)
- LMZ gold deposit: mined out predominantly by underground methods in 2009.
- UMZ copper-gold-silver deposit: overlies the LMZ.
- CF gold deposit: 0.5 km north of LMZ and UMZ; saw limited open pit production from 2009 to 2011; CF was a low copper grade and high gold grade deposit amenable for the CIL plant.

Unnamed Shear Zone (Eastern Schist Belt)
- LT gold deposit – mined out in 2011 & 2019
- Oscar gold prospect northwest of LT has not been thoroughly tested by drilling and trenching to date
- In addition to the known deposits, several geophysical and geochemically defined targets for exploration drilling have been identified along the 40 km length of this schist belt.

The UMZ forms a prominent, oval shaped, treeless hill that is oriented at approximately 315º, parallel to the regional shear fabric trend of the Cristal Schist Belt. The mineralized zone plunges northwest at approximately 15º. The UMZ has been divided into 9 main rock types, the most prevalent of which are calc-silicates such as diopside tremolite rock and massive tremolite rock plus dolomite/ophicalcite and talc schist.

The main UMZ calc silicate bearing zone is approximately 500 m long and forms the Cerro Don Mario, which is a ridge approximately 120 m high. This rock package has a maximum horizontal width of approximately 150 m and ranges from 5 m to 100 m thick. Part of the magnesio-silicate alteration and UMZ mineralization is weathered and is divided into four mineralization zones based on mineralogy:

- The Porous zone is characterized by vuggy cavities left by the dissolution of calcite and locally abundant masses of white and orange brown amorphous zinc carbonates and hydroxides, including smithsonite.

- The Oxide zone is characterized by abundant malachite with lesser chrysocolla, azurite, native copper, cuprite, pitch-imonite, and silver sulfosalts

- The Transition zone features traces of pyrite, bornite, sphalerite, and galena withweathered limonite and chalcocite coatings, as well as minor copper oxides

-The Sulphide zone consists of dark green tremolite with bornite, chalcopyrite, and sphalerite. Gold and silver grades are associated with chalcopyrite and bornite mineralization.

The method of oxide stock exploitation will be based on the load and haulage the blended of different rock types with average grade for recovery of Au-Cu-Ag.

The Don Mario’s operation stopped in first quarter 2020 the exploitation. The mine Las Tojas, unit were mined by open pit method that produced a nominal average of 2,000 tonnes per day of ore of two material types – transitional and sulphides. Oxides ores were stockpiled during the mine life to recover at the end of the mine life the gold, copper and silver contents by another recovery method such as “Sulphidization”.

Crushing & Grinding
Oxide mineralization will be ground in the existing mill grinding circuit to a grind size of 90% minus 150 mesh.

Crushing
Ore extracted from the UMZ pit is stockpiled and classified according to mineralogy, gold, copper, and/or deleterious element grades. When possible, a suitable ore blend is prepared to feed the mill. A front end loader collects the ore from the plant stockpile and delivers it to the crusher feed bin equipped with a 500 mm aperture slotted grizzly screen. The crusher feed bin has an apron feeder that feeds the primary single toggle jaw crusher and any apron feeder spillage is collected on a conveyor belt below. The jaw crusher set to 153 mm. The spillage and the crushed ore which is less than 90 mm in size are transferred to the next conveyor belt equipped with load cell type belt weightometer and this belt discharges into the 800 ton fine ore mill feed bin. A level indicator and controller in the mill feed bin controls the apron feeder feed rate to the jaw crusher to maintain the set level in the bin.

Grinding
Dry crushed ore at P80 < 90 mm is fed to the SAG mill (5.5 m internal diameter by 2.7 m effective grinding length) by means of a conveyor belt equipped with a load cell type belt weightometer. The load signal controls the feed rate from the mill feed bin discharge conveyor onto the conveyor belt feeding the SAG mill. The pulp density in the mill is controlled by adding process water to the SAG mill inlet. Oversize material is removed from the mill discharge pulp with the discharge end trommel screen. The oversize fraction is delivered back to the SAG mill inlet, while the undersize fraction flows to the common pump box for both the SAG mill discharge and the ball mill discharge. The combined mill discharge is pumped to a cluster of three 380 mm diameter Krebs hydrocyclones for classification (there is one on standby). The cyclone overflow reports to the flotation section and the cyclone underflow is split, with part reporting to the gravity concentration section (approximately 100 tph) and the balance reporting to the ball mill feed. The ball mill has a 3.6 m internal diameter by 6 m effective grinding length. The cyclone overflow at 40% solids has a size of P80 < 106 µm.

Since 2018, the Company has been re-evaluating the economic potential of processing existing mineral Oxide Stockpile. The preliminary assumption was that it would be processed by flotation and would not be included in the carbon-in-leach circuit. However, from fiscal 2018, the Company has been evaluating metallurgical alternatives to process the Oxide Stockpile, involving different international metallurgical consultants, concluded that a sulphidization circuit would maximize the value of the stockpile. The Company plans to complete final evaluation of the Project by the end of the third quarter of fiscal 2021 (the Company’s fiscal year 2021 runs from October 2020 to September 2021), after completion of detailed engineering works, whose purpose is to de-risk technical CAPEX assumptions and sourcing costs. Subject to the favorable completion of technical, economic and funding analysis, the sulphidization circuit and ancillary facilities development is expected to require approximately t ........