The Lindero Project contains two known porphyry gold-copper deposits. The Lindero Deposit is the focus of the Feasibility Study and the Lindero Technical Report; whereas the Arizaro Deposit, located 3.2 km southeast of the Lindero Deposit, is described only in terms of exploration conducted to date.

In the Central Andes, the altiplano or puna is a high plateau of more subdued relief between the Eastern Cordillera, a rugged region usually rising to between 3 km and 4.5 km, and the Western Cordillera, which is a high spine of mountains that may reach as much as 5 km in height. The Arizaro Volcanic Complex consists of two superimposed concentric volcanic centers, the Arizaro and the Lindero cones, located in the Archibarca volcanic arc at the southern margin of the Salar de Arizaro basin. Basement rocks crop out to the north of the Lindero Deposit, and consist of coarse- grained Ordovician granites uncomformably overlain by Early Tertiary red bed sandstones. The Lindero– Arizaro complex, a series of diorite to monzonite porphyritic stocks, intrudes these units.

Mineralized zones at the Lindero Deposit form a semi-circular shape about 600 m in diameter which extends to a depth of 600 m, consisting of four different zones at the surface. The distribution of gold–copper mineralization at Lindero shows a strong relationship to lithology, stockwork veinlets, and alteration assemblages. Gold values average 0.70 g/t Au and copper values are typically about 0.11 % Cu. Higher grades of gold–copper (approximately 1 g/t Au and 0.1 % Cu) are commonly associated with sigmoidal quartz, quartz–magnetite–sulfide, biotite-magnetite–chalcopyrite, magnetite–chalcopyrite and quartz–limonite–hematite stockworks that are strongly associated with K- feldspar alteration. This association is very common in the east zone of the deposit, where the highest gold grades occur. At other locations where one or more stockwork types are missing or the intensity of fracturing is lower, mineralization tends to be weaker and the grades of gold tends to be lower (approximately 0.4 g/t Au).

Gold mineralization at Lindero is characterized by native, free-milling gold associated with chalcopyrite and/or magnetite grains with rare interstitial quartz.

The weathered oxidation zone at Lindero is generally poorly developed and averages 44 m in thickness.

The Arizaro volcanic center is characterized by fine- to medium-grained hornblende diorite to monzonite porphyritic stocks. The Arizaro Deposit is dominated by a main, moderately to strongly mineralized intrusive unit that crops out in the central part of the prospect area. It consists of fine hornblende porphyritic diorite intruded by several stocks, dikes, igneous-cemented breccias and hydrothermal breccias. Smaller stocks are exposed in a few areas. Dikes of andesitic and dacitic composition are generally distributed radially to the main intrusive unit.

Arizaro gold–copper mineralization is hosted in one body which has a semi-oval shape at the surface. In the center there is a high-grade body with a semi-ellipsoidal form, extending north-south for 480 m and about 50 m wide. The Arizaro Deposit has mineralization styles with copper– gold grades that are strongly correlated with different alteration assemblages. Mineralization is mainly associated with potassic alteration. This occurs generally in multidirectional veins, vein stockworks and disseminations. In some areas, the vein density is high, forming vein stockworks in the intrusive rocks. These vein stockworks are limited to magnetite–biotite veinlets, quartz– magnetite–chalcopyrite veinlets, late magnetite breccias and in late-stage mineralization events, anhydrite–sulfide veinlets. Chalcopyrite and bornite are the main copper minerals. Coarse gold was observed and confirmed with Xray diffraction analysis in the University of Neuquen, Argentina, laboratory.

Lindero and Arizaro are examples of gold-rich porphyry copper deposits as described by Sillitoe (2000). More specifically, they show affinities with the porphyry gold deposit model (Rytuba and Cox, 1991; also termed dioritic porphyry gold deposits by Seedorff et al., 2005). These are exemplified by the Refugio, Cerro Casale, Marte, and Lobo gold deposits of the Miocene-age Maricunga belt, Chile, approximately 200 km south of Lindero. Vila and Sillitoe (1991) and Muntean and Einaudi (2000, 2001) described those deposits in detail.

The deposits of the Project area are considered to be examples of porphyry-style deposits, in particular gold-rich porphyries based on the following:
• High level (epizonal) stock emplacement levels in magmatic arc;
• High-level stocks and related dikes intrude their coeval and cogenetic volcanic piles. Intrusions range from fine through coarse-grained, equigranular to coarsely porphyritic;
• Mineralization in or adjoining porphyritic intrusions of quartz diorite/monzonite composition;
• Mineralization is spatially, temporally, and genetically associated with hydrothermal alteration of the intrusive bodies and host rocks;
• Gold–copper mineralization formed during intrusion of multiple phases of similar composition intrusive rocks;
• Large zones of quartz veining, stockwork mineralization, and disseminated pyrite;
• Tenor of gold and copper grades, i.e., large tonnage but low grade.

At the Lindero Deposit, native gold and electrum are finely disseminated in subparallel to stockwork quartz + sulfide ± magnetite ± anhydrite veins and in some cases in matrices of hydrothermal breccias. Magnetite is common to abundant in mineralized zones. These mineralized stockworks and potassic alteration are interpreted to have formed as the result of degassing of the early intrusive bodies. Fluid pressures during degassing triggered fracturing of the intrusions and wall rock, allowing gold-rich fluids to circulate and precipitate, forming a gold– copper orebody. Later intrusions resulted in weak to moderate gold–copper mineralization forming mostly along and immediately fringing these intrusive contacts. Finally, post mineralized intrusives were overprinted onto the north and west of the deposit.

Mining Methods
The Lindero Deposit is suitable for open pit mining methods. Gold grade distribution and the results of the mineral processing testing indicate that ore from Lindero can be processed by conventional heap leaching methods.

The Lindero Project has been planned as an open pit truck and wheel loader operation. The truck and wheel loader method provide reasonable cost benefits and selectivity for this type of deposit. Only open pit mining methods are considered for mining at Lindero.

Pit designs
Detailed pit design was completed, including an ultimate pit and five internal phased pits. The ultimate pit was designed to allow mining of mill feed material identified by NPVS optimization while providing safe access for people and equipment. Internal pits or phases within the ultimate pits were designed to enhance the Project economics by providing higher-value material to the leach pad earlier in the mine life

Bench height
Pit designs were developed based on 8 m benches for mining. This corresponds to the resource model block heights, and Fortuna believes this to be reasonable with respect to dilution and equipment anticipated to be used in mining.

Feb. 20, 2019
All mine equipment required for the start of operations has arrived and has been assembled on site including; six 100 ton trucks, two 17 cubic yard wheel loaders, one 5 cubic yard crawler excavator, two 449 HP dozers, two 250 HP motor graders,­­ and two 800 HP rotary blast hole drill rigs.

Crushing
Run-of-mill (ROM) ore will be transported from the mine in 91-tonne surface haul trucks and dumped in a 200-tonne capacity ROM feed bin.

Material will be fed from the ROM feed bin to a 1.2 m x 7.9 m apron feeder and then to a grizzly feeder with 150 mm openings. The grizzly oversize will be fed to a 1500 mm x 1300 mm jaw crusher and the grizzly undersize will be recombined with the jaw crusher product on the primary crusher discharge conveyor which will feed a 175-t secondary crushing distribution bin. A tramp metal electromagnet and metal detector will be installed on the primary crusher discharge conveyor to protect the secondary crushers.

Ore from the distribution bin will be fed equally to three 1.8 m x 6.1 m secondary double deck screens by belt feeders. Screen over-size will report to a 300 kW cone crusher. Three screens/cone crushers in parallel are planned. The cones will be run in closed-circuit with the screens.

Stockpiled material will be reclaimed using vibrating feeders underneath the pile, which will feed a conveyor and then into a 140-t tertiary crusher surge bin. Discharge from the surge bin will be transported to the feed chute immediately above the HPGR. A tramp metal electromagnet and metal detector will be installed on the feed belt immediately before the HPGR chute to protect the HPGR from tramp metal.

The HPGR is a Weir-KHD Model RPS 16-170/180 with 1.7 m diameter by 1.8 m wide rolls, and was purchased by Goldrock. The edge material which represents roughly 25 % of the total product will be recycled back to the HPGR feed bin. The final plant product from the HPGR will be nominally 80% passing 6 mm. The center product will be fed to the flake breaker.

Flake breaker
Observation shows that HPGR crushing will generate flakes when treating the Lindero ore. These flakes will be sufficiently durable that they will survive the agglomerating drum and will pass unagglomerated to the heap. In order to break these flakes, a Gundlach continuous tooth roll crusher will be placed in the circuit. The roll crusher will contain two opposing inter-meshed timed rolls with a 25 mm gap. A fixed scalping screen will divert any non-flaked material around the crusher. The product of the de-flaking crusher will report to the agglomeration surge bin.

Run-of-mill (ROM) ore will be transported from the mine in 91-tonne surface haul trucks and dumped in a 200-tonne capacity ROM feed bin.

The agglomeration circuit is designed to mix concentrated cyanide and cement with the HPGR- crushed ore, and adhere the fine particles to the coarse rock by tumbling the mixture in a rotating drum.

Agglomerated ore stacking will be undertaken using conventional conveyors and a radial stacker. Due to the size of the Lindero heap leach pad, the conveyor stacking system requires a considerable quantity of equipment. Most of the ore will be retreat stacked; however due to the steep side slopes, portions near the edge of each lift will be advance stacked. The entire heap stacking sequence was designed such that the quantity of advance stacking was minimized. Each cell was divided into 60 m x 60 m x 10 m blocks and ore was assigned to each block based on the mine plan.

Once the heap has been stacked and the agglomerates ........