Name of the Mine
Puna Operations.

Location  
Puna region of north-western Argentina, in the province of Jujuy, Department of Rinconada.

Mine Owner/s  
Denver-based gold, silver, copper, lead and zinc producer SSR Mining.

Brief Description  
The Puna Operations consist of the Chinchillas mine and the Pirquitas property, which includes the Pirquitas processing facilities.

Brief History  
The Chinchillas silver/lead/zinc mine achieved commercial production in December 2018. 

The Pirquitas processing facilities have been in commercial production since 2009, processing ore from the San Miguel openpit, which concluded mining activities in January 2017 and currently hosts the tailings deposit facility.

Primary Metals/Minerals  
Silver, lead and zinc.

Secondary Metals/Minerals  
None stated.

Geology/Mineralisation  
The Chinchillas and Pirquitas deposits occur within the Bolivian tin/silver/zinc belt, which occupies the back-arc portion of the central Andes and extends from southern Peru to northern Argentina.

North-western Argentina geology encompasses three main geological belts, or terranes, that together trend north-north-east: the sub-Andean Range (Sierras Subandinas), the Eastern Cordillera (Cordillera Oriental) and the Argentine Altiplano, or Puna, belt. 

The Pirquitas and Chinchillas deposits are located in the Puna belt and are hosted in the Ordovician Acoite Formation. This formation is an interbedded sandstone, siltstone and mudstone turbidite sequence deposited in a back-arc basin.

The Chinchillas deposit occurs within a 13±1 Ma dacitic volcanic centre and is the product of a phreatomagmatic diatreme. The deposit is controlled by an east-west-trending regional scale fault, where dilatation accommodated magma to intrude through the Acoite Formation.

Significant silver/lead/zinc mineralisation occurs in four main areas at Chinchillas: the Silver Mantos and Basement Mantos zones in the western part of the caldera, and the Socavon del Diablo and Socavon Basement/Melina zones in the eastern part. Mineralisation is dominated by silver, with lesser amounts of lead and zinc. Mineralisation occurs as disseminated sulphides, matrix
infilling within the volcanic tuffs, and as matrix and fracture filling in breccias within the metasedimentary rocks.

The property geology of the Pirquitas mine comprises exposures of the Acoite and Tiomayo formations. Folding plays an important role in vein formation and geometry. At the San Miguel pit, veins are intrinsically related to the San Miguel anticline, occurring proximal to the fold apex and most commonly striking perpendicular to the fold planes. West-northwest-striking regional faults are also observed throughout the property. This structural fabric is interpreted to control the geometry and location of the Cortaderas breccia body. 

Pirquitas comprises two types of mineralisation: polymetallic veins with peripheral disseminated mineralisation and mineralised hydrothermal breccia. Vein type is the dominant mineralisation style and has been the main source of extracted ore.

Reserves  
As at December 31, 2024, the Chinchillas openpit had proven and probable reserves of 3.16-million tonnes grading 142.39 g/t silver, 1.17% lead and 0.16% zinc. 

The Chinchilla stockpile had proven and probable reserves of 1.11-million tonnes grading 141.26 g/t silver, 1.2% lead and 0.24% zinc.

Resources  
As at December 31, 2024, the Chinchillas openpit had measured and indicated resources of 2.8-million tonnes grading 122.58 g/t silver, 1.05% lead and 0.27% zinc. Inferred resources were estimated at 76 000 t grading 119.4 g/t silver, 1.05% lead and 0.04% zinc

The Chinchilla low-grade stockpile had measured and indicated resources of 396 000 t grading 71.38 g/t silver, 0.56% lead and 0.55% zinc. 

As at December 31, 2024, Pirquitas underground had measured and indicated resources of 2.48-million tonnes grading 300.91 g/t silver and 5.85% zinc. 

Inferred resources were estimated at 1.32-million tonnes grading 194.9 g/t silver.

Type of Mine
Chinchillas is an openpit mining operation.

Mining Method  
Chinchilla is mined using conventional drill, blast, truck and loading operations.

Major Infrastructure/Equipment  
The Chinchillas site comprises various facilities, including offices, workshops, a lunchroom, change room, explosives magazines, security and first aid buildings, a solid-waste storage facility, an openpit and waste dumps. The existing exploration infrastructure includes two office containers, a core logging facility, a core cutting machine, two storage tents, two diesel fuel cisterns and six warehouses designated for storing core boxes. Power for the Chinchillas mine site is sourced through existing power lines connected to the natural gas-powered generators at Pirquitas. 

Pirquitas’ existing infrastructure includes a processing plant; an authorised tailing facility; a fully serviced workers camp; a communications system, including cellular and intranet access; fully serviced office buildings; and wastewater treatment facilities, organic waste landfill and a recycling centre. 

The Pirquitas processing plant consists of primary, secondary and tertiary crushing operations, which deliver ore to a stockpile. The crushing circuit throughput is 6 000 t/d. Ore is transferred from the crushed ore stockpile to a ball mill and after that a differential flotation circuit to obtain lead/silver/zinc concentrates. The Pirquitas plant uses a tailings thickener to improve water recovery. After thickening, tailings are deposited in the tailings storage facility and secondary water recovery is achieved using barge-mounted reclaim pumps. Electricity at the site is produced from natural gas and diesel generators. Water supply is from San Marcos, located in the property and a short distance downstream from where the Pirquitas river drains into the Collahuaima river. Domestic water is pumped from a diversion upstream of the openpit for use at the camp. Potable water is supplied by MPSA from bottled water.

Prospects  
Technical work continues to evaluate opportunities to extend the Puna life-of-mine through mineral reserve conversion at Chinchillas, as well as continued evaluation of Cortaderas on the Pirquitas property.

Contact Details
SSR Mining
Tel +1 719 851 4127
Email invest@ssrmining.com
Website https://www.ssrmining.com/