Name of the Mine
Turquoise Ridge Complex.

Location
About 64 km north-east of Winnemucca, Humboldt County, Nevada, in the US.

Mine Owner/s
The mine is operated as a joint venture (JV) through Nevada Gold Mines (NGM), which was established in 2019. Barrick is the JV operator and owns 61.5%, with Newmont owning the remaining 38.5%.

Brief Description
Turquoise Ridge is a gold mining operation that uses underground and openpit mining methods. The operation includes the Turquoise Ridge underground and Vista underground, and various surface mining areas.

Brief History
The complex has a long history, with sporadic operations dating back to 1883. Modern openpit mining started in 1987 and underground operations in 1994. 

Primary Metals/Minerals
Gold.

Secondary Metals/Minerals
Silver (associated with gold mineralisation in some deposits).

Geology/Mineralisation
The Turquoise Ridge Complex deposits are considered examples of Carlin-type or carbonate-hosted disseminated gold/silver deposits. 

Preferred host lithologies for gold mineralisation are the Comus Formation, followed by the Valmy and Etchart formations.

The mineralisation is primarily hosted in thinly bedded, silty or argillaceous carbonaceous limestone or dolomite, with some zones in noncarbonate siliciclastic and metavolcanic rocks. 

Gold is often found in micrometer-sized sulphide grains disseminated in silicified and decarbonated calcareous rocks, and are commonly associated with jasperoids. Other associated minerals to mineralisation include pyrite, arsenian pyrite, stibnite, realgar, orpiment, cinnabar, fluorite, barite and rare thallium minerals. The deposits are structurally controlled, and are often found at lithologic contacts, anticlines and fault intersections, as well as beneath basaltic sills.

Reserves
As at December 31, 2023, the total proven and probable reserves at the Turquoise Ridge Complex are estimated at 69-million tonnes with an average grade of 6.29 g/t gold, containing about 14-million ounces of gold.

Resources
The measured and indicated resources as of December 31, 2023, are estimated at 110-million tonnes grading 5.42 g/t gold, containing about 20-million ounces of gold. Inferred resources are estimated at 16-million tonnes grading 3.2 g/t gold, containing about 1.6-million ounces of gold.

Type of Mine
Underground and openpit.

Mining Method
The underground mining operations primarily use drift-and-fill and longhole stoping methods, while the openpit operations use conventional surface mining techniques. 

Major Infrastructure/Equipment
The complex includes multiple mining areas (underground and openpit), a Juniper oxide mill, Sage autoclave, heap-leach pads, various waste-rock storage facilities and extensive infrastructure such as roads, power lines and water management systems. The processing facilities are designed to handle oxide and refractory ores.

Prospects
Exploration at the Turquoise Ridge Complex is ongoing, with significant potential for further resource expansion at depth, along strike and down plunge from current operations. Near-mine exploration focuses on high-angle faults and fractures while regional exploration targets favourable lithologies and structural features that could host additional mineralisation.

Contact Details
Barrick Gold Corporation
Tel +1 416 861 9911

Sources
Barrick Gold Corporation. Website: https://www.barrick.com/