The Cortez deposits are Carlin-type sedimentary rock-hosted deposits.
A secondary deposit model that is applicable to the Cortez Complex is an intrusion-related gold model.
Cortez mineralization occurs approximately between elevations 1,630–1,240 m, is approximately 400 m wide northeast–southwest by 1,219 m long northwest–southeast, and ranges in thickness from approximately 90–455 m.
Mineralization is hosted within the Roberts Mountains Formation and the Hanson Creek Formation.
A series of north–northwest trending and northeast trending faults cut the lithologies, with mineralization forming where these faults intersect shallow east-dipping thrust breccia zones (thrust duplexes).
Most of the Cortez NW Deep higher-grade gold mineralization (<3.43 g/t Au) occurs in two zones lying between the 1,280–1,325 m elevations beneath the old Cortez open pit floor. One zone consists of an oxidized and strongly altered thrust zone within the Roberts Mountains Formation and the other is an unoxidized, sulfide-bearing thrust zone at the top of the Hanson Creek Formation.
Mineralization becomes dominantly refractory at about 1,280–1,325 m elevation.
Breccia gold mineralization is hosted in hydrothermally brecciated and fractured rocks that are spatially associated with the WSW dipping faults and attendant structures. Altered, matrixsupported breccia bodies contain the highest gold grades and are surrounded by “crackle” breccias and highly-frac ........

The Cortez Complex consists of both open pit and underground mines. Open pit mines consist of Pipeline, Crossroads, and Cortez pits, while underground operations consist of Cortez Hills Underground (Middle Zone, Lower Zone, and Deep South), and Goldrush Underground operations (Red Hill, Crow’s Nest, 3 ½, Ranch, Meadow).

Open pit mining is conducted using conventional open pit techniques and equipment.

Cortez Hills Underground is a mechanized decline access underground mine based upon the mining of up to 4,700 t/d of ore and waste. The Middle Zone is being exploited using cut-and-fill mining methods and minor amounts of longhole stoping; while the Lower and Deep South Zones are planned to be mined by longhole stoping.

Goldrush underground is a mechanized decline access underground mine with intensive lateral development required to open up the orebody. The primary mining method will be longhole stoping with minor amounts of cut-and-fill where the orebody geometry does not allow for longhole stopes.

As the permitting process progresses, mine development has continued in the Red Hill mining zone at Goldrush. Development is currently focused on the upper portions of Red Hill, where dewatering of the ore body is not required. Test mining of underground longhole stopes commenced in November 2021.

OPEN PITS
Open pit ore is mined by a conventional shovel-truck process at the rate of approximately 12.4 Mt/a with a LOM str ........

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